ui/base/android/system_ui_resource_manager.h

   1 // Copyright 2014 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 UI_BASE_ANDROID_SYSTEM_UI_RESOURCE_MANAGER_H_
   6 #define UI_BASE_ANDROID_SYSTEM_UI_RESOURCE_MANAGER_H_
   7
   8 #include "cc/resources/ui_resource_client.h"
   9 #include "ui/base/ui_base_export.h"
  10
  11 namespace ui {
  12
  13 // Interface for loading and accessing shared system UI resources.
  14 class UI_BASE_EXPORT SystemUIResourceManager {
  15  public:
  16   enum ResourceType {
  17     OVERSCROLL_EDGE = 0,
  18     OVERSCROLL_GLOW,
  19     OVERSCROLL_GLOW_L,
  20     RESOURCE_TYPE_FIRST = OVERSCROLL_EDGE,
  21     RESOURCE_TYPE_LAST = OVERSCROLL_GLOW_L
  22   };
  23
  24   virtual ~SystemUIResourceManager() {}
  25
  26   // Optionally trigger bitmap loading for a given |resource|, if necessary.
  27   // Note that this operation may be asynchronous, and subsequent queries to
  28   // |GetUIResourceId()| will yield a valid result only after loading finishes.
  29   // This method is particularly useful for idly loading a resource before an
  30   // explicit cc::UIResourceId is required. Repeated calls will be ignored.
  31   virtual void PreloadResource(ResourceType resource) = 0;
  32
  33   // Return the resource id associated with |resource|. If loading hasn't yet
  34   // begun for the given |resource|, it will be triggered immediately. If
  35   // loading is asynchronous, 0 will be returned until loading has finished, and
  36   // the caller is responsible for re-querying until a valid id is returned.
  37   virtual cc::UIResourceId GetUIResourceId(ResourceType resource) = 0;
  38 };
  39
  40 }  // namespace ui
  41
  42 #endif  // UI_BASE_ANDROID_SYSTEM_UI_RESOURCE_MANAGER_H_