SL-9774 [Render] dragging active Second Life session to second monitor zooms in making viewer unusable

indra/llwindow/llopenglview-objc.mm

@@ -167,6 +167,9 @@ attributedStringInfo getSegments(NSAttributedString *str)
     [[NSNotificationCenter defaultCenter] addObserver:self
 											 selector:@selector(windowDidBecomeKey:) name:NSWindowDidBecomeKeyNotification
 											   object:[self window]];
+	[[NSNotificationCenter defaultCenter] addObserver:self
+											 selector:@selector(windowDidChangeScreen:) name:NSWindowDidChangeScreenNotification
+											   object:[self window]];
 
 
     NSRect wnd_rect = [[self window] frame];
@@ -206,6 +209,11 @@ attributedStringInfo getSegments(NSAttributedString *str)
     mModifiers = [NSEvent modifierFlags];
 }
 
+-(void)windowDidChangeScreen:(NSNotification *)notification;
+{
+	callWindowDidChangeScreen();
+}
+
 - (void)dealloc
 {
 	[[NSNotificationCenter defaultCenter] removeObserver:self];

indra/llwindow/llwindowcallbacks.cpp

@@ -180,6 +180,11 @@ BOOL LLWindowCallbacks::handleDPIChanged(LLWindow *window, F32 ui_scale_factor,
 	return FALSE;
 }
 
+BOOL LLWindowCallbacks::handleWindowDidChangeScreen(LLWindow *window)
+{
+	return FALSE;
+}
+
 void LLWindowCallbacks::handlePingWatchdog(LLWindow *window, const char * msg)
 {
 

indra/llwindow/llwindowcallbacks.h

@@ -66,6 +66,7 @@ public:
 	virtual BOOL handleTimerEvent(LLWindow *window);
 	virtual BOOL handleDeviceChange(LLWindow *window);
 	virtual BOOL handleDPIChanged(LLWindow *window, F32 ui_scale_factor, S32 window_width, S32 window_height);
+	virtual BOOL handleWindowDidChangeScreen(LLWindow *window);
 
 	enum DragNDropAction {
 		DNDA_START_TRACKING = 0,// Start tracking an incoming drag

indra/llwindow/llwindowmacosx-objc.h

@@ -147,6 +147,7 @@ void callWindowFocus();
 void callWindowUnfocus();
 void callWindowHide();
 void callWindowUnhide();
+void callWindowDidChangeScreen();
 void callDeltaUpdate(float *delta, unsigned int mask);
 void callMiddleMouseDown(float *pos, unsigned int mask);
 void callMiddleMouseUp(float *pos, unsigned int mask);

indra/llwindow/llwindowmacosx.cpp

@@ -400,6 +400,14 @@ void callWindowUnhide()
 	}
 }
 
+void callWindowDidChangeScreen()
+{
+	if ( gWindowImplementation && gWindowImplementation->getCallbacks() )
+	{
+		gWindowImplementation->getCallbacks()->handleWindowDidChangeScreen(gWindowImplementation);
+	}
+}
+
 void callDeltaUpdate(float *delta, MASK mask)
 {
 	gWindowImplementation->updateMouseDeltas(delta);

indra/newview/llviewerwindow.cpp

@@ -1607,6 +1607,14 @@ BOOL LLViewerWindow::handleDPIChanged(LLWindow *window, F32 ui_scale_factor, S32
     }
 }
 
+BOOL LLViewerWindow::handleWindowDidChangeScreen(LLWindow *window)
+{
+	LLCoordScreen window_rect;
+	mWindow->getSize(&window_rect);
+	reshape(window_rect.mX, window_rect.mY);
+	return TRUE;
+}
+
 void LLViewerWindow::handlePingWatchdog(LLWindow *window, const char * msg)
 {
 	LLAppViewer::instance()->pingMainloopTimeout(msg);

indra/newview/llviewerwindow.h

@@ -212,6 +212,7 @@ public:
 	/*virtual*/ BOOL handleTimerEvent(LLWindow *window);
 	/*virtual*/ BOOL handleDeviceChange(LLWindow *window);
 	/*virtual*/ BOOL handleDPIChanged(LLWindow *window, F32 ui_scale_factor, S32 window_width, S32 window_height);
+	/*virtual*/ BOOL handleWindowDidChangeScreen(LLWindow *window);
 
 	/*virtual*/ void handlePingWatchdog(LLWindow *window, const char * msg);
 	/*virtual*/ void handlePauseWatchdog(LLWindow *window);