diff --git a/toonz/sources/common/tmsgcore.cpp b/toonz/sources/common/tmsgcore.cpp
index 888d01a..fc480b5 100644
--- a/toonz/sources/common/tmsgcore.cpp
+++ b/toonz/sources/common/tmsgcore.cpp
@@ -140,11 +140,11 @@ void TMsgCore::readFromSocket(QTcpSocket *socket) //server side
 		QString str = messages.at(i).simplified();
 		str.chop(4); //rimuovo i "#END" alla fine
 		if (str.startsWith("ERROR"))
-			DVGui::MsgBox(CRITICAL, str.right(str.size() - 5));
+			DVGui::MsgBox(DVGui::CRITICAL, str.right(str.size() - 5));
 		else if (str.startsWith("WARNING"))
-			DVGui::MsgBox(WARNING, str.right(str.size() - 7));
+			DVGui::MsgBox(DVGui::WARNING, str.right(str.size() - 7));
 		else if (str.startsWith("INFO"))
-			DVGui::MsgBox(INFORMATION, str.right(str.size() - 4));
+			DVGui::MsgBox(DVGui::INFORMATION, str.right(str.size() - 4));
 		else
 			assert(false);
 	}
@@ -166,13 +166,13 @@ TMsgCore::~TMsgCore()
 
 //----------------------------------
 
-bool TMsgCore::send(MsgType type, const QString &message) //client side
+bool TMsgCore::send(DVGui::MsgType type, const QString &message) //client side
 {
 	if (receivers(SIGNAL(sendMessage(int, const QString &))) == 0) {
 		if (m_clientSocket == 0 || m_clientSocket->state() != QTcpSocket::ConnectedState)
 			return false;
 
-		QString socketMessage = (type == CRITICAL ? "#TMSG ERROR " : (type == WARNING ? "#TMSG WARNING " : "#TMSG INFO ")) + message + " #END\n";
+		QString socketMessage = (type == DVGui::CRITICAL ? "#TMSG ERROR " : (type == DVGui::WARNING ? "#TMSG WARNING " : "#TMSG INFO ")) + message + " #END\n";
 
 #if QT_VERSION >= 0x050000
 		m_clientSocket->write(socketMessage.toLatin1());
diff --git a/toonz/sources/include/tmsgcore.h b/toonz/sources/include/tmsgcore.h
index 8e328da..36f8e11 100644
--- a/toonz/sources/include/tmsgcore.h
+++ b/toonz/sources/include/tmsgcore.h
@@ -41,8 +41,6 @@ void DVAPI warning(const QString &msg);
 void DVAPI info(const QString &msg);
 };
 
-using namespace DVGui;
-
 class DVAPI TMsgCore : public QObject
 {
 	Q_OBJECT
@@ -59,7 +57,7 @@ public:
 
 	//client side
 	// 'send' returns false if the tmessage is not active in the application (tipically, in console applications such as tcomposer)
-	bool send(MsgType type, const QString &message);
+	bool send(DVGui::MsgType type, const QString &message);
 	void connectTo(const QString &address = "");
 
 	//server side
diff --git a/toonz/sources/include/toonzqt/fxsettings.h b/toonz/sources/include/toonzqt/fxsettings.h
index fbec7b3..19ced46 100644
--- a/toonz/sources/include/toonzqt/fxsettings.h
+++ b/toonz/sources/include/toonzqt/fxsettings.h
@@ -50,8 +50,6 @@ class TXshLevelHandle;
 class TObjectHandle;
 class ToonzScene;
 
-using namespace DVGui;
-
 //=============================================================================
 /*! \brief ParamsPage. View a page with fx params.
 
@@ -132,7 +130,7 @@ class DVAPI ParamsPageSet : public QWidget
 	Q_OBJECT
 
 	TabBarContainter *m_tabBarContainer;
-	TabBar *m_tabBar;
+	DVGui::TabBar *m_tabBar;
 	QStackedWidget *m_pagesList;
 
 	ParamViewer *m_parent;
diff --git a/toonz/sources/include/toonzqt/styleeditor.h b/toonz/sources/include/toonzqt/styleeditor.h
index 269c2c8..a47981a 100644
--- a/toonz/sources/include/toonzqt/styleeditor.h
+++ b/toonz/sources/include/toonzqt/styleeditor.h
@@ -76,8 +76,6 @@ class StyleEditor;
 
 //=============================================
 
-using namespace DVGui;
-
 //=============================================================================
 namespace StyleEditorGUI
 {
@@ -337,7 +335,7 @@ signals:
 /*! \brief The ChannelLineEdit is a cutomized version of IntLineEdit for channel value.
     It calls selectAll() at the moment of the first click.
 */
-class ChannelLineEdit : public IntLineEdit
+class ChannelLineEdit : public DVGui::IntLineEdit
 {
 	Q_OBJECT
 
@@ -591,11 +589,11 @@ class DVAPI StyleEditor : public QWidget
 
 	TXshLevelHandle *m_levelHandle; //!< for clearing the level cache when the color changed
 
-	TabBar *m_styleBar;
+	DVGui::TabBar *m_styleBar;
 	QStackedWidget *m_styleChooser;
 
-	StyleSample *m_newColor; //!< New style viewer (lower-right panel side).
-	StyleSample *m_oldColor; //!< Old style viewer (lower-right panel side).
+	DVGui::StyleSample *m_newColor; //!< New style viewer (lower-right panel side).
+	DVGui::StyleSample *m_oldColor; //!< Old style viewer (lower-right panel side).
 
 #ifndef STUDENT
 	QPushButton *m_autoButton;  //!< "Auto Apply" checkbox on the right panel side.
diff --git a/toonz/sources/include/toonzqt/tmessageviewer.h b/toonz/sources/include/toonzqt/tmessageviewer.h
index 7376030..427ef44 100644
--- a/toonz/sources/include/toonzqt/tmessageviewer.h
+++ b/toonz/sources/include/toonzqt/tmessageviewer.h
@@ -23,8 +23,6 @@ class MySortFilterProxyModel;
 class QCheckBox;
 class QStandardItemModel;
 
-using namespace DVGui;
-
 class DVAPI TMessageRepository : public QObject
 {
 	QStandardItemModel *m_sim;
diff --git a/toonz/sources/tcleanupper/tcleanupper.cpp b/toonz/sources/tcleanupper/tcleanupper.cpp
index 3dffc5e..55cb5fc 100644
--- a/toonz/sources/tcleanupper/tcleanupper.cpp
+++ b/toonz/sources/tcleanupper/tcleanupper.cpp
@@ -129,7 +129,7 @@ void fatalError(string msg)
 {
 #ifdef _WIN32
 	msg = "Application can't start:\n" + msg;
-	DVGui::MsgBox(CRITICAL, QString::fromStdString(msg));
+	DVGui::MsgBox(DVGui::CRITICAL, QString::fromStdString(msg));
 	//MessageBox(0,msg.c_str(),"Fatal error",MB_ICONERROR);
 	exit(1);
 #else
@@ -411,7 +411,7 @@ void cleanupLevel(TXshSimpleLevel *xl, std::set<TFrameId> fidsInXsheet,
 	string info = "cleanupping " + toString(xl->getPath());
 	LevelUpdater updater(xl);
 	m_userLog.info(info);
-	DVGui::MsgBox(INFORMATION, QString::fromStdString(info));
+	DVGui::MsgBox(DVGui::INFORMATION, QString::fromStdString(info));
 	bool firstImage = true;
 	std::set<TFrameId>::iterator it = fidsInXsheet.begin();
 	for (it; it != fidsInXsheet.end(); it++) {
@@ -425,7 +425,7 @@ void cleanupLevel(TXshSimpleLevel *xl, std::set<TFrameId> fidsInXsheet,
 		if (0 != (status & TXshSimpleLevel::Cleanupped) && !overwrite) {
 			cout << "  skipped" << endl;
 			m_userLog.info("  skipped");
-			DVGui::MsgBox(INFORMATION, QString("--skipped frame ") + QString::fromStdString(fid.expand()));
+			DVGui::MsgBox(DVGui::INFORMATION, QString("--skipped frame ") + QString::fromStdString(fid.expand()));
 			continue;
 		}
 		TRasterImageP original = xl->getFrameToCleanup(fid);
@@ -831,7 +831,7 @@ int main(int argc, char *argv[])
 		TImageCache::instance()->clear(true);
 	}
 
-	DVGui::MsgBox(INFORMATION, "Cleanup Done.");
+	DVGui::MsgBox(DVGui::INFORMATION, "Cleanup Done.");
 	return 0;
 }
 //------------------------------------------------------------------------
diff --git a/toonz/sources/tcomposer/tcomposer.cpp b/toonz/sources/tcomposer/tcomposer.cpp
index 600c57c..05116d4 100644
--- a/toonz/sources/tcomposer/tcomposer.cpp
+++ b/toonz/sources/tcomposer/tcomposer.cpp
@@ -310,7 +310,7 @@ bool MyMovieRenderListener::onFrameCompleted(int frame)
 		msg = toString(fp.getWideString()) + " computed";
 	cout << msg << endl;
 	m_userLog->info(msg);
-	DVGui::MsgBox(INFORMATION, QString::fromStdString(msg));
+	DVGui::MsgBox(DVGui::INFORMATION, QString::fromStdString(msg));
 	if (FarmController) {
 		try {
 			FarmController->taskProgress(TaskId, m_frameCompletedCount + m_frameFailedCount, m_frameCount, frame + 1, FrameDone);
@@ -1029,7 +1029,7 @@ int main(int argc, char *argv[])
 					  toString(TStopWatch::global(8).getTotalTime() / 1000.0, 2) + " seconds spent on rendering" + "\n";
 		cout << msg + msg2;
 		m_userLog->info(msg + msg2);
-		DVGui::MsgBox(INFORMATION, QString::fromStdString(msg));
+		DVGui::MsgBox(DVGui::INFORMATION, QString::fromStdString(msg));
 		TImageCache::instance()->clear(true);
 		/*
     cout << "Compositing completed in " + toString(Sw1.getTotalTime()/1000.0, 2) + " seconds";
diff --git a/toonz/sources/tnztools/tooloptions.cpp b/toonz/sources/tnztools/tooloptions.cpp
index 08abfd7..28b37c2 100644
--- a/toonz/sources/tnztools/tooloptions.cpp
+++ b/toonz/sources/tnztools/tooloptions.cpp
@@ -1016,7 +1016,7 @@ SelectionToolOptionsBox::SelectionToolOptionsBox(QWidget *parent, TTool *tool, T
 	hLayout()->addWidget(m_scaleYField);
 	ret = ret && connect(m_scaleYField, SIGNAL(valueChange()), SLOT(onScaleYValueChanged()));
 	hLayout()->addSpacing(4);
-	m_scaleLink = new CheckBox(tr("Link"), this);
+	m_scaleLink = new DVGui::CheckBox(tr("Link"), this);
 	hLayout()->addWidget(m_scaleLink);
 
 	addSeparator();
@@ -1494,7 +1494,7 @@ public:
 		: Dialog(0, true)
 	{
 		setWindowTitle(tr("Preset Name"));
-		m_nameFld = new LineEdit();
+		m_nameFld = new DVGui::LineEdit();
 		addWidget(m_nameFld);
 
 		QPushButton *okBtn = new QPushButton(tr("OK"), this);
diff --git a/toonz/sources/tnztools/tooloptionscontrols.h b/toonz/sources/tnztools/tooloptionscontrols.h
index af6eae8..4c60b07 100644
--- a/toonz/sources/tnztools/tooloptionscontrols.h
+++ b/toonz/sources/tnztools/tooloptionscontrols.h
@@ -41,8 +41,6 @@
 #define DVVAR DV_IMPORT_VAR
 #endif
 
-using namespace DVGui;
-
 class TTool;
 class TFrameHandle;
 class TObjectHandle;
@@ -84,7 +82,7 @@ public:
 //    ToolOptionControl derivative  declarations
 //***********************************************************************************
 
-class ToolOptionCheckbox : public CheckBox, public ToolOptionControl
+class ToolOptionCheckbox : public DVGui::CheckBox, public ToolOptionControl
 {
 	Q_OBJECT
 
@@ -105,7 +103,7 @@ protected:
 
 //-----------------------------------------------------------------------------
 
-class ToolOptionSlider : public DoubleField, public ToolOptionControl
+class ToolOptionSlider : public DVGui::DoubleField, public ToolOptionControl
 {
 	Q_OBJECT
 
@@ -126,7 +124,7 @@ protected slots:
 
 //-----------------------------------------------------------------------------
 
-class ToolOptionPairSlider : public DoublePairField, public ToolOptionControl
+class ToolOptionPairSlider : public DVGui::DoublePairField, public ToolOptionControl
 {
 	Q_OBJECT
 
@@ -150,7 +148,7 @@ protected slots:
 
 //-----------------------------------------------------------------------------
 
-class ToolOptionIntPairSlider : public IntPairField, public ToolOptionControl
+class ToolOptionIntPairSlider : public DVGui::IntPairField, public ToolOptionControl
 {
 	Q_OBJECT
 
@@ -174,7 +172,7 @@ protected slots:
 
 //-----------------------------------------------------------------------------
 
-class ToolOptionIntSlider : public IntField, public ToolOptionControl
+class ToolOptionIntSlider : public DVGui::IntField, public ToolOptionControl
 {
 	Q_OBJECT
 
@@ -239,7 +237,7 @@ public slots:
 
 //-----------------------------------------------------------------------------
 
-class ToolOptionTextField : public LineEdit, public ToolOptionControl
+class ToolOptionTextField : public DVGui::LineEdit, public ToolOptionControl
 {
 	Q_OBJECT
 
@@ -257,7 +255,7 @@ public slots:
 
 //-----------------------------------------------------------------------------
 
-class StyleIndexFieldAndChip : public StyleIndexLineEdit, public ToolOptionControl
+class StyleIndexFieldAndChip : public DVGui::StyleIndexLineEdit, public ToolOptionControl
 {
 	Q_OBJECT
 
@@ -288,7 +286,7 @@ public slots:
   \li Editing with global keyframes (ie affecting multiple parameters other than the edited one)
   \li Undo/Redo of user interactions.
 */
-class ToolOptionParamRelayField : public MeasuredDoubleLineEdit, public ToolOptionControl
+class ToolOptionParamRelayField : public DVGui::MeasuredDoubleLineEdit, public ToolOptionControl
 {
 	Q_OBJECT
 
@@ -319,7 +317,7 @@ protected slots:
 //
 //=============================================================================
 
-class DVAPI MeasuredValueField : public LineEdit
+class DVAPI MeasuredValueField : public DVGui::LineEdit
 {
 	Q_OBJECT
 
diff --git a/toonz/sources/toonz/addfilmstripframespopup.cpp b/toonz/sources/toonz/addfilmstripframespopup.cpp
index 555c247..6a6f423 100644
--- a/toonz/sources/toonz/addfilmstripframespopup.cpp
+++ b/toonz/sources/toonz/addfilmstripframespopup.cpp
@@ -24,9 +24,9 @@ AddFilmstripFramesPopup::AddFilmstripFramesPopup()
 {
 	setWindowTitle(tr("Add Frames"));
 
-	m_startFld = new IntLineEdit(this);
-	m_endFld = new IntLineEdit(this);
-	m_stepFld = new IntLineEdit(this);
+	m_startFld = new DVGui::IntLineEdit(this);
+	m_endFld = new DVGui::IntLineEdit(this);
+	m_stepFld = new DVGui::IntLineEdit(this);
 
 	m_okBtn = new QPushButton(tr("Add"), this);
 	m_cancelBtn = new QPushButton(tr("Cancel"), this);
diff --git a/toonz/sources/toonz/addfilmstripframespopup.h b/toonz/sources/toonz/addfilmstripframespopup.h
index 2b09085..f4df9a2 100644
--- a/toonz/sources/toonz/addfilmstripframespopup.h
+++ b/toonz/sources/toonz/addfilmstripframespopup.h
@@ -10,20 +10,18 @@
 class QPushButton;
 class QLineEdit;
 
-using namespace DVGui;
-
 //=============================================================================
 // AddFilmstripFramesPopup
 //-----------------------------------------------------------------------------
 
-class AddFilmstripFramesPopup : public Dialog
+class AddFilmstripFramesPopup : public DVGui::Dialog
 {
 	Q_OBJECT
 
 	QPushButton *m_okBtn;
 	QPushButton *m_cancelBtn;
 
-	IntLineEdit *m_startFld, *m_endFld, *m_stepFld;
+	DVGui::IntLineEdit *m_startFld, *m_endFld, *m_stepFld;
 
 public slots:
 	void onOk();
diff --git a/toonz/sources/toonz/batches.cpp b/toonz/sources/toonz/batches.cpp
index 66c52b0..f0c785c 100644
--- a/toonz/sources/toonz/batches.cpp
+++ b/toonz/sources/toonz/batches.cpp
@@ -114,10 +114,10 @@ bool LoadTaskPopup::execute()
 		DVGui::error(toQString(fp) + tr(" does not exist."));
 		return false;
 	} else if (m_isRenderTask && fp.getType() != "tnz") {
-		error(toQString(fp) + tr(" you can load only TNZ files for render task."));
+		DVGui::error(toQString(fp) + tr(" you can load only TNZ files for render task."));
 		return false;
 	} else if (!m_isRenderTask && fp.getType() != "tnz" && fp.getType() != "cln") {
-		error(toQString(fp) + tr(" you can load only TNZ or CLN files for cleanup task."));
+		DVGui::error(toQString(fp) + tr(" you can load only TNZ or CLN files for cleanup task."));
 		return false;
 	}
 
@@ -478,7 +478,7 @@ void BatchesController::removeTask(const QString &id)
 
 	TFarmTask *task = it->second;
 	if (task->m_status == Running || task->m_status == Waiting) {
-		MsgBox(WARNING, taskBusyStr().arg(task->m_name));
+		DVGui::MsgBox(DVGui::WARNING, taskBusyStr().arg(task->m_name));
 		return;
 	}
 
@@ -531,7 +531,7 @@ void BatchesController::removeAllTasks()
 	for (tt = m_tasks.begin(); tt != tEnd; ++tt) {
 		TFarmTask *task = tt->second;
 		if (task->m_status == Running || task->m_status == Waiting) {
-			MsgBox(WARNING, taskBusyStr().arg(task->m_name));
+			DVGui::MsgBox(DVGui::WARNING, taskBusyStr().arg(task->m_name));
 			return;
 		}
 	}
@@ -826,7 +826,7 @@ void BatchesController::onExit(bool &ret)
 	int answer = 0;
 
 	if (m_dirtyFlag)
-		answer = MsgBox(QString(tr("The current task list has been modified.\nDo you want to save your changes?")), tr("Save"), tr("Discard"), tr("Cancel"), 1);
+		answer = DVGui::MsgBox(QString(tr("The current task list has been modified.\nDo you want to save your changes?")), tr("Save"), tr("Discard"), tr("Cancel"), 1);
 
 	ret = true;
 	if (answer == 3)
@@ -858,7 +858,7 @@ void BatchesController::loadTask(bool isRenderTask)
 void BatchesController::doLoad(const TFilePath &fp)
 {
 	if (m_dirtyFlag) {
-		int ret = MsgBox(QString(tr("The current task list has been modified.\nDo you want to save your changes?")), tr("Save"), tr("Discard"), tr("Cancel"));
+		int ret = DVGui::MsgBox(QString(tr("The current task list has been modified.\nDo you want to save your changes?")), tr("Save"), tr("Discard"), tr("Cancel"));
 		if (ret == 1)
 			save();
 		else if (ret == 3 || ret == 0)
@@ -930,7 +930,7 @@ QString BatchesController::getListName() const
 void BatchesController::saveas()
 {
 	if (getTaskCount() == 0) {
-		MsgBox(WARNING, tr("The Task List is empty!"));
+		DVGui::MsgBox(DVGui::WARNING, tr("The Task List is empty!"));
 		return;
 	}
 
diff --git a/toonz/sources/toonz/batchserversviewer.cpp b/toonz/sources/toonz/batchserversviewer.cpp
index 9def75e..278aa75 100644
--- a/toonz/sources/toonz/batchserversviewer.cpp
+++ b/toonz/sources/toonz/batchserversviewer.cpp
@@ -55,7 +55,7 @@ void FarmServerListView::update()
 			new MyListItem(sid.m_id, sid.m_name, this);
 		}
 	} catch (TException &e) {
-		MsgBox(WARNING, QString::fromStdString(toString(e.getMessage())));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(toString(e.getMessage())));
 	}
 }
 
@@ -73,7 +73,7 @@ void FarmServerListView::activate()
 		BatchesController::instance()->update();
 		static_cast<BatchServersViewer *>(parentWidget())->updateSelected();
 	} catch (TException &e) {
-		MsgBox(WARNING, QString::fromStdString(toString(e.getMessage())));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(toString(e.getMessage())));
 	}
 }
 
@@ -91,7 +91,7 @@ void FarmServerListView::deactivate()
 		BatchesController::instance()->update();
 		static_cast<BatchServersViewer *>(parentWidget())->updateSelected();
 	} catch (TException &e) {
-		MsgBox(WARNING, QString::fromStdString(toString(e.getMessage())));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(toString(e.getMessage())));
 	}
 }
 //-----------------------------------------------------------------------------
@@ -109,7 +109,7 @@ void FarmServerListView::openContextMenu(const QPoint &p)
 	try {
 		state = controller->queryServerState2(item->m_id);
 	} catch (TException &e) {
-		MsgBox(WARNING, QString::fromStdString(toString(e.getMessage())));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(toString(e.getMessage())));
 		return;
 	}
 
@@ -181,7 +181,7 @@ void BatchServersViewer::updateServerInfo(const QString &id)
 	try {
 		controller->queryServerInfo(id, info);
 	} catch (TException &e) {
-		MsgBox(WARNING, QString::fromStdString(toString(e.getMessage())));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(toString(e.getMessage())));
 	}
 
 	switch (info.m_state) {
@@ -223,7 +223,7 @@ void BatchServersViewer::updateServerInfo(const QString &id)
 			m_tasks->setText("<" + task.m_id + "> " + task.m_name);
 		} catch (TException &e) {
 			m_tasks->setText("");
-			MsgBox(WARNING, QString::fromStdString(toString(e.getMessage())));
+			DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(toString(e.getMessage())));
 		}
 	}
 
@@ -353,15 +353,15 @@ void BatchServersViewer::onProcessWith(int index)
 	try {
 		connected = TFarmStuff::testConnectionToController();
 	} catch (TMissingGRootEnvironmentVariable &) {
-		MsgBox(WARNING, QString(tr("In order to use the render farm you have to define the Farm Global Root first.")));
+		DVGui::MsgBox(DVGui::WARNING, QString(tr("In order to use the render farm you have to define the Farm Global Root first.")));
 		m_processWith->setCurrentIndex(0);
 		return;
 	} catch (TMissingGRootFolder &) {
-		MsgBox(WARNING, tr("The Farm Global Root folder doesn't exist\nPlease create this folder before using the render farm."));
+		DVGui::MsgBox(DVGui::WARNING, tr("The Farm Global Root folder doesn't exist\nPlease create this folder before using the render farm."));
 		m_processWith->setCurrentIndex(0);
 		return;
 	} catch (TException &e) {
-		MsgBox(WARNING, QString::fromStdString(toString(e.getMessage())));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(toString(e.getMessage())));
 		m_processWith->setCurrentIndex(0);
 		return;
 	}
@@ -377,7 +377,7 @@ void BatchServersViewer::onProcessWith(int index)
 						.arg(hostName)
 						.arg(QString::number(port)));
 
-		MsgBox(WARNING, msg);
+		DVGui::MsgBox(DVGui::WARNING, msg);
 		m_processWith->setCurrentIndex(0);
 		return;
 	}
diff --git a/toonz/sources/toonz/batchserversviewer.h b/toonz/sources/toonz/batchserversviewer.h
index a72f024..a8c85b6 100644
--- a/toonz/sources/toonz/batchserversviewer.h
+++ b/toonz/sources/toonz/batchserversviewer.h
@@ -14,7 +14,6 @@
 class QComboBox;
 class FarmServerListView;
 class QListWidgetItem;
-using namespace DVGui;
 
 //=============================================================================
 // BatchServersViewer
@@ -61,17 +60,17 @@ protected slots:
 
 private:
 	QString m_serverId;
-	LineEdit *m_farmRootField;
+	DVGui::LineEdit *m_farmRootField;
 	QComboBox *m_processWith;
 	FarmServerListView *m_serverList;
 
-	LineEdit *m_name;
-	LineEdit *m_ip;
-	LineEdit *m_port;
-	LineEdit *m_tasks;
-	LineEdit *m_state;
-	LineEdit *m_cpu;
-	LineEdit *m_mem;
+	DVGui::LineEdit *m_name;
+	DVGui::LineEdit *m_ip;
+	DVGui::LineEdit *m_port;
+	DVGui::LineEdit *m_tasks;
+	DVGui::LineEdit *m_state;
+	DVGui::LineEdit *m_cpu;
+	DVGui::LineEdit *m_mem;
 	void updateServerInfo(const QString &id);
 };
 
diff --git a/toonz/sources/toonz/cleanuppaletteviewer.h b/toonz/sources/toonz/cleanuppaletteviewer.h
index 52dd3b7..32296c0 100644
--- a/toonz/sources/toonz/cleanuppaletteviewer.h
+++ b/toonz/sources/toonz/cleanuppaletteviewer.h
@@ -22,8 +22,6 @@ namespace DVGui
 class CleanupColorField;
 }
 
-using namespace DVGui;
-
 //------------------------------------------------------------------
 
 //********************************************************************************
@@ -38,7 +36,7 @@ class CleanupPaletteViewer : public QWidget
 
 	QFrame *m_scrollWidget;
 	QScrollArea *m_scrollArea;
-	std::vector<CleanupColorField *> m_colorFields;
+	std::vector<DVGui::CleanupColorField *> m_colorFields;
 	QPushButton *m_remove, *m_add;
 
 	bool m_greyMode;
diff --git a/toonz/sources/toonz/cleanuppopup.cpp b/toonz/sources/toonz/cleanuppopup.cpp
index d19135d..acd5e95 100644
--- a/toonz/sources/toonz/cleanuppopup.cpp
+++ b/toonz/sources/toonz/cleanuppopup.cpp
@@ -204,19 +204,19 @@ void addCleanupDefaultPalette(TXshSimpleLevelP sl)
 	TFileStatus pfs(palettePath);
 
 	if (!pfs.doesExist() || !pfs.isReadable()) {
-		MsgBox(WARNING, QString("CleanupDefaultPalette file: %1 is not found!").arg(QString::fromStdWString(palettePath.getWideString())));
+		DVGui::MsgBox(DVGui::WARNING, QString("CleanupDefaultPalette file: %1 is not found!").arg(QString::fromStdWString(palettePath.getWideString())));
 		return;
 	}
 
 	TIStream is(palettePath);
 	if (!is) {
-		MsgBox(WARNING, QString("CleanupDefaultPalette file: failed to get TIStream"));
+		DVGui::MsgBox(DVGui::WARNING, QString("CleanupDefaultPalette file: failed to get TIStream"));
 		return;
 	}
 
 	string tagName;
 	if (!is.matchTag(tagName) || tagName != "palette") {
-		MsgBox(WARNING, QString("CleanupDefaultPalette file: This is not palette file"));
+		DVGui::MsgBox(DVGui::WARNING, QString("CleanupDefaultPalette file: This is not palette file"));
 		return;
 	}
 
@@ -662,7 +662,7 @@ bool CleanupPopup::analyzeCleanupList()
 		}
 		question += QObject::tr("\nAre you sure ?");
 
-		int ret = MsgBox(question, QObject::tr("Delete"), QObject::tr("Cancel"), 0);
+		int ret = DVGui::MsgBox(question, QObject::tr("Delete"), QObject::tr("Cancel"), 0);
 		if (ret == 0 || ret == 2) {
 			return false;
 		} else if (ret == 1) {
@@ -946,7 +946,7 @@ QString CleanupPopup::setupLevel()
 					TIStream is(targetPalettePath);
 					string tagName;
 					if (!is.matchTag(tagName) || tagName != "palette") {
-						MsgBox(WARNING, QString("CleanupDefaultPalette file: This is not palette file"));
+						DVGui::MsgBox(DVGui::WARNING, QString("CleanupDefaultPalette file: This is not palette file"));
 						return NULL;
 					}
 					m_originalPalette = new TPalette();
diff --git a/toonz/sources/toonz/cleanupsettingsmodel.cpp b/toonz/sources/toonz/cleanupsettingsmodel.cpp
index 9871041..9f4c8ef 100644
--- a/toonz/sources/toonz/cleanupsettingsmodel.cpp
+++ b/toonz/sources/toonz/cleanupsettingsmodel.cpp
@@ -100,7 +100,7 @@ public:
 
 		savePath = savePath.withNoFrame().withType("cln"); //Just to be sure
 		if (TFileStatus(savePath).doesExist()) {
-			int ret = MsgBox(QObject::tr("The cleanup settings file for the %1 level already exists.\n Do you want to overwrite it?")
+			int ret = DVGui::MsgBox(QObject::tr("The cleanup settings file for the %1 level already exists.\n Do you want to overwrite it?")
 								 .arg(toQString(savePath.withoutParentDir())),
 							 QObject::tr("Overwrite"), QObject::tr("Don't Overwrite"), 0);
 
@@ -135,7 +135,7 @@ public:
 			return false;
 
 		if (!TSystem::doesExistFileOrLevel(loadPath)) {
-			error(tr("%1 does not exist.").arg(toQString(loadPath)));
+			DVGui::error(tr("%1 does not exist.").arg(toQString(loadPath)));
 			return false;
 		}
 
diff --git a/toonz/sources/toonz/cleanupsettingspane.cpp b/toonz/sources/toonz/cleanupsettingspane.cpp
index 72c34f6..7bafe83 100644
--- a/toonz/sources/toonz/cleanupsettingspane.cpp
+++ b/toonz/sources/toonz/cleanupsettingspane.cpp
@@ -499,7 +499,7 @@ void CleanupSettingsPane::onSaveSettings()
 {
 	/*--- Clueaup保存先を指定していないとエラーを返す ---*/
 	if (m_pathField->getPath().isEmpty()) {
-		MsgBox(WARNING, "Please fill the Save In field.");
+		DVGui::MsgBox(DVGui::WARNING, "Please fill the Save In field.");
 		return;
 	}
 	CleanupSettingsModel::instance()->promptSave();
diff --git a/toonz/sources/toonz/cleanupsettingspopup.cpp b/toonz/sources/toonz/cleanupsettingspopup.cpp
index 9d735b4..a89ae7b 100644
--- a/toonz/sources/toonz/cleanupsettingspopup.cpp
+++ b/toonz/sources/toonz/cleanupsettingspopup.cpp
@@ -68,10 +68,10 @@ CleanupTab::CleanupTab()
 	int row = 0;
 
 	//  AutoCenter
-	m_autoCenter = new CheckBox(tr("Autocenter"), this);
+	m_autoCenter = new DVGui::CheckBox(tr("Autocenter"), this);
 	settingsLayout->addWidget(m_autoCenter, row++, 1, Qt::AlignLeft);
 
-	m_autoCenter->setFixedSize(150, WidgetHeight);
+	m_autoCenter->setFixedSize(150, DVGui::WidgetHeight);
 
 	//  Pegbar Holes
 	settingsLayout->addWidget(new QLabel(tr("Pegbar Holes:")), row, 0, Qt::AlignRight);
@@ -79,7 +79,7 @@ CleanupTab::CleanupTab()
 	m_pegHolesOm = new QComboBox(this);
 	settingsLayout->addWidget(m_pegHolesOm, row++, 1, Qt::AlignLeft);
 
-	m_pegHolesOm->setFixedHeight(WidgetHeight);
+	m_pegHolesOm->setFixedHeight(DVGui::WidgetHeight);
 	m_pegHolesOm->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Maximum);
 
 	QStringList pegbarHoles;
@@ -95,7 +95,7 @@ CleanupTab::CleanupTab()
 	m_fieldGuideOm = new QComboBox(this);
 	settingsLayout->addWidget(m_fieldGuideOm, row++, 1, Qt::AlignLeft);
 
-	m_fieldGuideOm->setFixedHeight(WidgetHeight);
+	m_fieldGuideOm->setFixedHeight(DVGui::WidgetHeight);
 	m_fieldGuideOm->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Maximum);
 
 	std::vector<string> fdgNames;
@@ -104,7 +104,7 @@ CleanupTab::CleanupTab()
 	for (int i = 0; i < (int)fdgNames.size(); i++)
 		m_fieldGuideOm->addItem(QString(fdgNames[i].c_str()));
 
-	settingsLayout->addWidget(new Separator(), row++, 0, 1, 2);
+	settingsLayout->addWidget(new DVGui::Separator(), row++, 0, 1, 2);
 
 	//  Rotate
 	settingsLayout->addWidget(new QLabel(tr("Rotate:")), row, 0, Qt::AlignRight);
@@ -112,7 +112,7 @@ CleanupTab::CleanupTab()
 	m_rotateOm = new QComboBox(this);
 	settingsLayout->addWidget(m_rotateOm, row++, 1, Qt::AlignLeft);
 
-	m_rotateOm->setFixedHeight(WidgetHeight);
+	m_rotateOm->setFixedHeight(DVGui::WidgetHeight);
 	m_rotateOm->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Maximum);
 
 	QStringList rotate;
@@ -134,25 +134,25 @@ CleanupTab::CleanupTab()
 	flipLayout->setSizeConstraint(QLayout::SetFixedSize);
 	flipLayout->setMargin(0);
 
-	m_flipX = new CheckBox(tr("Horizontal"), flipWidget);
+	m_flipX = new DVGui::CheckBox(tr("Horizontal"), flipWidget);
 	flipLayout->addWidget(m_flipX, 0, Qt::AlignLeft);
 
-	m_flipX->setFixedHeight(WidgetHeight);
+	m_flipX->setFixedHeight(DVGui::WidgetHeight);
 
-	m_flipY = new CheckBox(tr("Vertical"), flipWidget);
+	m_flipY = new DVGui::CheckBox(tr("Vertical"), flipWidget);
 	flipLayout->addWidget(m_flipY, 0, Qt::AlignLeft);
 
-	m_flipY->setFixedHeight(WidgetHeight);
+	m_flipY->setFixedHeight(DVGui::WidgetHeight);
 
 	flipLayout->addStretch(1);
 
 	//  Save In
 	settingsLayout->addWidget(new QLabel(tr("Save in:")), row, 0, Qt::AlignRight);
 
-	m_pathField = new FileField(this, QString(""));
+	m_pathField = new DVGui::FileField(this, QString(""));
 	settingsLayout->addWidget(m_pathField, row++, 1);
 
-	m_pathField->setFixedHeight(WidgetHeight);
+	m_pathField->setFixedHeight(DVGui::WidgetHeight);
 
 	//  Connections
 	bool ret = true;
@@ -256,7 +256,7 @@ ProcessingTab::ProcessingTab()
 	settingsLayout->addWidget(new QLabel(tr("Line Processing:")), row, 0, Qt::AlignRight);
 
 	m_lineProcessing = new QComboBox(this);
-	m_lineProcessing->setFixedHeight(WidgetHeight);
+	m_lineProcessing->setFixedHeight(DVGui::WidgetHeight);
 	m_lineProcessing->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Maximum);
 
 	QStringList items;
@@ -270,7 +270,7 @@ ProcessingTab::ProcessingTab()
 	settingsLayout->addWidget(m_antialiasLabel, row, 0, Qt::AlignRight);
 
 	m_antialias = new QComboBox(this);
-	m_antialias->setFixedHeight(WidgetHeight);
+	m_antialias->setFixedHeight(DVGui::WidgetHeight);
 	m_antialias->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Maximum);
 
 	items.clear();
@@ -284,7 +284,7 @@ ProcessingTab::ProcessingTab()
 	settingsLayout->addWidget(m_autoadjustLabel, row, 0, Qt::AlignRight);
 
 	m_autoadjustOm = new QComboBox(this);
-	m_autoadjustOm->setFixedHeight(WidgetHeight);
+	m_autoadjustOm->setFixedHeight(DVGui::WidgetHeight);
 	m_autoadjustOm->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Maximum);
 
 	items.clear();
@@ -299,30 +299,30 @@ ProcessingTab::ProcessingTab()
 	//  Sharpness
 	m_sharpLabel = new QLabel(tr("Sharpness:"));
 	settingsLayout->addWidget(m_sharpLabel, row, 0, Qt::AlignRight);
-	m_sharpness = new DoubleField(this);
-	m_sharpness->setFixedHeight(WidgetHeight);
+	m_sharpness = new DVGui::DoubleField(this);
+	m_sharpness->setFixedHeight(DVGui::WidgetHeight);
 	m_sharpness->setValues(90, 0, 100);
 	settingsLayout->addWidget(m_sharpness, row++, 1);
 
 	//  Despeckling
 	m_despeckLabel = new QLabel(tr("Despeckling:"));
 	settingsLayout->addWidget(m_despeckLabel, row, 0, Qt::AlignRight);
-	m_despeckling = new IntField(this);
-	m_despeckling->setFixedHeight(WidgetHeight);
+	m_despeckling = new DVGui::IntField(this);
+	m_despeckling->setFixedHeight(DVGui::WidgetHeight);
 	m_despeckling->setValues(2, 0, 20);
 	settingsLayout->addWidget(m_despeckling, row++, 1);
 
 	//  MLAA Value
 	m_aaValueLabel = new QLabel(tr("MLAA Intensity:"));
 	settingsLayout->addWidget(m_aaValueLabel, row, 0, Qt::AlignRight);
-	m_aaValue = new IntField(this);
-	m_aaValue->setFixedHeight(WidgetHeight);
+	m_aaValue = new DVGui::IntField(this);
+	m_aaValue->setFixedHeight(DVGui::WidgetHeight);
 	m_aaValue->setValues(70, 0, 100);
 	settingsLayout->addWidget(m_aaValue, row++, 1);
 
 	//---------------------- Palette ----------------------------
 
-	m_paletteSep = new Separator();
+	m_paletteSep = new DVGui::Separator();
 	mainLayout->addWidget(m_paletteSep);
 	m_paletteViewer = new CleanupPaletteViewer(this);
 	mainLayout->addWidget(m_paletteViewer, 1); // The palette viewer dominates on the stretch below
diff --git a/toonz/sources/toonz/comboviewerpane.h b/toonz/sources/toonz/comboviewerpane.h
index 7dee56e..f4b4277 100644
--- a/toonz/sources/toonz/comboviewerpane.h
+++ b/toonz/sources/toonz/comboviewerpane.h
@@ -24,8 +24,6 @@ class FlipConsole;
 class TXshLevel;
 class ToolOptions;
 
-using namespace DVGui;
-
 //=============================================================================
 // ComboViewerPanel
 //-----------------------------------------------------------------------------
diff --git a/toonz/sources/toonz/convertpopup.cpp b/toonz/sources/toonz/convertpopup.cpp
index c055192..835a735 100644
--- a/toonz/sources/toonz/convertpopup.cpp
+++ b/toonz/sources/toonz/convertpopup.cpp
@@ -117,7 +117,7 @@ void ConvertPopup::Converter::run()
 
 		if (TSystem::doesExistFileOrLevel(dstFilePath)) {
 			if (m_parent->m_skip->isChecked()) {
-				DVGui::MsgBox(INFORMATION, tr("Level %1 already exists; skipped.").arg(levelName));
+				DVGui::MsgBox(DVGui::INFORMATION, tr("Level %1 already exists; skipped.").arg(levelName));
 				m_skippedCount++;
 				continue;
 			} else {
@@ -168,7 +168,7 @@ void ConvertPopup::Converter::convertLevel(const TFilePath &sourceFileFullPath)
 		popup->getFrameRange(sourceFileFullPath, from, to);
 
 		if (from == TFrameId() || to == TFrameId()) {
-			DVGui::MsgBox(WARNING, tr("Level %1 has no frame; skipped.").arg(levelName));
+			DVGui::MsgBox(DVGui::WARNING, tr("Level %1 has no frame; skipped.").arg(levelName));
 			popup->m_notifier->notifyError();
 
 			return;
@@ -212,7 +212,7 @@ void ConvertPopup::Converter::convertLevelWithConvert2Tlv(const TFilePath &sourc
 
 	string errorMessage;
 	if (!tlvConverter->init(errorMessage)) {
-		DVGui::MsgBox(WARNING, QString::fromStdString(errorMessage));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(errorMessage));
 		tlvConverter->abort();
 	} else {
 		int count = tlvConverter->getFramesToConvertCount();
@@ -220,7 +220,7 @@ void ConvertPopup::Converter::convertLevelWithConvert2Tlv(const TFilePath &sourc
 		for (int j = 0; j < count && !stop; j++) {
 			if (!tlvConverter->convertNext(errorMessage)) {
 				stop = true;
-				DVGui::MsgBox(WARNING, QString::fromStdString(errorMessage));
+				DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(errorMessage));
 			}
 			if (popup->m_progressDialog->wasCanceled())
 				stop = true;
@@ -287,10 +287,10 @@ ConvertPopup::ConvertPopup(bool specifyInput)
 	SameAsPainted = tr("Same as Painted");
 	CreateNewPalette = tr("Create new palette");
 
-	m_fromFld = new IntLineEdit(this);
-	m_toFld = new IntLineEdit(this);
-	m_saveInFileFld = new FileField(0, QString(""));
-	m_fileNameFld = new LineEdit(QString(""));
+	m_fromFld = new DVGui::IntLineEdit(this);
+	m_toFld = new DVGui::IntLineEdit(this);
+	m_saveInFileFld = new DVGui::FileField(0, QString(""));
+	m_fileNameFld = new DVGui::LineEdit(QString(""));
 	m_fileFormat = new QComboBox();
 	m_formatOptions = new QPushButton(tr("Options"), this);
 	m_bgColorField = new DVGui::ColorField(this, true, TPixel32::Transparent, 35, false);
@@ -303,12 +303,12 @@ ConvertPopup::ConvertPopup(bool specifyInput)
 	m_notifier = new ImageUtils::FrameTaskNotifier();
 
 	m_progressDialog = new DVGui::ProgressDialog("", tr("Cancel"), 0, 0);
-	m_skip = new CheckBox(tr("Skip Existing Files"), this);
+	m_skip = new DVGui::CheckBox(tr("Skip Existing Files"), this);
 
 	m_removeDotBeforeFrameNumber = new QCheckBox(tr("Remove dot before frame number"), this);
 
 	if (specifyInput)
-		m_convertFileFld = new FileField(0, QString(""), true);
+		m_convertFileFld = new DVGui::FileField(0, QString(""), true);
 	else
 		m_convertFileFld = 0;
 
@@ -486,15 +486,15 @@ QFrame *ConvertPopup::createTlvSettings()
 
 	m_tlvMode = new QComboBox();
 	m_unpaintedFolderLabel = new QLabel(tr("Unpainted File Folder:"));
-	m_unpaintedFolder = new FileField(0, QString(tr("Same as Painted")), true);
+	m_unpaintedFolder = new DVGui::FileField(0, QString(tr("Same as Painted")), true);
 	m_suffixLabel = new QLabel(tr(" Unpainted File Suffix:"));
-	m_unpaintedSuffix = new LineEdit("_np");
+	m_unpaintedSuffix = new DVGui::LineEdit("_np");
 	m_applyAutoclose = new QCheckBox(tr("Apply Autoclose"));
 	m_saveBackupToNopaint = new QCheckBox(tr("Save Backup to \"nopaint\" Folder"));
 	m_antialias = new QComboBox();
-	m_antialiasIntensity = new IntLineEdit(0, 50, 0, 100);
-	m_palettePath = new FileField(0, QString(CreateNewPalette), true);
-	m_tolerance = new IntLineEdit(0, 0, 0, 255);
+	m_antialiasIntensity = new DVGui::IntLineEdit(0, 50, 0, 100);
+	m_palettePath = new DVGui::FileField(0, QString(CreateNewPalette), true);
+	m_tolerance = new DVGui::IntLineEdit(0, 0, 0, 255);
 
 	m_unpaintedFolder->setFileMode(QFileDialog::DirectoryOnly);
 	m_unpaintedSuffix->setMaximumWidth(40);
@@ -862,7 +862,7 @@ void ConvertPopup::convertToTlv(bool toPainted)
 		if (skipped == 0)
 			MsgBox(INFORMATION, tr("Level %1 converted to TLV Format").arg(QString::fromStdWString(m_srcFilePaths[0].withoutParentDir().getWideString())));
 		else
-			MsgBox(WARNING, tr("Warning: Level %1 NOT converted to TLV Format").arg(QString::fromStdWString(m_srcFilePaths[0].withoutParentDir().getWideString())));
+			DVGui::MsgBox(DVGui::WARNING, tr("Warning: Level %1 NOT converted to TLV Format").arg(QString::fromStdWString(m_srcFilePaths[0].withoutParentDir().getWideString())));
 	} else
 		MsgBox(skipped == 0 ? INFORMATION : WARNING, tr("Converted %1 out of %2 Levels to TLV Format").arg(QString::number(m_srcFilePaths.size() - skipped)).arg(QString::number(m_srcFilePaths.size())));
 
@@ -914,7 +914,7 @@ TPalette *ConvertPopup::readUserProvidedPalette() const
 		is >> palette;
 		// note! refCount==0
 	} catch (...) {
-		MsgBox(WARNING, tr("Warning: Can't read palette '%1' ").arg(m_palettePath->getPath()));
+		DVGui::MsgBox(DVGui::WARNING, tr("Warning: Can't read palette '%1' ").arg(m_palettePath->getPath()));
 		if (palette) {
 			delete palette;
 			palette = 0;
@@ -964,14 +964,14 @@ void ConvertPopup::getFrameRange(const TFilePath &sourceFilePath,
 bool ConvertPopup::checkParameters() const
 {
 	if (m_srcFilePaths.size() == 1 && m_fileNameFld->text().isEmpty()) {
-		MsgBox(WARNING, tr("No output filename specified: please choose a valid level name."));
+		DVGui::MsgBox(DVGui::WARNING, tr("No output filename specified: please choose a valid level name."));
 		return false;
 	}
 
 	if (m_fileFormat->currentText() == TlvExtension) {
 		if (m_tlvMode->currentText() == TlvMode_PaintedFromTwoImages) {
 			if (m_unpaintedSuffix->text() == "") {
-				MsgBox(WARNING, tr("No unpainted suffix specified: cannot convert."));
+				DVGui::MsgBox(DVGui::WARNING, tr("No unpainted suffix specified: cannot convert."));
 				return false;
 			}
 		}
@@ -1046,11 +1046,11 @@ void ConvertPopup::onConvertFinished()
 	int skippedCount = m_converter->getSkippedCount();
 	if (errorCount > 0) {
 		if (skippedCount > 0)
-			MsgBox(CRITICAL, tr("Convert completed with %1 error(s) and %2 level(s) skipped").arg(errorCount).arg(skippedCount));
+			DVGui::MsgBox(DVGui::CRITICAL, tr("Convert completed with %1 error(s) and %2 level(s) skipped").arg(errorCount).arg(skippedCount));
 		else
-			MsgBox(CRITICAL, tr("Convert completed with %1 error(s) ").arg(errorCount));
+			DVGui::MsgBox(DVGui::CRITICAL, tr("Convert completed with %1 error(s) ").arg(errorCount));
 	} else if (skippedCount > 0) {
-		MsgBox(WARNING, tr("%1 level(s) skipped").arg(skippedCount));
+		DVGui::MsgBox(DVGui::WARNING, tr("%1 level(s) skipped").arg(skippedCount));
 	}
 	/*
   if (m_srcFilePaths.size()==1)
@@ -1058,7 +1058,7 @@ void ConvertPopup::onConvertFinished()
     if (skipped==0)
         MsgBox(INFORMATION, tr("Level %1 converted to TLV Format").arg(QString::fromStdWString(m_srcFilePaths[0].withoutParentDir().getWideString())));
     else
-        MsgBox(WARNING, tr("Warning: Level %1 NOT converted to TLV Format").arg(QString::fromStdWString(m_srcFilePaths[0].withoutParentDir().getWideString())));
+        DVGui::MsgBox(DVGui::WARNING, tr("Warning: Level %1 NOT converted to TLV Format").arg(QString::fromStdWString(m_srcFilePaths[0].withoutParentDir().getWideString())));
   }
   else
     MsgBox(skipped==0?INFORMATION:WARNING, tr("Converted %1 out of %2 Levels to TLV Format").arg( QString::number(m_srcFilePaths.size()-skipped)).arg(QString::number(m_srcFilePaths.size())));
diff --git a/toonz/sources/toonz/duplicatepopup.cpp b/toonz/sources/toonz/duplicatepopup.cpp
index 8f5f8cd..d6c1d0f 100644
--- a/toonz/sources/toonz/duplicatepopup.cpp
+++ b/toonz/sources/toonz/duplicatepopup.cpp
@@ -109,8 +109,8 @@ DuplicatePopup::DuplicatePopup()
 {
 	setWindowTitle(tr("Repeat"));
 
-	m_countFld = new IntLineEdit(this);
-	m_upToFld = new IntLineEdit(this);
+	m_countFld = new DVGui::IntLineEdit(this);
+	m_upToFld = new DVGui::IntLineEdit(this);
 
 	m_okBtn = new QPushButton(tr("Repeat"), this);
 	m_cancelBtn = new QPushButton(tr("Close"), this);
@@ -182,7 +182,7 @@ void DuplicatePopup::onApplyPressed()
 		TApp::instance()->getCurrentScene()->setDirtyFlag(true);
 		TApp::instance()->getCurrentXsheet()->notifyXsheetChanged();
 	} catch (...) {
-		error(("Cannot duplicate"));
+		DVGui::error(("Cannot duplicate"));
 	}
 }
 
diff --git a/toonz/sources/toonz/duplicatepopup.h b/toonz/sources/toonz/duplicatepopup.h
index d735231..0426cbb 100644
--- a/toonz/sources/toonz/duplicatepopup.h
+++ b/toonz/sources/toonz/duplicatepopup.h
@@ -11,8 +11,6 @@
 // forward declaration
 class QPushButton;
 
-using namespace DVGui;
-
 //=============================================================================
 // DuplicatePopup
 //-----------------------------------------------------------------------------
@@ -25,7 +23,7 @@ class DuplicatePopup : public QDialog
 	QPushButton *m_cancelBtn;
 	QPushButton *m_applyBtn;
 
-	IntLineEdit *m_countFld, *m_upToFld;
+	DVGui::IntLineEdit *m_countFld, *m_upToFld;
 
 	int m_count, m_upTo;
 
diff --git a/toonz/sources/toonz/dvdirtreeview.cpp b/toonz/sources/toonz/dvdirtreeview.cpp
index b2db6c7..0f8a551 100644
--- a/toonz/sources/toonz/dvdirtreeview.cpp
+++ b/toonz/sources/toonz/dvdirtreeview.cpp
@@ -617,7 +617,7 @@ void DvDirTreeView::updateVersionControl(DvDirVersionControlNode *node)
 	if (rootNode) {
 		QString localPath = QString::fromStdWString(rootNode->getLocalPath());
 		if (!QFile::exists(localPath)) {
-			MsgBox(WARNING, tr("The local path does not exist:") + " " + localPath);
+			DVGui::MsgBox(DVGui::WARNING, tr("The local path does not exist:") + " " + localPath);
 			return;
 		}
 
diff --git a/toonz/sources/toonz/exportlevelpopup.cpp b/toonz/sources/toonz/exportlevelpopup.cpp
index d7c2fe8..47bbf74 100644
--- a/toonz/sources/toonz/exportlevelpopup.cpp
+++ b/toonz/sources/toonz/exportlevelpopup.cpp
@@ -72,7 +72,7 @@ struct MultiExportOverwriteCB : public IoCmd::OverwriteCallbacks {
 		if (m_stopped)
 			return false;
 
-		int ret = MsgBox(QObject::tr("Warning: file %1 already exists.").arg(toQString(fp)), QObject::tr("Continue Exporting"), QObject::tr("Continue to All"), QObject::tr("Stop Exporting"), 1);
+		int ret = DVGui::MsgBox(QObject::tr("Warning: file %1 already exists.").arg(toQString(fp)), QObject::tr("Continue Exporting"), QObject::tr("Continue to All"), QObject::tr("Stop Exporting"), 1);
 
 		m_yesToAll = (ret == 2);
 		m_stopped = (ret == 0) || (ret == 3);
@@ -84,7 +84,7 @@ struct MultiExportOverwriteCB : public IoCmd::OverwriteCallbacks {
 
 struct MultiExportProgressCB : public IoCmd::ProgressCallbacks {
 	QString m_processedName;
-	ProgressDialog m_pb;
+	DVGui::ProgressDialog m_pb;
 
 public:
 	MultiExportProgressCB() : m_pb("", QObject::tr("Cancel"), 0, 0) { m_pb.show(); }
@@ -235,7 +235,7 @@ ExportLevelPopup::ExportLevelPopup()
 	QLabel *formatLabel = new QLabel(tr("Format:"));
 	m_format = new QComboBox(this);
 	// Retas compliant checkbox
-	m_retas = new CheckBox(tr("Retas Compliant"));
+	m_retas = new DVGui::CheckBox(tr("Retas Compliant"));
 	// Format options button
 	m_formatOptions = new QPushButton(tr("Options"));
 	//-----
@@ -260,8 +260,8 @@ ExportLevelPopup::ExportLevelPopup()
 	m_levelFrameIndexHandle.setFrame(0);					  // Due to TFrameHandle's initialization, the initial frame
 	frameNavigator->setFrameHandle(&m_levelFrameIndexHandle); // is -1. Don't ask me why. Patching to 0.
 
-	formatLabel->setFixedHeight(WidgetHeight);
-	m_format->setFixedHeight(WidgetHeight);
+	formatLabel->setFixedHeight(DVGui::WidgetHeight);
+	m_format->setFixedHeight(DVGui::WidgetHeight);
 	m_format->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Maximum);
 
 	QStringList formats;
@@ -273,7 +273,7 @@ ExportLevelPopup::ExportLevelPopup()
 	formats.sort();
 	m_format->addItems(formats);
 
-	m_retas->setMinimumHeight(WidgetHeight);
+	m_retas->setMinimumHeight(DVGui::WidgetHeight);
 	m_formatOptions->setMinimumSize(60, 25);
 
 	//layout
@@ -647,7 +647,7 @@ bool ExportLevelPopup::execute()
 		return ret;
 	} else {
 		if (!isValidFileName(QString::fromStdString(fp.getName()))) {
-			MsgBox(CRITICAL, tr("The file name cannot be empty or contain any of the following characters:(new line)  \\ / : * ? \"  |"));
+			DVGui::MsgBox(DVGui::CRITICAL, tr("The file name cannot be empty or contain any of the following characters:(new line)  \\ / : * ? \"  |"));
 			return false;
 		}
 
diff --git a/toonz/sources/toonz/exportpanel.cpp b/toonz/sources/toonz/exportpanel.cpp
index c145908..024f0fb 100644
--- a/toonz/sources/toonz/exportpanel.cpp
+++ b/toonz/sources/toonz/exportpanel.cpp
@@ -246,12 +246,12 @@ void RenderController::generateMovie(TFilePath outPath, bool emitSignal)
 		else
 			msg = QObject::tr("There were problems loading the scene %1.\n Some files may be missing.").arg(QString::fromStdWString(fp.getWideString()));
 
-		MsgBox(WARNING, msg);
+		DVGui::MsgBox(DVGui::WARNING, msg);
 		return;
 	} catch (...) {
 		QString msg = QObject::tr("There were problems loading the scene %1.\n Some files may be missing.").arg(QString::fromStdWString(fp.getWideString()));
 
-		MsgBox(WARNING, msg);
+		DVGui::MsgBox(DVGui::WARNING, msg);
 		return;
 	}
 
@@ -315,7 +315,7 @@ void RenderController::generateMovie(TFilePath outPath, bool emitSignal)
 
 				if (!TSystem::showDocument(outPath)) {
 					QString msg(QObject::tr("It is not possible to display the file %1: no player associated with its format").arg(QString::fromStdWString(outPath.withoutParentDir().getWideString())));
-					MsgBox(WARNING, msg);
+					DVGui::MsgBox(DVGui::WARNING, msg);
 				}
 			} else {
 				int r0 = 1, r1 = totalFrameCount, step = 1;
diff --git a/toonz/sources/toonz/exportscenepopup.cpp b/toonz/sources/toonz/exportscenepopup.cpp
index f241e49..7192938 100644
--- a/toonz/sources/toonz/exportscenepopup.cpp
+++ b/toonz/sources/toonz/exportscenepopup.cpp
@@ -613,7 +613,7 @@ void ExportScenePopup::onExport()
 		DvDirModelFileFolderNode *node = (DvDirModelFileFolderNode *)m_projectTreeView->getCurrentNode();
 		if (!node || !pm->isProject(node->getPath())) {
 			QApplication::restoreOverrideCursor();
-			MsgBox(WARNING, tr("The folder you selected is not a project."));
+			DVGui::MsgBox(DVGui::WARNING, tr("The folder you selected is not a project."));
 			return;
 		}
 		projectPath = pm->projectFolderToProjectPath(node->getPath());
@@ -639,7 +639,7 @@ void ExportScenePopup::onExport()
 	pm->setCurrentProjectPath(oldProjectPath);
 	if (newScenes.empty()) {
 		QApplication::restoreOverrideCursor();
-		MsgBox(WARNING, tr("There was an error exporting the scene."));
+		DVGui::MsgBox(DVGui::WARNING, tr("There was an error exporting the scene."));
 		return;
 	}
 	for (i = 0; i < newScenes.size(); i++)
@@ -656,17 +656,17 @@ TFilePath ExportScenePopup::createNewProject()
 	TProjectManager *pm = TProjectManager::instance();
 	TFilePath projectName(m_newProjectName->text().toStdWString());
 	if (projectName == TFilePath()) {
-		MsgBox(WARNING, tr("The project name cannot be empty or contain any of the following characters:(new line)   \\ / : * ? \"  |"));
+		DVGui::MsgBox(DVGui::WARNING, tr("The project name cannot be empty or contain any of the following characters:(new line)   \\ / : * ? \"  |"));
 		return TFilePath();
 	}
 	if (projectName.isAbsolute()) {
 		// bad project name
-		MsgBox(WARNING, tr("The project name cannot be empty or contain any of the following characters:(new line)   \\ / : * ? \"  |"));
+		DVGui::MsgBox(DVGui::WARNING, tr("The project name cannot be empty or contain any of the following characters:(new line)   \\ / : * ? \"  |"));
 		return TFilePath();
 	}
 	if (pm->getProjectPathByName(projectName) != TFilePath()) {
 		// project already exists
-		MsgBox(WARNING, tr("The project name you specified is already used."));
+		DVGui::MsgBox(DVGui::WARNING, tr("The project name you specified is already used."));
 		return TFilePath();
 	}
 
diff --git a/toonz/sources/toonz/exportscenepopup.h b/toonz/sources/toonz/exportscenepopup.h
index 82f179f..9751eb4 100644
--- a/toonz/sources/toonz/exportscenepopup.h
+++ b/toonz/sources/toonz/exportscenepopup.h
@@ -16,8 +16,6 @@ class QLabel;
 class ExportSceneTreeView;
 class QRadioButton;
 
-using namespace DVGui;
-
 //=============================================================================
 // ExportSceneDvDirModelFileFolderNode
 
@@ -142,7 +140,7 @@ signals:
 //=============================================================================
 // ExportScenePopup
 
-class ExportScenePopup : public Dialog
+class ExportScenePopup : public DVGui::Dialog
 {
 	Q_OBJECT
 
diff --git a/toonz/sources/toonz/filebrowser.h b/toonz/sources/toonz/filebrowser.h
index 6776211..6888b72 100644
--- a/toonz/sources/toonz/filebrowser.h
+++ b/toonz/sources/toonz/filebrowser.h
@@ -236,13 +236,11 @@ private:
 };
 
 //--------------------------------------------------------------------
-using namespace DVGui;
-
-class RenameAsToonzPopup : public Dialog
+class RenameAsToonzPopup : public DVGui::Dialog
 {
 	Q_OBJECT
 	QPushButton *m_okBtn, *m_cancelBtn;
-	LineEdit *m_name;
+	DVGui::LineEdit *m_name;
 	QCheckBox *m_overwrite;
 
 public:
diff --git a/toonz/sources/toonz/filebrowserpopup.cpp b/toonz/sources/toonz/filebrowserpopup.cpp
index a883e4f..f579c3b 100644
--- a/toonz/sources/toonz/filebrowserpopup.cpp
+++ b/toonz/sources/toonz/filebrowserpopup.cpp
@@ -75,7 +75,7 @@ FileBrowserPopup::FileBrowserPopup(const QString &title, Options options, QStrin
 
 	m_browser = new FileBrowser(this, 0, false, m_multiSelectionEnabled);
 	m_nameFieldLabel = new QLabel(tr("File name:"));
-	m_nameField = new LineEdit(this);
+	m_nameField = new DVGui::LineEdit(this);
 	m_okButton = new QPushButton(tr("OK"), this);
 	m_cancelButton = new QPushButton(tr("Cancel"), this);
 	QPushButton *applyButton = 0;
@@ -212,7 +212,7 @@ void FileBrowserPopup::onOkPressed()
 	if (!m_nameField->text().isEmpty()) {
 		const QString &str = m_nameField->text();
 		if (!isValidFileName(QFileInfo(str).baseName()) && !m_isDirectoryOnly) {
-			error(QObject::tr("A filename cannot be empty or contain any of the following characters:\n \\ / : * ? \" < > |"));
+			DVGui::error(QObject::tr("A filename cannot be empty or contain any of the following characters:\n \\ / : * ? \" < > |"));
 			return;
 		}
 
@@ -232,7 +232,7 @@ void FileBrowserPopup::onOkPressed()
 			// history                                      // That means, TFilePath() represents
 			if (*pt == TFilePath() || !pt->isAbsolute()) // the History folder? Really? That's lame...
 			{
-				MsgBox(CRITICAL, tr("Invalid file"));
+				DVGui::MsgBox(DVGui::CRITICAL, tr("Invalid file"));
 				return;
 			}
 		} else {
@@ -276,7 +276,7 @@ void FileBrowserPopup::onApplyPressed()
 		if (folder == TFilePath()) {
 			// history
 			if (*it == TFilePath() || !it->isAbsolute()) {
-				MsgBox(CRITICAL, tr("Invalid file"));
+				DVGui::MsgBox(DVGui::CRITICAL, tr("Invalid file"));
 				return;
 			}
 		} else {
@@ -429,7 +429,7 @@ bool GenericSaveFilePopup::execute()
 	if (TFileStatus(path).doesExist()) {
 		const QString &question = QObject::tr("File %1 already exists.\nDo you want to overwrite it?").arg(toQString(path));
 
-		int ret = MsgBox(question, QObject::tr("Overwrite"), QObject::tr("Cancel"));
+		int ret = DVGui::MsgBox(question, QObject::tr("Overwrite"), QObject::tr("Cancel"));
 		if (ret == 0 || ret == 2)
 			return false;
 	}
@@ -467,12 +467,12 @@ bool LoadScenePopup::execute()
 	const TFilePath &fp = *m_selectedPaths.begin();
 
 	if (fp.getType() != "tnz") {
-		MsgBox(CRITICAL, toQString(fp) + tr(" is not a scene file."));
+		DVGui::MsgBox(DVGui::CRITICAL, toQString(fp) + tr(" is not a scene file."));
 		return false;
 	}
 
 	if (!TFileStatus(fp).doesExist()) {
-		MsgBox(CRITICAL, toQString(fp) + tr(" does not exist."));
+		DVGui::MsgBox(DVGui::CRITICAL, toQString(fp) + tr(" does not exist."));
 		return false;
 	}
 
@@ -523,12 +523,12 @@ bool LoadSubScenePopup::execute()
 	const TFilePath &fp = *m_selectedPaths.begin();
 
 	if (fp.getType() != "tnz") {
-		MsgBox(CRITICAL, toQString(fp) + tr(" is not a scene file."));
+		DVGui::MsgBox(DVGui::CRITICAL, toQString(fp) + tr(" is not a scene file."));
 		return false;
 	}
 
 	if (!TFileStatus(fp).doesExist()) {
-		MsgBox(CRITICAL, toQString(fp) + tr(" does not exist."));
+		DVGui::MsgBox(DVGui::CRITICAL, toQString(fp) + tr(" does not exist."));
 		return false;
 	}
 
@@ -636,20 +636,20 @@ LoadLevelPopup::LoadLevelPopup()
 	QPushButton *showSubsequenceButton = new QPushButton("", this);
 	QLabel *subsequenceLabel = new QLabel(tr("Load Subsequence Level"), this);
 	m_subsequenceFrame = new QFrame(this);
-	m_fromFrame = new LineEdit(this);
-	m_toFrame = new LineEdit(this);
+	m_fromFrame = new DVGui::LineEdit(this);
+	m_toFrame = new DVGui::LineEdit(this);
 
 	//----Arrangement in Xsheet
 	QPushButton *showArrangementButton = new QPushButton("", this);
 	QLabel *arrangementLabel = new QLabel(tr("Arrangement in Xsheet"), this);
 	m_arrangementFrame = new QFrame(this);
-	m_xFrom = new LineEdit(this);
-	m_xTo = new LineEdit(this);
+	m_xFrom = new DVGui::LineEdit(this);
+	m_xTo = new DVGui::LineEdit(this);
 	m_stepCombo = new QComboBox(this);
 	m_incCombo = new QComboBox(this);
-	m_levelName = new LineEdit(this);
-	m_posFrom = new LineEdit(this);
-	m_posTo = new LineEdit(this);
+	m_levelName = new DVGui::LineEdit(this);
+	m_posFrom = new DVGui::LineEdit(this);
+	m_posTo = new DVGui::LineEdit(this);
 
 	m_notExistLabel = new QLabel(tr("(FILE DOES NOT EXIST)"));
 
@@ -1375,7 +1375,7 @@ bool SaveLevelAsPopup::execute()
 		doExpose = false;
 	else if (ret && !Preferences::instance()->isReplaceAfterSaveLevelAsEnabled()) {
 		QString question(QObject::tr("Do you want to expose the renamed level ?"));
-		int val = MsgBox(question,
+		int val = DVGui::MsgBox(question,
 						 QObject::tr("Expose"),			  //val = 1
 						 QObject::tr("Don't expose"), 0); //val = 2
 		if (val == 0)
@@ -1512,7 +1512,7 @@ void ReplaceLevelPopup::show()
 	TCellSelection *cellSel = dynamic_cast<TCellSelection *>(sel);
 	TColumnSelection *columnSel = dynamic_cast<TColumnSelection *>(sel);
 	if ((!cellSel && !columnSel) || sel->isEmpty()) {
-		MsgBox(CRITICAL, tr("Nothing to replace: no cells selected."));
+		DVGui::MsgBox(DVGui::CRITICAL, tr("Nothing to replace: no cells selected."));
 		return;
 	}
 
@@ -1631,7 +1631,7 @@ bool SavePaletteAsPopup::execute()
 	TPalette *palette = paletteHandle->getPalette();
 
 	if (!palette) {
-		MsgBox(WARNING, "No current palette exists");
+		DVGui::MsgBox(DVGui::WARNING, "No current palette exists");
 		return true;
 	}
 
@@ -1644,7 +1644,7 @@ bool SavePaletteAsPopup::execute()
 
 	if (TFileStatus(fp).doesExist()) {
 		const QString &question = QObject::tr("The palette %1 already exists.\nDo you want to overwrite it?").arg(toQString(fp));
-		int ret = MsgBox(question, QObject::tr("Overwrite"), QObject::tr("Cancel"), 0);
+		int ret = DVGui::MsgBox(question, QObject::tr("Overwrite"), QObject::tr("Cancel"), 0);
 		if (ret == 2 || ret == 0)
 			return false;
 	}
@@ -1684,7 +1684,7 @@ LoadColorModelPopup::LoadColorModelPopup()
 	: FileBrowserPopup(tr("Load Color Model"), Options(), "", new QFrame(0))
 {
 	QFrame *optionFrame = (QFrame *)m_customWidget;
-	m_paletteFrame = new LineEdit("", this);
+	m_paletteFrame = new DVGui::LineEdit("", this);
 
 	//layout
 	QHBoxLayout *mainLayout = new QHBoxLayout();
@@ -1762,7 +1762,7 @@ bool LoadColorModelPopup::execute()
 
 	TPalette *palette = paletteHandle->getPalette();
 	if (!palette || palette->isCleanupPalette()) {
-		error(QObject::tr("Cannot load Color Model in current palette."));
+		DVGui::error(QObject::tr("Cannot load Color Model in current palette."));
 		return false;
 	}
 
@@ -1847,7 +1847,7 @@ void ReplaceParentDirectoryPopup::show()
 	TCellSelection *cellSel = dynamic_cast<TCellSelection *>(sel);
 	TColumnSelection *columnSel = dynamic_cast<TColumnSelection *>(sel);
 	if ((!cellSel && !columnSel) || sel->isEmpty()) {
-		MsgBox(CRITICAL, tr("Nothing to replace: no cells or columns selected."));
+		DVGui::MsgBox(DVGui::CRITICAL, tr("Nothing to replace: no cells or columns selected."));
 		return;
 	}
 	if (cellSel) {
@@ -1970,7 +1970,7 @@ bool ImportMagpieFilePopup::execute()
 	const TFilePath &fp = *m_selectedPaths.begin();
 
 	if (!TSystem::doesExistFileOrLevel(fp)) {
-		MsgBox(CRITICAL, tr("%1 does not exist.").arg(toQString(fp)));
+		DVGui::MsgBox(DVGui::CRITICAL, tr("%1 does not exist.").arg(toQString(fp)));
 		return false;
 	}
 
diff --git a/toonz/sources/toonz/filebrowserpopup.h b/toonz/sources/toonz/filebrowserpopup.h
index 7153c9f..8c09abf 100644
--- a/toonz/sources/toonz/filebrowserpopup.h
+++ b/toonz/sources/toonz/filebrowserpopup.h
@@ -89,7 +89,7 @@ protected:
 	FileBrowser *m_browser;
 
 	QLabel *m_nameFieldLabel;
-	LineEdit *m_nameField;
+	DVGui::LineEdit *m_nameField;
 
 	//QLabel*               m_fromFrameLabel;
 	//LineEdit*	            m_fromFrame;
@@ -275,17 +275,17 @@ class LoadLevelPopup : public FileBrowserPopup
 	Q_OBJECT
 
 	QFrame *m_subsequenceFrame;
-	LineEdit *m_fromFrame;
-	LineEdit *m_toFrame;
+	DVGui::LineEdit *m_fromFrame;
+	DVGui::LineEdit *m_toFrame;
 
 	QFrame *m_arrangementFrame;
-	LineEdit *m_xFrom;
-	LineEdit *m_xTo;
+	DVGui::LineEdit *m_xFrom;
+	DVGui::LineEdit *m_xTo;
 	QComboBox *m_stepCombo;
 	QComboBox *m_incCombo;
-	LineEdit *m_levelName;
-	LineEdit *m_posFrom;
-	LineEdit *m_posTo;
+	DVGui::LineEdit *m_levelName;
+	DVGui::LineEdit *m_posFrom;
+	DVGui::LineEdit *m_posTo;
 
 	QLabel *m_notExistLabel;
 	QComboBox *m_loadTlvBehaviorComboBox;
@@ -384,7 +384,7 @@ class LoadColorModelPopup : public FileBrowserPopup
 {
 	Q_OBJECT
 
-	LineEdit *m_paletteFrame;
+	DVGui::LineEdit *m_paletteFrame;
 
 public:
 	LoadColorModelPopup();
diff --git a/toonz/sources/toonz/filebrowserversioncontrol.cpp b/toonz/sources/toonz/filebrowserversioncontrol.cpp
index 27d160c..41a4138 100644
--- a/toonz/sources/toonz/filebrowserversioncontrol.cpp
+++ b/toonz/sources/toonz/filebrowserversioncontrol.cpp
@@ -181,7 +181,7 @@ void FileBrowser::editVersionControl()
 	}
 
 	if (hasCurrentSceneFile) {
-		MsgBox(WARNING, tr("Some files that you want to edit are currently opened. Close them first."));
+		DVGui::MsgBox(DVGui::WARNING, tr("Some files that you want to edit are currently opened. Close them first."));
 		return;
 	}
 
@@ -404,7 +404,7 @@ void FileBrowser::unlockVersionControl()
 	}
 
 	if (hasCurrentSceneFile) {
-		MsgBox(WARNING, tr("Some files that you want to unlock are currently opened. Close them first."));
+		DVGui::MsgBox(DVGui::WARNING, tr("Some files that you want to unlock are currently opened. Close them first."));
 		return;
 	}
 	vc->unlock(this, path, files, sceneIconsCount);
diff --git a/toonz/sources/toonz/filedata.cpp b/toonz/sources/toonz/filedata.cpp
index f5d79b7..2e65436 100644
--- a/toonz/sources/toonz/filedata.cpp
+++ b/toonz/sources/toonz/filedata.cpp
@@ -51,7 +51,7 @@ void FileData::getFiles(TFilePath folder, std::vector<TFilePath> &newFiles) cons
 		TFilePath path = folder + TFilePath(oldPath.getLevelNameW());
 
 		if (!TSystem::doesExistFileOrLevel(oldPath)) {
-			MsgBox(WARNING, tr("It is not possible to find the %1 level.").arg(QString::fromStdWString(oldPath.getWideString())));
+			DVGui::MsgBox(DVGui::WARNING, tr("It is not possible to find the %1 level.").arg(QString::fromStdWString(oldPath.getWideString())));
 			return;
 		}
 
diff --git a/toonz/sources/toonz/fileinfopopup.h b/toonz/sources/toonz/fileinfopopup.h
index 115e582..3205728 100644
--- a/toonz/sources/toonz/fileinfopopup.h
+++ b/toonz/sources/toonz/fileinfopopup.h
@@ -11,13 +11,11 @@ class QPushButton;
 class QLabel;
 class TFilePath;
 
-using namespace DVGui;
-
 //=============================================================================
 // FileInfoPopup
 //-----------------------------------------------------------------------------
 
-class FileInfoPopup : public Dialog
+class FileInfoPopup : public DVGui::Dialog
 {
 	Q_OBJECT
 
diff --git a/toonz/sources/toonz/filmstrip.h b/toonz/sources/toonz/filmstrip.h
index 4531316..55be730 100644
--- a/toonz/sources/toonz/filmstrip.h
+++ b/toonz/sources/toonz/filmstrip.h
@@ -24,8 +24,6 @@ class QComboBox;
 class InbetweenDialog;
 class TXshLevel;
 
-using namespace DVGui;
-
 const int fs_leftMargin = 2;
 const int fs_rightMargin = 3;
 const int fs_frameSpacing = 6;
@@ -237,7 +235,7 @@ private:
 // inbetweenDialog
 //-----------------------------------------------------------------------------
 
-class InbetweenDialog : public Dialog
+class InbetweenDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 	QComboBox *m_comboBox;
diff --git a/toonz/sources/toonz/filmstripselection.cpp b/toonz/sources/toonz/filmstripselection.cpp
index 90ba76c..b9f9edf 100644
--- a/toonz/sources/toonz/filmstripselection.cpp
+++ b/toonz/sources/toonz/filmstripselection.cpp
@@ -398,7 +398,7 @@ void TFilmstripSelection::renumberFrames()
 	int startFrame = 0, stepFrame = 0;
 	popup.getValues(startFrame, stepFrame);
 	if (startFrame < 1 || stepFrame < 1) {
-		error(("Bad renumber values"));
+		DVGui::error(("Bad renumber values"));
 		return;
 	}
 	FilmstripCmd::renumber(sl, m_selectedFrames, startFrame, stepFrame);
diff --git a/toonz/sources/toonz/flipbook.cpp b/toonz/sources/toonz/flipbook.cpp
index 8d83441..cb7d7c0 100644
--- a/toonz/sources/toonz/flipbook.cpp
+++ b/toonz/sources/toonz/flipbook.cpp
@@ -292,7 +292,7 @@ enum { eBegin,
 	   eIncrement,
 	   eEnd };
 
-static ProgressDialog *Pd = 0;
+static DVGui::ProgressDialog *Pd = 0;
 
 class ProgressBarMessager : public TThread::Message
 {
@@ -306,7 +306,7 @@ public:
 		switch (m_choice) {
 		case eBegin:
 			if (!Pd)
-				Pd = new ProgressDialog(QObject::tr("Saving previewed frames...."), QObject::tr("Cancel"), 0, m_val);
+				Pd = new DVGui::ProgressDialog(QObject::tr("Saving previewed frames...."), QObject::tr("Cancel"), 0, m_val);
 			else
 				Pd->setMaximum(m_val);
 			Pd->show();
@@ -346,10 +346,10 @@ LoadImagesPopup::LoadImagesPopup(FlipBook *flip)
 	frameRangeFrame->setFrameStyle(QFrame::StyledPanel);
 	//frameRangeFrame->setFixedHeight(30);
 
-	m_fromField = new LineEdit(this);
-	m_toField = new LineEdit(this);
-	m_stepField = new LineEdit("1", this);
-	m_shrinkField = new LineEdit("1", this);
+	m_fromField = new DVGui::LineEdit(this);
+	m_toField = new DVGui::LineEdit(this);
+	m_stepField = new DVGui::LineEdit("1", this);
+	m_shrinkField = new DVGui::LineEdit("1", this);
 
 	//Define the append/load filter types
 	m_appendFilterTypes
@@ -604,7 +604,7 @@ bool FlipBook::doSaveImages(TFilePath fp)
 	// Open a notice that the previewFx is rendered in 8bpc regardless of the output settings.
 	if (m_isPreviewFx && outputSettings->getRenderSettings().m_bpp == 64) {
 		QString question = "Save previewed images :\nImages will be saved in 8 bit per channel with this command.\nDo you want to save images?";
-		int ret = MsgBox(question, QObject::tr("Save"), QObject::tr("Cancel"), 0);
+		int ret = DVGui::MsgBox(question, QObject::tr("Save"), QObject::tr("Cancel"), 0);
 		if (ret == 2 || ret == 0)
 			return false;
 	}
@@ -616,7 +616,7 @@ bool FlipBook::doSaveImages(TFilePath fp)
 		TDimension res = scene->getCurrentCamera()->getRes();
 		if (!AviCodecRestrictions::canWriteMovie(toWideString(codecName), res)) {
 			QString msg(QObject::tr("The resolution of the output camera does not fit with the options chosen for the output file format."));
-			MsgBox(WARNING, msg);
+			DVGui::MsgBox(DVGui::WARNING, msg);
 			return false;
 		}
 	}
@@ -627,12 +627,12 @@ bool FlipBook::doSaveImages(TFilePath fp)
 		fp = fp.withType(ext);
 	}
 	if (fp.getName() == "") {
-		MsgBox(WARNING, tr("The file name cannot be empty or contain any of the following characters:(new line)  \\ / : * ? \"  |"));
+		DVGui::MsgBox(DVGui::WARNING, tr("The file name cannot be empty or contain any of the following characters:(new line)  \\ / : * ? \"  |"));
 		return false;
 	}
 
 	if (!formats.contains(QString::fromStdString(ext))) {
-		MsgBox(WARNING, tr("It is not possible to save because the selected file format is not supported."));
+		DVGui::MsgBox(DVGui::WARNING, tr("It is not possible to save because the selected file format is not supported."));
 		return false;
 	}
 
@@ -640,7 +640,7 @@ bool FlipBook::doSaveImages(TFilePath fp)
 	m_flipConsole->getFrameRange(from, to, step);
 
 	if (m_currentFrameToSave != 0) {
-		info("Already saving!");
+		DVGui::info("Already saving!");
 		return true;
 	}
 
@@ -655,17 +655,17 @@ bool FlipBook::doSaveImages(TFilePath fp)
 			TSystem::mkDir(parent);
 			DvDirModel::instance()->refreshFolder(parent.getParentDir());
 		} catch (TException &e) {
-			error("Cannot create " + toQString(fp.getParentDir()) + " : " + QString(toString(e.getMessage()).c_str()));
+			DVGui::error("Cannot create " + toQString(fp.getParentDir()) + " : " + QString(toString(e.getMessage()).c_str()));
 			return false;
 		} catch (...) {
-			error("Cannot create " + toQString(fp.getParentDir()));
+			DVGui::error("Cannot create " + toQString(fp.getParentDir()));
 			return false;
 		}
 	}
 
 	if (TSystem::doesExistFileOrLevel(fp)) {
 		QString question(tr("File %1 already exists.\nDo you want to overwrite it?").arg(toQString(fp)));
-		int ret = MsgBox(question, QObject::tr("Overwrite"), QObject::tr("Cancel"));
+		int ret = DVGui::MsgBox(question, QObject::tr("Overwrite"), QObject::tr("Cancel"));
 		if (ret == 2)
 			return false;
 	}
@@ -673,7 +673,7 @@ bool FlipBook::doSaveImages(TFilePath fp)
 	try {
 		m_lw = TLevelWriterP(fp, outputSettings->getFileFormatProperties(fp.getType()));
 	} catch (...) {
-		error("It is not possible to save Flipbook content.");
+		DVGui::error("It is not possible to save Flipbook content.");
 		return false;
 	}
 
@@ -758,10 +758,10 @@ void FlipBook::onButtonPressed(FlipConsole::EGadget button)
 			TImageP img = getCurrentImage(m_flipConsole->getCurrentFrame());
 			m_loadbox = loadbox;
 			if (!img) {
-				MsgBox(WARNING, tr("There are no rendered images to save."));
+				DVGui::MsgBox(DVGui::WARNING, tr("There are no rendered images to save."));
 				return;
 			} else if ((TVectorImageP)img) {
-				MsgBox(WARNING, tr("It is not possible to take or compare snapshots for Toonz vector levels."));
+				DVGui::MsgBox(DVGui::WARNING, tr("It is not possible to take or compare snapshots for Toonz vector levels."));
 				return;
 			}
 			TRasterImageP ri(img);
@@ -775,7 +775,7 @@ void FlipBook::onButtonPressed(FlipConsole::EGadget button)
 		}
 		CASE FlipConsole::eCompare : if ((TVectorImageP)getCurrentImage(m_flipConsole->getCurrentFrame()))
 		{
-			MsgBox(WARNING, tr("It is not possible to take or compare snapshots for Toonz vector levels."));
+			DVGui::MsgBox(DVGui::WARNING, tr("It is not possible to take or compare snapshots for Toonz vector levels."));
 			m_flipConsole->setChecked(FlipConsole::eCompare, false);
 			return;
 		}
@@ -2194,7 +2194,7 @@ void viewFile(const TFilePath &path, int from, int to, int step, int shrink,
 		 path.getType() == "avi" ||
 		 path.getType() == "3gp") &&
 		path.isLevelName()) {
-		MsgBox(WARNING, QObject::tr("%1  has an invalid extension format.")
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("%1  has an invalid extension format.")
 							.arg(QString::fromStdString(path.getLevelName())));
 		return;
 	}
diff --git a/toonz/sources/toonz/flipbook.h b/toonz/sources/toonz/flipbook.h
index 5b59b90..642368b 100644
--- a/toonz/sources/toonz/flipbook.h
+++ b/toonz/sources/toonz/flipbook.h
@@ -41,10 +41,10 @@ class LoadImagesPopup : public FileBrowserPopup
 {
 	Q_OBJECT
 
-	LineEdit *m_fromField;
-	LineEdit *m_toField;
-	LineEdit *m_stepField;
-	LineEdit *m_shrinkField;
+	DVGui::LineEdit *m_fromField;
+	DVGui::LineEdit *m_toField;
+	DVGui::LineEdit *m_stepField;
+	DVGui::LineEdit *m_shrinkField;
 
 	int m_minFrame, m_maxFrame;
 	int m_from, m_to, m_step, m_shrink;
diff --git a/toonz/sources/toonz/formatsettingspopups.cpp b/toonz/sources/toonz/formatsettingspopups.cpp
index eb073fb..99d1ead 100644
--- a/toonz/sources/toonz/formatsettingspopups.cpp
+++ b/toonz/sources/toonz/formatsettingspopups.cpp
@@ -74,7 +74,7 @@ FormatSettingsPopup::FormatSettingsPopup(
 		m_codecRestriction->setStyleSheet("border: 1px solid rgb(200,200,200);");
 		m_mainLayout->addWidget(m_codecRestriction, m_mainLayout->rowCount(), 0, 1, 2);
 		m_configureCodec = new QPushButton("Configure Codec", this);
-		m_configureCodec->setFixedSize(100, WidgetHeight);
+		m_configureCodec->setFixedSize(100, DVGui::WidgetHeight);
 		m_mainLayout->addWidget(m_configureCodec, m_mainLayout->rowCount(), 0, 1, 2);
 		connect(m_configureCodec, SIGNAL(released()), this, SLOT(onAviCodecConfigure()));
 	}
@@ -105,7 +105,7 @@ void FormatSettingsPopup::buildPropertyComboBox(int index, TPropertyGroup *props
 	TEnumProperty *prop = (TEnumProperty *)(props->getProperty(index));
 	assert(prop);
 
-	PropertyComboBox *comboBox = new PropertyComboBox(this, prop);
+	DVGui::PropertyComboBox *comboBox = new DVGui::PropertyComboBox(this, prop);
 	m_widgets[prop->getName()] = comboBox;
 	connect(comboBox, SIGNAL(currentIndexChanged(const QString)), this, SLOT(onComboBoxIndexChanged(const QString)));
 	TEnumProperty::Range range = prop->getRange();
@@ -144,7 +144,7 @@ void FormatSettingsPopup::buildValueField(int index, TPropertyGroup *props)
 	TIntProperty *prop = (TIntProperty *)(props->getProperty(index));
 	assert(prop);
 
-	PropertyIntField *v = new PropertyIntField(this, prop);
+	DVGui::PropertyIntField *v = new DVGui::PropertyIntField(this, prop);
 	m_widgets[prop->getName()] = v;
 
 	int row = m_mainLayout->rowCount();
@@ -161,7 +161,7 @@ void FormatSettingsPopup::buildPropertyCheckBox(int index, TPropertyGroup *props
 	TBoolProperty *prop = (TBoolProperty *)(props->getProperty(index));
 	assert(prop);
 
-	PropertyCheckBox *v = new PropertyCheckBox(tr(prop->getName().c_str()), this, prop);
+	DVGui::PropertyCheckBox *v = new DVGui::PropertyCheckBox(tr(prop->getName().c_str()), this, prop);
 	m_widgets[prop->getName()] = v;
 
 	m_mainLayout->addWidget(v, m_mainLayout->rowCount(), 1);
@@ -176,7 +176,7 @@ void FormatSettingsPopup::buildPropertyLineEdit(int index, TPropertyGroup *props
 	TStringProperty *prop = (TStringProperty *)(props->getProperty(index));
 	assert(prop);
 
-	PropertyLineEdit *lineEdit = new PropertyLineEdit(this, prop);
+	DVGui::PropertyLineEdit *lineEdit = new DVGui::PropertyLineEdit(this, prop);
 	m_widgets[prop->getName()] = lineEdit;
 	lineEdit->setText(tr(toString(prop->getValue()).c_str()));
 
diff --git a/toonz/sources/toonz/formatsettingspopups.h b/toonz/sources/toonz/formatsettingspopups.h
index 3951385..ce9c512 100644
--- a/toonz/sources/toonz/formatsettingspopups.h
+++ b/toonz/sources/toonz/formatsettingspopups.h
@@ -46,7 +46,7 @@ private:
 	TPropertyGroup *m_props;
 	TFilePath m_levelPath;
 
-	QMap<std::string, PropertyWidget *> m_widgets; //!< Property name -> PropertyWidget
+	QMap<std::string, DVGui::PropertyWidget *> m_widgets; //!< Property name -> PropertyWidget
 
 	QGridLayout *m_mainLayout;
 
@@ -54,7 +54,7 @@ private:
 
 	// AVI codec - related members
 	QLabel *m_codecRestriction;
-	PropertyComboBox *m_codecComboBox;
+	DVGui::PropertyComboBox *m_codecComboBox;
 	QPushButton *m_configureCodec;
 
 #endif
diff --git a/toonz/sources/toonz/fxparameditorpopup.h b/toonz/sources/toonz/fxparameditorpopup.h
index f4eb7a8..9af35c0 100644
--- a/toonz/sources/toonz/fxparameditorpopup.h
+++ b/toonz/sources/toonz/fxparameditorpopup.h
@@ -5,8 +5,6 @@
 
 #include "toonzqt/dvdialog.h"
 
-using namespace DVGui;
-
 //=============================================================================
 // FxParamEditorPopup
 //-----------------------------------------------------------------------------
diff --git a/toonz/sources/toonz/histogrampopup.h b/toonz/sources/toonz/histogrampopup.h
index 7e6235e..9486952 100644
--- a/toonz/sources/toonz/histogrampopup.h
+++ b/toonz/sources/toonz/histogrampopup.h
@@ -7,8 +7,6 @@
 #include "timage.h"
 #include "tpixel.h"
 
-using namespace DVGui;
-
 class ComboHistogram;
 
 //=============================================================================
diff --git a/toonz/sources/toonz/insertfxpopup.h b/toonz/sources/toonz/insertfxpopup.h
index 70f4718..dda1503 100644
--- a/toonz/sources/toonz/insertfxpopup.h
+++ b/toonz/sources/toonz/insertfxpopup.h
@@ -14,13 +14,11 @@ class TFx;
 
 #include <QIcon>
 
-using namespace DVGui;
-
 //=============================================================================
 // InsertFxPopup
 //-----------------------------------------------------------------------------
 
-class InsertFxPopup : public Dialog
+class InsertFxPopup : public DVGui::Dialog
 {
 	Q_OBJECT
 
diff --git a/toonz/sources/toonz/iocommand.cpp b/toonz/sources/toonz/iocommand.cpp
index 8ab77b4..2e701be 100644
--- a/toonz/sources/toonz/iocommand.cpp
+++ b/toonz/sources/toonz/iocommand.cpp
@@ -1448,7 +1448,7 @@ bool IoCmd::saveScene(const TFilePath &path, int flags)
 		scene->save(scenePath, xsheet);
 		TApp::instance()->getPaletteController()->getCurrentLevelPalette()->notifyPaletteChanged(); //non toglieva l'asterisco alla paletta...forse non va qua? vinz
 	} catch (const TSystemException &se) {
-		MsgBox(WARNING, QString::fromStdWString(se.getMessage()));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdWString(se.getMessage()));
 	} catch (...) {
 		MsgBox(CRITICAL, QObject::tr("Couldn't save %1").arg(toQString(scenePath)));
 	}
@@ -1620,7 +1620,7 @@ bool IoCmd::saveLevel(const TFilePath &fp, TXshSimpleLevel *sl, bool overwrite)
 		sl->save(fp, TFilePath(), overwritePalette);
 	} catch (TSystemException se) {
 		QApplication::restoreOverrideCursor();
-		MsgBox(WARNING, QString::fromStdWString(se.getMessage()));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdWString(se.getMessage()));
 		return false;
 	} catch (...) {
 		QApplication::restoreOverrideCursor();
@@ -1818,7 +1818,7 @@ bool IoCmd::loadScene(const TFilePath &path, bool updateRecentFile, bool checkSa
 	if (!sceneProject) {
 		QString msg;
 		msg = QObject::tr("It is not possible to load the scene %1 because it does not belong to any project.").arg(QString::fromStdWString(scenePath.getWideString()));
-		MsgBox(WARNING, msg);
+		DVGui::MsgBox(DVGui::WARNING, msg);
 	}
 	if (sceneProject && !sceneProject->isCurrent()) {
 		QString currentProjectName =
@@ -1886,14 +1886,14 @@ bool IoCmd::loadScene(const TFilePath &path, bool updateRecentFile, bool checkSa
 			msg = QObject::tr("The scene %1 was created with Toonz and cannot be loaded in LineTest.").arg(QString::fromStdWString(scenePath.getWideString()));
 		else
 			msg = QObject::tr("There were problems loading the scene %1.\n Some files may be missing.").arg(QString::fromStdWString(scenePath.getWideString()));
-		MsgBox(WARNING, msg);
+		DVGui::MsgBox(DVGui::WARNING, msg);
 	}
 #endif
 	catch (...) {
 		printf("%s:%s Exception ...:\n", __FILE__, __FUNCTION__);
 		QString msg;
 		msg = QObject::tr("There were problems loading the scene %1.\n Some files may be missing.").arg(QString::fromStdWString(scenePath.getWideString()));
-		MsgBox(WARNING, msg);
+		DVGui::MsgBox(DVGui::WARNING, msg);
 	}
 	printf("%s:%s end load:\n", __FILE__, __FUNCTION__);
 	TProject *project = scene->getProject();
@@ -1944,7 +1944,7 @@ bool IoCmd::loadScene(const TFilePath &path, bool updateRecentFile, bool checkSa
 	if (forbiddenLevelCount > 0) {
 		QString msg;
 		msg = QObject::tr("There were problems loading the scene %1.\nSome levels have not been loaded because their version is not supported").arg(QString::fromStdWString(scenePath.getWideString()));
-		MsgBox(WARNING, msg);
+		DVGui::MsgBox(DVGui::WARNING, msg);
 	}
 
 	bool exist = TSystem::doesExistFileOrLevel(scene->decodeFilePath(scene->getScenePath()));
@@ -2601,16 +2601,16 @@ public:
 #else
 		TXshSimpleLevel *sl = TApp::instance()->getCurrentLevel()->getSimpleLevel();
 		if (!sl) {
-			MsgBox(WARNING, QObject::tr("No Current Level"));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("No Current Level"));
 			return;
 		}
 		if (!sl->getPalette()) {
-			MsgBox(WARNING, QObject::tr("Toonz cannot Save this Level"));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("Toonz cannot Save this Level"));
 			return;
 		}
 		ToonzScene *scene = TApp::instance()->getCurrentScene()->getScene();
 		if (!scene) {
-			MsgBox(WARNING, QObject::tr("No Current Scene"));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("No Current Scene"));
 			return; // non dovrebbe succedere mai
 		}
 		TFilePath levelPath = sl->getPath();
@@ -2649,7 +2649,7 @@ public:
 		try {
 			TProjectManager::instance()->saveTemplate(scene);
 		} catch (TSystemException se) {
-			MsgBox(WARNING, QString::fromStdWString(se.getMessage()));
+			DVGui::MsgBox(DVGui::WARNING, QString::fromStdWString(se.getMessage()));
 			return;
 		}
 	}
@@ -2760,13 +2760,13 @@ public:
 
 		TXshLevel *level = TApp::instance()->getCurrentLevel()->getLevel();
 		if (!level) {
-			MsgBox(WARNING, "No current level.");
+			DVGui::MsgBox(DVGui::WARNING, "No current level.");
 			return;
 		}
 		TXshSimpleLevel *sl = level->getSimpleLevel();
 		TXshPaletteLevel *pl = level->getPaletteLevel();
 		if (!sl && !pl) {
-			MsgBox(WARNING, "Current level has no palette.");
+			DVGui::MsgBox(DVGui::WARNING, "Current level has no palette.");
 			return;
 		}
 		/*-- SimpleLevel/PaletteLevelの場合毎にパレット/パスの取得の仕方を変える --*/
@@ -2776,7 +2776,7 @@ public:
 		if (sl) {
 			palette = sl->getPalette();
 			if (!palette) {
-				MsgBox(WARNING, "No current palette");
+				DVGui::MsgBox(DVGui::WARNING, "No current palette");
 				return;
 			}
 			if (sl->getPath().getType() == "pli")
@@ -2788,12 +2788,12 @@ public:
 		else if (pl) {
 			palette = pl->getPalette();
 			if (!palette) {
-				MsgBox(WARNING, "No current palette");
+				DVGui::MsgBox(DVGui::WARNING, "No current palette");
 				return;
 			}
 			palettePath = pl->getPath();
 		} else {
-			MsgBox(WARNING, "This level is not SimpleLevel or PaletteLevel");
+			DVGui::MsgBox(DVGui::WARNING, "This level is not SimpleLevel or PaletteLevel");
 			return;
 		}
 
diff --git a/toonz/sources/toonz/levelcreatepopup.cpp b/toonz/sources/toonz/levelcreatepopup.cpp
index af4a103..f5d44cb 100644
--- a/toonz/sources/toonz/levelcreatepopup.cpp
+++ b/toonz/sources/toonz/levelcreatepopup.cpp
@@ -178,10 +178,10 @@ LevelCreatePopup::LevelCreatePopup()
 	setWindowTitle(tr("New Level"));
 
 	m_nameFld = new LineEdit(this);
-	m_fromFld = new IntLineEdit(this);
-	m_toFld = new IntLineEdit(this);
-	m_stepFld = new IntLineEdit(this);
-	m_incFld = new IntLineEdit(this);
+	m_fromFld = new DVGui::IntLineEdit(this);
+	m_toFld = new DVGui::IntLineEdit(this);
+	m_stepFld = new DVGui::IntLineEdit(this);
+	m_incFld = new DVGui::IntLineEdit(this);
 	m_levelTypeOm = new QComboBox();
 
 	m_pathFld = new FileField(0);
diff --git a/toonz/sources/toonz/levelcreatepopup.h b/toonz/sources/toonz/levelcreatepopup.h
index 8d3c06d..ee75fae 100644
--- a/toonz/sources/toonz/levelcreatepopup.h
+++ b/toonz/sources/toonz/levelcreatepopup.h
@@ -13,29 +13,27 @@ class QLabel;
 class QComboBox;
 //class DVGui::MeasuredDoubleLineEdit;
 
-using namespace DVGui;
-
 //=============================================================================
 // LevelCreatePopup
 //-----------------------------------------------------------------------------
 
-class LevelCreatePopup : public Dialog
+class LevelCreatePopup : public DVGui::Dialog
 {
 	Q_OBJECT
 
-	LineEdit *m_nameFld;
-	IntLineEdit *m_fromFld;
-	IntLineEdit *m_toFld;
+	DVGui::LineEdit *m_nameFld;
+	DVGui::IntLineEdit *m_fromFld;
+	DVGui::IntLineEdit *m_toFld;
 	QComboBox *m_levelTypeOm;
-	IntLineEdit *m_stepFld;
-	IntLineEdit *m_incFld;
-	FileField *m_pathFld;
+	DVGui::IntLineEdit *m_stepFld;
+	DVGui::IntLineEdit *m_incFld;
+	DVGui::FileField *m_pathFld;
 	QLabel *m_widthLabel;
 	QLabel *m_heightLabel;
 	QLabel *m_dpiLabel;
 	DVGui::MeasuredDoubleLineEdit *m_widthFld;
 	DVGui::MeasuredDoubleLineEdit *m_heightFld;
-	DoubleLineEdit *m_dpiFld;
+	DVGui::DoubleLineEdit *m_dpiFld;
 
 public:
 	LevelCreatePopup();
diff --git a/toonz/sources/toonz/levelsettingspopup.cpp b/toonz/sources/toonz/levelsettingspopup.cpp
index a336031..5d7e4e1 100644
--- a/toonz/sources/toonz/levelsettingspopup.cpp
+++ b/toonz/sources/toonz/levelsettingspopup.cpp
@@ -134,7 +134,7 @@ LevelSettingsPopup::LevelSettingsPopup()
 
 	//subsampling
 	m_subsamplingLabel = new QLabel(tr("Subsampling:"));
-	m_subsamplingFld = new IntLineEdit(this);
+	m_subsamplingFld = new DVGui::IntLineEdit(this);
 
 	m_doPremultiply = new CheckBox(tr("Premultiply"), this);
 
@@ -143,7 +143,7 @@ LevelSettingsPopup::LevelSettingsPopup()
 #endif
 
 	m_doAntialias = new CheckBox(tr("Add Antialiasing"), this);
-	m_antialiasSoftness = new IntLineEdit(0, 10, 0, 100);
+	m_antialiasSoftness = new DVGui::IntLineEdit(0, 10, 0, 100);
 
 	//----
 
@@ -773,11 +773,11 @@ void LevelSettingsPopup::onScanPathChanged()
 		if (cleanupLevelPath != TFilePath()) {
 			TFilePath codedCleanupLevelPath = TApp::instance()->getCurrentScene()->getScene()->codeFilePath(cleanupLevelPath);
 			if (m_sl->getPath().getParentDir() != cleanupLevelPath && m_sl->getPath().getParentDir() != codedCleanupLevelPath)
-				MsgBox(WARNING, "\"Save In\" path of the Cleanup Settings does not match.");
+				DVGui::MsgBox(DVGui::WARNING, "\"Save In\" path of the Cleanup Settings does not match.");
 		} else
-			MsgBox(WARNING, "Loading Cleanup Settings failed.");
+			DVGui::MsgBox(DVGui::WARNING, "Loading Cleanup Settings failed.");
 	} else
-		MsgBox(WARNING, ".cln file for the Scanned Level not found.");
+		DVGui::MsgBox(DVGui::WARNING, ".cln file for the Scanned Level not found.");
 
 	m_sl->setScannedPath(newScanPath);
 
diff --git a/toonz/sources/toonz/linetestpane.h b/toonz/sources/toonz/linetestpane.h
index 48894cd..2b394f3 100644
--- a/toonz/sources/toonz/linetestpane.h
+++ b/toonz/sources/toonz/linetestpane.h
@@ -16,8 +16,6 @@
 #include <QThread>
 #include <QWaitCondition>
 
-using namespace DVGui;
-
 class QStackedWidget;
 
 //=============================================================================
diff --git a/toonz/sources/toonz/magpiefileimportpopup.cpp b/toonz/sources/toonz/magpiefileimportpopup.cpp
index b39e247..87e1b0b 100644
--- a/toonz/sources/toonz/magpiefileimportpopup.cpp
+++ b/toonz/sources/toonz/magpiefileimportpopup.cpp
@@ -92,11 +92,11 @@ MagpieFileImportPopup::MagpieFileImportPopup()
 	addWidget(tr("Phoneme"), frameLabel);
 	int i;
 	for (i = 0; i < 9; i++) {
-		IntLineEdit *field = new IntLineEdit(this, 1, 1);
+		DVGui::IntLineEdit *field = new DVGui::IntLineEdit(this, 1, 1);
 		QLabel *label = new QLabel("", this);
 		label->setAlignment(Qt::AlignRight | Qt::AlignVCenter);
 		label->setFixedSize(getLabelWidth(), field->height());
-		m_actFields.append(QPair<QLabel *, IntLineEdit *>(label, field));
+		m_actFields.append(QPair<QLabel *, DVGui::IntLineEdit *>(label, field));
 		addWidgets(label, field);
 	}
 
@@ -149,7 +149,7 @@ void MagpieFileImportPopup::showEvent(QShowEvent *)
 	int i;
 	QList<QString> actsIdentifier = m_info->getActsIdentifier();
 	for (i = 0; i < m_actFields.size(); i++) {
-		IntLineEdit *field = m_actFields.at(i).second;
+		DVGui::IntLineEdit *field = m_actFields.at(i).second;
 		QLabel *label = m_actFields.at(i).first;
 		if (i >= actsIdentifier.size()) {
 			field->hide();
@@ -237,7 +237,7 @@ void MagpieFileImportPopup::onOkPressed()
 		}
 		int j;
 		for (j = 0; j < m_actFields.size(); j++) {
-			IntLineEdit *field = m_actFields.at(j).second;
+			DVGui::IntLineEdit *field = m_actFields.at(j).second;
 			QString act = field->property("act").toString();
 			if (actorAct != act)
 				continue;
diff --git a/toonz/sources/toonz/magpiefileimportpopup.h b/toonz/sources/toonz/magpiefileimportpopup.h
index 7735279..ea240d2 100644
--- a/toonz/sources/toonz/magpiefileimportpopup.h
+++ b/toonz/sources/toonz/magpiefileimportpopup.h
@@ -15,8 +15,6 @@ class FileField;
 class LineEdit;
 }
 
-using namespace DVGui;
-
 class MagpieInfo
 {
 	QList<QString> m_actorActs;
@@ -39,17 +37,17 @@ public:
 // MagpieFileImportPopup
 //-----------------------------------------------------------------------------
 
-class MagpieFileImportPopup : public Dialog
+class MagpieFileImportPopup : public DVGui::Dialog
 {
 	Q_OBJECT
 
 	MagpieInfo *m_info;
 
-	FileField *m_levelField;
-	IntLineEdit *m_fromField;
-	IntLineEdit *m_toField;
+	DVGui::FileField *m_levelField;
+	DVGui::IntLineEdit *m_fromField;
+	DVGui::IntLineEdit *m_toField;
 
-	QList<QPair<QLabel *, IntLineEdit *>> m_actFields;
+	QList<QPair<QLabel *, DVGui::IntLineEdit *>> m_actFields;
 
 	FlipBook *m_flipbook;
 	TFilePath m_levelPath;
diff --git a/toonz/sources/toonz/mainwindow.cpp b/toonz/sources/toonz/mainwindow.cpp
index a38fcb9..62f8437 100644
--- a/toonz/sources/toonz/mainwindow.cpp
+++ b/toonz/sources/toonz/mainwindow.cpp
@@ -108,7 +108,7 @@ bool readRoomList(std::vector<TFilePath> &roomPaths,
 	if (!argumentLayoutFileName.isEmpty()) {
 		fp = ToonzFolder::getModuleFile(argumentLayoutFileName.toStdString());
 		if (!TFileStatus(fp).doesExist()) {
-			MsgBox(WARNING, "Room layout file " + argumentLayoutFileName + " not found!");
+			DVGui::MsgBox(DVGui::WARNING, "Room layout file " + argumentLayoutFileName + " not found!");
 			fp = ToonzFolder::getModuleFile(layoutsFileName);
 			if (!TFileStatus(fp).doesExist())
 				return false;
diff --git a/toonz/sources/toonz/matchline.cpp b/toonz/sources/toonz/matchline.cpp
index ae67dc7..e870179 100644
--- a/toonz/sources/toonz/matchline.cpp
+++ b/toonz/sources/toonz/matchline.cpp
@@ -709,7 +709,7 @@ void doMatchlines(int column, int mColumn, int index, int inkPrevalence, int Mer
 		/*-- 左カラムに複数のLevelが入っている場合、警告を出して抜ける --*/
 		else if (level != cell[i].getSimpleLevel()) {
 			getImageProgressBar->close();
-			MsgBox(WARNING, QObject::tr("It is not possible to apply match lines to a column containing more than one level."));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to apply match lines to a column containing more than one level."));
 			/*-- 前に遡ってキャッシュを消去 --*/
 			i--;
 			for (; i >= 0; i--) {
@@ -725,7 +725,7 @@ void doMatchlines(int column, int mColumn, int index, int inkPrevalence, int Mer
 			mLevel = mCell[i].getSimpleLevel();
 		else if (mLevel != mCell[i].getSimpleLevel()) {
 			getImageProgressBar->close();
-			MsgBox(WARNING, QObject::tr("It is not possible to use a match lines column containing more than one level."));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to use a match lines column containing more than one level."));
 			/*-- 前に遡ってキャッシュを消去 --*/
 			i--;
 			for (; i >= 0; i--) {
@@ -752,7 +752,7 @@ void doMatchlines(int column, int mColumn, int index, int inkPrevalence, int Mer
 			//ラスタLevelじゃないとき、エラーを返す
 			if (!timg || !tmatch) {
 				getImageProgressBar->close();
-				MsgBox(WARNING, QObject::tr("Match lines can be applied to Toonz raster levels only."));
+				DVGui::MsgBox(DVGui::WARNING, QObject::tr("Match lines can be applied to Toonz raster levels only."));
 				/*-- 前に遡ってキャッシュを消去 --*/
 				i--;
 				for (; i >= 0; i--) {
@@ -779,7 +779,7 @@ void doMatchlines(int column, int mColumn, int index, int inkPrevalence, int Mer
 	getImageProgressBar->close();
 
 	if (matchingLevels.empty()) {
-		MsgBox(WARNING, QObject::tr("Match lines can be applied to Toonz raster levels only."));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("Match lines can be applied to Toonz raster levels only."));
 		return;
 	}
 
@@ -787,7 +787,7 @@ void doMatchlines(int column, int mColumn, int index, int inkPrevalence, int Mer
 	{
 		TPalette *plt = level->getPalette();
 		if (!plt) {
-			MsgBox(WARNING, QObject::tr("The level you are using has not a valid palette."));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("The level you are using has not a valid palette."));
 			return;
 		}
 
@@ -813,7 +813,7 @@ void doMatchlines(int column, int mColumn, int index, int inkPrevalence, int Mer
 
 			index = md->getInkIndex();
 			if (index >= styleCount)
-				MsgBox(WARNING, QObject::tr("The style index you specified is not available in the palette of the destination level."));
+				DVGui::MsgBox(DVGui::WARNING, QObject::tr("The style index you specified is not available in the palette of the destination level."));
 			if (index != -1)
 				LastMatchlineIndex = index;
 		}
@@ -1037,13 +1037,13 @@ void doDeleteMatchlines(TXshSimpleLevel *sl, const std::set<TFrameId> &fids, boo
 				return;
 			indexes = md->getInkIndexes();
 			if (indexes.empty()) {
-				MsgBox(WARNING, QObject::tr("The style index range you specified is not valid: please separate values with a comma (e.g. 1,2,5) or with a dash (e.g. 4-7 will refer to indexes 4, 5, 6 and 7)."));
+				DVGui::MsgBox(DVGui::WARNING, QObject::tr("The style index range you specified is not valid: please separate values with a comma (e.g. 1,2,5) or with a dash (e.g. 4-7 will refer to indexes 4, 5, 6 and 7)."));
 				continue;
 			}
 
 			frames = md->getFrames();
 			if (frames.empty()) {
-				MsgBox(WARNING, QObject::tr("The frame range you specified is not valid: please separate values with a comma (e.g. 1,2,5) or with a dash (e.g. 4-7 will refer to frames 4, 5, 6 and 7)."));
+				DVGui::MsgBox(DVGui::WARNING, QObject::tr("The frame range you specified is not valid: please separate values with a comma (e.g. 1,2,5) or with a dash (e.g. 4-7 will refer to frames 4, 5, 6 and 7)."));
 				continue;
 			}
 			for (i = 0; i < frames.size(); i++) {
@@ -1066,7 +1066,7 @@ void doDeleteMatchlines(TXshSimpleLevel *sl, const std::set<TFrameId> &fids, boo
 	}
 
 	if (fidsToProcess.empty()) {
-		MsgBox(WARNING, QObject::tr("No drawing is available in the frame range you specified."));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("No drawing is available in the frame range you specified."));
 		return;
 	}
 
diff --git a/toonz/sources/toonz/matchline.h b/toonz/sources/toonz/matchline.h
index 4646a11..f2fa2c9 100644
--- a/toonz/sources/toonz/matchline.h
+++ b/toonz/sources/toonz/matchline.h
@@ -26,7 +26,7 @@ class TXsheet;
 
 //==================================================
 
-class MergeCmappedDialog : public Dialog
+class MergeCmappedDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -47,13 +47,13 @@ protected slots:
 
 //----------------------------------------------------------------
 
-class MatchlinesDialog : public Dialog
+class MatchlinesDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
 	QRadioButton *m_button1, *m_button2;
-	StyleIndexLineEdit *m_inkIndex;
-	IntField *m_inkPrevalence;
+	DVGui::StyleIndexLineEdit *m_inkIndex;
+	DVGui::IntField *m_inkPrevalence;
 	TPaletteHandle *m_pltHandle;
 
 	QPushButton *m_lup_noGapButton;
@@ -82,12 +82,12 @@ public:
 
 //----------------------------------------------------------------
 
-class DeleteInkDialog : public Dialog
+class DeleteInkDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
-	LineEdit *m_inkIndex;
-	LineEdit *m_frames;
+	DVGui::LineEdit *m_inkIndex;
+	DVGui::LineEdit *m_frames;
 
 public:
 	DeleteInkDialog(const QString &str, int inkIndex);
diff --git a/toonz/sources/toonz/matchlinecommand.cpp b/toonz/sources/toonz/matchlinecommand.cpp
index 83d96f6..d62fbf2 100644
--- a/toonz/sources/toonz/matchlinecommand.cpp
+++ b/toonz/sources/toonz/matchlinecommand.cpp
@@ -68,12 +68,12 @@ MergeCmappedDialog::MergeCmappedDialog(TFilePath &levelPath)
 	QString name = QString::fromStdString(m_levelPath.getName());
 
 	setWindowTitle(tr(" Merge Tlv Levels"));
-	m_saveInFileFld = new FileField(0, path);
+	m_saveInFileFld = new DVGui::FileField(0, path);
 	ret = ret && connect(m_saveInFileFld, SIGNAL(pathChanged()), this, SLOT(onPathChanged()));
 	addWidget(tr("Save in:"), m_saveInFileFld);
 
-	m_fileNameFld = new LineEdit(name + "_merged");
-	m_fileNameFld->setMaximumHeight(WidgetHeight);
+	m_fileNameFld = new DVGui::LineEdit(name + "_merged");
+	m_fileNameFld->setMaximumHeight(DVGui::WidgetHeight);
 	ret = ret && connect(m_fileNameFld, SIGNAL(editingFinished()), SLOT(onNameChanged()));
 	addWidget(tr("File Name:"), m_fileNameFld);
 
@@ -102,12 +102,12 @@ public:
 		std::set<int> indices = selection ? selection->getIndices() : std::set<int>();
 
 		if (indices.empty()) {
-			MsgBox(WARNING, tr("It is not possible to execute the merge column command because no column was selected."));
+			DVGui::MsgBox(DVGui::WARNING, tr("It is not possible to execute the merge column command because no column was selected."));
 			return;
 		}
 
 		if (indices.size() == 1) {
-			MsgBox(WARNING, tr("It is not possible to execute the merge column command  because only one columns is  selected."));
+			DVGui::MsgBox(DVGui::WARNING, tr("It is not possible to execute the merge column command  because only one columns is  selected."));
 			return;
 		}
 
@@ -130,14 +130,14 @@ public:
 	{
 		TColumnSelection *selection = dynamic_cast<TColumnSelection *>(TSelection::getCurrent());
 		if (!selection) {
-			MsgBox(WARNING, tr("It is not possible to apply the match lines because no column was selected."));
+			DVGui::MsgBox(DVGui::WARNING, tr("It is not possible to apply the match lines because no column was selected."));
 			return;
 		}
 
 		std::set<int> indices = selection->getIndices();
 
 		if (indices.size() != 2) {
-			MsgBox(WARNING, tr("It is not possible to apply the match lines because two columns have to be selected."));
+			DVGui::MsgBox(DVGui::WARNING, tr("It is not possible to apply the match lines because two columns have to be selected."));
 			return;
 		}
 
@@ -177,11 +177,11 @@ bool checkColumnValidity(int column)
 			level = cell[i].getSimpleLevel();
 
 		if (cell[i].getSimpleLevel()->getType() != TZP_XSHLEVEL) {
-			MsgBox(WARNING, QObject::tr("Match lines can be applied to Toonz raster levels only."));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("Match lines can be applied to Toonz raster levels only."));
 			return false;
 		}
 		if (level != cell[i].getSimpleLevel()) {
-			MsgBox(WARNING, QObject::tr("It is not possible to merge tlv columns containing more than one level"));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to merge tlv columns containing more than one level"));
 			return false;
 		}
 	}
@@ -190,7 +190,7 @@ bool checkColumnValidity(int column)
 		return false;
 
 	if (!level->getPalette()) {
-		MsgBox(WARNING, QObject::tr("The level you are using has not a valid palette."));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("The level you are using has not a valid palette."));
 		return false;
 	}
 	return true;
@@ -402,14 +402,14 @@ public:
 	{
 		TColumnSelection *selection = dynamic_cast<TColumnSelection *>(TSelection::getCurrent());
 		if (!selection) {
-			MsgBox(WARNING, tr("It is not possible to merge tlv columns because no column was selected."));
+			DVGui::MsgBox(DVGui::WARNING, tr("It is not possible to merge tlv columns because no column was selected."));
 			return;
 		}
 
 		std::set<int> indices = selection->getIndices();
 
 		if (indices.size() < 2) {
-			MsgBox(WARNING, tr("It is not possible to merge tlv columns because at least two columns have to be selected."));
+			DVGui::MsgBox(DVGui::WARNING, tr("It is not possible to merge tlv columns because at least two columns have to be selected."));
 			return;
 		}
 
@@ -486,14 +486,14 @@ void doDeleteCommand(bool isMatchline)
 			TApp::instance()->getCurrentXsheet()->notifyXsheetChanged();
 			return;
 		} else if (!columnSelection || (indices = columnSelection->getIndices()).size() != 1) {
-			MsgBox(WARNING, QObject::tr("It is not possible to delete lines because no column, cell or level strip frame was selected."));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to delete lines because no column, cell or level strip frame was selected."));
 			return;
 		}
 		int from, to;
 		int columnIndex = *indices.begin();
 		TXsheet *xsh = TApp::instance()->getCurrentXsheet()->getXsheet();
 		if (!xsh->getCellRange(*indices.begin(), from, to)) {
-			MsgBox(WARNING, QObject::tr("The selected column is empty."));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("The selected column is empty."));
 			return;
 		}
 		r.y0 = from;
@@ -503,7 +503,7 @@ void doDeleteCommand(bool isMatchline)
 		sel->getSelectedCells(r.y0, r.x0, r.y1, r.x1);
 
 	if (r.x0 != r.x1) {
-		MsgBox(WARNING, QObject::tr("Selected cells must be in the same column."));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("Selected cells must be in the same column."));
 		return;
 	}
 
@@ -514,11 +514,11 @@ void doDeleteCommand(bool isMatchline)
 	for (i = r.y0; i <= r.y1; i++) {
 		TXshCell cell = xsh->getCell(i, r.x0);
 		if (cell.isEmpty()) {
-			MsgBox(WARNING, QObject::tr("It is not possible to delete lines because no column, cell or level strip frame was selected."));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to delete lines because no column, cell or level strip frame was selected."));
 			return;
 		}
 		if (cell.m_level->getType() != TZP_XSHLEVEL) {
-			MsgBox(WARNING, QObject::tr("Match lines can be deleted from Toonz raster levels only"));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("Match lines can be deleted from Toonz raster levels only"));
 			return;
 		}
 	}
diff --git a/toonz/sources/toonz/mergecolumns.cpp b/toonz/sources/toonz/mergecolumns.cpp
index 95f9321..18d0756 100644
--- a/toonz/sources/toonz/mergecolumns.cpp
+++ b/toonz/sources/toonz/mergecolumns.cpp
@@ -68,7 +68,7 @@ void mergeRasterColumns(const vector<MatchlinePair> &matchingLevels)
 		TRaster32P ras = img->getRaster();		  // img->getCMapped(false);
 		TRaster32P matchRas = match->getRaster(); // match->getCMapped(true);
 		if (!ras || !matchRas) {
-			MsgBox(WARNING, QObject::tr("The merge command is not available for greytones images."));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("The merge command is not available for greytones images."));
 			return;
 		}
 		TAffine aff = matchingLevels[i].m_imgAff.inv() * matchingLevels[i].m_matchAff;
@@ -321,14 +321,14 @@ void mergeColumns(int column, int mColumn, bool isRedo)
 		}
 
 		else if (level != cell[i].getSimpleLevel()) {
-			MsgBox(WARNING, QObject::tr("It is not possible to perform a merging involving more than one level per column."));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to perform a merging involving more than one level per column."));
 			return;
 		}
 
 		if (!mLevel)
 			mLevel = mCell[i].getSimpleLevel();
 		else if (mLevel != mCell[i].getSimpleLevel()) {
-			MsgBox(WARNING, QObject::tr("It is not possible to perform a merging involving more than one level per column."));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to perform a merging involving more than one level per column."));
 			return;
 		}
 		TImageP img = cell[i].getImage(true);
@@ -347,17 +347,17 @@ void mergeColumns(int column, int mColumn, bool isRedo)
 
 			if (timg) {
 				if (!tmatch) {
-					MsgBox(WARNING, QObject::tr("Only raster levels can be merged to a raster level."));
+					DVGui::MsgBox(DVGui::WARNING, QObject::tr("Only raster levels can be merged to a raster level."));
 					return;
 				}
 				areRasters = true;
 			} else if (vimg) {
 				if (!vmatch) {
-					MsgBox(WARNING, QObject::tr("Only vector levels can be merged to a vector level."));
+					DVGui::MsgBox(DVGui::WARNING, QObject::tr("Only vector levels can be merged to a vector level."));
 					return;
 				}
 			} else {
-				MsgBox(WARNING, QObject::tr("It is possible to merge only Toonz vector levels or standard raster levels."));
+				DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is possible to merge only Toonz vector levels or standard raster levels."));
 				return;
 			}
 
@@ -375,7 +375,7 @@ void mergeColumns(int column, int mColumn, bool isRedo)
 	}
 
 	if (matchingLevels.empty()) {
-		MsgBox(WARNING, QObject::tr("It is possible to merge only Toonz vector levels or standard raster levels."));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is possible to merge only Toonz vector levels or standard raster levels."));
 		return;
 	}
 
diff --git a/toonz/sources/toonz/meshifypopup.cpp b/toonz/sources/toonz/meshifypopup.cpp
index 81d0af4..7213ec3 100644
--- a/toonz/sources/toonz/meshifypopup.cpp
+++ b/toonz/sources/toonz/meshifypopup.cpp
@@ -294,7 +294,7 @@ TXshSimpleLevel *createMeshLevel(TXshLevel *texturesLevel)
 						<< MeshifyPopup::tr("Keep the old level and overwrite processed frames")
 						<< MeshifyPopup::tr("Choose a different path (%1)").arg(QString::fromStdWString(codedDstPath.getWideString()));
 
-			answer = DVGui::RadioButtonMsgBox(QUESTION, question, optionsList, TApp::instance()->getMainWindow());
+			answer = DVGui::RadioButtonMsgBox(DVGui::QUESTION, question, optionsList, TApp::instance()->getMainWindow());
 		}
 
 		// Apply decision
@@ -637,7 +637,7 @@ MeshifyPopup::MeshifyPopup()
 	QLabel *edgesLengthLabel = new QLabel(tr("Mesh Edges Length:"));
 	topLayout->addWidget(edgesLengthLabel, row, 0, Qt::AlignRight | Qt::AlignVCenter);
 
-	m_edgesLength = new MeasuredDoubleField;
+	m_edgesLength = new DVGui::MeasuredDoubleField;
 	m_edgesLength->setMeasure("length.x");
 	m_edgesLength->setRange(0.0, 1.0); // In inches (standard unit)
 	m_edgesLength->setValue(0.2);
@@ -647,7 +647,7 @@ MeshifyPopup::MeshifyPopup()
 	QLabel *rasterizationDpiLabel = new QLabel(tr("Rasterization DPI:"));
 	topLayout->addWidget(rasterizationDpiLabel, row, 0, Qt::AlignRight | Qt::AlignVCenter);
 
-	m_rasterizationDpi = new DoubleLineEdit;
+	m_rasterizationDpi = new DVGui::DoubleLineEdit;
 	m_rasterizationDpi->setRange(1.0, (std::numeric_limits<double>::max)());
 	m_rasterizationDpi->setValue(300.0);
 
@@ -656,7 +656,7 @@ MeshifyPopup::MeshifyPopup()
 	QLabel *shapeMarginLabel = new QLabel(tr("Mesh Margin (pixels):"));
 	topLayout->addWidget(shapeMarginLabel, row, 0, Qt::AlignRight | Qt::AlignVCenter);
 
-	m_margin = new IntLineEdit;
+	m_margin = new DVGui::IntLineEdit;
 	m_margin->setRange(2, (std::numeric_limits<int>::max)());
 	m_margin->setValue(5);
 
diff --git a/toonz/sources/toonz/outputsettingspopup.cpp b/toonz/sources/toonz/outputsettingspopup.cpp
index 200d566..730f1bd 100644
--- a/toonz/sources/toonz/outputsettingspopup.cpp
+++ b/toonz/sources/toonz/outputsettingspopup.cpp
@@ -125,9 +125,9 @@ OutputSettingsPopup::OutputSettingsPopup(bool isPreview)
 	QFrame *cameraParametersBox;
 	if (!isPreview) {
 		//Save In
-		m_saveInFileFld = new FileField(0, QString(""));
+		m_saveInFileFld = new DVGui::FileField(0, QString(""));
 		//File Name
-		m_fileNameFld = new LineEdit(QString(""));
+		m_fileNameFld = new DVGui::LineEdit(QString(""));
 		//File Format
 		m_fileFormat = new QComboBox();
 		m_fileFormatButton = new QPushButton(tr("Options"));
@@ -143,18 +143,18 @@ OutputSettingsPopup::OutputSettingsPopup(bool isPreview)
 	if (isPreview) {
 #ifndef LINETEST
 		//Subcamera checkbox
-		m_subcameraChk = new CheckBox(tr("Use Sub-Camera"));
+		m_subcameraChk = new DVGui::CheckBox(tr("Use Sub-Camera"));
 #endif
 	}
 
 	//Frame Start-End
-	m_startFld = new IntLineEdit(this);
-	m_endFld = new IntLineEdit(this);
+	m_startFld = new DVGui::IntLineEdit(this);
+	m_endFld = new DVGui::IntLineEdit(this);
 	//Step-Shrink
-	m_stepFld = new IntLineEdit(this);
-	m_shrinkFld = new IntLineEdit(this);
+	m_stepFld = new DVGui::IntLineEdit(this);
+	m_shrinkFld = new DVGui::IntLineEdit(this);
 	if (isPreview)
-		m_applyShrinkChk = new CheckBox(tr("Apply Shrink to Main Viewer"), this);
+		m_applyShrinkChk = new DVGui::CheckBox(tr("Apply Shrink to Main Viewer"), this);
 	else
 		m_applyShrinkChk = 0;
 	//Resample Balance
@@ -176,7 +176,7 @@ OutputSettingsPopup::OutputSettingsPopup(bool isPreview)
 		otherSettingsFrame = new QFrame(this);
 
 		//Gamma
-		m_gammaFld = new DoubleLineEdit();
+		m_gammaFld = new DVGui::DoubleLineEdit();
 		//Dominant Field
 		m_dominantFieldOm = new QComboBox();
 
@@ -185,10 +185,10 @@ OutputSettingsPopup::OutputSettingsPopup(bool isPreview)
 
 		//Scene Settings FPS
 		double frameRate = getProperties()->getFrameRate();
-		m_frameRateFld = new DoubleLineEdit(this, frameRate);
+		m_frameRateFld = new DVGui::DoubleLineEdit(this, frameRate);
 
-		m_stretchFromFld = new DoubleLineEdit(this, rs.m_timeStretchFrom);
-		m_stretchToFld = new DoubleLineEdit(this, rs.m_timeStretchTo);
+		m_stretchFromFld = new DVGui::DoubleLineEdit(this, rs.m_timeStretchFrom);
+		m_stretchToFld = new DVGui::DoubleLineEdit(this, rs.m_timeStretchTo);
 		m_multimediaOm = new QComboBox(this);
 
 		showCameraSettingsButton = new QPushButton("", this);
@@ -196,8 +196,8 @@ OutputSettingsPopup::OutputSettingsPopup(bool isPreview)
 		removePresetButton = new QPushButton(tr("Remove"), this);
 		m_presetCombo = new QComboBox(this);
 
-		m_doStereoscopy = new CheckBox("Do stereoscopy", this);
-		m_stereoShift = new DoubleLineEdit(this, 0.05);
+		m_doStereoscopy = new DVGui::CheckBox("Do stereoscopy", this);
+		m_stereoShift = new DVGui::DoubleLineEdit(this, 0.05);
 	}
 	//Threads
 	m_threadsComboOm = new QComboBox();
@@ -878,7 +878,7 @@ void OutputSettingsPopup::onNameChanged()
 
 	QString name = m_fileNameFld->text();
 	if (!isValidFileName(name)) {
-		error("A filename cannot be empty or contain any of the following characters:\n \\ / : * ? \" < > |");
+		DVGui::error("A filename cannot be empty or contain any of the following characters:\n \\ / : * ? \" < > |");
 		TOutputProperties *prop = getProperties();
 		TFilePath fp = prop->getPath();
 		QString name = QString::fromStdString(fp.getName());
@@ -1186,7 +1186,7 @@ void OutputSettingsPopup::onDominantFieldChanged(int type)
 	TOutputProperties *prop = getProperties();
 	TRenderSettings rs = prop->getRenderSettings();
 	if (type != c_none && m_stretchFromFld->getValue() != m_stretchToFld->getValue()) {
-		error("Can't apply field rendering in a time stretched scene");
+		DVGui::error("Can't apply field rendering in a time stretched scene");
 		rs.m_fieldPrevalence = TRenderSettings::NoField;
 		m_dominantFieldOm->setCurrentIndex(c_none);
 	} else if (type == c_odd)
@@ -1215,7 +1215,7 @@ void OutputSettingsPopup::onStretchFldEditFinished()
 	TOutputProperties *prop = getProperties();
 	TRenderSettings rs = prop->getRenderSettings();
 	if (m_dominantFieldOm->currentIndex() != c_none) {
-		error("Can't stretch time in a field rendered scene\n");
+		DVGui::error("Can't stretch time in a field rendered scene\n");
 		m_stretchFromFld->setValue(rs.m_timeStretchFrom);
 		m_stretchToFld->setValue(rs.m_timeStretchTo);
 	} else {
diff --git a/toonz/sources/toonz/overwritepopup.cpp b/toonz/sources/toonz/overwritepopup.cpp
index d4aff6e..370bea0 100644
--- a/toonz/sources/toonz/overwritepopup.cpp
+++ b/toonz/sources/toonz/overwritepopup.cpp
@@ -47,7 +47,7 @@ bool OverwriteDialog::DecodeFileExistsFunc::operator()(const TFilePath &fp) cons
 //************************************************************************************
 
 OverwriteDialog::OverwriteDialog()
-	: Dialog(TApp::instance()->getMainWindow(), true)
+	: DVGui::Dialog(TApp::instance()->getMainWindow(), true)
 {
 	setModal(true);
 	setWindowTitle(tr("Warning!"));
@@ -72,7 +72,7 @@ OverwriteDialog::OverwriteDialog()
 	m_rename = new QRadioButton(tr("Rename the new file adding the suffix"), this);
 	buttonGroup->addButton(m_rename);
 
-	m_suffix = new LineEdit("_1", this);
+	m_suffix = new DVGui::LineEdit("_1", this);
 	m_suffix->setFixedWidth(25);
 	m_suffix->setEnabled(false);
 
@@ -266,13 +266,13 @@ std::wstring OverwriteDialog::execute(ToonzScene *scene, const TFilePath &srcLev
 
 	if (m_rename->isChecked()) {
 		if (m_suffix->text() == "") {
-			MsgBox(WARNING, tr("The suffix field is empty. Please specify a suffix."));
+			DVGui::MsgBox(DVGui::WARNING, tr("The suffix field is empty. Please specify a suffix."));
 			return execute(scene, srcLevelPath, multiload);
 		}
 		levelPath = addSuffix(srcLevelPath);
 		actualLevelPath = scene->decodeFilePath(levelPath);
 		if (TSystem::doesExistFileOrLevel(actualLevelPath)) {
-			MsgBox(WARNING, tr("File %1 exists as well; please choose a different suffix.").arg(toQString(levelPath)));
+			DVGui::MsgBox(DVGui::WARNING, tr("File %1 exists as well; please choose a different suffix.").arg(toQString(levelPath)));
 			return execute(scene, srcLevelPath, multiload);
 		}
 		m_choice = RENAME;
diff --git a/toonz/sources/toonz/overwritepopup.h b/toonz/sources/toonz/overwritepopup.h
index 1dd353f..4d1ebfc 100644
--- a/toonz/sources/toonz/overwritepopup.h
+++ b/toonz/sources/toonz/overwritepopup.h
@@ -41,7 +41,7 @@ class QPushButton;
   Additionally, the dialog could be \t CANCELED, either by closing it
   or pressing the "Cancel" button.
 */
-class OverwriteDialog : public Dialog
+class OverwriteDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -112,7 +112,7 @@ private:
 	QRadioButton *m_overwrite;
 	QRadioButton *m_keep;
 	QRadioButton *m_rename;
-	LineEdit *m_suffix;
+	DVGui::LineEdit *m_suffix;
 	QPushButton *m_okBtn, *m_okToAllBtn, *m_cancelBtn;
 
 private:
diff --git a/toonz/sources/toonz/pltgizmopopup.h b/toonz/sources/toonz/pltgizmopopup.h
index e775248..1beb435 100644
--- a/toonz/sources/toonz/pltgizmopopup.h
+++ b/toonz/sources/toonz/pltgizmopopup.h
@@ -8,8 +8,6 @@
 #include "toonzqt/doublefield.h"
 #include "toonzqt/colorfield.h"
 
-using namespace DVGui;
-
 //=============================================================================
 // ValueAdjuster
 //-----------------------------------------------------------------------------
@@ -18,7 +16,7 @@ class ValueAdjuster : public QWidget
 {
 	Q_OBJECT
 
-	DoubleLineEdit *m_valueLineEdit;
+	DVGui::DoubleLineEdit *m_valueLineEdit;
 
 public:
 #if QT_VERSION >= 0x050500
@@ -44,7 +42,7 @@ class ValueShifter : public QWidget
 {
 	Q_OBJECT
 
-	DoubleLineEdit *m_valueLineEdit;
+	DVGui::DoubleLineEdit *m_valueLineEdit;
 
 public:
 #if QT_VERSION >= 0x050500
@@ -72,7 +70,7 @@ class ColorFader : public QWidget
 {
 	Q_OBJECT
 
-	DoubleLineEdit *m_valueLineEdit;
+	DVGui::DoubleLineEdit *m_valueLineEdit;
 
 public:
 #if QT_VERSION >= 0x050500
@@ -93,11 +91,11 @@ signals:
 // PltGizmoPopup
 //-----------------------------------------------------------------------------
 
-class PltGizmoPopup : public Dialog
+class PltGizmoPopup : public DVGui::Dialog
 {
 	Q_OBJECT
 
-	ColorField *m_colorFld;
+	DVGui::ColorField *m_colorFld;
 
 public:
 	PltGizmoPopup();
diff --git a/toonz/sources/toonz/preferencespopup.cpp b/toonz/sources/toonz/preferencespopup.cpp
index 4b7e42c..8eeb75b 100644
--- a/toonz/sources/toonz/preferencespopup.cpp
+++ b/toonz/sources/toonz/preferencespopup.cpp
@@ -839,7 +839,7 @@ PreferencesPopup::PreferencesPopup()
 	CheckBox *useDefaultViewerCB = new CheckBox(tr("Use Default Viewer for Movie Formats"), this);
 	CheckBox *minimizeRasterMemoryCB = new CheckBox(tr("Minimize Raster Memory Fragmentation *"), this);
 	CheckBox *autoSaveCB = new CheckBox(tr("Save Automatically Every Minutes"));
-	m_minuteFld = new IntLineEdit(this, 15, 1, 60);
+	m_minuteFld = new DVGui::IntLineEdit(this, 15, 1, 60);
 	CheckBox *replaceAfterSaveLevelAsCB = new CheckBox(tr("Replace Toonz Level after SaveLevelAs command"), this);
 
 	m_cellsDragBehaviour = new QComboBox();
@@ -872,10 +872,10 @@ PreferencesPopup::PreferencesPopup()
 	QComboBox *styleSheetType = new QComboBox(this);
 	QComboBox *unitOm = new QComboBox(this);
 	QComboBox *cameraUnitOm = new QComboBox(this);
-	m_iconSizeLx = new IntLineEdit(this, 80, 10, 400);
-	m_iconSizeLy = new IntLineEdit(this, 60, 10, 400);
-	m_viewShrink = new IntLineEdit(this, 1, 1, 20);
-	m_viewStep = new IntLineEdit(this, 1, 1, 20);
+	m_iconSizeLx = new DVGui::IntLineEdit(this, 80, 10, 400);
+	m_iconSizeLy = new DVGui::IntLineEdit(this, 60, 10, 400);
+	m_viewShrink = new DVGui::IntLineEdit(this, 1, 1, 20);
+	m_viewStep = new DVGui::IntLineEdit(this, 1, 1, 20);
 
 	CheckBox *moveCurrentFrameCB = new CheckBox(tr("Move Current Frame by Clicking on Xsheet / Numerical Columns Cell Area"), this);
 	//Viewer BG color
@@ -948,12 +948,12 @@ PreferencesPopup::PreferencesPopup()
 	categoryList->addItem(tr("Animation"));
 
 	m_keyframeType = new QComboBox(this);
-	m_animationStepField = new IntLineEdit(this, 1, 1, 500);
+	m_animationStepField = new DVGui::IntLineEdit(this, 1, 1, 500);
 
 	//--- Preview ------------------------------
 	categoryList->addItem(tr("Preview"));
 
-	m_blanksCount = new IntLineEdit(this, 0, 0, 1000);
+	m_blanksCount = new DVGui::IntLineEdit(this, 0, 0, 1000);
 	m_blankColor = new ColorField(this, false, TPixel::Black);
 	CheckBox *rewindAfterPlaybackCB = new CheckBox(tr("Rewind after Playback"), this);
 	CheckBox *displayInNewFlipBookCB = new CheckBox(tr("Display in a New Flipbook Window"), this);
@@ -972,7 +972,7 @@ PreferencesPopup::PreferencesPopup()
 	m_inksOnly->setChecked(onlyInks);
 
 	int thickness = m_pref->getOnionPaperThickness();
-	m_onionPaperThickness = new IntLineEdit(this, thickness, 0, 100);
+	m_onionPaperThickness = new DVGui::IntLineEdit(this, thickness, 0, 100);
 
 	//--- Transparency Check ------------------------------
 	categoryList->addItem(tr("Transparency Check"));
diff --git a/toonz/sources/toonz/previewer.cpp b/toonz/sources/toonz/previewer.cpp
index 79b3220..4c68e69 100644
--- a/toonz/sources/toonz/previewer.cpp
+++ b/toonz/sources/toonz/previewer.cpp
@@ -742,7 +742,7 @@ enum { eBegin,
 	   eIncrement,
 	   eEnd };
 
-static ProgressDialog *Pd = 0;
+static DVGui::ProgressDialog *Pd = 0;
 
 //-----------------------------------------------------------------------------
 
@@ -758,7 +758,7 @@ public:
 		switch (m_choice) {
 		case eBegin:
 			if (!Pd)
-				Pd = new ProgressDialog(QObject::tr("Saving previewed frames...."), QObject::tr("Cancel"), 0, m_val);
+				Pd = new DVGui::ProgressDialog(QObject::tr("Saving previewed frames...."), QObject::tr("Cancel"), 0, m_val);
 			else
 				Pd->setMaximum(m_val);
 			Pd->show();
@@ -837,12 +837,12 @@ bool Previewer::Imp::doSaveRenderedFrames(TFilePath fp)
 		fp = fp.withType(ext);
 	}
 	if (fp.getName() == "") {
-		MsgBox(WARNING, tr("The file name cannot be empty or contain any of the following characters:(new line)  \\ / : * ? \"  |"));
+		DVGui::MsgBox(DVGui::WARNING, tr("The file name cannot be empty or contain any of the following characters:(new line)  \\ / : * ? \"  |"));
 		return false;
 	}
 
 	if (!formats.contains(QString::fromStdString(ext))) {
-		MsgBox(WARNING, "Unsopporter raster format, cannot save");
+		DVGui::MsgBox(DVGui::WARNING, "Unsopporter raster format, cannot save");
 		return false;
 	}
 
diff --git a/toonz/sources/toonz/projectpopup.cpp b/toonz/sources/toonz/projectpopup.cpp
index adf6702..671965b 100644
--- a/toonz/sources/toonz/projectpopup.cpp
+++ b/toonz/sources/toonz/projectpopup.cpp
@@ -520,7 +520,7 @@ void ProjectSettingsPopup::onFolderChanged()
 	try {
 		project->save();
 	} catch (TSystemException se) {
-		MsgBox(WARNING, QString::fromStdWString(se.getMessage()));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdWString(se.getMessage()));
 		return;
 	}
 	DvDirModel::instance()->refreshFolder(project->getProjectFolder());
@@ -535,7 +535,7 @@ void ProjectSettingsPopup::onUseSceneChekboxChanged(int)
 	try {
 		project->save();
 	} catch (TSystemException se) {
-		MsgBox(WARNING, QString::fromStdWString(se.getMessage()));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdWString(se.getMessage()));
 		return;
 	}
 	DvDirModel::instance()->refreshFolder(project->getProjectFolder());
@@ -633,7 +633,7 @@ void ProjectCreatePopup::createProject()
 		if (!isSaved)
 			MsgBox(CRITICAL, tr("It is not possible to create the %1 project.").arg(toQString(projectPath)));
 	} catch (TSystemException se) {
-		MsgBox(WARNING, QString::fromStdWString(se.getMessage()));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdWString(se.getMessage()));
 		return;
 	}
 	pm->setCurrentProjectPath(projectPath);
diff --git a/toonz/sources/toonz/rendercommand.cpp b/toonz/sources/toonz/rendercommand.cpp
index dc13df1..1d71b93 100644
--- a/toonz/sources/toonz/rendercommand.cpp
+++ b/toonz/sources/toonz/rendercommand.cpp
@@ -214,7 +214,7 @@ public:
 
 				if (!TSystem::showDocument(m_fp)) {
 					QString msg(QObject::tr("It is not possible to display the file %1: no player associated with its format").arg(QString::fromStdWString(m_fp.withoutParentDir().getWideString())));
-					MsgBox(WARNING, msg);
+					DVGui::MsgBox(DVGui::WARNING, msg);
 				}
 
 			}
@@ -301,7 +301,7 @@ bool RenderCommand::init(bool isPreview)
 	if (m_r1 >= scene->getFrameCount())
 		m_r1 = scene->getFrameCount() - 1;
 	if (m_r1 < m_r0) {
-		MsgBox(WARNING, QObject::tr("The command cannot be executed because the scene is empty."));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("The command cannot be executed because the scene is empty."));
 		return false;
 		// throw TException("empty scene");
 		// non so perche', ma termina il programma
@@ -345,10 +345,10 @@ bool RenderCommand::init(bool isPreview)
 			TSystem::mkDir(parent);
 			DvDirModel::instance()->refreshFolder(parent.getParentDir());
 		} catch (TException &e) {
-			MsgBox(WARNING, QObject::tr("It is not possible to create folder : %1").arg(QString::fromStdString(toString(e.getMessage()))));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to create folder : %1").arg(QString::fromStdString(toString(e.getMessage()))));
 			return false;
 		} catch (...) {
-			MsgBox(WARNING, QObject::tr("It is not possible to create a folder."));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to create a folder."));
 			return false;
 		}
 	}
@@ -387,7 +387,7 @@ void RenderCommand::flashRender()
 	FILE *fileP = fopen(m_fp, "wb");
 	if (!fileP)
 		return;
-	ProgressDialog pb("rendering " + toQString(m_fp), "Cancel", 0, m_numFrames);
+	DVGui::ProgressDialog pb("rendering " + toQString(m_fp), "Cancel", 0, m_numFrames);
 	pb.show();
 
 	TDimension cameraSize = scene->getCurrentCamera()->getRes();
@@ -446,7 +446,7 @@ void RenderCommand::flashRender()
 //===================================================================
 
 class RenderListener
-	: public ProgressDialog,
+	: public DVGui::ProgressDialog,
 	  public MovieRenderer::Listener
 {
 	QString m_progressBarString;
@@ -476,7 +476,7 @@ class RenderListener
 
 public:
 	RenderListener(TRenderer *renderer, const TFilePath &path, int steps, bool isPreview)
-		: ProgressDialog("Precomputing " + QString::number(steps) + " Frames" + ((isPreview) ? "" : " of " + toQString(path)), "Cancel", 0, steps, TApp::instance()->getMainWindow()), m_renderer(renderer), m_frameCounter(0), m_error(false)
+		: DVGui::ProgressDialog("Precomputing " + QString::number(steps) + " Frames" + ((isPreview) ? "" : " of " + toQString(path)), "Cancel", 0, steps, TApp::instance()->getMainWindow()), m_renderer(renderer), m_frameCounter(0), m_error(false)
 	{
 #ifdef MACOSX
 		//Modal dialogs seem to be preventing the execution of Qt::BlockingQueuedConnections on MAC...!
@@ -537,7 +537,7 @@ void RenderCommand::rasterRender(bool isPreview)
 		TDimension res = scene->getCurrentCamera()->getRes();
 		if (!AviCodecRestrictions::canWriteMovie(toWideString(codecName), res)) {
 			QString msg(QObject::tr("The resolution of the output camera does not fit with the options chosen for the output file format."));
-			MsgBox(WARNING, msg);
+			DVGui::MsgBox(DVGui::WARNING, msg);
 			return;
 		}
 	}
@@ -632,7 +632,7 @@ void RenderCommand::rasterRender(bool isPreview)
 //===================================================================
 
 class MultimediaProgressBar
-	: public ProgressDialog,
+	: public DVGui::ProgressDialog,
 	  public MultimediaRenderer::Listener
 {
 	QString m_progressBarString;
@@ -747,7 +747,7 @@ void RenderCommand::multimediaRender()
 		TDimension res = scene->getCurrentCamera()->getRes();
 		if (!AviCodecRestrictions::canWriteMovie(toWideString(codecName), res)) {
 			QString msg(QObject::tr("The resolution of the output camera does not fit with the options chosen for the output file format."));
-			MsgBox(WARNING, msg);
+			DVGui::MsgBox(DVGui::WARNING, msg);
 			return;
 		}
 	}
@@ -846,7 +846,7 @@ void RenderCommand::doRender(bool isPreview)
 	if (!isWritable) {
 		string str = "It is not possible to write the output:  the file";
 		str += isMultiFrame ? "s are read only." : " is read only.";
-		MsgBox(WARNING, QString::fromStdString(str));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(str));
 		return;
 	}
 
@@ -865,9 +865,9 @@ void RenderCommand::doRender(bool isPreview)
 			/*-- 通常のRendering --*/
 			rasterRender(isPreview);
 	} catch (TException &e) {
-		MsgBox(WARNING, QString::fromStdString(toString(e.getMessage())));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(toString(e.getMessage())));
 	} catch (...) {
-		MsgBox(WARNING, QObject::tr("It is not possible to complete the rendering."));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to complete the rendering."));
 	}
 }
 
diff --git a/toonz/sources/toonz/renumberpopup.cpp b/toonz/sources/toonz/renumberpopup.cpp
index c0638a7..a2765fc 100644
--- a/toonz/sources/toonz/renumberpopup.cpp
+++ b/toonz/sources/toonz/renumberpopup.cpp
@@ -21,9 +21,9 @@ RenumberPopup::RenumberPopup()
 	setWindowTitle(tr("Renumber"));
 
 	beginHLayout();
-	addWidget(tr("Start:"), m_startFld = new IntLineEdit(this));
+	addWidget(tr("Start:"), m_startFld = new DVGui::IntLineEdit(this));
 	addSpacing(10);
-	addWidget(tr("Step:"), m_stepFld = new IntLineEdit(this));
+	addWidget(tr("Step:"), m_stepFld = new DVGui::IntLineEdit(this));
 	endHLayout();
 
 	m_okBtn = new QPushButton(tr("Renumber"), this);
diff --git a/toonz/sources/toonz/renumberpopup.h b/toonz/sources/toonz/renumberpopup.h
index febcf5d..a04ff26 100644
--- a/toonz/sources/toonz/renumberpopup.h
+++ b/toonz/sources/toonz/renumberpopup.h
@@ -10,20 +10,18 @@
 // forward declaration
 class QPushButton;
 
-using namespace DVGui;
-
 //=============================================================================
 // RenumberPopup
 //-----------------------------------------------------------------------------
 
-class RenumberPopup : public Dialog
+class RenumberPopup : public DVGui::Dialog
 {
 	Q_OBJECT
 
 	QPushButton *m_okBtn;
 	QPushButton *m_cancelBtn;
 
-	IntLineEdit *m_startFld, *m_stepFld;
+	DVGui::IntLineEdit *m_startFld, *m_stepFld;
 
 public:
 	RenumberPopup();
diff --git a/toonz/sources/toonz/savepresetpopup.cpp b/toonz/sources/toonz/savepresetpopup.cpp
index 628f765..45c18ca 100644
--- a/toonz/sources/toonz/savepresetpopup.cpp
+++ b/toonz/sources/toonz/savepresetpopup.cpp
@@ -36,7 +36,7 @@ SavePresetPopup::SavePresetPopup()
 	: Dialog(TApp::instance()->getMainWindow(), true, true, "SavePreset")
 {
 	setWindowTitle(tr("Save Preset"));
-	addWidget(tr("Preset Name:"), m_nameFld = new LineEdit(this));
+	addWidget(tr("Preset Name:"), m_nameFld = new DVGui::LineEdit(this));
 	m_nameFld->setMinimumWidth(170);
 
 	QPushButton *okBtn = new QPushButton(tr("Save"), this);
@@ -77,12 +77,12 @@ bool SavePresetPopup::apply()
 			TSystem::mkDir(parent);
 			DvDirModel::instance()->refreshFolder(parent.getParentDir());
 		} catch (...) {
-			error(tr("It is not possible to create the preset folder %1.").arg(QString::fromStdString(fp.getParentDir().getName())));
+			DVGui::error(tr("It is not possible to create the preset folder %1.").arg(QString::fromStdString(fp.getParentDir().getName())));
 			return 0;
 		}
 	}
 	if (TFileStatus(fp).doesExist()) {
-		if (MsgBox(tr("Do you want to overwrite?"), tr("Yes"), tr("No")) == 2)
+		if (DVGui::MsgBox(tr("Do you want to overwrite?"), tr("Yes"), tr("No")) == 2)
 			return 0;
 	}
 	if (isMacro) {
diff --git a/toonz/sources/toonz/savepresetpopup.h b/toonz/sources/toonz/savepresetpopup.h
index 25541bd..41a0bbd 100644
--- a/toonz/sources/toonz/savepresetpopup.h
+++ b/toonz/sources/toonz/savepresetpopup.h
@@ -6,17 +6,15 @@
 #include "toonzqt/dvdialog.h"
 #include "toonzqt/lineedit.h"
 
-using namespace DVGui;
-
 //=============================================================================
 // SavePresetPopup
 //-----------------------------------------------------------------------------
 
-class SavePresetPopup : public Dialog
+class SavePresetPopup : public DVGui::Dialog
 {
 	Q_OBJECT
 
-	LineEdit *m_nameFld;
+	DVGui::LineEdit *m_nameFld;
 
 public:
 	SavePresetPopup();
diff --git a/toonz/sources/toonz/scanpopup.cpp b/toonz/sources/toonz/scanpopup.cpp
index 45139ae..b10bcb3 100644
--- a/toonz/sources/toonz/scanpopup.cpp
+++ b/toonz/sources/toonz/scanpopup.cpp
@@ -63,7 +63,7 @@ void checkPaperFormat(TScannerParameters *parameters)
 	if (parameters->getPaperOverflow()) {
 		TScanner *scanner = TScanner::instance();
 		QString scannerName = scanner ? scanner->getName() : "no scanner";
-		MsgBox(WARNING, QObject::tr("The selected paper format is not available for %1.").arg(scannerName));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("The selected paper format is not available for %1.").arg(scannerName));
 	}
 }
 
@@ -78,7 +78,7 @@ bool defineScanner(const QString &scannerType)
 
 	try {
 		if (!TScanner::instance()->isDeviceAvailable()) {
-			MsgBox(WARNING, TScanner::m_isTwain ? QObject::tr("No TWAIN scanner is available") : QObject::tr("No scanner is available"));
+			DVGui::MsgBox(DVGui::WARNING, TScanner::m_isTwain ? QObject::tr("No TWAIN scanner is available") : QObject::tr("No scanner is available"));
 			/* FIXME: try/catch からの goto って合法じゃないだろ……。とりあえず応急処置したところ"例外ってナニ?"って感じになったのが
 		 indent も腐っておりつらいので後で直す */
 			//goto end;
@@ -87,7 +87,7 @@ bool defineScanner(const QString &scannerType)
 		}
 		TScanner::instance()->selectDevice();
 	} catch (TException &e) {
-		MsgBox(WARNING, QString::fromStdWString(e.getMessage()));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdWString(e.getMessage()));
 		QApplication::restoreOverrideCursor();
 		return false;
 		//goto end;
@@ -101,7 +101,7 @@ bool defineScanner(const QString &scannerType)
 	try {
 		scanParameters->adaptToCurrentScanner();
 	} catch (TException &e) {
-		MsgBox(WARNING, QString::fromStdWString(e.getMessage()));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdWString(e.getMessage()));
 		//goto end;
 		QApplication::restoreOverrideCursor();
 		return false;
@@ -645,12 +645,12 @@ MyScannerListener::MyScannerListener(const ScanList &scanList)
 void MyScannerListener::onImage(const TRasterImageP &rasImg)
 {
 	if (!rasImg || !rasImg->getRaster()) {
-		MsgBox(WARNING, tr("The pixel type is not supported."));
+		DVGui::MsgBox(DVGui::WARNING, tr("The pixel type is not supported."));
 		m_current += m_inc;
 		return;
 	}
 	if (!m_isPreview && (m_current < 0 || m_current >= m_scanList.getFrameCount())) {
-		MsgBox(WARNING, tr("The scanning process is completed."));
+		DVGui::MsgBox(DVGui::WARNING, tr("The scanning process is completed."));
 		return;
 	}
 	if (m_isPreview) {
@@ -665,7 +665,7 @@ void MyScannerListener::onImage(const TRasterImageP &rasImg)
 			cl->setParameters(cp);
 			TRasterImageP outImg = cl->autocenterOnly(rasImg, false, autocentered);
 			if (!autocentered)
-				MsgBox(WARNING, QObject::tr("The autocentering failed on the current drawing."));
+				DVGui::MsgBox(DVGui::WARNING, QObject::tr("The autocentering failed on the current drawing."));
 			else
 				rasImg->setRaster(outImg->getRaster());
 		}
@@ -696,7 +696,7 @@ void MyScannerListener::onError()
 {
 	if (m_progressDialog)
 		m_progressDialog->hide();
-	MsgBox(WARNING, tr("There was an error during the scanning process."));
+	DVGui::MsgBox(DVGui::WARNING, tr("There was an error during the scanning process."));
 }
 
 //-----------------------------------------------------------------------------
@@ -766,7 +766,7 @@ void doScan()
 		scanList.update(true);
 
 	if (scanList.getFrameCount() == 0) {
-		MsgBox(WARNING, QObject::tr("There are no frames to scan."));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("There are no frames to scan."));
 		return;
 	}
 
@@ -775,7 +775,7 @@ void doScan()
 
 		int rc = scanner->isDeviceAvailable();
 		if (!rc) {
-			MsgBox(WARNING, QObject::tr("TWAIN is not available."));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("TWAIN is not available."));
 			return;
 		}
 
@@ -791,7 +791,7 @@ void doScan()
 		if (cropboxCheck->isEnabled())
 			cropboxCheck->uncheck();
 	} catch (TException &e) {
-		MsgBox(WARNING, QString::fromStdWString(e.getMessage()));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdWString(e.getMessage()));
 	}
 
 	//If some levels were scanned successfully, their renumber table must be updated.
@@ -870,7 +870,7 @@ public:
 
 			int rc = scanner->isDeviceAvailable();
 			if (!rc) {
-				MsgBox(WARNING, QObject::tr("TWAIN is not available."));
+				DVGui::MsgBox(DVGui::WARNING, QObject::tr("TWAIN is not available."));
 				return;
 			}
 
@@ -895,7 +895,7 @@ public:
 			if (resetCropAction)
 				resetCropAction->setDisabled(false);
 		} catch (TException &e) {
-			MsgBox(WARNING, QString::fromStdWString(e.getMessage()));
+			DVGui::MsgBox(DVGui::WARNING, QString::fromStdWString(e.getMessage()));
 		}
 	}
 } setCropboxCommand;
diff --git a/toonz/sources/toonz/scenesettingspopup.cpp b/toonz/sources/toonz/scenesettingspopup.cpp
index 3bdbee2..d9b2e61 100644
--- a/toonz/sources/toonz/scenesettingspopup.cpp
+++ b/toonz/sources/toonz/scenesettingspopup.cpp
@@ -98,23 +98,23 @@ SceneSettingsPopup::SceneSettingsPopup()
 
 	//Field Guide Size - A/R
 	int fieldGuideSize = sprop->getFieldGuideSize();
-	m_fieldGuideFld = new IntLineEdit(this, fieldGuideSize, 0, 50);
+	m_fieldGuideFld = new DVGui::IntLineEdit(this, fieldGuideSize, 0, 50);
 	m_aspectRatioFld = new DoubleLineEdit(this, 1.38);
 	m_aspectRatioFld->setRange(-10000.0, 10000.0);
 	m_aspectRatioFld->setDecimals(5);
 
 	//Image Subsampling  - Tlv Subsampling
 	int fullcolorSubsampling = sprop->getFullcolorSubsampling();
-	m_fullcolorSubsamplingFld = new IntLineEdit(this, fullcolorSubsampling, 1);
+	m_fullcolorSubsamplingFld = new DVGui::IntLineEdit(this, fullcolorSubsampling, 1);
 
 	int tlvSubsampling = sprop->getTlvSubsampling();
-	m_tlvSubsamplingFld = new IntLineEdit(this, tlvSubsampling, 1);
+	m_tlvSubsamplingFld = new DVGui::IntLineEdit(this, tlvSubsampling, 1);
 
 	//Marker Interval - Start Frame
 	int distance, offset;
 	sprop->getMarkers(distance, offset);
-	m_markerIntervalFld = new IntLineEdit(this, distance, 0);
-	m_startFrameFld = new IntLineEdit(this, offset);
+	m_markerIntervalFld = new DVGui::IntLineEdit(this, distance, 0);
+	m_startFrameFld = new DVGui::IntLineEdit(this, offset);
 
 	// layout
 	QGridLayout *mainLayout = new QGridLayout();
diff --git a/toonz/sources/toonz/scenesettingspopup.h b/toonz/sources/toonz/scenesettingspopup.h
index d37d42a..949c6b9 100644
--- a/toonz/sources/toonz/scenesettingspopup.h
+++ b/toonz/sources/toonz/scenesettingspopup.h
@@ -13,8 +13,6 @@
 class TSceneProperties;
 class QComboBox;
 
-using namespace DVGui;
-
 //=============================================================================
 // SceneSettingsPopup
 //-----------------------------------------------------------------------------
@@ -23,17 +21,17 @@ class SceneSettingsPopup : public QDialog
 {
 	Q_OBJECT
 
-	DoubleLineEdit *m_frameRateFld;
-	ColorField *m_bgColorFld;
+	DVGui::DoubleLineEdit *m_frameRateFld;
+	DVGui::ColorField *m_bgColorFld;
 
-	IntLineEdit *m_fieldGuideFld;
-	DoubleLineEdit *m_aspectRatioFld;
+	DVGui::IntLineEdit *m_fieldGuideFld;
+	DVGui::DoubleLineEdit *m_aspectRatioFld;
 
-	IntLineEdit *m_fullcolorSubsamplingFld;
-	IntLineEdit *m_tlvSubsamplingFld;
+	DVGui::IntLineEdit *m_fullcolorSubsamplingFld;
+	DVGui::IntLineEdit *m_tlvSubsamplingFld;
 
-	IntLineEdit *m_markerIntervalFld;
-	IntLineEdit *m_startFrameFld;
+	DVGui::IntLineEdit *m_markerIntervalFld;
+	DVGui::IntLineEdit *m_startFrameFld;
 
 	TSceneProperties *getProperties() const;
 
diff --git a/toonz/sources/toonz/sceneviewerevents.cpp b/toonz/sources/toonz/sceneviewerevents.cpp
index 9a20034..dd22405 100644
--- a/toonz/sources/toonz/sceneviewerevents.cpp
+++ b/toonz/sources/toonz/sceneviewerevents.cpp
@@ -144,7 +144,7 @@ void SceneViewer::onButtonPressed(FlipConsole::EGadget button)
 		CASE FlipConsole::eSaveImg:
 		{
 			if (m_previewMode == NO_PREVIEW) {
-				DVGui::MsgBox(WARNING, QObject::tr("It is not possible to save images in camera stand view."));
+				DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to save images in camera stand view."));
 				return;
 			}
 			TApp *app = TApp::instance();
@@ -152,7 +152,7 @@ void SceneViewer::onButtonPressed(FlipConsole::EGadget button)
 
 			Previewer *previewer = Previewer::instance(m_previewMode == SUBCAMERA_PREVIEW);
 			if (!previewer->isFrameReady(row)) {
-				DVGui::MsgBox(WARNING, QObject::tr("The preview images are not ready yet."));
+				DVGui::MsgBox(DVGui::WARNING, QObject::tr("The preview images are not ready yet."));
 				return;
 			}
 
@@ -474,7 +474,7 @@ void SceneViewer::mouseReleaseEvent(QMouseEvent *event)
 	if (!tool || !tool->isEnabled()) {
 		if (!m_toolDisableReason.isEmpty() && m_mouseButton == Qt::LeftButton &&
 			!m_editPreviewSubCamera)
-			MsgBox(WARNING, m_toolDisableReason);
+			DVGui::MsgBox(DVGui::WARNING, m_toolDisableReason);
 	}
 
 	if (m_freezedStatus != NO_FREEZED)
diff --git a/toonz/sources/toonz/shortcutpopup.cpp b/toonz/sources/toonz/shortcutpopup.cpp
index 78970d9..7331eba 100644
--- a/toonz/sources/toonz/shortcutpopup.cpp
+++ b/toonz/sources/toonz/shortcutpopup.cpp
@@ -139,7 +139,7 @@ void ShortcutViewer::keyPressEvent(QKeyEvent *event)
 			return;
 		if (oldAction) {
 			QString msg = tr("%1 is already assigned to '%2'\nAssign to '%3'?").arg(keySequence.toString()).arg(oldAction->iconText()).arg(m_action->iconText());
-			int ret = MsgBox(msg, tr("Yes"), tr("No"), 1);
+			int ret = DVGui::MsgBox(msg, tr("Yes"), tr("No"), 1);
 			activateWindow();
 			if (ret == 2 || ret == 0)
 				return;
diff --git a/toonz/sources/toonz/shortcutpopup.h b/toonz/sources/toonz/shortcutpopup.h
index d4c645d..2e5192d 100644
--- a/toonz/sources/toonz/shortcutpopup.h
+++ b/toonz/sources/toonz/shortcutpopup.h
@@ -12,8 +12,6 @@
 class QPushButton;
 class ShortcutItem;
 
-using namespace DVGui;
-
 //=============================================================================
 // ShortcutViewer
 // --------------
@@ -81,7 +79,7 @@ signals:
 // Questo e' il popup che l'utente utilizza per modificare gli shortcut
 //-----------------------------------------------------------------------------
 
-class ShortcutPopup : public Dialog
+class ShortcutPopup : public DVGui::Dialog
 {
 	Q_OBJECT
 	QPushButton *m_removeBtn;
diff --git a/toonz/sources/toonz/svncleanupdialog.h b/toonz/sources/toonz/svncleanupdialog.h
index 7d6fc8c..0ea9021 100644
--- a/toonz/sources/toonz/svncleanupdialog.h
+++ b/toonz/sources/toonz/svncleanupdialog.h
@@ -6,14 +6,12 @@
 #include "toonzqt/dvdialog.h"
 #include "versioncontrol.h"
 
-using namespace DVGui;
-
 class QPushButton;
 class QLabel;
 
 //-----------------------------------------------------------------------------
 
-class SVNCleanupDialog : public Dialog
+class SVNCleanupDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -31,6 +29,4 @@ protected slots:
 	void onError(const QString &);
 };
 
-using namespace DVGui;
-
 #endif // SVN_CLEANUP_DIALOG_H
diff --git a/toonz/sources/toonz/svncommitdialog.h b/toonz/sources/toonz/svncommitdialog.h
index c47812f..8f8f47f 100644
--- a/toonz/sources/toonz/svncommitdialog.h
+++ b/toonz/sources/toonz/svncommitdialog.h
@@ -10,8 +10,6 @@
 #include <QMap>
 #include <QDir>
 
-using namespace DVGui;
-
 class QLabel;
 class QPushButton;
 class QTreeWidget;
@@ -24,7 +22,7 @@ class TXshLevel;
 
 //-----------------------------------------------------------------------------
 
-class SVNCommitDialog : public Dialog
+class SVNCommitDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -119,7 +117,7 @@ signals:
 
 //-----------------------------------------------------------------------------
 
-class SVNCommitFrameRangeDialog : public Dialog
+class SVNCommitFrameRangeDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
diff --git a/toonz/sources/toonz/svndeletedialog.h b/toonz/sources/toonz/svndeletedialog.h
index f10dce0..9986950 100644
--- a/toonz/sources/toonz/svndeletedialog.h
+++ b/toonz/sources/toonz/svndeletedialog.h
@@ -6,8 +6,6 @@
 #include "toonzqt/dvdialog.h"
 #include "versioncontrol.h"
 
-using namespace DVGui;
-
 class QLabel;
 class QPushButton;
 class QCheckBox;
@@ -17,7 +15,7 @@ class QFile;
 
 //-----------------------------------------------------------------------------
 
-class SVNDeleteDialog : public Dialog
+class SVNDeleteDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
diff --git a/toonz/sources/toonz/svnlockdialog.h b/toonz/sources/toonz/svnlockdialog.h
index 5818f4e..b2f75aa 100644
--- a/toonz/sources/toonz/svnlockdialog.h
+++ b/toonz/sources/toonz/svnlockdialog.h
@@ -8,8 +8,6 @@
 
 #include <QList>
 
-using namespace DVGui;
-
 class QLabel;
 class QPushButton;
 class QCheckBox;
@@ -19,7 +17,7 @@ class QFile;
 
 //-----------------------------------------------------------------------------
 
-class SVNLockDialog : public Dialog
+class SVNLockDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -79,7 +77,7 @@ signals:
 
 //-----------------------------------------------------------------------------
 
-class SVNLockInfoDialog : public Dialog
+class SVNLockInfoDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 	SVNStatus m_status;
diff --git a/toonz/sources/toonz/svnlockframerangedialog.cpp b/toonz/sources/toonz/svnlockframerangedialog.cpp
index 8d38a15..2e09230 100644
--- a/toonz/sources/toonz/svnlockframerangedialog.cpp
+++ b/toonz/sources/toonz/svnlockframerangedialog.cpp
@@ -66,12 +66,12 @@ SVNLockFrameRangeDialog::SVNLockFrameRangeDialog(QWidget *parent,
 	m_toLabel->setMaximumWidth(60);
 	m_toLabel->hide();
 
-	m_fromLineEdit = new IntLineEdit;
+	m_fromLineEdit = new DVGui::IntLineEdit;
 	m_fromLineEdit->setRange(1, frameCount);
 	m_fromLineEdit->hide();
 	connect(m_fromLineEdit, SIGNAL(textChanged(const QString &)), this, SLOT(onFromLineEditTextChanged()));
 
-	m_toLineEdit = new IntLineEdit;
+	m_toLineEdit = new DVGui::IntLineEdit;
 	m_toLineEdit->setRange(1, frameCount);
 	m_toLineEdit->hide();
 	m_toLineEdit->setValue(frameCount);
@@ -391,12 +391,12 @@ SVNLockMultiFrameRangeDialog::SVNLockMultiFrameRangeDialog(QWidget *parent,
 
 	int frameCount = m_files.size();
 
-	m_fromLineEdit = new IntLineEdit;
+	m_fromLineEdit = new DVGui::IntLineEdit;
 	m_fromLineEdit->setRange(1, frameCount);
 	m_fromLineEdit->hide();
 	connect(m_fromLineEdit, SIGNAL(textChanged(const QString &)), this, SLOT(onFromLineEditTextChanged()));
 
-	m_toLineEdit = new IntLineEdit;
+	m_toLineEdit = new DVGui::IntLineEdit;
 	m_toLineEdit->setRange(1, frameCount);
 	m_toLineEdit->hide();
 	m_toLineEdit->setValue(frameCount);
diff --git a/toonz/sources/toonz/svnlockframerangedialog.h b/toonz/sources/toonz/svnlockframerangedialog.h
index 518a033..cf64552 100644
--- a/toonz/sources/toonz/svnlockframerangedialog.h
+++ b/toonz/sources/toonz/svnlockframerangedialog.h
@@ -9,15 +9,13 @@
 
 #include <QList>
 
-using namespace DVGui;
-
 class QLabel;
 class QPushButton;
 class QPlainTextEdit;
 
 //-----------------------------------------------------------------------------
 
-class SVNLockFrameRangeDialog : public Dialog
+class SVNLockFrameRangeDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -29,8 +27,8 @@ class SVNLockFrameRangeDialog : public Dialog
 
 	QLabel *m_fromLabel;
 	QLabel *m_toLabel;
-	IntLineEdit *m_fromLineEdit;
-	IntLineEdit *m_toLineEdit;
+	DVGui::IntLineEdit *m_fromLineEdit;
+	DVGui::IntLineEdit *m_toLineEdit;
 
 	QPushButton *m_lockButton;
 	QPushButton *m_cancelButton;
@@ -77,7 +75,7 @@ signals:
 
 //-----------------------------------------------------------------------------
 
-class SVNLockMultiFrameRangeDialog : public Dialog
+class SVNLockMultiFrameRangeDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -89,8 +87,8 @@ class SVNLockMultiFrameRangeDialog : public Dialog
 
 	QLabel *m_fromLabel;
 	QLabel *m_toLabel;
-	IntLineEdit *m_fromLineEdit;
-	IntLineEdit *m_toLineEdit;
+	DVGui::IntLineEdit *m_fromLineEdit;
+	DVGui::IntLineEdit *m_toLineEdit;
 
 	QPushButton *m_lockButton;
 	QPushButton *m_cancelButton;
@@ -134,7 +132,7 @@ signals:
 
 //-----------------------------------------------------------------------------
 
-class SVNUnlockFrameRangeDialog : public Dialog
+class SVNUnlockFrameRangeDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -180,7 +178,7 @@ signals:
 
 //-----------------------------------------------------------------------------
 
-class SVNUnlockMultiFrameRangeDialog : public Dialog
+class SVNUnlockMultiFrameRangeDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -222,7 +220,7 @@ signals:
 
 //-----------------------------------------------------------------------------
 
-class SVNFrameRangeLockInfoDialog : public Dialog
+class SVNFrameRangeLockInfoDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -245,7 +243,7 @@ protected slots:
 
 //-----------------------------------------------------------------------------
 
-class SVNMultiFrameRangeLockInfoDialog : public Dialog
+class SVNMultiFrameRangeLockInfoDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
diff --git a/toonz/sources/toonz/svnpurgedialog.h b/toonz/sources/toonz/svnpurgedialog.h
index 4f6416b..d46bfab 100644
--- a/toonz/sources/toonz/svnpurgedialog.h
+++ b/toonz/sources/toonz/svnpurgedialog.h
@@ -7,14 +7,12 @@
 #include "versioncontrol.h"
 #include <QList>
 
-using namespace DVGui;
-
 class QPushButton;
 class QLabel;
 
 //-----------------------------------------------------------------------------
 
-class SVNPurgeDialog : public Dialog
+class SVNPurgeDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -49,6 +47,4 @@ signals:
 	void done(const QStringList &);
 };
 
-using namespace DVGui;
-
 #endif // SVN_PURGE_DIALOG_H
diff --git a/toonz/sources/toonz/svnrevertdialog.h b/toonz/sources/toonz/svnrevertdialog.h
index aaf884d..ae4f3b4 100644
--- a/toonz/sources/toonz/svnrevertdialog.h
+++ b/toonz/sources/toonz/svnrevertdialog.h
@@ -8,15 +8,13 @@
 
 #include <QList>
 
-using namespace DVGui;
-
 class QPushButton;
 class QTreeWidget;
 class QCheckBox;
 
 //-----------------------------------------------------------------------------
 
-class SVNRevertDialog : public Dialog
+class SVNRevertDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -75,7 +73,7 @@ signals:
 
 //-----------------------------------------------------------------------------
 
-class SVNRevertFrameRangeDialog : public Dialog
+class SVNRevertFrameRangeDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
diff --git a/toonz/sources/toonz/svnupdateandlockdialog.h b/toonz/sources/toonz/svnupdateandlockdialog.h
index 7030762..00e0c2f 100644
--- a/toonz/sources/toonz/svnupdateandlockdialog.h
+++ b/toonz/sources/toonz/svnupdateandlockdialog.h
@@ -8,8 +8,6 @@
 
 #include <QList>
 
-using namespace DVGui;
-
 class QLabel;
 class QPushButton;
 class QPlainTextEdit;
@@ -17,7 +15,7 @@ class QCheckBox;
 
 //-----------------------------------------------------------------------------
 
-class SVNUpdateAndLockDialog : public Dialog
+class SVNUpdateAndLockDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
diff --git a/toonz/sources/toonz/svnupdatedialog.h b/toonz/sources/toonz/svnupdatedialog.h
index 8156f38..ce9ca3f 100644
--- a/toonz/sources/toonz/svnupdatedialog.h
+++ b/toonz/sources/toonz/svnupdatedialog.h
@@ -8,8 +8,6 @@
 
 #include <QList>
 
-using namespace DVGui;
-
 class QLabel;
 class QPushButton;
 class DateChooserWidget;
@@ -19,7 +17,7 @@ class QCheckBox;
 
 //-----------------------------------------------------------------------------
 
-class SVNUpdateDialog : public Dialog
+class SVNUpdateDialog : public DVGui::Dialog
 {
 	Q_OBJECT
 
diff --git a/toonz/sources/toonz/tasksviewer.cpp b/toonz/sources/toonz/tasksviewer.cpp
index 436e192..c941c1a 100644
--- a/toonz/sources/toonz/tasksviewer.cpp
+++ b/toonz/sources/toonz/tasksviewer.cpp
@@ -1271,7 +1271,7 @@ void TaskTreeModel::start(bool)
 				BatchesController::instance()->start(task->m_id);
 			}
 	} catch (TException &e) {
-		MsgBox(WARNING, QString::fromStdString(toString(e.getMessage())));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(toString(e.getMessage())));
 	}
 
 	emit layoutChanged();
@@ -1304,7 +1304,7 @@ void TaskTreeModel::stop(bool)
 				BatchesController::instance()->stop(task->m_id);
 			}
 	} catch (TException &e) {
-		MsgBox(WARNING, QString::fromStdString(toString(e.getMessage())));
+		DVGui::MsgBox(DVGui::WARNING, QString::fromStdString(toString(e.getMessage())));
 	}
 
 	emit layoutChanged();
diff --git a/toonz/sources/toonz/timestretchpopup.cpp b/toonz/sources/toonz/timestretchpopup.cpp
index 68e360f..c9d4777 100644
--- a/toonz/sources/toonz/timestretchpopup.cpp
+++ b/toonz/sources/toonz/timestretchpopup.cpp
@@ -233,7 +233,7 @@ TimeStretchPopup::TimeStretchPopup()
 	m_oldRange->setFixedSize(43, DVGui::WidgetHeight);
 	rangeLayout->addWidget(m_oldRange);
 	rangeLayout->addSpacing(10);
-	m_newRangeFld = new IntLineEdit(this);
+	m_newRangeFld = new DVGui::IntLineEdit(this);
 	rangeLayout->addWidget(new QLabel(tr("New Range:")), 1, Qt::AlignRight);
 	rangeLayout->addWidget(m_newRangeFld, 0, Qt::AlignRight);
 	addLayout(tr("Old Range:"), rangeLayout);
diff --git a/toonz/sources/toonz/timestretchpopup.h b/toonz/sources/toonz/timestretchpopup.h
index fbf750b..6046c3b 100644
--- a/toonz/sources/toonz/timestretchpopup.h
+++ b/toonz/sources/toonz/timestretchpopup.h
@@ -14,13 +14,11 @@ class QLabel;
 class QComboBox;
 class TSelection;
 
-using namespace DVGui;
-
 //=============================================================================
 // TimeStretchPopup
 //-----------------------------------------------------------------------------
 
-class TimeStretchPopup : public Dialog
+class TimeStretchPopup : public DVGui::Dialog
 {
 	Q_OBJECT
 
@@ -28,7 +26,7 @@ class TimeStretchPopup : public Dialog
 	QPushButton *m_cancelBtn;
 
 	QComboBox *m_stretchType;
-	IntLineEdit *m_newRangeFld;
+	DVGui::IntLineEdit *m_newRangeFld;
 	QLabel *m_oldRange;
 
 public:
diff --git a/toonz/sources/toonz/tpanels.cpp b/toonz/sources/toonz/tpanels.cpp
index 18e590d..966a74c 100644
--- a/toonz/sources/toonz/tpanels.cpp
+++ b/toonz/sources/toonz/tpanels.cpp
@@ -274,7 +274,7 @@ public:
 	{
 		TFx *currentFx = TApp::instance()->getCurrentFx()->getFx();
 		if (!currentFx) {
-			MsgBox(WARNING, "Preview Fx : No Current Fx !");
+			DVGui::MsgBox(DVGui::WARNING, "Preview Fx : No Current Fx !");
 			return;
 		}
 		/*-- 
@@ -284,7 +284,7 @@ public:
 		TPaletteColumnFx *pfx = dynamic_cast<TPaletteColumnFx *>(currentFx);
 		TOutputFx *ofx = dynamic_cast<TOutputFx *>(currentFx);
 		if (pfx || ofx) {
-			MsgBox(WARNING, "Preview Fx command is not available on Palette or Output node !");
+			DVGui::MsgBox(DVGui::WARNING, "Preview Fx command is not available on Palette or Output node !");
 			return;
 		}
 
@@ -660,7 +660,7 @@ ColorFieldEditorController::ColorFieldEditorController()
 
 //-----------------------------------------------------------------------------
 
-void ColorFieldEditorController::edit(ColorField *colorField)
+void ColorFieldEditorController::edit(DVGui::ColorField *colorField)
 {
 	if (m_currentColorField && m_currentColorField->isEditing())
 		m_currentColorField->setIsEditing(false);
@@ -729,7 +729,7 @@ CleanupColorFieldEditorController::CleanupColorFieldEditorController()
 
 //-----------------------------------------------------------------------------
 
-void CleanupColorFieldEditorController::edit(CleanupColorField *colorField)
+void CleanupColorFieldEditorController::edit(DVGui::CleanupColorField *colorField)
 {
 	if (m_currentColorField && m_currentColorField->isEditing())
 		m_currentColorField->setIsEditing(false);
diff --git a/toonz/sources/toonz/trackerpopup.cpp b/toonz/sources/toonz/trackerpopup.cpp
index c5d2aba..240fa37 100644
--- a/toonz/sources/toonz/trackerpopup.cpp
+++ b/toonz/sources/toonz/trackerpopup.cpp
@@ -234,7 +234,7 @@ bool TrackerPopup::apply()
 	m_tracker = new Tracker(threshold, sensibility, activeBackground,
 							manageOcclusion, variationWindow, frameStart, framesNumber);
 	if (m_tracker->getLastError() != 0) {
-		DVGui::MsgBox(WARNING, m_tracker->getLastError());
+		DVGui::MsgBox(DVGui::WARNING, m_tracker->getLastError());
 		return false;
 	}
 
diff --git a/toonz/sources/toonz/versioncontrol.cpp b/toonz/sources/toonz/versioncontrol.cpp
index 6b4d700..e2fd6a4 100644
--- a/toonz/sources/toonz/versioncontrol.cpp
+++ b/toonz/sources/toonz/versioncontrol.cpp
@@ -486,7 +486,7 @@ void VersionControlManager::onError(const QString &text)
 		m_levelSet = 0;
 	}
 	m_scene = 0;
-	DVGui::MsgBox(WARNING, text);
+	DVGui::MsgBox(DVGui::WARNING, text);
 }
 
 //=============================================================================
@@ -543,7 +543,7 @@ bool VersionControl::testSetup()
 
 	// Test configuration file
 	if (repositoriesCount == 0) {
-		MsgBox(CRITICAL, tr("The version control configuration file is empty or wrongly defined.\nPlease refer to the user guide for details."));
+		DVGui::MsgBox(DVGui::CRITICAL, tr("The version control configuration file is empty or wrongly defined.\nPlease refer to the user guide for details."));
 		return false;
 	}
 
@@ -554,7 +554,7 @@ bool VersionControl::testSetup()
 	if (!path.isEmpty() && !QFile::exists(path + "/svn.exe"))
 #endif
 	{
-		MsgBox(CRITICAL, tr("The version control client application specified on the configuration file cannot be found.\nPlease refer to the user guide for details."));
+		DVGui::MsgBox(DVGui::CRITICAL, tr("The version control client application specified on the configuration file cannot be found.\nPlease refer to the user guide for details."));
 		return false;
 	}
 
@@ -571,12 +571,12 @@ bool VersionControl::testSetup()
 		p.start("svn", QStringList("--version"));
 
 		if (!p.waitForStarted()) {
-			MsgBox(CRITICAL, tr("The version control client application is not installed on your computer.\nSubversion 1.5 or later is required.\nPlease refer to the user guide for details."));
+			DVGui::MsgBox(DVGui::CRITICAL, tr("The version control client application is not installed on your computer.\nSubversion 1.5 or later is required.\nPlease refer to the user guide for details."));
 			return false;
 		}
 
 		if (!p.waitForFinished()) {
-			MsgBox(CRITICAL, tr("The version control client application is not installed on your computer.\nSubversion 1.5 or later is required.\nPlease refer to the user guide for details."));
+			DVGui::MsgBox(DVGui::CRITICAL, tr("The version control client application is not installed on your computer.\nSubversion 1.5 or later is required.\nPlease refer to the user guide for details."));
 			return false;
 		}
 
@@ -590,7 +590,7 @@ bool VersionControl::testSetup()
 
 			double version = firstLine.left(3).toDouble();
 			if (version <= 1.5) {
-				MsgBox(WARNING, tr("The version control client application installed on your computer needs to be updated, otherwise some features may not be available.\nSubversion 1.5 or later is required.\nPlease refer to the user guide for details."));
+				DVGui::MsgBox(DVGui::WARNING, tr("The version control client application installed on your computer needs to be updated, otherwise some features may not be available.\nSubversion 1.5 or later is required.\nPlease refer to the user guide for details."));
 				return true;
 			}
 		}
diff --git a/toonz/sources/toonz/viewerpane.h b/toonz/sources/toonz/viewerpane.h
index 17958f1..c3079db 100644
--- a/toonz/sources/toonz/viewerpane.h
+++ b/toonz/sources/toonz/viewerpane.h
@@ -19,8 +19,6 @@ class QButtonGroup;
 class QToolBar;
 class Ruler;
 
-using namespace DVGui;
-
 //=============================================================================
 // ViewerPanel
 //-----------------------------------------------------------------------------
diff --git a/toonz/sources/toonz/xshcolumnviewer.cpp b/toonz/sources/toonz/xshcolumnviewer.cpp
index 0a28dc2..dacc690 100644
--- a/toonz/sources/toonz/xshcolumnviewer.cpp
+++ b/toonz/sources/toonz/xshcolumnviewer.cpp
@@ -1314,7 +1314,7 @@ ColumnTransparencyPopup::ColumnTransparencyPopup(QWidget *parent)
 	m_slider->setFixedHeight(14);
 	m_slider->setFixedWidth(100);
 
-	m_value = new IntLineEdit(this, 1, 1, 100);
+	m_value = new DVGui::IntLineEdit(this, 1, 1, 100);
 	/*m_value->setValidator(new QIntValidator (1, 100, m_value));
 m_value->setFixedHeight(16);
 m_value->setFixedWidth(30);
diff --git a/toonz/sources/toonz/xsheetcmd.cpp b/toonz/sources/toonz/xsheetcmd.cpp
index fa58b0b..4992404 100644
--- a/toonz/sources/toonz/xsheetcmd.cpp
+++ b/toonz/sources/toonz/xsheetcmd.cpp
@@ -1683,7 +1683,7 @@ void PrintXsheetCommand::execute()
 	copyCss(fp);
 
 	QString str = QObject::tr("The %1 file has been generated").arg(toQString(fp));
-	MsgBox(WARNING, str);
+	DVGui::MsgBox(DVGui::WARNING, str);
 
 	TSystem::showDocument(fp);
 }
diff --git a/toonz/sources/toonzqt/camerasettingswidget.cpp b/toonz/sources/toonzqt/camerasettingswidget.cpp
index 1a57b12..37732a7 100644
--- a/toonz/sources/toonzqt/camerasettingswidget.cpp
+++ b/toonz/sources/toonzqt/camerasettingswidget.cpp
@@ -199,8 +199,8 @@ CameraSettingsWidget::CameraSettingsWidget(bool forCleanup)
 
 	m_arFld = new SimpleExpField(this);
 
-	m_xResFld = new IntLineEdit();
-	m_yResFld = new IntLineEdit();
+	m_xResFld = new DVGui::IntLineEdit();
+	m_yResFld = new DVGui::IntLineEdit();
 	m_xDpiFld = new DoubleLineEdit();
 	m_yDpiFld = new DoubleLineEdit();
 
diff --git a/toonz/sources/toonzqt/colorfield.cpp b/toonz/sources/toonzqt/colorfield.cpp
index 9f18c28..171dfb4 100644
--- a/toonz/sources/toonzqt/colorfield.cpp
+++ b/toonz/sources/toonzqt/colorfield.cpp
@@ -183,7 +183,7 @@ ChannelField::ChannelField(QWidget *parent,
 	assert(0 <= value && value <= m_maxValue);
 
 	QLabel *channelName = new QLabel(string, this);
-	m_channelEdit = new IntLineEdit(this, value, 0, maxValue);
+	m_channelEdit = new DVGui::IntLineEdit(this, value, 0, maxValue);
 	m_channelSlider = new QSlider(Qt::Horizontal, this);
 
 	channelName->setAlignment(Qt::AlignRight | Qt::AlignVCenter);
diff --git a/toonz/sources/toonzqt/flipconsole.cpp b/toonz/sources/toonzqt/flipconsole.cpp
index b8f163a..3056e69 100644
--- a/toonz/sources/toonzqt/flipconsole.cpp
+++ b/toonz/sources/toonzqt/flipconsole.cpp
@@ -1545,7 +1545,7 @@ QFrame *FlipConsole::createFrameSlider()
 {
 	QFrame *frameSliderFrame = new QFrame(this);
 
-	m_editCurrFrame = new IntLineEdit(frameSliderFrame, m_currentFrame);
+	m_editCurrFrame = new DVGui::IntLineEdit(frameSliderFrame, m_currentFrame);
 	m_editCurrFrame->setToolTip(tr("Set the current frame"));
 	m_editCurrFrame->setFixedWidth(40);
 
@@ -1595,7 +1595,7 @@ QFrame *FlipConsole::createFpsSlider()
 	//frame per second
 	m_fpsLabel = new QLabel(QString(" FPS -- /"), fpsSliderFrame);
 	m_fpsSlider = new QScrollBar(Qt::Horizontal, fpsSliderFrame);
-	m_fpsField = new IntLineEdit(fpsSliderFrame, m_fps, -60, 60);
+	m_fpsField = new DVGui::IntLineEdit(fpsSliderFrame, m_fps, -60, 60);
 	m_fpsField->setFixedWidth(40);
 
 	m_fpsLabel->setMinimumWidth(m_fpsLabel->fontMetrics().width("_FPS_24___"));
diff --git a/toonz/sources/toonzqt/framenavigator.cpp b/toonz/sources/toonzqt/framenavigator.cpp
index 78db5ed..9447a6b 100644
--- a/toonz/sources/toonzqt/framenavigator.cpp
+++ b/toonz/sources/toonzqt/framenavigator.cpp
@@ -25,7 +25,7 @@ FrameNavigator::FrameNavigator(QWidget *parent)
 	connect(prevButton, SIGNAL(triggered()), this, SLOT(prevFrame()));
 	addAction(prevButton);
 
-	m_lineEdit = new IntLineEdit(this);
+	m_lineEdit = new DVGui::IntLineEdit(this);
 
 	m_lineEdit->setFixedHeight(16);
 	bool ret = connect(m_lineEdit, SIGNAL(editingFinished()), this, SLOT(onEditingFinished()));
diff --git a/toonz/sources/toonzqt/imageutils.cpp b/toonz/sources/toonzqt/imageutils.cpp
index 67be463..d77c9c4 100644
--- a/toonz/sources/toonzqt/imageutils.cpp
+++ b/toonz/sources/toonzqt/imageutils.cpp
@@ -143,7 +143,7 @@ TFilePath duplicate(const TFilePath &levelPath)
 		return TFilePath();
 
 	if (!TSystem::doesExistFileOrLevel(levelPath)) {
-		MsgBox(WARNING, QObject::tr("It is not possible to find the %1 level.").arg(QString::fromStdWString(levelPath.getWideString())));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to find the %1 level.").arg(QString::fromStdWString(levelPath.getWideString())));
 		return TFilePath();
 	}
 
@@ -168,7 +168,7 @@ TFilePath duplicate(const TFilePath &levelPath)
 		}
 	} catch (...) {
 		QString msg = QObject::tr("There was an error copying %1").arg(toQString(levelPath));
-		MsgBox(CRITICAL, msg);
+		DVGui::MsgBox(DVGui::CRITICAL, msg);
 		return TFilePath();
 	}
 
@@ -189,21 +189,21 @@ void premultiply(const TFilePath &levelPath)
 		return;
 
 	if (!TSystem::doesExistFileOrLevel(levelPath)) {
-		MsgBox(WARNING, QObject::tr("It is not possible to find the level %1").arg(QString::fromStdWString(levelPath.getWideString())));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to find the level %1").arg(QString::fromStdWString(levelPath.getWideString())));
 		return;
 	}
 
 	TFileType::Type type = TFileType::getInfo(levelPath);
 	if (type == TFileType::CMAPPED_LEVEL) {
-		MsgBox(WARNING, QObject::tr("Cannot premultiply the selected file."));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("Cannot premultiply the selected file."));
 		return;
 	}
 	if (type == TFileType::VECTOR_LEVEL || type == TFileType::VECTOR_IMAGE) {
-		MsgBox(WARNING, QObject::tr("Cannot premultiply a vector-based level."));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("Cannot premultiply a vector-based level."));
 		return;
 	}
 	if (type != TFileType::RASTER_LEVEL && type != TFileType::RASTER_IMAGE) {
-		MsgBox(INFORMATION, QObject::tr("Cannot premultiply the selected file."));
+		DVGui::MsgBox(DVGui::INFORMATION, QObject::tr("Cannot premultiply the selected file."));
 		return;
 	}
 
@@ -267,14 +267,14 @@ void premultiply(const TFilePath &levelPath)
 			lw->save(level);
 		}
 	} catch (...) {
-		MsgBox(WARNING, QObject::tr("Cannot premultiply the selected file."));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("Cannot premultiply the selected file."));
 		QApplication::restoreOverrideCursor();
 		return;
 	}
 
 	QApplication::restoreOverrideCursor();
 	QString msg = QObject::tr("Level %1 premultiplied.").arg(QString::fromStdString(levelPath.getLevelName()));
-	MsgBox(INFORMATION, msg);
+	DVGui::MsgBox(DVGui::INFORMATION, msg);
 }
 
 //-----------------------------------------------------------------------------
@@ -429,8 +429,7 @@ void convertFromVI(const TLevelReaderP &lr, const TPaletteP &plt, const TLevelWr
 			maxBbox += img->getBBox();
 		} catch (...) {
 			msg = QObject::tr("Frame %1 : conversion failed!").arg(QString::fromStdString(frames[i].expand()));
-			MsgBox(INFORMATION, msg);
-			;
+			DVGui::MsgBox(DVGui::INFORMATION, msg);
 		}
 	}
 	maxBbox = maxBbox.enlarge(2);
@@ -458,7 +457,7 @@ void convertFromVI(const TLevelReaderP &lr, const TPaletteP &plt, const TLevelWr
 			}
 		} catch (...) {
 			msg = QObject::tr("Frame %1 : conversion failed!").arg(QString::fromStdString(frames[i].expand()));
-			MsgBox(INFORMATION, msg);
+			DVGui::MsgBox(DVGui::INFORMATION, msg);
 		}
 		frameNotifier->notifyFrameCompleted(100 * (i + 1) / frames.size());
 	}
@@ -614,7 +613,7 @@ void convert(const TFilePath &source, const TFilePath &dest,
 		if (!AviCodecRestrictions::canWriteMovie(toWideString(codecName), res)) {
 			return;
 			//QString msg=QObject::tr("The image resolution does not fit the chosen output file format.");
-			//MsgBox(WARNING,msg);
+			//DVGui::MsgBox(DVGui::WARNING,msg);
 		}
 	}
 #endif;
diff --git a/toonz/sources/toonzqt/infoviewer.cpp b/toonz/sources/toonzqt/infoviewer.cpp
index 6eaf529..2328c41 100644
--- a/toonz/sources/toonzqt/infoviewer.cpp
+++ b/toonz/sources/toonzqt/infoviewer.cpp
@@ -584,7 +584,7 @@ bool InfoViewerImp::setItem(const TLevelP &level, TPalette *palette, const TFile
 		assert(!m_level);
 
 		if (!TSystem::doesExistFileOrLevel(m_path)) {
-			MsgBox(WARNING, QObject::tr("The file %1 does not exist.").arg(QString::fromStdWString(path.getWideString())));
+			DVGui::MsgBox(DVGui::WARNING, QObject::tr("The file %1 does not exist.").arg(QString::fromStdWString(path.getWideString())));
 
 			return false;
 		}
diff --git a/toonz/sources/toonzqt/intfield.cpp b/toonz/sources/toonzqt/intfield.cpp
index 344b8f0..147929b 100644
--- a/toonz/sources/toonzqt/intfield.cpp
+++ b/toonz/sources/toonzqt/intfield.cpp
@@ -248,7 +248,7 @@ IntField::IntField(QWidget *parent, bool isMaxRangeLimited, bool isRollerHide)
 	vLayout->setMargin(0);
 	vLayout->setSpacing(0);
 
-	m_lineEdit = new IntLineEdit(field);
+	m_lineEdit = new DVGui::IntLineEdit(field);
 	bool ret = connect(m_lineEdit, SIGNAL(editingFinished()), this, SLOT(onEditingFinished()));
 	vLayout->addWidget(m_lineEdit);
 
diff --git a/toonz/sources/toonzqt/intpairfield.cpp b/toonz/sources/toonzqt/intpairfield.cpp
index 2f55da4..8ee766e 100644
--- a/toonz/sources/toonzqt/intpairfield.cpp
+++ b/toonz/sources/toonzqt/intpairfield.cpp
@@ -31,10 +31,10 @@ IntPairField::IntPairField(QWidget *parent, bool isMaxRangeLimited)
 	setFixedHeight(WidgetHeight);
 
 	m_leftLabel = new QLabel("", this);
-	m_leftLineEdit = new IntLineEdit(this);
+	m_leftLineEdit = new DVGui::IntLineEdit(this);
 
 	m_rightLabel = new QLabel("", this);
-	m_rightLineEdit = new IntLineEdit(this);
+	m_rightLineEdit = new DVGui::IntLineEdit(this);
 
 	m_leftLineEdit->setFixedWidth(40);
 	m_rightLineEdit->setFixedWidth(40);
diff --git a/toonz/sources/toonzqt/menubarcommand.cpp b/toonz/sources/toonzqt/menubarcommand.cpp
index eea1883..45193f4 100644
--- a/toonz/sources/toonzqt/menubarcommand.cpp
+++ b/toonz/sources/toonzqt/menubarcommand.cpp
@@ -317,7 +317,7 @@ void CommandManager::setShortcut(QAction *action, std::string shortcutString)
 	assert(ks.count() == 1 || ks.count() == 0 && shortcut == "");
 
 	if (node->m_type == ZoomCommandType && ks.count() > 1) {
-		MsgBox(WARNING, QObject::tr("It is not possible to assing a shortcut with modifiers to the visualization commands."));
+		DVGui::MsgBox(DVGui::WARNING, QObject::tr("It is not possible to assing a shortcut with modifiers to the visualization commands."));
 		return;
 	}
 	// lo shortcut e' gia' assegnato?
diff --git a/toonz/sources/toonzqt/palettesscanpopup.cpp b/toonz/sources/toonzqt/palettesscanpopup.cpp
index 2c3a6f9..e9f3852 100644
--- a/toonz/sources/toonzqt/palettesscanpopup.cpp
+++ b/toonz/sources/toonzqt/palettesscanpopup.cpp
@@ -27,7 +27,7 @@ PalettesScanPopup::PalettesScanPopup()
 	setWindowTitle(tr("Search for Palettes"));
 	setFixedWidth(250);
 
-	m_field = new FileField();
+	m_field = new DVGui::FileField();
 	addWidget(m_field);
 
 	m_label = new QLabel();
diff --git a/toonz/sources/toonzqt/palettesscanpopup.h b/toonz/sources/toonzqt/palettesscanpopup.h
index 33c5785..abd46d7 100644
--- a/toonz/sources/toonzqt/palettesscanpopup.h
+++ b/toonz/sources/toonzqt/palettesscanpopup.h
@@ -18,17 +18,15 @@
 #define DVVAR DV_IMPORT_VAR
 #endif
 
-using namespace DVGui;
-
 //=============================================================================
 // PalettesScanPopup
 //-----------------------------------------------------------------------------
 
-class DVAPI PalettesScanPopup : public Dialog
+class DVAPI PalettesScanPopup : public DVGui::Dialog
 {
 	Q_OBJECT
 
-	FileField *m_field;
+	DVGui::FileField *m_field;
 	QLabel *m_label;
 
 	TFilePath m_folderPath;
diff --git a/toonz/sources/toonzqt/studiopaletteviewer.cpp b/toonz/sources/toonzqt/studiopaletteviewer.cpp
index a8b4052..8c2a55d 100644
--- a/toonz/sources/toonzqt/studiopaletteviewer.cpp
+++ b/toonz/sources/toonzqt/studiopaletteviewer.cpp
@@ -771,7 +771,7 @@ void StudioPaletteTreeViewer::loadInCurrentPalette()
 		return;
 
 	if (palette->isLocked()) {
-		MsgBox(WARNING, "Palette is Locked!");
+		DVGui::MsgBox(DVGui::WARNING, "Palette is Locked!");
 		return;
 	}
 
diff --git a/toonz/sources/toonzqt/styleeditor.cpp b/toonz/sources/toonzqt/styleeditor.cpp
index d3d93ad..955aeed 100644
--- a/toonz/sources/toonzqt/styleeditor.cpp
+++ b/toonz/sources/toonzqt/styleeditor.cpp
@@ -2883,7 +2883,7 @@ StyleEditor::StyleEditor(PaletteController *paletteController, QWidget *parent)
 	TFilePath libraryPath = ToonzFolder::getLibraryFolder();
 	setRootPath(libraryPath);
 
-	m_styleBar = new TabBar(this);
+	m_styleBar = new DVGui::TabBar(this);
 	m_styleBar->setDrawBase(false);
 	m_styleBar->setObjectName("StyleEditorTabBar");
 
@@ -3004,8 +3004,8 @@ QFrame *StyleEditor::createBottomWidget()
 {
 	QFrame *bottomWidget = new QFrame(this);
 	m_autoButton = new QPushButton(tr("Auto  \nApply"));
-	m_oldColor = new StyleSample(this, 42, 20);
-	m_newColor = new StyleSample(this, 42, 20);
+	m_oldColor = new DVGui::StyleSample(this, 42, 20);
+	m_newColor = new DVGui::StyleSample(this, 42, 20);
 	m_applyButton = new QPushButton(tr("Apply"));
 
 	bottomWidget->setFrameStyle(QFrame::StyledPanel);
diff --git a/toonz/sources/toonzqt/tmessageviewer.cpp b/toonz/sources/toonzqt/tmessageviewer.cpp
index 489fab5..897d77a 100644
--- a/toonz/sources/toonzqt/tmessageviewer.cpp
+++ b/toonz/sources/toonzqt/tmessageviewer.cpp
@@ -118,15 +118,15 @@ void TMessageRepository::messageReceived(int type, const QString &message)
 	}
 
 	switch (type) {
-	case INFORMATION:
+	case DVGui::INFORMATION:
 		m_sim->appendRow(new QStandardItem(gGreenIcon, message));
-		CASE WARNING : m_sim->appendRow(new QStandardItem(gYellowIcon, message));
-		CASE CRITICAL : m_sim->appendRow(new QStandardItem(gRedIcon, message));
+		CASE DVGui::WARNING : m_sim->appendRow(new QStandardItem(gYellowIcon, message));
+		CASE DVGui::CRITICAL : m_sim->appendRow(new QStandardItem(gRedIcon, message));
 	DEFAULT:;
 	}
 
-	if (type == CRITICAL || (type == WARNING && !TMessageViewer::isTMsgVisible()))
-		MsgBoxInPopup(MsgType(type), message);
+	if (type == DVGui::CRITICAL || (type == DVGui::WARNING && !TMessageViewer::isTMsgVisible()))
+		MsgBoxInPopup(DVGui::MsgType(type), message);
 }
 
 //---------------------------------------------------------------------------------