1 2// Copyright (c) 2011 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_LINUX_H_ 7#define UI_GFX_CANVAS_PAINT_LINUX_H_ 8 9#include "base/logging.h" 10#include "skia/ext/platform_canvas.h" 11#include "ui/gfx/canvas.h" 12#include <gdk/gdk.h> 13 14namespace gfx { 15 16// A class designed to translate skia painting into a region in a GdkWindow. 17// On construction, it will set up a context for painting into, and on 18// destruction, it will commit it to the GdkWindow. 19// Note: The created context is always inialized to (0, 0, 0, 0). 20class GFX_EXPORT CanvasSkiaPaint : public Canvas { 21 public: 22 // This constructor assumes the result is opaque. 23 explicit CanvasSkiaPaint(GdkEventExpose* event); 24 CanvasSkiaPaint(GdkEventExpose* event, bool opaque); 25 virtual ~CanvasSkiaPaint(); 26 27 // Sets whether the bitmap is composited in such a way that the alpha channel 28 // is honored. This is only useful if you've enabled an RGBA colormap on the 29 // widget. The default is false. 30 void set_composite_alpha(bool composite_alpha) { 31 composite_alpha_ = composite_alpha; 32 } 33 34 // Returns true if the invalid region is empty. The caller should call this 35 // function to determine if anything needs painting. 36 bool is_empty() const { 37 return gdk_region_empty(region_); 38 } 39 40 GdkRectangle rectangle() const { 41 GdkRectangle bounds; 42 gdk_region_get_clipbox(region_, &bounds); 43 return bounds; 44 } 45 46 private: 47 void Init(bool opaque); 48 49 cairo_t* context_; 50 GdkWindow* window_; 51 GdkRegion* region_; 52 // See description above setter. 53 bool composite_alpha_; 54 55 // Disallow copy and assign. 56 CanvasSkiaPaint(const CanvasSkiaPaint&); 57 CanvasSkiaPaint& operator=(const CanvasSkiaPaint&); 58}; 59 60// A class designed to translate skia painting into a region in a Cairo context. 61// On construction, it will set up a context for painting into, and on 62// destruction, it will commit it to the Cairo context. If there are any 63// transformations applied to the Cairo context, they will affect the drawing. 64class GFX_EXPORT CanvasSkiaPaintCairo : public Canvas { 65 public: 66 CanvasSkiaPaintCairo(cairo_t* cairo, Size size, bool opaque); 67 virtual ~CanvasSkiaPaintCairo(); 68 69 // Sets whether the bitmap is composited in such a way that the alpha channel 70 // is honored. This is only useful if you've enabled an RGBA colormap on the 71 // widget. The default is false. 72 void set_composite_alpha(bool composite_alpha) { 73 composite_alpha_ = composite_alpha; 74 } 75 76 // Returns true if size of the drawing region is empty. The caller should call 77 // this function to determine if anything needs painting. 78 bool is_empty() const { 79 return size_.IsEmpty(); 80 } 81 82 Size size() const { 83 return size_; 84 } 85 86 private: 87 void Init(bool opaque); 88 89 cairo_t* context_; 90 cairo_t* dest_; 91 Size size_; 92 // See description above setter. 93 bool composite_alpha_; 94 95 // Disallow copy and assign. 96 CanvasSkiaPaintCairo(const CanvasSkiaPaintCairo&); 97 CanvasSkiaPaintCairo& operator=(const CanvasSkiaPaintCairo&); 98}; 99 100} // namespace gfx 101 102#endif // UI_GFX_CANVAS_PAINT_LINUX_H_ 103