react-native/Examples/UIExplorer/AnimatedGratuitousApp/AnExChained.js

115 lines
4.1 KiB
JavaScript

/**
* The examples provided by Facebook are for non-commercial testing and
* evaluation purposes only.
*
* Facebook reserves all rights not expressly granted.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON INFRINGEMENT. IN NO EVENT SHALL
* FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* @providesModule AnExChained
* @flow
*/
'use strict';
var React = require('react-native');
var {
Animated,
Image,
PanResponder,
StyleSheet,
View,
} = React;
class AnExChained extends React.Component {
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}
source={{uri: 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 = [
'https://scontent-sea1-1.xx.fbcdn.net/hphotos-xpf1/t39.1997-6/p160x160/10574705_1529175770666007_724328156_n.png',
'https://fbcdn-dragon-a.akamaihd.net/hphotos-ak-xfa1/t39.1997-6/p160x160/851575_392309884199657_1917957497_n.png',
'https://fbcdn-dragon-a.akamaihd.net/hphotos-ak-xfa1/t39.1997-6/p160x160/851567_555288911225630_1628791128_n.png',
'https://scontent-sea1-1.xx.fbcdn.net/hphotos-xfa1/t39.1997-6/p160x160/851583_531111513625557_903469595_n.png',
'https://scontent-sea1-1.xx.fbcdn.net/hphotos-xpa1/t39.1997-6/p160x160/851577_510515972354399_2147096990_n.png',
];
module.exports = AnExChained;