| // Copyright 2013 The Flutter 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 "flutter/flow/layers/opacity_layer.h" |
| |
| #include "flutter/flow/layers/cacheable_layer.h" |
| #include "flutter/flow/raster_cache_util.h" |
| #include "third_party/skia/include/core/SkPaint.h" |
| |
| namespace flutter { |
| |
| // the opacity_layer couldn't cache itself, so the cache_threshold is the |
| // max_int |
| OpacityLayer::OpacityLayer(SkAlpha alpha, const SkPoint& offset) |
| : CacheableContainerLayer(std::numeric_limits<int>::max(), true), |
| alpha_(alpha), |
| offset_(offset), |
| children_can_accept_opacity_(false) {} |
| |
| void OpacityLayer::Diff(DiffContext* context, const Layer* old_layer) { |
| DiffContext::AutoSubtreeRestore subtree(context); |
| auto* prev = static_cast<const OpacityLayer*>(old_layer); |
| if (!context->IsSubtreeDirty()) { |
| FML_DCHECK(prev); |
| if (alpha_ != prev->alpha_ || offset_ != prev->offset_) { |
| context->MarkSubtreeDirty(context->GetOldLayerPaintRegion(old_layer)); |
| } |
| } |
| context->PushTransform(SkMatrix::Translate(offset_.fX, offset_.fY)); |
| if (context->has_raster_cache()) { |
| context->SetTransform( |
| RasterCacheUtil::GetIntegralTransCTM(context->GetTransform())); |
| } |
| DiffChildren(context, prev); |
| context->SetLayerPaintRegion(this, context->CurrentSubtreeRegion()); |
| } |
| |
| void OpacityLayer::Preroll(PrerollContext* context) { |
| FML_DCHECK(!layers().empty()); // We can't be a leaf. |
| |
| auto mutator = context->state_stack.save(); |
| mutator.translate(offset_); |
| mutator.applyOpacity(SkRect(), DlColor::toOpacity(alpha_)); |
| |
| AutoCache auto_cache = AutoCache(layer_raster_cache_item_.get(), context, |
| context->state_stack.transform_3x3()); |
| Layer::AutoPrerollSaveLayerState save = |
| Layer::AutoPrerollSaveLayerState::Create(context); |
| |
| ContainerLayer::Preroll(context); |
| // We store the inheritance ability of our children for |Paint| |
| set_children_can_accept_opacity((context->renderable_state_flags & |
| LayerStateStack::kCallerCanApplyOpacity) != |
| 0); |
| |
| // Now we let our parent layers know that we, too, can inherit opacity |
| // regardless of what our children are capable of |
| context->renderable_state_flags |= LayerStateStack::kCallerCanApplyOpacity; |
| |
| set_paint_bounds(paint_bounds().makeOffset(offset_.fX, offset_.fY)); |
| |
| if (children_can_accept_opacity()) { |
| // For opacity layer, we can use raster_cache children only when the |
| // children can't accept opacity so if the children_can_accept_opacity we |
| // should tell the AutoCache object don't do raster_cache. |
| auto_cache.ShouldNotBeCached(); |
| } |
| } |
| |
| void OpacityLayer::Paint(PaintContext& context) const { |
| FML_DCHECK(needs_painting(context)); |
| |
| auto mutator = context.state_stack.save(); |
| mutator.translate(offset_.fX, offset_.fY); |
| if (context.raster_cache) { |
| mutator.integralTransform(); |
| } |
| |
| mutator.applyOpacity(child_paint_bounds(), opacity()); |
| |
| if (!children_can_accept_opacity()) { |
| SkPaint paint; |
| if (layer_raster_cache_item_->Draw(context, |
| context.state_stack.fill(paint))) { |
| return; |
| } |
| } |
| |
| if (!context.state_stack.painting_is_nop()) { |
| PaintChildren(context); |
| } |
| } |
| |
| } // namespace flutter |