mirror of
https://github.com/zhigang1992/react-native.git
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9a0047f368
Summary: With recent changes, simple cloning a component does not mean that underlying Yoga node will be dirtied. Autodirtying is only performed if the child nodes were dirtied and/or if the YGStyles were changed. That's not the case for Text component which does not have direct layotable children, so we have to call `dirtyLayout` explicitly. Reviewed By: JoshuaGross Differential Revision: D14508277 fbshipit-source-id: 2c52d7d40da963a976c7d28a13781cc1755ef591
88 lines
2.9 KiB
C++
88 lines
2.9 KiB
C++
/**
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*/
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#pragma once
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#include "ParagraphMeasurementCache.h"
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#include "ParagraphShadowNode.h"
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#include <folly/container/EvictingCacheMap.h>
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#include <react/core/ConcreteComponentDescriptor.h>
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#include <react/textlayoutmanager/TextLayoutManager.h>
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#include <react/uimanager/ContextContainer.h>
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namespace facebook {
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namespace react {
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/*
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* Descriptor for <Paragraph> component.
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*/
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class ParagraphComponentDescriptor final
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: public ConcreteComponentDescriptor<ParagraphShadowNode> {
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public:
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ParagraphComponentDescriptor(
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EventDispatcher::Shared eventDispatcher,
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const SharedContextContainer &contextContainer)
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: ConcreteComponentDescriptor<ParagraphShadowNode>(eventDispatcher) {
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// Every single `ParagraphShadowNode` will have a reference to
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// a shared `TextLayoutManager`.
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textLayoutManager_ = std::make_shared<TextLayoutManager>(contextContainer);
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// Every single `ParagraphShadowNode` will have a reference to
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// a shared `EvictingCacheMap`, a simple LRU cache for Paragraph
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// measurements.
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#ifdef ANDROID
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auto paramName = "react_fabric:enabled_paragraph_measure_cache_android";
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#else
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auto paramName = "react_fabric:enabled_paragraph_measure_cache_ios";
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#endif
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// TODO: T39927960 - get rid of this if statement
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bool enableCache =
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(contextContainer != nullptr
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? contextContainer
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->getInstance<std::shared_ptr<const ReactNativeConfig>>(
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"ReactNativeConfig")
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->getBool(paramName)
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: false);
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if (enableCache) {
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measureCache_ = std::make_unique<ParagraphMeasurementCache>();
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} else {
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measureCache_ = nullptr;
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}
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}
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protected:
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void adopt(UnsharedShadowNode shadowNode) const override {
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ConcreteComponentDescriptor::adopt(shadowNode);
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assert(std::dynamic_pointer_cast<ParagraphShadowNode>(shadowNode));
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auto paragraphShadowNode =
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std::static_pointer_cast<ParagraphShadowNode>(shadowNode);
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// `ParagraphShadowNode` uses `TextLayoutManager` to measure text content
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// and communicate text rendering metrics to mounting layer.
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paragraphShadowNode->setTextLayoutManager(textLayoutManager_);
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// `ParagraphShadowNode` uses this to cache the results of text rendering
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// measurements.
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paragraphShadowNode->setMeasureCache(
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measureCache_ ? measureCache_.get() : nullptr);
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paragraphShadowNode->dirtyLayout();
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// All `ParagraphShadowNode`s must have leaf Yoga nodes with properly
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// setup measure function.
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paragraphShadowNode->enableMeasurement();
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}
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private:
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SharedTextLayoutManager textLayoutManager_;
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std::unique_ptr<const ParagraphMeasurementCache> measureCache_;
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};
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} // namespace react
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} // namespace facebook
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