react-native/Libraries/Experimental/IncrementalPresenter.js
Spencer Ahrens f21da3aa31 <Incremental> for incremental rendering
Summary:Everything wrapped in `<Incremental>` is rendered sequentially via `InteractionManager`.
The `onDone` callback is called when all descendent incremental components have
finished rendering, used by `<IncrementalPresenter>` to make the story visible all at once
instead of the parts popping in randomly.

This includes an example that demonstrates streaming rendering and the use of
`<IncrementalPresenter>`.  Pressing down pauses rendering and you can see the
`TouchableOpacity` animation runs smoothly.  Video:

https://youtu.be/4UNf4-8orQ4

Ideally this will be baked into React Core at some point, but according to jordwalke that's
going to require a major refactoring and take a long time, so going with this for now.

Reviewed By: ericvicenti

Differential Revision: D2506522

fb-gh-sync-id: 5969bf248de10d38b0ac22f34d7d49bf1b3ac4b6
shipit-source-id: 5969bf248de10d38b0ac22f34d7d49bf1b3ac4b6
2016-03-10 08:14:23 -08:00

96 lines
2.8 KiB
JavaScript

/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
* @providesModule IncrementalPresenter
* @flow
*/
'use strict';
const IncrementalGroup = require('IncrementalGroup');
const React = require('React');
const View = require('View');
import type {Context} from 'Incremental';
/**
* WARNING: EXPERIMENTAL. Breaking changes will probably happen a lot and will
* not be reliably announced. The whole thing might be deleted, who knows? Use
* at your own risk.
*
* `<IncrementalPresenter>` can be used to group sets of `<Incremental>` renders
* such that they are initially invisible and removed from layout until all
* decendents have finished rendering, at which point they are drawn all at once
* so the UI doesn't jump around during the incremental rendering process.
*
* See Incremental.js for more info.
*/
type Props = {
name: string;
disabled: boolean;
onDone: () => void;
onLayout: (event: Object) => void;
style: mixed;
children: any;
}
class IncrementalPresenter extends React.Component {
props: Props;
context: Context;
_isDone: boolean;
constructor(props: Props, context: Context) {
super(props, context);
this._isDone = false;
(this: any).onDone = this.onDone.bind(this);
}
onDone() {
this._isDone = true;
if (this.props.disabled !== true &&
this.context.incrementalGroupEnabled !== false) {
// Avoid expensive re-renders and use setNativeProps
this.refs.view.setNativeProps(
{style: [this.props.style, {opacity: 1, position: 'relative'}]}
);
}
this.props.onDone && this.props.onDone();
}
render() {
if (this.props.disabled !== true &&
this.context.incrementalGroupEnabled !== false &&
!this._isDone) {
var style = [this.props.style, {opacity: 0, position: 'absolute'}];
} else {
var style = this.props.style;
}
return (
<IncrementalGroup
onDone={this.onDone}
name={this.props.name}
disabled={this.props.disabled}>
<View
children={this.props.children}
ref="view"
style={style}
onLayout={this.props.onLayout}
/>
</IncrementalGroup>
);
}
}
IncrementalPresenter.propTypes = {
name: React.PropTypes.string,
disabled: React.PropTypes.bool,
onDone: React.PropTypes.func,
onLayout: React.PropTypes.func,
style: View.propTypes.style,
};
IncrementalPresenter.contextTypes = {
incrementalGroup: React.PropTypes.object,
incrementalGroupEnabled: React.PropTypes.bool,
};
module.exports = IncrementalPresenter;