react-native/ReactCommon/fabric/text/paragraph/ParagraphComponentDescriptor.h

54 lines
1.6 KiB
C++

/**
* Copyright (c) 2015-present, Facebook, Inc.
*
* 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 <fabric/core/ConcreteComponentDescriptor.h>
#include <fabric/text/ParagraphShadowNode.h>
#include <fabric/textlayoutmanager/TextLayoutManager.h>
namespace facebook {
namespace react {
/*
* Descriptor for <Paragraph> component.
*/
class ParagraphComponentDescriptor final:
public ConcreteComponentDescriptor<ParagraphShadowNode> {
public:
ParagraphComponentDescriptor(SharedEventDispatcher eventDispatcher):
ConcreteComponentDescriptor<ParagraphShadowNode>(eventDispatcher) {
// Every single `ParagraphShadowNode` will have a reference to
// a shared `TextLayoutManager`.
textLayoutManager_ = std::make_shared<TextLayoutManager>();
}
void adopt(UnsharedShadowNode shadowNode) const override {
ConcreteComponentDescriptor<ParagraphShadowNode>::adopt(shadowNode);
assert(std::dynamic_pointer_cast<ParagraphShadowNode>(shadowNode));
auto paragraphShadowNode = std::static_pointer_cast<ParagraphShadowNode>(shadowNode);
// `ParagraphShadowNode` uses `TextLayoutManager` to measure text content
// and communicate text rendering metrics to mounting layer.
paragraphShadowNode->setTextLayoutManager(textLayoutManager_);
// All `ParagraphShadowNode`s must have leaf Yoga nodes with properly
// setup measure function.
paragraphShadowNode->enableMeasurement();
}
private:
SharedTextLayoutManager textLayoutManager_;
};
} // namespace react
} // namespace facebook