* Source/NSWindow.m (initWithContentRect:styleMask:backing:defer:):

added observer of NSApplicationDidChangeScreenParametersNotification.
  (applicationDidChangeScreenParameters:): callback for added notification -
  updates window position, set new screen object and saves frame if
  autosave name exists.

* Source/NSScreen.m (initialize): remove observer of
  NSApplicationDidChangeScreenParametersNotification - NSScreen shouldn't
  do it. Backend explicitely calls -resetScreens before posting notification.
  (_initWithScreenNumber:): ditto.
  (_resetScreens): removed.
  (deviceDescription): removed duplicated addition of NSDeviceSize object.

* Source/NSApplication.m (finishLaunching): remove observer of
  NSApplicationDidChangeScreenParametersNotification.

ChangeLog

@@ -1,3 +1,21 @@
+2020-01-26  Sergii Stoian  <stoyan255@gmail.com>
+
+	* Source/NSWindow.m (initWithContentRect:styleMask:backing:defer:):
+	added observer of NSApplicationDidChangeScreenParametersNotification.
+	(applicationDidChangeScreenParameters:): callback for added notification -
+	updates window position, set new screen object and saves frame if
+	autosave name exists.
+
+	* Source/NSScreen.m (initialize): remove observer of
+	NSApplicationDidChangeScreenParametersNotification - NSScreen shouldn't
+	do it. Backend explicitely calls -resetScreens before posting notification.
+	(_initWithScreenNumber:): ditto.
+	(_resetScreens): removed.
+	(deviceDescription): removed duplicated addition of NSDeviceSize object.
+
+	* Source/NSApplication.m (finishLaunching): remove observer of
+	NSApplicationDidChangeScreenParametersNotification.
+
 2020-01-24  Sergii Stoian  <stoyan255@gmail.com>
 
 	* Source/NSScreen.m (_initWithScreenNumber:): add self as observer to

Source/NSApplication.m

@@ -1100,12 +1100,6 @@ static BOOL _isAutolaunchChecked = NO;
   [nc addObserver: self selector: @selector(_windowDidResignMain:)
       name: NSWindowDidResignMainNotification object: nil];
 
-  /* Register self as observer to window events. */
-  [nc addObserver: self
-         selector: @selector(applicationDidChangeScreenParameters:)
-             name: NSApplicationDidChangeScreenParametersNotification
-           object: nil];
-
   /* register as observer for hide/unhide notifications */
   [[[NSWorkspace sharedWorkspace] notificationCenter]
     addObserver: self selector: @selector(_workspaceNotification:)

Source/NSScreen.m

@@ -60,12 +60,7 @@
   if (self == [NSScreen class])
     {
       [self setVersion: 1];
-      [[NSNotificationCenter defaultCenter]
-          addObserver: self
-          selector: @selector(_resetScreens:)
-          name: NSApplicationDidChangeScreenParametersNotification
-          object: nil];
-     }
+    }
 }
 
 static NSMutableArray *screenArray = nil;
@@ -73,11 +68,6 @@ static NSMutableArray *screenArray = nil;
 /**
  * Resets the cached list of screens.
  */
-+ (void) _resetScreens: (NSNotification*)notification
-{
-  [self resetScreens];
-}
-
 + (void) resetScreens
 {
   DESTROY(screenArray);
@@ -228,14 +218,6 @@ static NSMutableArray *screenArray = nil;
   _depth = [srv windowDepthForScreen: _screenNumber];
   _supportedWindowDepths = NULL;
 
-  /* Register self as observer to screen events. */
-  [[NSNotificationCenter defaultCenter]
-    addObserver: self
-       selector: @selector(applicationDidChangeScreenParameters:)
-           name: NSApplicationDidChangeScreenParametersNotification
-         object: nil];
-
-
   return self;
 }
 
@@ -325,10 +307,6 @@ static NSMutableArray *screenArray = nil;
       [devDesc setObject: colorSpaceName
 		  forKey: NSDeviceColorSpaceName];
 		    
-      // Add size. For screen it's resolution (e.g. 1600x1200).
-      [devDesc setObject: [NSValue valueWithSize: [self frame].size]
-		  forKey: NSDeviceSize];
-
       _reserved = (void*)[devDesc copy];
       RELEASE(devDesc);
     }
@@ -416,7 +394,7 @@ static NSMutableArray *screenArray = nil;
 // Release the memory for the depths array.
 - (void) dealloc
 {
-  [[NSNotificationCenter defaultCenter] removeObserver: self];
+  NSLog(@"[NSScreen] dealloc");
   // _supportedWindowDepths can be NULL since it may or may not
   // be necessary to get this info.  The most common use of NSScreen
   // is to get the depth and frame attributes.
@@ -461,16 +439,6 @@ static NSMutableArray *screenArray = nil;
   return 1.0;
 }
 
-// This notification callback shouldn't be called. But some objects (NSWindow)
-// may retain NSScren instance and not handle screen parameters changes.
-// Update our ivars for them.
-- (void) applicationDidChangeScreenParameters: (NSNotification*)aNotification
-{
-  GSDisplayServer *srv = GSCurrentServer();
-  _frame = [srv boundsForScreen: _screenNumber];
-  _depth = [srv windowDepthForScreen: _screenNumber];
-}
-
 @end
 
 

Source/NSWindow.m

@@ -1106,6 +1106,10 @@ many times.
          selector: @selector(colorListChanged:)
              name: NSColorListDidChangeNotification
            object: nil];
+  [nc addObserver: self
+         selector: @selector(applicationDidChangeScreenParameters:)
+             name: NSApplicationDidChangeScreenParametersNotification
+           object: NSApp];
 
   NSDebugLLog(@"NSWindow", @"NSWindow end of init\n");
   return self;
@@ -2701,6 +2705,44 @@ titleWithRepresentedFilename(NSString *representedFilename)
   return _screen;
 }
 
+- (void) applicationDidChangeScreenParameters: (NSNotification *)aNotif
+{
+  NSSize oldScreenSize = [_screen frame].size;
+  int    screenNumber = [_screen screenNumber];
+  NSSize newScreenSize;
+  NSRect newFrame;
+
+  // NSLog(@"[NSWindow - %@] Old/New Screen RC: %lu/%lu",
+  //       [self className], [_screen retainCount],
+  //       [[[NSScreen screens] objectAtIndex: 0] retainCount]);
+  // We need to get new screen from renewed screen list because
+  // [NSScreen mainScreen] returns NSScreen object of key window and that object
+  // will never be released.
+  for (NSScreen *scr in [NSScreen screens])
+    {
+      if ([scr screenNumber] == screenNumber)
+        ASSIGN(_screen, scr);
+    }
+  
+  // Do not adjust frame for mini and appicon windows - it's a WM's job. 
+  if ([self isKindOfClass: [NSMiniWindow class]] || self == [NSApp iconWindow])
+    return;
+
+  newScreenSize = [_screen frame].size;
+
+  // NSLog(@"[NSWindow - %@] Old/New Screen (%lu): %.0f/%.0f",
+  //       [self className], [_screen retainCount],
+  //       oldScreenSize.width, newScreenSize.width);
+
+  newFrame = _frame;
+  newFrame.origin.y += newScreenSize.height - oldScreenSize.height;
+  [self setFrame: newFrame display: NO];
+  if (_autosaveName != nil)
+    {
+      [self saveFrameUsingName: _autosaveName];
+    }
+}
+
 - (void) setDepthLimit: (NSWindowDepth)limit
 {
   if (limit == 0)