mac: Add tests for reading images from NSPasteboard.

ui/base/clipboard/clipboard_mac_unittest.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/base/clipboard/clipboard_mac.h"
+
+#include "base/mac/scoped_cftyperef.h"
+#include "base/mac/scoped_nsobject.h"
+#include "base/memory/free_deleter.h"
+#include "base/memory/ref_counted.h"
+#include "testing/platform_test.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "ui/base/clipboard/clipboard_types.h"
+#include "ui/base/clipboard/clipboard_util_mac.h"
+
+namespace ui {
+
+class ClipboardMacTest : public PlatformTest {
+ public:
+  ClipboardMacTest() { }
+
+  base::scoped_nsobject<NSImage> CreateImage(int32_t width,
+                                             int32_t height,
+                                             bool retina) {

[Avi (use Gerrit), 2016/08/25 18:53:46]

It feels weird to be creating an NSImage via this whole CGImage thing. If you're
trying to create an NSImage with raw data, you should make an NSBitmapImageRep
object with 
-
initWithBitmapDataPlanes:pixelsWide:pixelsHigh:bitsPerSample:samplesPerPixel:hasAlpha:isPlanar:colorSpaceName:bytesPerRow:bitsPerPixel:

[erikchen, 2016/08/26 17:52:31]

That was the first thing I tried. It doesn't work because of how NSPasteboard
serialization works. I added a comment.

+    int32_t pixel_width = retina ? width * 2 : width;
+    int32_t pixel_height = retina ? height * 2 : height;
+    std::unique_ptr<uint8_t, base::FreeDeleter> buffer(
+        static_cast<uint8_t*>(malloc(pixel_width * pixel_height * 4)));
+    base::ScopedCFTypeRef<CGDataProviderRef> provider(
+        CGDataProviderCreateWithData(
+            nullptr, buffer.get(), (pixel_width * pixel_height * 4), nullptr));

[Avi (use Gerrit), 2016/08/25 18:53:45]

You never initialized the malloc memory, so won't this complain about a read of
uninitialized?

[erikchen, 2016/08/26 17:52:30]

It didn't...but calloc it is!

+    base::ScopedCFTypeRef<CGColorSpaceRef> color_space(
+        CGColorSpaceCreateWithName(kCGColorSpaceSRGB));
+    base::ScopedCFTypeRef<CGImageRef> image_ref(
+        CGImageCreate(pixel_width, pixel_height, 8, 32, 4 * pixel_width,
+                      color_space.get(), kCGBitmapByteOrderDefault,
+                      provider.get(), nullptr, NO, kCGRenderingIntentDefault));
+    return base::scoped_nsobject<NSImage>([[NSImage alloc]
+        initWithCGImage:image_ref.get()
+                   size:NSMakeSize(width, height)]);
+  }
+};
+
+TEST_F(ClipboardMacTest, ReadImageRetina) {
+  int32_t width = 99;
+  int32_t height = 101;
+  scoped_refptr<ui::UniquePasteboard> pasteboard = new ui::UniquePasteboard;
+  base::scoped_nsobject<NSImage> image = CreateImage(width, height, true);
+  [pasteboard->get() writeObjects:@[ image.get() ]];
+
+  ui::Clipboard* clipboard = ui::Clipboard::GetForCurrentThread();
+  ui::ClipboardMac* clipboard_mac = static_cast<ui::ClipboardMac*>(clipboard);
+
+  SkBitmap bitmap = clipboard_mac->ReadImage(ui::CLIPBOARD_TYPE_COPY_PASTE,
+                                             pasteboard->get());
+  EXPECT_EQ(width, bitmap.width());
+  EXPECT_EQ(height, bitmap.height());
+}
+
+TEST_F(ClipboardMacTest, ReadImageNonRetina) {
+  int32_t width = 99;
+  int32_t height = 101;
+  scoped_refptr<ui::UniquePasteboard> pasteboard = new ui::UniquePasteboard;
+  base::scoped_nsobject<NSImage> image = CreateImage(width, height, false);
+  [pasteboard->get() writeObjects:@[ image.get() ]];
+
+  ui::Clipboard* clipboard = ui::Clipboard::GetForCurrentThread();
+  ui::ClipboardMac* clipboard_mac = static_cast<ui::ClipboardMac*>(clipboard);
+
+  SkBitmap bitmap = clipboard_mac->ReadImage(ui::CLIPBOARD_TYPE_COPY_PASTE,
+                                             pasteboard->get());
+  EXPECT_EQ(width, bitmap.width());
+  EXPECT_EQ(height, bitmap.height());
+}
+
+}  // namespace ui