chromium/cc/trees/mutator_host.h

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CC_TREES_MUTATOR_HOST_H_
#define CC_TREES_MUTATOR_HOST_H_

#include <memory>
#include <vector>

#include "base/time/time.h"
#include "cc/paint/element_id.h"
#include "cc/trees/layer_tree_mutator.h"
#include "cc/trees/mutator_host_client.h"
#include "ui/gfx/geometry/box_f.h"
#include "ui/gfx/geometry/point_f.h"
#include "ui/gfx/geometry/vector2d_f.h"

namespace cc {

class MutatorEvents;
class MutatorHostClient;
class LayerTreeMutator;
class PropertyTrees;
class ScrollTree;

// Used as the return value of GetAnimationScales() to indicate that there is
// no active transform animation or the scale cannot be computed.
inline constexpr float kInvalidScale = …;

// A MutatorHost owns all the animation and mutation effects.
// There is just one MutatorHost for LayerTreeHost on main renderer thread
// and just one MutatorHost for LayerTreeHostImpl on the impl thread.
// We synchronize them during the commit in a one-way data-flow process
// (PushPropertiesTo).
// A MutatorHost talks to its correspondent LayerTreeHost via
// MutatorHostClient interface.
class MutatorHost { … };

class MutatorEvents { … };

}  // namespace cc

#endif  // CC_TREES_MUTATOR_HOST_H_