Public Member Functions
	BuildOnlyVisibleButtonsHelper (const View2D &v2d, const AbstractGridView &grid_view, int cols_per_row, const AbstractGridViewItem *force_visible_item)

bool	is_item_visible (int item_idx) const

void	fill_layout_before_visible (uiBlock &block) const

void	fill_layout_after_visible (uiBlock &block) const

Detailed Description

Helper for only adding layout items for grid items that are actually in view. 3 main functions:

is_item_visible(): Query if an item of a given index is visible in the view (others should be skipped when building the layout).
fill_layout_before_visible(): Add empty space to the layout before a visible row is drawn, so the layout height is the same as if all items were added (important to get the correct scroll height).
fill_layout_after_visible(): Same thing, just adds empty space for after the last visible row.

Does two assumptions:

Top-to-bottom flow (ymax = 0 and ymin < 0). If that's not good enough, View2D should probably provide queries for the scroll offset.
Only vertical scrolling. For horizontal scrolling, spacers would have to be added on the side(s) as well.

Definition at line 214 of file grid_view.cc.

Constructor & Destructor Documentation

blender::ui::BuildOnlyVisibleButtonsHelper::BuildOnlyVisibleButtonsHelper	(	const View2D &	v2d,
		const AbstractGridView &	grid_view,
		int	cols_per_row,
		const AbstractGridViewItem *	force_visible_item )