chrome/browser/ui/cocoa/table_row_nsimage_cache.h

   1 // Copyright (c) 2012 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 CHROME_BROWSER_UI_COCOA_TABLE_ROW_NSIMAGE_CACHE_H_
   6 #define CHROME_BROWSER_UI_COCOA_TABLE_ROW_NSIMAGE_CACHE_H_
   7
   8 #import <Cocoa/Cocoa.h>
   9
  10 #include "base/mac/scoped_nsobject.h"
  11
  12 namespace gfx {
  13 class ImageSkia;
  14 }
  15
  16 // There are several dialogs that display tabular data with one SkBitmap
  17 // per row. This class converts these SkBitmaps to NSImages on demand, and
  18 // caches the results.
  19 class TableRowNSImageCache {
  20  public:
  21   // Interface this cache expects for its table model.
  22   class Table {
  23    public:
  24     // Returns the number of rows in the table.
  25     virtual int RowCount() const = 0;
  26
  27     // Returns the icon of the |row|th row.
  28     virtual gfx::ImageSkia GetIcon(int row) const = 0;
  29
  30    protected:
  31     virtual ~Table() {}
  32   };
  33
  34   // |model| must outlive the cache.
  35   explicit TableRowNSImageCache(Table* model);
  36   ~TableRowNSImageCache();
  37
  38   // Lazily converts the image at the given row and caches it in |icon_images_|.
  39   NSImage* GetImageForRow(int row);
  40
  41   // Call these functions every time the table changes, to update the cache.
  42   void OnModelChanged();
  43   void OnItemsChanged(int start, int length);
  44   void OnItemsAdded(int start, int length);
  45   void OnItemsRemoved(int start, int length);
  46
  47  private:
  48   // The table model we query for row count and icons.
  49   Table* model_;  // weak
  50
  51   // Stores strong NSImage refs for icons. If an entry is NULL, it will be
  52   // created in GetImageForRow().
  53   base::scoped_nsobject<NSPointerArray> icon_images_;
  54 };
  55
  56 #endif  // CHROME_BROWSER_UI_COCOA_TABLE_ROW_NSIMAGE_CACHE_H_