Drag and Drop: rework RenderDragDropTargetRect() into RenderDragDropTargetRectForItem() and add RenderDragDropTargetRectEx(). (#1603, #5204)

imgui.cpp

@@ -14793,7 +14793,7 @@ const ImGuiPayload* ImGui::AcceptDragDropPayload(const char* type, ImGuiDragDrop
     payload.Preview = was_accepted_previously;
     flags |= (g.DragDropSourceFlags & ImGuiDragDropFlags_AcceptNoDrawDefaultRect); // Source can also inhibit the preview (useful for external sources that live for 1 frame)
     if (!(flags & ImGuiDragDropFlags_AcceptNoDrawDefaultRect) && payload.Preview)
-        RenderDragDropTargetRect(r, g.DragDropTargetClipRect);
+        RenderDragDropTargetRectForItem(r);
 
     g.DragDropAcceptFrameCount = g.FrameCount;
     if ((g.DragDropSourceFlags & ImGuiDragDropFlags_SourceExtern) && g.DragDropMouseButton == -1)
@@ -14809,21 +14809,26 @@ const ImGuiPayload* ImGui::AcceptDragDropPayload(const char* type, ImGuiDragDrop
 }
 
 // FIXME-STYLE FIXME-DRAGDROP: Settle on a proper default visuals for drop target.
-void ImGui::RenderDragDropTargetRect(const ImRect& bb, const ImRect& item_clip_rect)
+void ImGui::RenderDragDropTargetRectForItem(const ImRect& bb)
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
     ImRect bb_display = bb;
-    bb_display.ClipWith(item_clip_rect); // Clip THEN expand so we have a way to visualize that target is not entirely visible.
+    bb_display.ClipWith(g.DragDropTargetClipRect); // Clip THEN expand so we have a way to visualize that target is not entirely visible.
     bb_display.Expand(3.5f);
     bool push_clip_rect = !window->ClipRect.Contains(bb_display);
     if (push_clip_rect)
         window->DrawList->PushClipRectFullScreen();
-    window->DrawList->AddRect(bb_display.Min, bb_display.Max, GetColorU32(ImGuiCol_DragDropTarget), 0.0f, 0, 2.0f); // FIXME-DPI
+    RenderDragDropTargetRectEx(window->DrawList, bb_display);
     if (push_clip_rect)
         window->DrawList->PopClipRect();
 }
 
+void ImGui::RenderDragDropTargetRectEx(ImDrawList* draw_list, const ImRect& bb)
+{
+    draw_list->AddRect(bb.Min, bb.Max, GetColorU32(ImGuiCol_DragDropTarget), 0.0f, 0, 2.0f); // FIXME-DPI
+}
+
 const ImGuiPayload* ImGui::GetDragDropPayload()
 {
     ImGuiContext& g = *GImGui;

imgui_internal.h

@@ -3423,7 +3423,8 @@ namespace ImGui
     IMGUI_API bool          BeginDragDropTargetCustom(const ImRect& bb, ImGuiID id);
     IMGUI_API void          ClearDragDrop();
     IMGUI_API bool          IsDragDropPayloadBeingAccepted();
-    IMGUI_API void          RenderDragDropTargetRect(const ImRect& bb, const ImRect& item_clip_rect);
+    IMGUI_API void          RenderDragDropTargetRectForItem(const ImRect& bb);
+    IMGUI_API void          RenderDragDropTargetRectEx(ImDrawList* draw_list, const ImRect& bb);
 
     // Typing-Select API
     // (provide Windows Explorer style "select items by typing partial name" + "cycle through items by typing same letter" feature)