[Mac] Use a custom view to implement colored app windows.

chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm

Index: chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm b/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
index cd978fb1db12e2cb354d6576e75c2fb97257a1b4..9dc6c7638b7b25c33ded1254aefdf6470d72fe8d 100644
--- a/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
@@ -51,6 +51,8 @@ using extensions::AppWindow;
 
 namespace {
 
+const CGFloat kTitlebarBackgroundViewPaintHeight = 60.0;
+
 void SetFullScreenCollectionBehavior(NSWindow* window, bool allow_fullscreen) {
   NSWindowCollectionBehavior behavior = [window collectionBehavior];
   if (allow_fullscreen)
@@ -208,71 +210,19 @@ std::vector<gfx::Rect> CalculateNonDraggableRegions(
 
 @end
 
-// This is really a method on NSGrayFrame, so it should only be called on the
-// view passed into -[NSWindow drawCustomFrameRect:forView:].
-@interface NSView (PrivateMethods)
-- (CGFloat)roundedCornerRadius;
-@end
-
-// TODO(jamescook): Should these be AppNSWindow to match AppWindow?
-// http://crbug.com/344082
-@interface ShellNSWindow : ChromeEventProcessingWindow
-@end
-@implementation ShellNSWindow
-
-// Similar to ChromeBrowserWindow, don't draw the title, but allow it to be seen
-// in menus, Expose, etc.
-- (BOOL)_isTitleHidden {
-  return YES;
-}
-
-- (void)drawCustomFrameRect:(NSRect)frameRect forView:(NSView*)view {
-  // Make the background color of the content area white. We can't just call
-  // -setBackgroundColor as that causes the title bar to be drawn in a solid
-  // color.
-  NSRect rect = [self contentRectForFrameRect:frameRect];
-  [[NSColor whiteColor] set];
-  NSRectFill(rect);
-
-  // Draw the native title bar. We remove the content area since the native
-  // implementation draws a gray background.
-  rect.origin.y = NSMaxY(rect);
-  rect.size.height = CGFLOAT_MAX;
-  rect = NSIntersectionRect(rect, frameRect);
-
-  [NSBezierPath clipRect:rect];
-  [super drawCustomFrameRect:frameRect
-                     forView:view];
-}
-
-@end
-
-@interface ShellCustomFrameNSWindow : ShellNSWindow {
- @private
-  base::scoped_nsobject<NSColor> color_;
-  base::scoped_nsobject<NSColor> inactiveColor_;
-}
-
-- (void)setColor:(NSColor*)color
-    inactiveColor:(NSColor*)inactiveColor;
-
-@end
-
-@implementation ShellCustomFrameNSWindow
+@implementation TitlebarBackgroundView
 
-- (void)drawCustomFrameRect:(NSRect)rect forView:(NSView*)view {
-  [[NSBezierPath bezierPathWithRect:rect] addClip];
-  [[NSColor clearColor] set];
-  NSRectFill(rect);
-
-  // Set up our clip.
+- (void)drawRect:(NSRect)rect {
+  // Only the top corners are rounded. For simplicity, round all 4 corners but
+  // draw the bottom corners outside of the visible bounds.
   CGFloat cornerRadius = 4.0;
-  if ([view respondsToSelector:@selector(roundedCornerRadius)])
-    cornerRadius = [view roundedCornerRadius];
-  [[NSBezierPath bezierPathWithRoundedRect:[view bounds]
+  NSRect roundedRect = [self bounds];
+  roundedRect.origin.y -= cornerRadius;
+  roundedRect.size.height += cornerRadius;
+  [[NSBezierPath bezierPathWithRoundedRect:roundedRect
                                    xRadius:cornerRadius
                                    yRadius:cornerRadius] addClip];
-  if ([self isMainWindow] || [self isKeyWindow])
+  if ([[self window] isMainWindow] || [[self window] isKeyWindow])
     [color_ set];
   else
     [inactiveColor_ set];
@@ -280,20 +230,33 @@ std::vector<gfx::Rect> CalculateNonDraggableRegions(
 }
 
 - (void)setColor:(NSColor*)color
-    inactiveColor:(NSColor*)inactiveColor {
+   inactiveColor:(NSColor*)inactiveColor {

[tapted, 2015/02/19 03:11:02]

nit: 4 space indent

[jackhou1, 2015/02/19 04:28:58]

Done.

   color_.reset([color retain]);
   inactiveColor_.reset([inactiveColor retain]);
 }
 
 @end
 
+// TODO(jamescook): Should these be AppNSWindow to match AppWindow?
+// http://crbug.com/344082
+@interface ShellNSWindow : ChromeEventProcessingWindow
+@end
+
+@implementation ShellNSWindow
+
+// Similar to ChromeBrowserWindow, don't draw the title, but allow it to be seen
+// in menus, Expose, etc.
+- (BOOL)_isTitleHidden {
+  return YES;
+}
+
+@end
+
 @interface ShellFramelessNSWindow : ShellNSWindow
 @end
 
 @implementation ShellFramelessNSWindow
 
-- (void)drawCustomFrameRect:(NSRect)rect forView:(NSView*)view {}
-
 + (NSRect)frameRectForContentRect:(NSRect)contentRect
                         styleMask:(NSUInteger)mask {
   return contentRect;
@@ -350,13 +313,8 @@ NativeAppWindowCocoa::NativeAppWindowCocoa(
   Observe(WebContents());
 
   base::scoped_nsobject<NSWindow> window;
-  Class window_class;
-  if (has_frame_) {
-    window_class = has_frame_color_ ?
-        [ShellCustomFrameNSWindow class] : [ShellNSWindow class];
-  } else {
-    window_class = [ShellFramelessNSWindow class];
-  }
+  Class window_class = has_frame_ ?
+      [ShellNSWindow class] : [ShellFramelessNSWindow class];
 
   // Estimate the initial bounds of the window. Once the frame insets are known,
   // the window bounds and constraints can be set precisely.
@@ -375,7 +333,19 @@ NativeAppWindowCocoa::NativeAppWindowCocoa(
   [window setTitle:base::SysUTF8ToNSString(name)];
   [[window contentView] setWantsLayer:YES];
   if (has_frame_ && has_frame_color_) {
-    [base::mac::ObjCCastStrict<ShellCustomFrameNSWindow>(window)
+    NSView* window_view = [[window contentView] superview];

[tapted, 2015/02/19 03:11:02]

can you add a comment here? Something to the effect of ~AppKit only officially
supports adding subviews to the window's contentView and not its superview (an
NSNextStepFrame). The 10.10 SDK offers ... but it doesn't support .... 

[tapted, 2015/02/19 03:11:02]

nit: window_view -> frame_view ?

[jackhou1, 2015/02/19 04:28:58]

Done.

[jackhou1, 2015/02/19 04:28:58]

Done.

+    titlebar_background_view_.reset([[TitlebarBackgroundView alloc]
+        initWithFrame:NSMakeRect(0,

[tapted, 2015/02/19 03:11:02]

since it's autoresized, can you just pass 0 for the width?

[jackhou1, 2015/02/19 04:28:58]

Doesn't seem to work.

+                                 NSMaxY([window_view bounds]) -
+                                     kTitlebarBackgroundViewPaintHeight,
+                                 NSWidth([window_view bounds]),
+                                 kTitlebarBackgroundViewPaintHeight)]);
+    [titlebar_background_view_
+        setAutoresizingMask:NSViewWidthSizable | NSViewMinYMargin];
+    [window_view addSubview:titlebar_background_view_
+                positioned:NSWindowBelow
+                relativeTo:nil];
+    [titlebar_background_view_
              setColor:gfx::SkColorToSRGBNSColor(active_frame_color_)
         inactiveColor:gfx::SkColorToSRGBNSColor(inactive_frame_color_)];
   }
@@ -820,6 +790,7 @@ void NativeAppWindowCocoa::WindowWillClose() {
 }
 
 void NativeAppWindowCocoa::WindowDidBecomeKey() {
+  [titlebar_background_view_ setNeedsDisplay:YES];
   content::RenderWidgetHostView* rwhv =
       WebContents()->GetRenderWidgetHostView();
   if (rwhv)
@@ -837,6 +808,8 @@ void NativeAppWindowCocoa::WindowDidResignKey() {
   if ([NSApp isActive] && ([NSApp keyWindow] == window()))
     return;
 
+  [titlebar_background_view_ setNeedsDisplay:YES];
+
   WebContents()->StoreFocus();
 
   content::RenderWidgetHostView* rwhv =