111 lines
3.1 KiB
JavaScript
111 lines
3.1 KiB
JavaScript
/**
|
|
* 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.
|
|
*
|
|
* @format
|
|
* @flow
|
|
*/
|
|
|
|
'use strict';
|
|
|
|
var React = require('react');
|
|
var ReactNative = require('react-native');
|
|
var {Animated, PanResponder, StyleSheet, View} = ReactNative;
|
|
|
|
class AnExChained extends React.Component<Object, any> {
|
|
constructor(props: Object) {
|
|
super(props);
|
|
this.state = {
|
|
stickers: [new Animated.ValueXY()], // 1 leader
|
|
};
|
|
var stickerConfig = {tension: 2, friction: 3}; // soft spring
|
|
for (var i = 0; i < 4; i++) {
|
|
// 4 followers
|
|
var sticker = new Animated.ValueXY();
|
|
Animated.spring(sticker, {
|
|
...stickerConfig,
|
|
toValue: this.state.stickers[i], // Animated toValue's are tracked
|
|
}).start();
|
|
this.state.stickers.push(sticker); // push on the followers
|
|
}
|
|
var releaseChain = (e, gestureState) => {
|
|
this.state.stickers[0].flattenOffset(); // merges offset into value and resets
|
|
Animated.sequence([
|
|
// spring to start after decay finishes
|
|
Animated.decay(this.state.stickers[0], {
|
|
// coast to a stop
|
|
velocity: {x: gestureState.vx, y: gestureState.vy},
|
|
deceleration: 0.997,
|
|
}),
|
|
Animated.spring(this.state.stickers[0], {
|
|
toValue: {x: 0, y: 0}, // return to start
|
|
}),
|
|
]).start();
|
|
};
|
|
this.state.chainResponder = PanResponder.create({
|
|
onStartShouldSetPanResponder: () => true,
|
|
onPanResponderGrant: () => {
|
|
this.state.stickers[0].stopAnimation(value => {
|
|
this.state.stickers[0].setOffset(value); // start where sticker animated to
|
|
this.state.stickers[0].setValue({x: 0, y: 0}); // avoid flicker before next event
|
|
});
|
|
},
|
|
onPanResponderMove: Animated.event(
|
|
[null, {dx: this.state.stickers[0].x, dy: this.state.stickers[0].y}], // map gesture to leader
|
|
),
|
|
onPanResponderRelease: releaseChain,
|
|
onPanResponderTerminate: releaseChain,
|
|
});
|
|
}
|
|
|
|
render() {
|
|
return (
|
|
<View style={styles.chained}>
|
|
{this.state.stickers.map((_, i) => {
|
|
var j = this.state.stickers.length - i - 1; // reverse so leader is on top
|
|
var handlers = j === 0 ? this.state.chainResponder.panHandlers : {};
|
|
return (
|
|
<Animated.Image
|
|
{...handlers}
|
|
key={i}
|
|
source={CHAIN_IMGS[j]}
|
|
style={[
|
|
styles.sticker,
|
|
{
|
|
transform: this.state.stickers[j].getTranslateTransform(), // simple conversion
|
|
},
|
|
]}
|
|
/>
|
|
);
|
|
})}
|
|
</View>
|
|
);
|
|
}
|
|
}
|
|
|
|
var styles = StyleSheet.create({
|
|
chained: {
|
|
alignSelf: 'flex-end',
|
|
top: -160,
|
|
right: 126,
|
|
},
|
|
sticker: {
|
|
position: 'absolute',
|
|
height: 120,
|
|
width: 120,
|
|
backgroundColor: 'transparent',
|
|
},
|
|
});
|
|
|
|
var CHAIN_IMGS = [
|
|
require('../hawk.png'),
|
|
require('../bunny.png'),
|
|
require('../relay.png'),
|
|
require('../hawk.png'),
|
|
require('../bunny.png'),
|
|
];
|
|
|
|
module.exports = AnExChained;
|