components/wallpaper/wallpaper_resizer.h

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_WALLPAPER_WALLPAPER_RESIZER_H_
   6 #define COMPONENTS_WALLPAPER_WALLPAPER_RESIZER_H_
   7
   8 #include "base/memory/weak_ptr.h"
   9 #include "base/observer_list.h"
  10 #include "components/wallpaper/wallpaper_layout.h"
  11 #include "components/wallpaper/wallpaper_resizer_observer.h"
  12 #include "skia/ext/image_operations.h"
  13 #include "third_party/skia/include/core/SkBitmap.h"
  14 #include "ui/gfx/geometry/rect.h"
  15 #include "ui/gfx/geometry/size.h"
  16 #include "ui/gfx/image/image_skia.h"
  17
  18 namespace base {
  19 class SequencedWorkerPool;
  20 }
  21
  22 namespace wallpaper {
  23
  24 class WallpaperResizerObserver;
  25
  26 // Stores the current wallpaper data and resize it to |target_size| if needed.
  27 class WALLPAPER_EXPORT WallpaperResizer {
  28  public:
  29   // Returns a unique identifier corresponding to |image|, suitable for
  30   // comparison against the value returned by original_image_id(). If the image
  31   // is modified, its ID will change.
  32   static uint32_t GetImageId(const gfx::ImageSkia& image);
  33
  34   WallpaperResizer(const gfx::ImageSkia& image,
  35                    const gfx::Size& target_size,
  36                    WallpaperLayout layout,
  37                    base::SequencedWorkerPool* worker_pool_ptr);
  38
  39   ~WallpaperResizer();
  40
  41   const gfx::ImageSkia& image() const { return image_; }
  42   uint32_t original_image_id() const { return original_image_id_; }
  43   WallpaperLayout layout() const { return layout_; }
  44   base::SequencedWorkerPool* worker_pool() const { return worker_pool_; }
  45
  46   // Called on the UI thread to run Resize() on the worker pool and post an
  47   // OnResizeFinished() task back to the UI thread on completion.
  48   void StartResize();
  49
  50   // Add/Remove observers.
  51   void AddObserver(WallpaperResizerObserver* observer);
  52   void RemoveObserver(WallpaperResizerObserver* observer);
  53
  54  private:
  55   // Copies |resized_bitmap| to |image_| and notifies observers after Resize()
  56   // has finished running.
  57   void OnResizeFinished(SkBitmap* resized_bitmap);
  58
  59   ObserverList<WallpaperResizerObserver> observers_;
  60
  61   // Image that should currently be used for wallpaper. It initially
  62   // contains the original image and is updated to contain the resized
  63   // image by OnResizeFinished().
  64   gfx::ImageSkia image_;
  65
  66   // Unique identifier corresponding to the original (i.e. pre-resize) |image_|.
  67   uint32_t original_image_id_;
  68
  69   gfx::Size target_size_;
  70
  71   WallpaperLayout layout_;
  72
  73   base::SequencedWorkerPool* worker_pool_;
  74
  75   base::WeakPtrFactory<WallpaperResizer> weak_ptr_factory_;
  76
  77   DISALLOW_COPY_AND_ASSIGN(WallpaperResizer);
  78 };
  79
  80 }  // namespace wallpaper
  81
  82 #endif  // COMPONENTS_WALLPAPER_WALLPAPER_RESIZER_H_