Add `WINDOW_FLAG_MOUSE_PASSTHROUGH` flag and enabled it for tooltips. Expose `window_set_mouse_passthrough` to `Window`.

2 files changed, 17 insertions, 1 deletions

diff --git a/platform/windows/display_server_windows.cpp b/platform/windows/display_server_windows.cpp
index 969bcc3841..914cd07b50 100644
--- a/platform/windows/display_server_windows.cpp
+++ b/platform/windows/display_server_windows.cpp
@@ -735,6 +735,9 @@ DisplayServer::WindowID DisplayServerWindows::create_sub_window(WindowMode p_mod
 	if (p_flags & WINDOW_FLAG_NO_FOCUS_BIT) {
 		wd.no_focus = true;
 	}
+	if (p_flags & WINDOW_FLAG_MOUSE_PASSTHROUGH_BIT) {
+		wd.mpass = true;
+	}
 	if (p_flags & WINDOW_FLAG_POPUP_BIT) {
 		wd.is_popup = true;
 	}
@@ -918,7 +921,7 @@ void DisplayServerWindows::window_set_mouse_passthrough(const Vector<Vector2> &p
 void DisplayServerWindows::_update_window_mouse_passthrough(WindowID p_window) {
 	ERR_FAIL_COND(!windows.has(p_window));
 
-	if (windows[p_window].mpath.size() == 0) {
+	if (windows[p_window].mpass || windows[p_window].mpath.size() == 0) {
 		SetWindowRgn(windows[p_window].hWnd, nullptr, TRUE);
 	} else {
 		POINT *points = (POINT *)memalloc(sizeof(POINT) * windows[p_window].mpath.size());
@@ -1499,6 +1502,10 @@ void DisplayServerWindows::window_set_flag(WindowFlags p_flag, bool p_enabled, W
 			wd.no_focus = p_enabled;
 			_update_window_style(p_window);
 		} break;
+		case WINDOW_FLAG_MOUSE_PASSTHROUGH: {
+			wd.mpass = p_enabled;
+			_update_window_mouse_passthrough(p_window);
+		} break;
 		case WINDOW_FLAG_POPUP: {
 			ERR_FAIL_COND_MSG(p_window == MAIN_WINDOW_ID, "Main window can't be popup.");
 			ERR_FAIL_COND_MSG(IsWindowVisible(wd.hWnd) && (wd.is_popup != p_enabled), "Popup flag can't changed while window is opened.");
@@ -1530,6 +1537,9 @@ bool DisplayServerWindows::window_get_flag(WindowFlags p_flag, WindowID p_window
 		case WINDOW_FLAG_NO_FOCUS: {
 			return wd.no_focus;
 		} break;
+		case WINDOW_FLAG_MOUSE_PASSTHROUGH: {
+			return wd.mpass;
+		} break;
 		case WINDOW_FLAG_POPUP: {
 			return wd.is_popup;
 		} break;
@@ -2464,6 +2474,11 @@ LRESULT DisplayServerWindows::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARA
 
 	// Process window messages.
 	switch (uMsg) {
+		case WM_NCHITTEST: {
+			if (windows[window_id].mpass) {
+				return HTTRANSPARENT;
+			}
+		} break;
 		case WM_MOUSEACTIVATE: {
 			if (windows[window_id].no_focus) {
 				return MA_NOACTIVATEANDEAT; // Do not activate, and discard mouse messages.
diff --git a/platform/windows/display_server_windows.h b/platform/windows/display_server_windows.h
index 84f2dee35e..ce4b94af59 100644
--- a/platform/windows/display_server_windows.h
+++ b/platform/windows/display_server_windows.h
@@ -370,6 +370,7 @@ class DisplayServerWindows : public DisplayServer {
 		bool window_has_focus = false;
 		bool exclusive = false;
 		bool context_created = false;
+		bool mpass = false;
 
 		// Used to transfer data between events using timer.
 		WPARAM saved_wparam;