| // Copyright 2016 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 "platform/graphics/CompositorMutableStateProvider.h" |
| |
| #include "cc/layers/layer_impl.h" |
| #include "cc/trees/layer_tree_impl.h" |
| #include "platform/graphics/CompositorMutableState.h" |
| #include "platform/graphics/CompositorMutation.h" |
| #include "wtf/PassOwnPtr.h" |
| #include "wtf/PtrUtil.h" |
| |
| namespace blink { |
| |
| CompositorMutableStateProvider::CompositorMutableStateProvider(cc::LayerTreeImpl* treeImpl, CompositorMutations* mutations) |
| : m_tree(treeImpl) |
| , m_mutations(mutations) |
| { |
| } |
| |
| CompositorMutableStateProvider::~CompositorMutableStateProvider() {} |
| |
| std::unique_ptr<CompositorMutableState> |
| CompositorMutableStateProvider::getMutableStateFor(uint64_t elementId) |
| { |
| cc::LayerTreeImpl::ElementLayers layers = m_tree->GetMutableLayers(elementId); |
| |
| if (!layers.main && !layers.scroll) |
| return nullptr; |
| |
| // Ensure that we have an entry in the map for |elementId| but do as few |
| // allocations and queries as possible. This will update the map only if we |
| // have not added a value for |elementId|. |
| auto result = m_mutations->map.add(elementId, nullptr); |
| |
| // Only if this is a new entry do we want to allocate a new mutation. |
| if (result.isNewEntry) |
| result.storedValue->value = adoptPtr(new CompositorMutation); |
| |
| return wrapUnique(new CompositorMutableState(result.storedValue->value.get(), layers.main, layers.scroll)); |
| } |
| |
| } // namespace blink |