aura: Scale custom cursors appropriately.

webkit/glue/webcursor_aurax11.cc

 // Copyright (c) 2012 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 "webkit/glue/webcursor.h"
 
 #include <X11/Xcursor/Xcursor.h>
 #include <X11/Xlib.h>
 #include <X11/cursorfont.h>
 
 #include "base/logging.h"
+#include "skia/ext/image_operations.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebCursorInfo.h"
 #include "ui/base/cursor/cursor.h"
 #include "ui/base/x/x11_util.h"
 
 const ui::PlatformCursor WebCursor::GetPlatformCursor() {
   if (platform_cursor_)
     return platform_cursor_;
 
   SkBitmap bitmap;
   bitmap.setConfig(SkBitmap::kARGB_8888_Config,
                    custom_size_.width(), custom_size_.height());
   bitmap.allocPixels();
   memcpy(bitmap.getAddr32(0, 0), custom_data_.data(), custom_data_.size());
 
-  XcursorImage* image = ui::SkBitmapToXcursorImage(&bitmap, hotspot_);
+  XcursorImage* image = NULL;
+  if (scale_factor_ == 1.f) {
+    image = ui::SkBitmapToXcursorImage(&bitmap, hotspot_);
+  } else {
+    gfx::Size scaled_size = custom_size_.Scale(scale_factor_);
+    SkBitmap scaled_bitmap = skia::ImageOperations::Resize(bitmap,
+        skia::ImageOperations::RESIZE_BETTER,
+        scaled_size.width(),
+        scaled_size.height());
+    image = ui::SkBitmapToXcursorImage(&scaled_bitmap,
+                                       hotspot_.Scale(scale_factor_));
+  }
   platform_cursor_ = ui::CreateReffedCustomXCursor(image);
   return platform_cursor_;
 }
 
+void WebCursor::SetScaleFactor(float scale_factor) {
+  if (scale_factor_ == scale_factor)
+    return;
+
+  scale_factor_ = scale_factor;
+  if (platform_cursor_)
+    ui::UnrefCustomXCursor(platform_cursor_);
+  platform_cursor_ = 0;
+  // It is not necessary to recreate platform_cursor_ yet, since it will be
+  // recreated on demand when GetPlatformCursor is called.
+}
+
 void WebCursor::InitPlatformData() {
   platform_cursor_ = 0;
+  scale_factor_ = 1.f;
 }
 
 bool WebCursor::SerializePlatformData(Pickle* pickle) const {
   return true;
 }
 
 bool WebCursor::DeserializePlatformData(PickleIterator* iter) {
   return true;
 }
 
 bool WebCursor::IsPlatformDataEqual(const WebCursor& other) const {
   return true;
 }
 
 void WebCursor::CleanupPlatformData() {
   if (platform_cursor_) {
     ui::UnrefCustomXCursor(platform_cursor_);
     platform_cursor_ = 0;
   }
 }
 
 void WebCursor::CopyPlatformData(const WebCursor& other) {
   if (platform_cursor_)
     ui::UnrefCustomXCursor(platform_cursor_);
   platform_cursor_ = other.platform_cursor_;
   if (platform_cursor_)
     ui::RefCustomXCursor(platform_cursor_);
+
+  scale_factor_ = other.scale_factor_;
 }