skia/ext/opacity_filter_canvas.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 "skia/ext/opacity_filter_canvas.h"
   6 #include "third_party/skia/include/core/SkPaint.h"
   7 #include "third_party/skia/include/core/SkTLazy.h"
   8
   9 namespace skia {
  10
  11 OpacityFilterCanvas::OpacityFilterCanvas(SkCanvas* canvas,
  12                                          float opacity,
  13                                          bool disable_image_filtering)
  14     : INHERITED(canvas->imageInfo().width(), canvas->imageInfo().height()),
  15       alpha_(SkScalarRoundToInt(opacity * 255)),
  16       disable_image_filtering_(disable_image_filtering) {
  17   this->addCanvas(canvas);
  18 }
  19
  20 void OpacityFilterCanvas::onFilterPaint(SkPaint* paint, Type) const {
  21   if (alpha_ < 255)
  22     paint->setAlpha(alpha_);
  23
  24   if (disable_image_filtering_)
  25     paint->setFilterQuality(kNone_SkFilterQuality);
  26 }
  27
  28 void OpacityFilterCanvas::onDrawPicture(const SkPicture* picture,
  29                                         const SkMatrix* matrix,
  30                                         const SkPaint* paint) {
  31   SkTLazy<SkPaint> filteredPaint;
  32   if (paint) {
  33     this->onFilterPaint(filteredPaint.set(*paint), kPicture_Type);
  34   }
  35
  36   // Unfurl pictures in order to filter nested paints.
  37   this->SkCanvas::onDrawPicture(picture, matrix, filteredPaint.getMaybeNull());
  38 }
  39
  40 }  // namespace skia