ui/app_list/views/cached_label.h

   1 // Copyright 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 UI_APP_LIST_VIEWS_CACHED_LABEL_H_
   6 #define UI_APP_LIST_VIEWS_CACHED_LABEL_H_
   7
   8 #include "ui/gfx/image/image_skia.h"
   9 #include "ui/views/controls/label.h"
  10 #include "ui/views/view.h"
  11
  12 namespace gfx {
  13 class Canvas;
  14 }
  15
  16 namespace app_list {
  17
  18 // Subclass of views::Label that caches the rendered text in an ImageSkia.
  19 class CachedLabel : public views::Label {
  20  public:
  21   CachedLabel();
  22
  23   // Have the next call to OnPaint() update the backing image.
  24   void Invalidate() { needs_repaint_ = true; }
  25
  26   // Calls the base label's OnPaint() to paint into a backing image.
  27   void PaintToBackingImage();
  28
  29 #if defined(OS_WIN)
  30   // Overridden from views::View:
  31   void OnPaint(gfx::Canvas* canvas) override;
  32 #endif
  33
  34   // Overridden from ui::LayerDelegate:
  35   void OnDeviceScaleFactorChanged(float device_scale_factor) override;
  36
  37  private:
  38   bool needs_repaint_;
  39   gfx::ImageSkia image_;
  40 };
  41
  42 }  // namespace app_list
  43
  44 #endif  // UI_APP_LIST_VIEWS_CACHED_LABEL_H_