Crop images from custom themes before storing them into the theme pack

chrome/browser/themes/browser_theme_pack.h

 // 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.
 
 #ifndef CHROME_BROWSER_THEMES_BROWSER_THEME_PACK_H_
 #define CHROME_BROWSER_THEMES_BROWSER_THEME_PACK_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/sequenced_task_runner_helpers.h"
 #include "chrome/common/extensions/extension.h"
 #include "content/public/browser/browser_thread.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/base/layout.h"
 #include "ui/gfx/color_utils.h"
+#include "ui/gfx/image/image.h"
 
 namespace base {
 class DictionaryValue;
 class FilePath;
 class RefCountedMemory;
 }
 
 namespace extensions {
 class Extensions;
 }
 
-namespace gfx {
-class Image;
-}
-
 namespace ui {
 class DataPack;
 }
 
 // An optimized representation of a theme, backed by a mmapped DataPack.
 //
 // The idea is to pre-process all images (tinting, compositing, etc) at theme
 // install time, save all the PNG-ified data into an mmappable file so we don't
 // suffer multiple file system access times, therefore solving two of the
 // problems with the previous implementation.
@@ skipping 31 matching lines @@
   bool WriteToDisk(const base::FilePath& path) const;
 
   // If this theme specifies data for the corresponding |id|, return true and
   // write the corresponding value to the output parameter. These functions
   // don't return the default data. These methods should only be called from
   // the UI thread. (But this isn't enforced because of unit tests).
   bool GetTint(int id, color_utils::HSL* hsl) const;
   bool GetColor(int id, SkColor* color) const;
   bool GetDisplayProperty(int id, int* result) const;
 
-  // Returns an image if we have a custom image for |id|, otherwise NULL.
-  const gfx::Image* GetImageNamed(int id) const;
+  // Returns the theme pack image for |id|. Returns an empty image if an image
+  // is not found.
+  gfx::Image GetImageNamed(int id);
 
   // Returns the raw PNG encoded data for IDR_THEME_NTP_*. This method is only
   // supposed to work for the NTP attribution and background resources.
   base::RefCountedMemory* GetRawData(int id,
                                      ui::ScaleFactor scale_factor) const;
 
   // Returns the set of image idrs which can be overwritten by a user provided
   // theme.
   static void GetThemeableImageIDRs(std::set<int>* result);
 
   // Whether this theme provides an image for |id|.
   bool HasCustomImage(int id) const;
 
  private:
   friend struct content::BrowserThread::DeleteOnThread<
       content::BrowserThread::FILE>;
   friend class base::DeleteHelper<BrowserThemePack>;
   friend class BrowserThemePackTest;
 
-  // Cached images. We cache all retrieved and generated images and keep
-  // track of the pointers. We own these and will delete them when we're done
-  // using them.
-  typedef std::map<int, const gfx::Image*> ImageCache;
+  // Cached images.
+  typedef std::map<int, gfx::Image> ImageCache;
 
   // The raw PNG memory associated with a certain id.
   typedef std::map<int, scoped_refptr<base::RefCountedMemory> > RawImages;
 
   // The type passed to ui::DataPack::WritePack.
   typedef std::map<uint16, base::StringPiece> RawDataForWriting;
 
   // An association between an id and the base::FilePath that has the image data.
   typedef std::map<int, base::FilePath> FilePathMap;
 
@@ skipping 32 matching lines @@
   // Loads the unmodified images packed in the extension to SkBitmaps. Returns
   // true if all images loaded.
   bool LoadRawBitmapsTo(const FilePathMap& file_paths,
                         ImageCache* image_cache);
 
   // Populate |images| cache with empty gfx::Images. Image reps are lazily
   // generated when an image rep is requested via ImageSkia::GetRepresentation.
   // Source and destination is |images|.
   void CreateImages(ImageCache* images) const;
 
+  // Crops images down to a size such that most of the cropped image will be
+  // displayed in the UI. Cropping is useful because images from custom themes
+  // can be of any size. Source and destination is |images|.
+  void CropImages(ImageCache* images) const;
+
   // Creates tinted and composited frame images. Source and destination is
   // |images|.
   void CreateFrameImages(ImageCache* images) const;
 
   // Creates button images tinted with |button_tint| and places them in
   // processed_images.
   void CreateTintedButtons(const color_utils::HSL& button_tint,
                            ImageCache* processed_images) const;
 
   // Creates the semi-transparent tab background images, putting the results
@@ skipping 75 matching lines @@
 
   // References to raw PNG data. This map isn't touched when |data_pack_| is
   // non-NULL; |image_memory_| is only filled during BuildFromExtension(). Any
   // image data that needs to be written to the DataPack during WriteToDisk()
   // needs to be in |image_memory_|.
   RawImages image_memory_;
 
   // Loaded images. These are loaded from |image_memory_|, from |data_pack_|,
   // and by BuildFromExtension(). These images should only be accessed on the UI
   // thread.
-  mutable ImageCache images_on_ui_thread_;
+  ImageCache images_on_ui_thread_;
 
   // Cache of images created in BuildFromExtension(). Once the theme pack is
   // created, this cache should only be accessed on the file thread. There
   // should be no IDs in |image_memory_| that are in |images_on_file_thread_|
   // or vice versa.
   ImageCache images_on_file_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserThemePack);
 };
 
 #endif  // CHROME_BROWSER_THEMES_BROWSER_THEME_PACK_H_