Files
react-native/ReactCommon/fabric/components/text/paragraph/ParagraphShadowNode.h
T
Joshua GrossandFacebook Github Bot 10e4a851ad Address some paragraph measure cache follow-up nits
Summary: Changing some T& to const T&, removing unnecessary shared_ptr.

Reviewed By: shergin

Differential Revision: D13845619

fbshipit-source-id: 2678f67f24445e3db105619a07534f5200e313fe
2019-01-31 19:18:55 -08:00

85 lines
2.6 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 <folly/Optional.h>
#include <react/components/text/ParagraphMeasurementCache.h>
#include <react/components/text/ParagraphProps.h>
#include <react/components/text/TextShadowNode.h>
#include <react/components/view/ConcreteViewShadowNode.h>
#include <react/core/ConcreteShadowNode.h>
#include <react/core/LayoutContext.h>
#include <react/core/ShadowNode.h>
#include <react/textlayoutmanager/TextLayoutManager.h>
namespace facebook {
namespace react {
extern const char ParagraphComponentName[];
using ParagraphEventEmitter = ViewEventEmitter;
/*
* `ShadowNode` for <Paragraph> component, represents <View>-like component
* containing and displaying text. Text content is represented as nested <Text>
* and <RawText> components.
*/
class ParagraphShadowNode : public ConcreteViewShadowNode<
ParagraphComponentName,
ParagraphProps,
ParagraphEventEmitter>,
public BaseTextShadowNode {
public:
using ConcreteViewShadowNode::ConcreteViewShadowNode;
/*
* Returns a `AttributedString` which represents text content of the node.
*/
AttributedString getAttributedString() const;
/*
* Associates a shared TextLayoutManager with the node.
* `ParagraphShadowNode` uses the manager to measure text content
* and construct `ParagraphLocalData` objects.
*/
void setTextLayoutManager(SharedTextLayoutManager textLayoutManager);
/*
* Associates a shared LRU cache with the node.
* `ParagraphShadowNode` uses this to cache the results of
* text rendering measurements.
* By design, the ParagraphComponentDescriptor outlives all
* shadow nodes, so it's safe for this to be a raw pointer.
*/
void setMeasureCache(const ParagraphMeasurementCache *cache);
#pragma mark - LayoutableShadowNode
void layout(LayoutContext layoutContext) override;
Size measure(LayoutConstraints layoutConstraints) const override;
private:
/*
* Creates a `LocalData` object (with `AttributedText` and
* `TextLayoutManager`) if needed.
*/
void updateLocalDataIfNeeded();
SharedTextLayoutManager textLayoutManager_;
const ParagraphMeasurementCache *measureCache_;
/*
* Cached attributed string that represents the content of the subtree started
* from the node.
*/
mutable folly::Optional<AttributedString> cachedAttributedString_{};
};
} // namespace react
} // namespace facebook