const React = require('react'); const ReactDom = require('react-dom'); import PropTypes from 'prop-types'; const Velocity = require('velocity-vector'); /** * The Velociraptor contains components and animates transitions with velocity. * It will only pick up direct changes to properties ('left', currently), and so * will not work for animating positional changes where the position is implicit * from DOM order. This makes it a lot simpler and lighter: if you need fully * automatic positional animation, look at react-shuffle or similar libraries. */ module.exports = React.createClass({ displayName: 'Velociraptor', propTypes: { // either a list of child nodes, or a single child. children: PropTypes.any, // optional transition information for changing existing children transition: PropTypes.object, // a list of state objects to apply to each child node in turn startStyles: PropTypes.array, // a list of transition options from the corresponding startStyle enterTransitionOpts: PropTypes.array, }, getDefaultProps: function() { return { startStyles: [], enterTransitionOpts: [], }; }, componentWillMount: function() { this.nodes = {}; this._updateChildren(this.props.children); }, componentWillReceiveProps: function(nextProps) { this._updateChildren(nextProps.children); }, /** * update `this.children` according to the new list of children given */ _updateChildren: function(newChildren) { const self = this; const oldChildren = this.children || {}; this.children = {}; React.Children.toArray(newChildren).forEach(function(c) { if (oldChildren[c.key]) { const old = oldChildren[c.key]; const oldNode = ReactDom.findDOMNode(self.nodes[old.key]); if (oldNode && oldNode.style.left != c.props.style.left) { Velocity(oldNode, { left: c.props.style.left }, self.props.transition).then(function() { // special case visibility because it's nonsensical to animate an invisible element // so we always hidden->visible pre-transition and visible->hidden after if (oldNode.style.visibility == 'visible' && c.props.style.visibility == 'hidden') { oldNode.style.visibility = c.props.style.visibility; } }); //console.log("translation: "+oldNode.style.left+" -> "+c.props.style.left); } if (oldNode && oldNode.style.visibility == 'hidden' && c.props.style.visibility == 'visible') { oldNode.style.visibility = c.props.style.visibility; } // clone the old element with the props (and children) of the new element // so prop updates are still received by the children. self.children[c.key] = React.cloneElement(old, c.props, c.props.children); } else { // new element. If we have a startStyle, use that as the style and go through // the enter animations const newProps = {}; const restingStyle = c.props.style; const startStyles = self.props.startStyles; if (startStyles.length > 0) { const startStyle = startStyles[0]; newProps.style = startStyle; // console.log("mounted@startstyle0: "+JSON.stringify(startStyle)); } newProps.ref = ((n) => self._collectNode( c.key, n, restingStyle, )); self.children[c.key] = React.cloneElement(c, newProps); } }); }, /** * called when a child element is mounted/unmounted * * @param {string} k key of the child * @param {null|Object} node On mount: React node. On unmount: null * @param {Object} restingStyle final style */ _collectNode: function(k, node, restingStyle) { if ( node && this.nodes[k] === undefined && this.props.startStyles.length > 0 ) { const startStyles = this.props.startStyles; const transitionOpts = this.props.enterTransitionOpts; const domNode = ReactDom.findDOMNode(node); // start from startStyle 1: 0 is the one we gave it // to start with, so now we animate 1 etc. for (var i = 1; i < startStyles.length; ++i) { Velocity(domNode, startStyles[i], transitionOpts[i-1]); /* console.log("start:", JSON.stringify(transitionOpts[i-1]), "->", JSON.stringify(startStyles[i]), ); */ } // and then we animate to the resting state Velocity(domNode, restingStyle, transitionOpts[i-1]) .then(() => { // once we've reached the resting state, hide the element if // appropriate domNode.style.visibility = restingStyle.visibility; }); /* console.log("enter:", JSON.stringify(transitionOpts[i-1]), "->", JSON.stringify(restingStyle)); */ } else if (node === null) { // Velocity stores data on elements using the jQuery .data() // method, and assumes you'll be using jQuery's .remove() to // remove the element, but we don't use jQuery, so we need to // blow away the element's data explicitly otherwise it will leak. // This uses Velocity's internal jQuery compatible wrapper. // See the bug at // https://github.com/julianshapiro/velocity/issues/300 // and the FAQ entry, "Preventing memory leaks when // creating/destroying large numbers of elements" // (https://github.com/julianshapiro/velocity/issues/47) const domNode = ReactDom.findDOMNode(this.nodes[k]); if (domNode) Velocity.Utilities.removeData(domNode); } this.nodes[k] = node; }, render: function() { return ( { Object.values(this.children) } ); }, });