Initial release

engine/vendor/vst3sdk/vstgui4/vstgui/lib/viewlayouter/gridlayouter.h

@@ -0,0 +1,146 @@
+// This file is part of VSTGUI. It is subject to the license terms
+// in the LICENSE file found in the top-level directory of this
+// distribution and at http://github.com/steinbergmedia/vstgui/LICENSE
+
+#pragma once
+
+#include "../iviewlayouter.h"
+#include <vector>
+#include <variant>
+
+//------------------------------------------------------------------------
+namespace VSTGUI {
+
+//------------------------------------------------------------------------
+/** Properties for configuring a grid layout, compatible with CSS Grid Layout.
+ *
+ *  The GridProperties struct allows you to define a grid layout similar to CSS Grid.
+ *
+ *  - rows: Number of grid rows (default: 1).
+ *  - columns: Number of grid columns (default: 1).
+ *  - autoRows: Defines the height of each row, similar to 'grid-template-rows' in CSS.
+ *  - autoColumns: Defines the width of each column, similar to 'grid-template-columns' in CSS.
+ *  - rowGap: Space between rows, equivalent to 'row-gap' in CSS.
+ *  - columnGap: Space between columns, equivalent to 'column-gap' in CSS.
+ *  - alignItems: Controls alignment of items within their grid area (CSS: 'align-items').
+ *      Options: Start, Center, End, Stretch.
+ *  - justifyItems: Controls horizontal alignment of items within their grid area (CSS:
+ *      'justify-items'). Options: Start, Center, End, Stretch.
+ *  - alignContent: Controls vertical alignment of the grid as a whole (CSS: 'align-content').
+ *      Options: Start, Center, End, Stretch, SpaceBetween, SpaceAround.
+ *  - justifyContent: Controls horizontal alignment of the grid as a whole (CSS: 'justify-content').
+ *      Options: Start, Center, End, Stretch, SpaceBetween, SpaceAround.
+ *  - gridAreas: Optional. Defines the grid area (row, column, rowSpan, colSpan) for each
+ *                   child/view. If provided, each child can span multiple rows/columns, similar to
+ *                   CSS grid-area. If not provided, each child is placed in a single cell by
+ *                   default.
+ *
+ *    Note: justify-content is ignored when grid areas are used and the grid tracks exactly fit the
+ *        content (no extra free space). If grid areas are used and the grid is smaller than the
+ *        container, justify-content can affect the grid's position within the container.
+ *
+ *  This struct is designed to be compatible with the CSS Grid Layout specification:
+ *  https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_grid_layout
+ *
+ *	@ingroup new_in_4_15
+ */
+struct GridLayoutProperties
+{
+	enum class AlignItems
+	{
+		Start,
+		Center,
+		End,
+		Stretch
+	};
+	enum class JustifyItems
+	{
+		Start,
+		Center,
+		End,
+		Stretch
+	};
+	enum class AlignContent
+	{
+		Start,
+		Center,
+		End,
+		Stretch,
+		SpaceBetween,
+		SpaceAround
+	};
+	enum class JustifyContent
+	{
+		Start,
+		Center,
+		End,
+		Stretch,
+		SpaceBetween,
+		SpaceAround
+	};
+	struct GridArea
+	{
+		// 0-based indices
+		size_t row {0};
+		size_t column {0};
+		size_t rowSpan {1};
+		size_t colSpan {1};
+	};
+	struct Percentage
+	{
+		double value {0.0}; // 0.0 - 100.0
+	};
+	struct Auto
+	{
+	};
+	using SizeSpec = std::variant<Auto, CCoord, Percentage>;
+
+	size_t rows {1};
+	size_t columns {1};
+	std::vector<SizeSpec> autoRows;
+	std::vector<SizeSpec> autoColumns;
+	CCoord rowGap {0.0};
+	CCoord columnGap {0.0};
+	AlignItems alignItems {AlignItems::Stretch};
+	JustifyItems justifyItems {JustifyItems::Stretch};
+	AlignContent alignContent {AlignContent::Stretch};
+	JustifyContent justifyContent {JustifyContent::Stretch};
+
+	std::vector<GridArea> gridAreas; // Optional: one per child, defines grid area (span)
+};
+
+//------------------------------------------------------------------------
+/** grid view layouter
+ *
+ *	@ingroup new_in_4_15
+ */
+class GridLayouter : public IViewLayouter,
+					 public NonAtomicReferenceCounted
+{
+public:
+	using LayoutData = std::vector<std::pair<CRect, std::optional<ViewLayout>>>;
+
+	GridLayouter (const GridLayoutProperties& props = {});
+
+	void setProperties (const GridLayoutProperties& props);
+	const GridLayoutProperties& getProperties () const;
+	GridLayoutProperties& getProperties ();
+
+	bool applyLayout (CViewContainer& container, const Children& children,
+					  const ViewLayout& layout) override;
+	std::optional<ViewLayout> calculateLayout (const CViewContainer& view, const Children& children,
+											   const CRect& newSize) override;
+
+private:
+	static constexpr auto kAutoSize = std::numeric_limits<CCoord>::min ();
+
+	std::vector<CCoord> calculateAutoRows (CCoord& usedRowHeight, CCoord availableHeight,
+										   size_t& outNumAutoRows) const;
+	std::vector<CCoord> calculateAutoColumns (CCoord& usedColWidth, CCoord availableWidth,
+											  size_t& outNumAutoCols) const;
+
+	GridLayoutProperties gridProps;
+};
+
+//------------------------------------------------------------------------
+} // namespace VSTGUI