Fix drag&drop between window on Windows

akien-mga · Aug 16, 2024 · 0987a9d · 0987a9d
1 parent 5b6d9a7
commit 0987a9d
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/platform/windows/display_server_windows.cpp b/platform/windows/display_server_windows.cpp
@@ -4805,6 +4805,16 @@ LRESULT DisplayServerWindows::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARA
 				Input::get_singleton()->parse_input_event(mbd);
 			}
 
+			// Propagate the button up event to the window on which the button down
+			// event was triggered. This is needed for drag & drop to work between windows,
+			// because the engine expects events to keep being processed
+			// on the same window dragging started.
+			if (mb->is_pressed()) {
+				last_mouse_button_down_window = window_id;
+			} else if (last_mouse_button_down_window != INVALID_WINDOW_ID) {
+				mb->set_window_id(last_mouse_button_down_window);
+				last_mouse_button_down_window = INVALID_WINDOW_ID;
+			}
 		} break;
 
 		case WM_WINDOWPOSCHANGED: {

diff --git a/platform/windows/display_server_windows.h b/platform/windows/display_server_windows.h
@@ -531,7 +531,7 @@ class DisplayServerWindows : public DisplayServer {
 	RBMap<WindowID, WindowData> windows;
 
 	WindowID last_focused_window = INVALID_WINDOW_ID;
-
+	WindowID last_mouse_button_down_window = INVALID_WINDOW_ID;
 	HCURSOR hCursor;
 
 	WNDPROC user_proc = nullptr;