update the layer's scale when the screen changes

github · Apr 9, 2012 · 1e6362a · 1e6362a
1 parent fcb1553
commit 1e6362a
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Showing 4 changed files with 48 additions and 17 deletions.
diff --git a/lib/UIKit/TUINSView.m b/lib/UIKit/TUINSView.m
@@ -23,6 +23,7 @@
 @interface TUINSView ()
 - (void)windowDidResignKey:(NSNotification *)notification;
 - (void)windowDidBecomeKey:(NSNotification *)notification;
+- (void)screenDidChange:(NSNotification *)notification;
 @end
 
 
@@ -159,7 +160,11 @@ - (void)setNextResponder:(NSResponder *)r
 }
 
 - (void)viewWillMoveToWindow:(NSWindow *)newWindow {
-	[[NSNotificationCenter defaultCenter] removeObserver:self name:NSWindowDidResignKeyNotification object:self.window];
+	if(self.window != nil) {
+		[[NSNotificationCenter defaultCenter] removeObserver:self name:NSWindowDidBecomeKeyNotification object:self.window];
+		[[NSNotificationCenter defaultCenter] removeObserver:self name:NSWindowDidResignKeyNotification object:self.window];
+		[[NSNotificationCenter defaultCenter] removeObserver:self name:NSWindowDidChangeScreenNotification object:self.window];
+	}
 
 	if(newWindow != nil && rootView.layer.superlayer != [self layer]) {
 		rootView.layer.frame = self.layer.bounds;
@@ -179,8 +184,11 @@ - (void)viewDidMoveToWindow
 
 	[self.rootView didMoveToWindow];
 
-	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(windowDidResignKey:) name:NSWindowDidResignKeyNotification object:self.window];
-	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(windowDidBecomeKey:) name:NSWindowDidBecomeKeyNotification object:self.window];
+	if(self.window != nil) {
+		[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(windowDidResignKey:) name:NSWindowDidResignKeyNotification object:self.window];
+		[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(windowDidBecomeKey:) name:NSWindowDidBecomeKeyNotification object:self.window];
+		[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(screenDidChange:) name:NSWindowDidChangeScreenNotification object:self.window];
+	}
 }
 
 - (void)_updateLayerScaleFactor {
@@ -191,11 +199,24 @@ - (void)_updateLayerScaleFactor {
 		}
 
 		if([self.layer respondsToSelector:@selector(setContentsScale:)]) {
-			self.layer.contentsScale = scale;
+			if(fabs(self.layer.contentsScale - scale) > 0.1f) {
+				self.layer.contentsScale = scale;
+			}
 		}
+
+		[self.rootView _updateLayerScaleFactor];
 	}
 }
 
+- (void)screenDidChange:(NSNotification *)notification {
+	// at the time this is called, the window's backing scale hasn't been updated for the new screen
+	[self performSelector:@selector(backingScaleMayHaveChanged) withObject:nil afterDelay:0];
+}
+
+- (void)backingScaleMayHaveChanged {
+	[self _updateLayerScaleFactor];
+}
+
 - (TUIView *)viewForLocalPoint:(NSPoint)p
 {
 	return [rootView hitTest:p withEvent:nil];

diff --git a/lib/UIKit/TUIView+Private.h b/lib/UIKit/TUIView+Private.h
@@ -23,4 +23,6 @@
 
 - (TUITextRenderer *)textRendererAtPoint:(CGPoint)point;
 
+- (void)_updateLayerScaleFactor;
+
 @end
diff --git a/lib/UIKit/TUIView+Private.m b/lib/UIKit/TUIView+Private.m
@@ -52,4 +52,22 @@ - (TUITextRenderer *)textRendererAtPoint:(CGPoint)point
 	return nil;
 }
 
+- (void)_updateLayerScaleFactor {
+	if([self nsWindow] != nil) {
+		[self.subviews makeObjectsPerformSelector:_cmd];
+
+		CGFloat scale = 1.0f;
+		if([[self nsWindow] respondsToSelector:@selector(backingScaleFactor)]) {
+			scale = [[self nsWindow] backingScaleFactor];
+		}
+
+		if([self.layer respondsToSelector:@selector(setContentsScale:)]) {
+			if(fabs(self.layer.contentsScale - scale) > 0.1f) {
+				self.layer.contentsScale = scale;
+				[self.layer setNeedsDisplay];
+			}
+		}
+	}
+}
+
 @end
diff --git a/lib/UIKit/TUIView.m b/lib/UIKit/TUIView.m
@@ -803,21 +803,11 @@ - (void)willMoveToWindow:(TUINSWindow *)newWindow {
 
 	[[NSNotificationCenter defaultCenter] postNotificationName:TUIViewWillMoveToWindowNotification object:self userInfo:newWindow != nil ? [NSDictionary dictionaryWithObject:newWindow forKey:TUIViewWindow] : nil];
 }
+
 - (void)didMoveToWindow {
-	if([self nsWindow] != nil) {
-		CGFloat scale = 1.0f;
-		if([[self nsWindow] respondsToSelector:@selector(backingScaleFactor)]) {
-			scale = [[self nsWindow] backingScaleFactor];
-		}
-
-		if([self.layer respondsToSelector:@selector(setContentsScale:)]) {
-			self.layer.contentsScale = scale;
-		}
-	}
+	[self _updateLayerScaleFactor];
 
-	for(TUIView *subview in self.subviews) {
-		[subview didMoveToWindow];
-	}
+	[self.subviews makeObjectsPerformSelector:_cmd];
 
 	[[NSNotificationCenter defaultCenter] postNotificationName:TUIViewDidMoveToWindowNotification object:self userInfo:self.nsView.window != nil ? [NSDictionary dictionaryWithObject:self.nsView.window forKey:TUIViewWindow] : nil];
 }