ui/gfx/canvas_paint_mac.h

   1
   2 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   3 // Use of this source code is governed by a BSD-style license that can be
   4 // found in the LICENSE file.
   5
   6 #ifndef UI_GFX_CANVAS_PAINT_MAC_H_
   7 #define UI_GFX_CANVAS_PAINT_MAC_H_
   8
   9 #include "skia/ext/platform_canvas.h"
  10 #include "ui/gfx/canvas.h"
  11
  12 #import <Cocoa/Cocoa.h>
  13
  14 namespace gfx {
  15
  16 // A class designed to translate skia painting into a region to the current
  17 // graphics context.  On construction, it will set up a context for painting
  18 // into, and on destruction, it will commit it to the current context.
  19 // Note: The created context is always inialized to (0, 0, 0, 0).
  20 class GFX_EXPORT CanvasSkiaPaint : public Canvas {
  21  public:
  22   // This constructor assumes the result is opaque.
  23   explicit CanvasSkiaPaint(NSRect dirtyRect);
  24   CanvasSkiaPaint(NSRect dirtyRect, bool opaque);
  25   virtual ~CanvasSkiaPaint();
  26
  27   // If true, the data painted into the CanvasSkiaPaint is blended onto the
  28   // current context, else it is copied.
  29   void set_composite_alpha(bool composite_alpha) {
  30     composite_alpha_ = composite_alpha;
  31   }
  32
  33   // Returns true if the invalid region is empty. The caller should call this
  34   // function to determine if anything needs painting.
  35   bool is_empty() const {
  36     return NSIsEmptyRect(rectangle_);
  37   }
  38
  39   const NSRect& rectangle() const {
  40     return rectangle_;
  41   }
  42
  43  private:
  44   void Init(bool opaque);
  45
  46   CGContext* context_;
  47   NSRect rectangle_;
  48   // See description above setter.
  49   bool composite_alpha_;
  50
  51   // Disallow copy and assign.
  52   CanvasSkiaPaint(const CanvasSkiaPaint&);
  53   CanvasSkiaPaint& operator=(const CanvasSkiaPaint&);
  54 };
  55
  56 }  // namespace gfx
  57
  58
  59 #endif  // UI_GFX_CANVAS_PAINT_MAC_H_