react-native-macos/ReactCommon/fabric/mounting/ShadowTree.h

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2.7 KiB
C++

// Copyright (c) Facebook, Inc. and its affiliates.
// This source code is licensed under the MIT license found in the
// LICENSE file in the root directory of this source tree.
#pragma once
#include <better/mutex.h>
#include <memory>
#include <react/components/root/RootComponentDescriptor.h>
#include <react/components/root/RootShadowNode.h>
#include <react/core/LayoutConstraints.h>
#include <react/core/ReactPrimitives.h>
#include <react/core/ShadowNode.h>
#include <react/mounting/MountingCoordinator.h>
#include <react/mounting/ShadowTreeDelegate.h>
#include <react/mounting/ShadowTreeRevision.h>
namespace facebook {
namespace react {
using ShadowTreeCommitTransaction = std::function<UnsharedRootShadowNode(
const SharedRootShadowNode &oldRootShadowNode)>;
/*
* Represents the shadow tree and its lifecycle.
*/
class ShadowTree final {
public:
/*
* Creates a new shadow tree instance.
*/
ShadowTree(
SurfaceId surfaceId,
const LayoutConstraints &layoutConstraints,
const LayoutContext &layoutContext,
const RootComponentDescriptor &rootComponentDescriptor);
~ShadowTree();
/*
* Returns the `SurfaceId` associated with the shadow tree.
*/
SurfaceId getSurfaceId() const;
/*
* Performs commit calling `transaction` function with a `oldRootShadowNode`
* and expecting a `newRootShadowNode` as a return value.
* The `transaction` function can abort commit returning `nullptr`.
* Returns `true` if the operation finished successfully.
*/
bool tryCommit(ShadowTreeCommitTransaction transaction) const;
/*
* Calls `tryCommit` in a loop until it finishes successfully.
*/
void commit(ShadowTreeCommitTransaction transaction) const;
#pragma mark - Delegate
/*
* Sets and gets the delegate.
* The delegate is stored as a raw pointer, so the owner must null
* the pointer before being destroyed.
*/
void setDelegate(ShadowTreeDelegate const *delegate);
ShadowTreeDelegate const *getDelegate() const;
private:
UnsharedRootShadowNode cloneRootShadowNode(
const SharedRootShadowNode &oldRootShadowNode,
const LayoutConstraints &layoutConstraints,
const LayoutContext &layoutContext) const;
void emitLayoutEvents(
std::vector<LayoutableShadowNode const *> &affectedLayoutableNodes) const;
SurfaceId const surfaceId_;
mutable better::shared_mutex commitMutex_;
mutable SharedRootShadowNode rootShadowNode_; // Protected by `commitMutex_`.
mutable ShadowTreeRevision::Number revisionNumber_{
0}; // Protected by `commitMutex_`.
ShadowTreeDelegate const *delegate_;
MountingCoordinator::Shared mountingCoordinator_;
};
} // namespace react
} // namespace facebook