Drag and Drop: Clear state on EndDragDropTarget() with delivery + fixed handling of overlapping targets when smaller one is submitted before and can accept the same data type. (#6183, #5817)

docs/CHANGELOG.txt

@@ -47,6 +47,10 @@ Breaking Changes:
 
 Other changes:
 
+- Drag and Drop: Fixed handling of overlapping targets when smaller one is submitted
+  before and can accept the same data type. (#6183).
+- Drag and Drop: Clear drag and drop state as soon as delivery is accepted in order to
+  avoid inteferences. (#5817, #6183) [@DimaKoltun]
 - Backends: Win32: Use WM_NCMOUSEMOVE / WM_NCMOUSELEAVE to track mouse positions over
   non-client area (e.g. OS decorations) when app is not focused. (#6045, #6162)
 

imgui.cpp

@@ -12171,12 +12171,13 @@ const ImGuiPayload* ImGui::AcceptDragDropPayload(const char* type, ImGuiDragDrop
     const bool was_accepted_previously = (g.DragDropAcceptIdPrev == g.DragDropTargetId);
     ImRect r = g.DragDropTargetRect;
     float r_surface = r.GetWidth() * r.GetHeight();
-    if (r_surface <= g.DragDropAcceptIdCurrRectSurface)
-    {
-        g.DragDropAcceptFlags = flags;
-        g.DragDropAcceptIdCurr = g.DragDropTargetId;
-        g.DragDropAcceptIdCurrRectSurface = r_surface;
-    }
+    if (r_surface > g.DragDropAcceptIdCurrRectSurface)
+        return NULL;
+
+    g.DragDropAcceptFlags = flags;
+    g.DragDropAcceptIdCurr = g.DragDropTargetId;
+    g.DragDropAcceptIdCurrRectSurface = r_surface;
+    //IMGUI_DEBUG_LOG("AcceptDragDropPayload(): %08X: accept\n", g.DragDropTargetId);
 
     // Render default drop visuals
     payload.Preview = was_accepted_previously;
@@ -12185,10 +12186,11 @@ const ImGuiPayload* ImGui::AcceptDragDropPayload(const char* type, ImGuiDragDrop
         window->DrawList->AddRect(r.Min - ImVec2(3.5f,3.5f), r.Max + ImVec2(3.5f, 3.5f), GetColorU32(ImGuiCol_DragDropTarget), 0.0f, 0, 2.0f);
 
     g.DragDropAcceptFrameCount = g.FrameCount;
-    payload.Delivery = was_accepted_previously && !IsMouseDown(g.DragDropMouseButton); // For extern drag sources affecting os window focus, it's easier to just test !IsMouseDown() instead of IsMouseReleased()
+    payload.Delivery = was_accepted_previously && !IsMouseDown(g.DragDropMouseButton); // For extern drag sources affecting OS window focus, it's easier to just test !IsMouseDown() instead of IsMouseReleased()
     if (!payload.Delivery && !(flags & ImGuiDragDropFlags_AcceptBeforeDelivery))
         return NULL;
 
+    //IMGUI_DEBUG_LOG("AcceptDragDropPayload(): %08X: return payload\n", g.DragDropTargetId);
     return &payload;
 }
 
@@ -12204,13 +12206,16 @@ const ImGuiPayload* ImGui::GetDragDropPayload()
     return (g.DragDropActive && g.DragDropPayload.DataFrameCount != -1) ? &g.DragDropPayload : NULL;
 }
 
-// We don't really use/need this now, but added it for the sake of consistency and because we might need it later.
 void ImGui::EndDragDropTarget()
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(g.DragDropActive);
     IM_ASSERT(g.DragDropWithinTarget);
     g.DragDropWithinTarget = false;
+
+    // Clear drag and drop state payload right after delivery
+    if (g.DragDropPayload.Delivery)
+        ClearDragDrop();
 }
 
 //-----------------------------------------------------------------------------

imgui.h

@@ -23,7 +23,7 @@
 // Library Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals, e.g. '#if IMGUI_VERSION_NUM > 12345')
 #define IMGUI_VERSION               "1.89.4 WIP"
-#define IMGUI_VERSION_NUM           18932
+#define IMGUI_VERSION_NUM           18933
 #define IMGUI_HAS_TABLE
 
 /*