#ifndef EXPRESSIONFIELD_H
#define EXPRESSIONFIELD_H

#include "tgrammar.h"
#include <QWidget>
#include <QTextEdit>

#undef DVAPI
#undef DVVAR
#ifdef TOONZQT_EXPORTS
#define DVAPI DV_EXPORT_API
#define DVVAR DV_EXPORT_VAR
#else
#define DVAPI DV_IMPORT_API
#define DVVAR DV_IMPORT_VAR
#endif

// forward declaration
class QPushButton;
class QCompleter;
class QListView;
class QModelIndex;

//=============================================================================

namespace DVGui
{

//=============================================================================
/*! \class DVGui::ExpressionField
		\brief The ExpressionField allows to edit expressions (i.e. formulas as '34*(5-2)')

		Inherits \b QWidget.

*/

class DVAPI ExpressionField : public QTextEdit
{
	Q_OBJECT
	bool m_editing;
	const TSyntax::Grammar *m_grammar;

	class SyntaxHighlighter;
	SyntaxHighlighter *m_syntaxHighlighter;

	QListView *m_completerPopup;
	int m_completerStartPos;
	TSyntax::Grammar::Suggestions m_suggestions;

public:
	ExpressionField(QWidget *parent = 0);
	~ExpressionField();

	void setExpression(std::string expression);
	std::string getExpression() const;

	void setGrammar(const TSyntax::Grammar *grammar);
	const TSyntax::Grammar *getGrammar() const { return m_grammar; }

private:
	void openCompleterPopup();
	bool updateCompleterPopup();
	void insertCompletion();
	int computeSuggestions();

protected:
	bool event(QEvent *e);
	void keyPressEvent(QKeyEvent *e);
	void focusInEvent(QFocusEvent *e);
	void focusOutEvent(QFocusEvent *e);
	void showEvent(QShowEvent *);
	void hideEvent(QHideEvent *);
	bool eventFilter(QObject *obj, QEvent *e);

private slots:
	void onTextChanged();
	void onCursorPositionChanged();
	void insertCompletion(const QModelIndex &index);

signals:
	void expressionChanged();
};

//-----------------------------------------------------------------------------
} //namespace DVGui
//-----------------------------------------------------------------------------

#endif // FILEFIELD_H