MacViews: Clip contents for non-rectangular windows.

ui/views/cocoa/bridged_content_view.mm

Index: ui/views/cocoa/bridged_content_view.mm
diff --git a/ui/views/cocoa/bridged_content_view.mm b/ui/views/cocoa/bridged_content_view.mm
index 6022a44723bf99d9873d04bd6dcbebdb7bc66697..161614d304d858878448bf771e85b09bff082060 100644
--- a/ui/views/cocoa/bridged_content_view.mm
+++ b/ui/views/cocoa/bridged_content_view.mm
@@ -228,6 +228,7 @@ gfx::Rect GetFirstRectForRangeHelper(const ui::TextInputClient* client,
   hostedView_ = nullptr;
   [cursorTrackingArea_.get() clearOwner];
   [self removeTrackingArea:cursorTrackingArea_.get()];
+  windowMask_.reset();

[tapted, 2016/02/25 08:07:21]

is this needed here? (i.e. was it to fix an error?)

[karandeepb, 2016/03/04 03:01:55]

Not really. This is called here -
https://code.google.com/p/chromium/codesearch#chromium/src/ui/views/cocoa/bri...
and it has a comment to the effect that Cocoa may still have references to the
bridged_view_ object. Hence I thought we should free up windowMask_.

[tapted, 2016/03/04 04:15:01]

That shouldn't be necessary - if windowMask_ referred to some C++ object that
was about to be `delete`d by the caller we would, but since it's on ObjC object
we can just rely on the regular ObjC lifetime. So let's delete this line,
otherwise we're implying there's a more complicated lifetime issue than there
is.

 }
 
 - (void)processCapturedMouseEvent:(NSEvent*)theEvent {
@@ -268,8 +269,6 @@ gfx::Rect GetFirstRectForRangeHelper(const ui::TextInputClient* client,
 }
 
 - (void)updateWindowMask {
-  DCHECK(![self inLiveResize]);
-  DCHECK(base::mac::IsOSMavericksOrEarlier());
   DCHECK(hostedView_);
 
   views::Widget* widget = hostedView_->GetWidget();
@@ -291,6 +290,10 @@ gfx::Rect GetFirstRectForRangeHelper(const ui::TextInputClient* client,
   [windowMask_ transformUsingAffineTransform:flipTransform];
 }
 
+- (NSBezierPath*)windowMask {

[tapted, 2016/02/25 08:07:21]

nit: move up beneath clearView, since it roughly matches the declaration order
(initializers/dealloc should still always be before properties that aren't
synthesized)

[karandeepb, 2016/03/04 03:01:56]

Done.

+  return windowMask_.get();
+}
+
 // BridgedContentView private implementation.
 
 - (void)handleKeyEvent:(NSEvent*)theEvent {
@@ -435,13 +438,11 @@ gfx::Rect GetFirstRectForRangeHelper(const ui::TextInputClient* client,
 - (void)viewDidEndLiveResize {
   [super viewDidEndLiveResize];
 
-  // We prevent updating the window mask and clipping the border around the
-  // view, during a live resize. Hence update the window mask and redraw the
-  // view after resize has completed.
-  if (base::mac::IsOSMavericksOrEarlier()) {
-    [self updateWindowMask];
+  // During a live resize, we prevent clipping the border around the view, which
+  // is required to generate drop shadows on OSX 10.9. Hence redraw the view
+  // after resize has completed.
+  if (base::mac::IsOSMavericksOrEarlier())
     [self setNeedsDisplay:YES];
-  }
 }
 
 - (void)drawRect:(NSRect)dirtyRect {
@@ -464,8 +465,8 @@ gfx::Rect GetFirstRectForRangeHelper(const ui::TextInputClient* client,
   // boundary with clearColor and tell Cococa to regenerate drop shadow. See
   // crbug.com/543671.
   if (windowMask_ && ![self inLiveResize] &&
-      !IsRectInsidePath(dirtyRect, windowMask_)) {
-    DCHECK(base::mac::IsOSMavericksOrEarlier());
+      !IsRectInsidePath(dirtyRect, windowMask_) &&
+      base::mac::IsOSMavericksOrEarlier()) {
     gfx::ScopedNSGraphicsContextSaveGState state;
 
     // The outer rectangular path corresponding to the window.