ui/gfx/canvas_paint_gtk.cc

   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 #include "base/basictypes.h"
   6 #include "base/compiler_specific.h"
   7 #include "ui/gfx/canvas.h"
   8 #include "ui/gfx/canvas_skia_paint.h"
   9 #include "ui/gfx/rect.h"
  10
  11 namespace gfx {
  12
  13 CanvasSkiaPaint::CanvasSkiaPaint(GdkEventExpose* event)
  14     : context_(NULL),
  15       window_(event->window),
  16       region_(gdk_region_copy(event->region)),
  17       composite_alpha_(false) {
  18   Init(true);
  19 }
  20
  21 CanvasSkiaPaint::CanvasSkiaPaint(GdkEventExpose* event, bool opaque)
  22     : context_(NULL),
  23       window_(event->window),
  24       region_(gdk_region_copy(event->region)),
  25       composite_alpha_(false) {
  26   Init(opaque);
  27 }
  28
  29 CanvasSkiaPaint::~CanvasSkiaPaint() {
  30   if (!is_empty()) {
  31     platform_canvas()->restoreToCount(1);
  32
  33     // Blit the dirty rect to the window.
  34     CHECK(window_);
  35     cairo_t* cr = gdk_cairo_create(window_);
  36     CHECK(cr);
  37     if (composite_alpha_)
  38       cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
  39     cairo_surface_t* source_surface = cairo_get_target(context_);
  40     CHECK(source_surface);
  41     // Flush cairo's cache of the surface.
  42     cairo_surface_mark_dirty(source_surface);
  43     GdkRectangle bounds = rectangle();
  44     cairo_set_source_surface(cr, source_surface, bounds.x, bounds.y);
  45     gdk_cairo_region(cr, region_);
  46     cairo_fill(cr);
  47     cairo_destroy(cr);
  48   }
  49
  50   gdk_region_destroy(region_);
  51 }
  52
  53 void CanvasSkiaPaint::Init(bool opaque) {
  54   GdkRectangle bounds = rectangle();
  55   RecreateBackingCanvas(gfx::Size(bounds.width, bounds.height),
  56                         ui::SCALE_FACTOR_100P, opaque);
  57
  58   skia::PlatformCanvas* canvas = platform_canvas();
  59
  60   // Need to translate so that the dirty region appears at the origin of the
  61   // surface.
  62   canvas->translate(-SkIntToScalar(bounds.x), -SkIntToScalar(bounds.y));
  63
  64   context_ = skia::BeginPlatformPaint(canvas);
  65 }
  66
  67 } // namespace gfx
  68
  69