skia::PlatformCanvas is being deprecated. Going forward we will use gfx::Canvas wherever we need ...

ui/gfx/canvas_skia_paint_linux.cc

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/gfx/canvas_skia_paint_linux.h"
+
+#include "base/logging.h"
+#include "ui/gfx/canvas_skia.h"
+#include "ui/gfx/rect.h"
+
+namespace gfx {
+
+CanvasSkiaPaint::CanvasSkiaPaint(GdkEventExpose* event, bool opaque)
+    : window_(event->window),
+      region_(gdk_region_copy(event->region)) {
+  CHECK(InitCanvas());
+}
+
+CanvasSkiaPaint::~CanvasSkiaPaint() {
+  canvas_->skia_canvas()->restoreToCount(1);
+
+  if (!IsValid()) {
+    // Blit the dirty rect to the window.
+    CHECK(window_);
+    cairo_t* dst_context = gdk_cairo_create(window_);
+    CHECK(dst_context);
+    cairo_surface_t* src_surface = cairo_get_target(
+        canvas_->BeginPlatformPaint());
+    CHECK(src_surface);
+    // Flush cairo's cache of the surface.
+    cairo_surface_mark_dirty(src_surface);
+    gfx::Rect rect = GetInvalidRect();
+    cairo_set_source_surface(dst_context, src_surface, rect.x(), rect.y());
+    gdk_cairo_region(dst_context, region_);
+    cairo_fill(dst_context);
+    cairo_destroy(dst_context);
+    canvas_->EndPlatformPaint();
+  }
+
+  gdk_region_destroy(region_);
+}
+
+bool CanvasSkiaPaint::IsValid() const {
+  return gdk_region_empty(region_);
+}
+
+gfx::Rect CanvasSkiaPaint::GetInvalidRect() const {
+  GdkRectangle invalid_rect;
+  gdk_region_get_clipbox(region_, &invalid_rect);
+  return gfx::Rect(invalid_rect);
+}
+
+Canvas* CanvasSkiaPaint::AsCanvas() {
+  return canvas_.get();
+}
+
+bool CanvasSkiaPaint::InitCanvas() {
+  gfx::Rect rect = GetInvalidRect();
+  canvas_.reset(new CanvasSkia);
+  if (!canvas_->Init(rect.width(), rect.height(), true))
+    return false;
+
+  // Translate so that the dirty region appears at the origin.
+  canvas_->skia_canvas()->translate(-SkIntToScalar(rect.x()),
+                                    -SkIntToScalar(rect.y()));
+  return true;
+}
+
+}  // namespace gfx