Add support for multi resolution icons

skia/ext/skia_utils_mac.mm

 // Copyright (c) 2011 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.
 
 #include "skia/ext/skia_utils_mac.h"
 
 #import <AppKit/AppKit.h>
 
 #include "base/logging.h"
 #include "base/mac/scoped_cftyperef.h"
+#include "base/memory/scoped_nsobject.h"
 #include "base/memory/scoped_ptr.h"
 #include "skia/ext/bitmap_platform_device_mac.h"
 #include "third_party/skia/include/utils/mac/SkCGUtils.h"
 
 namespace gfx {
 
 CGAffineTransform SkMatrixToCGAffineTransform(const SkMatrix& matrix) {
   // CGAffineTransforms don't support perspective transforms, so make sure
   // we don't get those.
   DCHECK(matrix[SkMatrix::kMPersp0] == 0.0f);
@@ skipping 88 matching lines @@
   CGContextDrawImage(context, rect, image);
 
   // Because |device| will be cleaned up and will take its pixels with it, we
   // copy it to the stack and return it.
   SkBitmap bitmap = device->accessBitmap(false);
 
   return bitmap;
 }
 
 SkBitmap NSImageToSkBitmap(NSImage* image, NSSize size, bool is_opaque) {
+  return NSImageRepToSkBitmap([image bestRepresentationForDevice:nil],
+                              size, is_opaque);
+}
+
+SkBitmap NSImageRepToSkBitmap(NSImageRep* image, NSSize size, bool is_opaque) {
   SkBitmap bitmap;
   bitmap.setConfig(SkBitmap::kARGB_8888_Config, size.width, size.height);
-  if (bitmap.allocPixels() != true)
+  if (!bitmap.allocPixels())
     return bitmap;  // Return |bitmap| which should respond true to isNull().
 
   bitmap.setIsOpaque(is_opaque);
 
   base::mac::ScopedCFTypeRef<CGColorSpaceRef> color_space(
-    CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB));
+      CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB));
   void* data = bitmap.getPixels();
 
   // Allocate a bitmap context with 4 components per pixel (BGRA). Apple
   // recommends these flags for improved CG performance.
 #define HAS_ARGB_SHIFTS(a, r, g, b) \
             (SK_A32_SHIFT == (a) && SK_R32_SHIFT == (r) \
              && SK_G32_SHIFT == (g) && SK_B32_SHIFT == (b))
 #if defined(SK_CPU_LENDIAN) && HAS_ARGB_SHIFTS(24, 16, 8, 0)
   base::mac::ScopedCFTypeRef<CGContextRef> context(
     CGBitmapContextCreate(data, size.width, size.height, 8, size.width*4,
                           color_space,
                           kCGImageAlphaPremultipliedFirst |
                               kCGBitmapByteOrder32Host));
 #else
 #error We require that Skia's and CoreGraphics's recommended \
        image memory layout match.
 #endif
 #undef HAS_ARGB_SHIFTS
 
   // Something went really wrong. Best guess is that the bitmap data is invalid.
-  DCHECK(context != NULL);
+  DCHECK(context);
 
   // Save the current graphics context so that we can restore it later.
   [NSGraphicsContext saveGraphicsState];
 
   // Dummy context that we will draw into.
   NSGraphicsContext* context_cocoa =
-    [NSGraphicsContext graphicsContextWithGraphicsPort:context flipped:NO];
+      [NSGraphicsContext graphicsContextWithGraphicsPort:context flipped:NO];
   [NSGraphicsContext setCurrentContext:context_cocoa];
 
   // This will stretch any images to |size| if it does not fit or is non-square.
-  [image drawInRect:NSMakeRect(0, 0, size.width, size.height)
-           fromRect:NSZeroRect
-          operation:NSCompositeCopy
-           fraction:1.0];
+  [image drawInRect:NSMakeRect(0, 0, size.width, size.height)];
 
   // Done drawing, restore context.
   [NSGraphicsContext restoreGraphicsState];
 
   return bitmap;
 }
 
 NSImage* SkBitmapToNSImageWithColorSpace(const SkBitmap& skiaBitmap,
                                          CGColorSpaceRef colorSpace) {
   if (skiaBitmap.isNull())
     return nil;
 
   // First convert SkBitmap to CGImageRef.
-  CGImageRef cgimage =
-    SkCreateCGImageRefWithColorspace(skiaBitmap, colorSpace);
+  base::mac::ScopedCFTypeRef<CGImageRef> cgimage(
+      SkCreateCGImageRefWithColorspace(skiaBitmap, colorSpace));
 
   // Now convert to NSImage.
-  NSBitmapImageRep* bitmap = [[[NSBitmapImageRep alloc]
-                                   initWithCGImage:cgimage] autorelease];
-  CFRelease(cgimage);
+  scoped_nsobject<NSBitmapImageRep> bitmap(
+      [[NSBitmapImageRep alloc] initWithCGImage:cgimage]);
   NSImage* image = [[[NSImage alloc] init] autorelease];
   [image addRepresentation:bitmap];
   [image setSize:NSMakeSize(skiaBitmap.width(), skiaBitmap.height())];
   return image;
 }
 
 NSImage* SkBitmapToNSImage(const SkBitmap& skiaBitmap) {
   base::mac::ScopedCFTypeRef<CGColorSpaceRef> colorSpace(
       CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB));
   return SkBitmapToNSImageWithColorSpace(skiaBitmap, colorSpace.get());
 }
 
+NSImage* SkBitmapsToNSImage(const std::vector<const SkBitmap*>& bitmaps) {
+  if (bitmaps.empty())
+    return nil;
+
+  base::mac::ScopedCFTypeRef<CGColorSpaceRef> color_space(
+      CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB));
+  NSImage* image = [[[NSImage alloc] init] autorelease];
+  NSSize min_size = NSZeroSize;
+
+  for (std::vector<const SkBitmap*>::const_iterator it = bitmaps.begin();
+       it != bitmaps.end(); ++it) {
+    const SkBitmap& skiaBitmap = **it;
+    // First convert SkBitmap to CGImageRef.
+    base::mac::ScopedCFTypeRef<CGImageRef> cgimage(
+        SkCreateCGImageRefWithColorspace(skiaBitmap, color_space));
+
+    // Now convert to NSImage.
+    scoped_nsobject<NSBitmapImageRep> bitmap(
+        [[NSBitmapImageRep alloc] initWithCGImage:cgimage]);
+    [image addRepresentation:bitmap];
+
+    if (min_size.width == 0 || min_size.width > skiaBitmap.width()) {
+      min_size.width = skiaBitmap.width();
+      min_size.height = skiaBitmap.height();
+    }
+  }
+
+  [image setSize:min_size];
+  return image;
+}
+
 SkBitmap AppplicationIconAtSize(int size) {
   NSImage* image = [NSImage imageNamed:@"NSApplicationIcon"];
   return NSImageToSkBitmap(image, NSMakeSize(size, size), /* is_opaque=*/true);
 }
 
 }  // namespace gfx