#include "nuklear.h"

#include "nuklear_internal.h"

/* ===============================================================

 *

 *                          LIST VIEW

 *

 * ===============================================================*/

NK_API nk_bool

nk_list_view_begin(struct nk_context *ctx, struct nk_list_view *view,

    const char *title, nk_flags flags, int row_height, int row_count)

{

    int title_len;

    nk_hash title_hash;

    nk_uint *x_offset;

    nk_uint *y_offset;

    int result;

    struct nk_window *win;

    struct nk_panel *layout;

    const struct nk_style *style;

    struct nk_vec2 item_spacing;

    NK_ASSERT(ctx);

    NK_ASSERT(view);

    NK_ASSERT(title);

    if (!ctx || !view || !title) return 0;

    win = ctx->current;

    style = &ctx->style;

    item_spacing = style->window.spacing;

    row_height += NK_MAX(0, (int)item_spacing.y);

    /* find persistent list view scrollbar offset */

    title_len = (int)nk_strlen(title);

    title_hash = nk_murmur_hash(title, (int)title_len, NK_PANEL_GROUP);

    x_offset = nk_find_value(win, title_hash);

    if (!x_offset) {

        x_offset = nk_add_value(ctx, win, title_hash, 0);

        y_offset = nk_add_value(ctx, win, title_hash+1, 0);

        NK_ASSERT(x_offset);

        NK_ASSERT(y_offset);

        if (!x_offset || !y_offset) return 0;

        *x_offset = *y_offset = 0;

    } else y_offset = nk_find_value(win, title_hash+1);

    view->scroll_value = *y_offset;

    view->scroll_pointer = y_offset;

    *y_offset = 0;

    result = nk_group_scrolled_offset_begin(ctx, x_offset, y_offset, title, flags);

    win = ctx->current;

    layout = win->layout;

    view->total_height = row_height * NK_MAX(row_count,1);

    view->begin = (int)NK_MAX(((float)view->scroll_value / (float)row_height), 0.0f);

    view->count = (int)NK_MAX(nk_iceilf((layout->clip.h)/(float)row_height),0);

    view->count = NK_MIN(view->count, row_count - view->begin);

    view->end = view->begin + view->count;

    view->ctx = ctx;

    return result;

}

NK_API void

nk_list_view_end(struct nk_list_view *view)

{

    struct nk_context *ctx;

    struct nk_window *win;

    struct nk_panel *layout;

    NK_ASSERT(view);

    NK_ASSERT(view->ctx);

    NK_ASSERT(view->scroll_pointer);

    if (!view || !view->ctx) return;

    ctx = view->ctx;

    win = ctx->current;

    layout = win->layout;

    layout->at_y = layout->bounds.y + (float)view->total_height;

    *view->scroll_pointer = *view->scroll_pointer + view->scroll_value;

    nk_group_end(view->ctx);

}