ui/compositor/compositing_recorder.cc

   1 // Copyright 2015 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 "ui/compositor/compositing_recorder.h"
   6
   7 #include "cc/resources/compositing_display_item.h"
   8 #include "cc/resources/display_item_list.h"
   9 #include "ui/compositor/paint_context.h"
  10 #include "ui/gfx/canvas.h"
  11
  12 namespace ui {
  13
  14 CompositingRecorder::CompositingRecorder(const PaintContext& context,
  15                                          uint8_t alpha)
  16     : context_(context), saved_(alpha < 255) {
  17   if (!saved_)
  18     return;
  19
  20   if (context_.canvas_) {
  21     context_.canvas_->SaveLayerAlpha(alpha);
  22   } else {
  23     context_.list_->AppendItem(cc::CompositingDisplayItem::Create(
  24         alpha, SkXfermode::kSrcOver_Mode, nullptr /* no bounds */,
  25         skia::RefPtr<SkColorFilter>()));
  26   }
  27 }
  28
  29 CompositingRecorder::~CompositingRecorder() {
  30   if (!saved_)
  31     return;
  32
  33   if (context_.canvas_) {
  34     context_.canvas_->Restore();
  35   } else {
  36     context_.list_->AppendItem(cc::EndCompositingDisplayItem::Create());
  37   }
  38 }
  39
  40 }  // namespace ui