ui/compositor/paint_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/paint_recorder.h"
   6
   7 #include "cc/resources/display_item_list.h"
   8 #include "cc/resources/drawing_display_item.h"
   9 #include "third_party/skia/include/core/SkPictureRecorder.h"
  10 #include "ui/compositor/paint_cache.h"
  11 #include "ui/compositor/paint_context.h"
  12 #include "ui/gfx/skia_util.h"
  13
  14 namespace ui {
  15
  16 PaintRecorder::PaintRecorder(const PaintContext& context, PaintCache* cache)
  17     : context_(context),
  18       owned_canvas_(
  19           // If the |context| has a canvas, we'll just point to it in |canvas_|
  20           // so use anything here to initialize the gfx::Canvas without any
  21           // allocations.
  22           // The SkCanvas reference returned by beginRecording is shared with
  23           // the recorder_ so no need to store a RefPtr to it on this class.
  24           (context.canvas_
  25                ? context.canvas_->sk_canvas()
  26                : skia::SharePtr(
  27                      context.recorder_->beginRecording(
  28                          gfx::RectToSkRect(context.bounds_),
  29                          nullptr /* no SkRTreeFactory */,
  30                          SkPictureRecorder::kComputeSaveLayerInfo_RecordFlag))
  31                      .get()),
  32           context.device_scale_factor_),
  33       // In the case that we use a shared canvas from PaintContext, the user of
  34       // PaintRecorder is expected to Save/Restore any changes made to the
  35       // context while using PaintRecorder.
  36       canvas_(context.canvas_ ? context.canvas_ : &owned_canvas_),
  37       cache_(cache) {
  38 #if DCHECK_IS_ON()
  39   DCHECK(!context.inside_paint_recorder_);
  40   context.inside_paint_recorder_ = true;
  41 #endif
  42 }
  43
  44 PaintRecorder::PaintRecorder(const PaintContext& context)
  45     : PaintRecorder(context, nullptr) {
  46 }
  47
  48 PaintRecorder::~PaintRecorder() {
  49 #if DCHECK_IS_ON()
  50   context_.inside_paint_recorder_ = false;
  51 #endif
  52
  53   if (!context_.list_)
  54     return;
  55
  56   auto* item = context_.list_->CreateAndAppendItem<cc::DrawingDisplayItem>();
  57   item->SetNew(skia::AdoptRef(context_.recorder_->endRecordingAsPicture()));
  58   if (cache_)
  59     cache_->SetCache(item);
  60 }
  61
  62 }  // namespace ui