decorations: Decoration Positioner (#3800)

src/render/decorations/DecorationPositioner.hpp

@@ -0,0 +1,96 @@
+#pragma once
+
+#include <cstdint>
+#include <memory>
+#include <vector>
+#include <unordered_map>
+#include "../../helpers/Box.hpp"
+
+class CWindow;
+class IHyprWindowDecoration;
+
+enum eDecorationPositioningPolicy
+{
+    DECORATION_POSITION_ABSOLUTE = 0, /* Decoration does not interfere with anything else */
+    DECORATION_POSITION_STICKY,       /* Decoration is stuck to some edge of a window */
+};
+
+enum eDecorationEdges
+{
+    DECORATION_EDGE_TOP    = 1 << 0,
+    DECORATION_EDGE_BOTTOM = 1 << 1,
+    DECORATION_EDGE_LEFT   = 1 << 2,
+    DECORATION_EDGE_RIGHT  = 1 << 3
+};
+
+/*
+Request the positioner to position a decoration
+
+DECORATION_POSITION_ABSOLUTE:
+    - desiredExtents may contain the extents to be used when reserved is set. Edges has to have the edges used.
+DECORATION_POSITION_STICKY:
+    - one edge allowed
+    - priority allowed
+    - desiredExtents contains the desired extents. Any other edge than the one selected is ignored.
+    - reserved is allowed
+*/
+struct SDecorationPositioningInfo {
+    eDecorationPositioningPolicy policy   = DECORATION_POSITION_ABSOLUTE;
+    uint32_t                     edges    = 0;  // enum eDecorationEdges
+    uint32_t                     priority = 10; // priority, decos will be evaluated high -> low
+    SWindowDecorationExtents     desiredExtents;
+    bool                         reserved = false; // if true, geometry will use reserved area
+};
+
+/*
+A reply from the positioner. This may be sent multiple times, if anything changes.
+
+DECORATION_POSITION_ABSOLUTE:
+    - assignedGeometry is empty
+DECORATION_POSITION_STICKY:
+    - assignedGeometry is relative to the edge's center point
+    - ephemeral is sent
+*/
+struct SDecorationPositioningReply {
+    CBox assignedGeometry;
+    bool ephemeral = false; // if true, means it's a result of an animation and will change soon.
+};
+
+class CDecorationPositioner {
+  public:
+    CDecorationPositioner();
+
+    Vector2D getEdgeDefinedPoint(uint32_t edges, CWindow* pWindow);
+
+    // called on resize, or insert/removal of a new deco
+    void                     onWindowUpdate(CWindow* pWindow);
+    void                     uncacheDecoration(IHyprWindowDecoration* deco);
+    SWindowDecorationExtents getWindowDecorationReserved(CWindow* pWindow);
+    SWindowDecorationExtents getWindowDecorationExtents(CWindow* pWindow, bool inputOnly = false);
+    CBox                     getBoxWithIncludedDecos(CWindow* pWindow);
+    void                     repositionDeco(IHyprWindowDecoration* deco);
+    CBox                     getWindowDecorationBox(IHyprWindowDecoration* deco);
+
+  private:
+    struct SWindowPositioningData {
+        CWindow*                    pWindow     = nullptr;
+        IHyprWindowDecoration*      pDecoration = nullptr;
+        SDecorationPositioningInfo  positioningInfo;
+        SDecorationPositioningReply lastReply;
+        bool                        needsReposition = true;
+    };
+
+    struct SWindowData {
+        Vector2D                 lastWindowSize = {};
+        SWindowDecorationExtents reserved       = {};
+        SWindowDecorationExtents extents        = {};
+    };
+
+    std::unordered_map<CWindow*, SWindowData>            m_mWindowDatas;
+    std::vector<std::unique_ptr<SWindowPositioningData>> m_vWindowPositioningDatas;
+
+    SWindowPositioningData*                              getDataFor(IHyprWindowDecoration* pDecoration, CWindow* pWindow);
+    void                                                 onWindowUnmap(CWindow* pWindow);
+};
+
+inline std::unique_ptr<CDecorationPositioner> g_pDecorationPositioner;