MacViews: Clip contents for non-rectangular windows.

ui/gfx/path_mac.mm

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ui/gfx/path_mac.h"
 
-#import <Cocoa/Cocoa.h>
-
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/gfx/path.h"
 
 namespace {
 
 // Convert a quadratic bezier curve to a cubic bezier curve. Based on the
 // implementation of the private SkConvertQuadToCubic method inside Skia.
 void ConvertQuadToCubicBezier(NSPoint quad[3], NSPoint cubic[4]) {
   // The resultant cubic will have the same endpoints.
   cubic[0] = quad[0];
@@ skipping 96 matching lines @@
       break;
     case SkPath::kInverseWinding_FillType:
     case SkPath::kInverseEvenOdd_FillType:
       NOTREACHED() << "NSBezierCurve does not support inverse fill types.";
       break;
   }
 
   return result;
 }
 
+base::ScopedCFTypeRef<CGPathRef> CreateCGPathFromNSBezierPath(

[karandeepb, 2016/02/24 04:27:18]

This is slightly inspired from
https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/CocoaD....
Is that ok?

[tapted, 2016/02/24 05:05:03]

I think you can do

#import "third_party/google_toolbox_for_mac/src/AppKit/GTMNSBezierPath+CGPath.h"

in bridged_native_widget.mm then just call -[NSBezierPath gtm_CGPath]


(however, it seems to be missing the bit about the path being closed, so maybe a
helper function in an anonymous namespace is good for that)

[karandeepb, 2016/02/25 03:31:06]

Done. Weird that the src folder doesn't show up on code search -
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/google....

Don't think closing the path is necessary. That is only required during hit
testing. Here we are using the path to fill the mask layer, thereby changing its
alpha channel. And while filling, Quartz treats each subpath as closed.

+    NSBezierPath* path) {
+  base::ScopedCFTypeRef<CGMutablePathRef> result(CGPathCreateMutable());
+  NSPoint points[3];
+  bool path_closed = true;
+  for (int i = 0; i < [path elementCount]; i++) {
+    switch ([path elementAtIndex:i associatedPoints:points]) {
+      case NSMoveToBezierPathElement:
+        CGPathMoveToPoint(result, nullptr, points[0].x, points[0].y);
+        break;
+
+      case NSLineToBezierPathElement:
+        CGPathAddLineToPoint(result, nullptr, points[0].x, points[0].y);
+        path_closed = false;
+        break;
+
+      case NSCurveToBezierPathElement:
+        CGPathAddCurveToPoint(result, nullptr, points[0].x, points[0].y,
+                              points[1].x, points[1].y, points[2].x,
+                              points[2].y);
+        path_closed = false;
+        break;
+
+      case NSClosePathBezierPathElement:
+        CGPathCloseSubpath(result);
+        path_closed = true;
+        break;
+    }
+  }
+
+  // For valid hit detection, path must be closed.
+  if (!path_closed)
+    CGPathCloseSubpath(result);
+
+  // Return immutable copy of result.
+  return base::ScopedCFTypeRef<CGPathRef>(CGPathCreateCopy(result));
+}
+
 }  // namespace gfx