animation-debug.js

这是YUI的源码及相关示例。里面有很多很炫的Javascript效果。

/*
Copyright (c) 2008, Yahoo! Inc. All rights reserved.
Code licensed under the BSD License:
http://developer.yahoo.net/yui/license.txt
version: 2.6.0
*/
(function() {

var Y = YAHOO.util;

/*
Copyright (c) 2006, Yahoo! Inc. All rights reserved.
Code licensed under the BSD License:
http://developer.yahoo.net/yui/license.txt
*/

/**
 * The animation module provides allows effects to be added to HTMLElements.
 * @module animation
 * @requires yahoo, event, dom
 */

/**
 *
 * Base animation class that provides the interface for building animated effects.
 * <p>Usage: var myAnim = new YAHOO.util.Anim(el, { width: { from: 10, to: 100 } }, 1, YAHOO.util.Easing.easeOut);</p>
 * @class Anim
 * @namespace YAHOO.util
 * @requires YAHOO.util.AnimMgr
 * @requires YAHOO.util.Easing
 * @requires YAHOO.util.Dom
 * @requires YAHOO.util.Event
 * @requires YAHOO.util.CustomEvent
 * @constructor
 * @param {String | HTMLElement} el Reference to the element that will be animated
 * @param {Object} attributes The attribute(s) to be animated.  
 * Each attribute is an object with at minimum a "to" or "by" member defined.  
 * Additional optional members are "from" (defaults to current value), "units" (defaults to "px").  
 * All attribute names use camelCase.
 * @param {Number} duration (optional, defaults to 1 second) Length of animation (frames or seconds), defaults to time-based
 * @param {Function} method (optional, defaults to YAHOO.util.Easing.easeNone) Computes the values that are applied to the attributes per frame (generally a YAHOO.util.Easing method)
 */

var Anim = function(el, attributes, duration, method) {
    if (!el) {
        YAHOO.log('element required to create Anim instance', 'error', 'Anim');
    }
    this.init(el, attributes, duration, method); 
};

Anim.NAME = 'Anim';

Anim.prototype = {
    /**
     * Provides a readable name for the Anim instance.
     * @method toString
     * @return {String}
     */
    toString: function() {
        var el = this.getEl() || {};
        var id = el.id || el.tagName;
        return (this.constructor.NAME + ': ' + id);
    },
    
    patterns: { // cached for performance
        noNegatives:        /width|height|opacity|padding/i, // keep at zero or above
        offsetAttribute:  /^((width|height)|(top|left))$/, // use offsetValue as default
        defaultUnit:        /width|height|top$|bottom$|left$|right$/i, // use 'px' by default
        offsetUnit:         /\d+(em|%|en|ex|pt|in|cm|mm|pc)$/i // IE may return these, so convert these to offset
    },
    
    /**
     * Returns the value computed by the animation's "method".
     * @method doMethod
     * @param {String} attr The name of the attribute.
     * @param {Number} start The value this attribute should start from for this animation.
     * @param {Number} end  The value this attribute should end at for this animation.
     * @return {Number} The Value to be applied to the attribute.
     */
    doMethod: function(attr, start, end) {
        return this.method(this.currentFrame, start, end - start, this.totalFrames);
    },
    
    /**
     * Applies a value to an attribute.
     * @method setAttribute
     * @param {String} attr The name of the attribute.
     * @param {Number} val The value to be applied to the attribute.
     * @param {String} unit The unit ('px', '%', etc.) of the value.
     */
    setAttribute: function(attr, val, unit) {
        if ( this.patterns.noNegatives.test(attr) ) {
            val = (val > 0) ? val : 0;
        }

        Y.Dom.setStyle(this.getEl(), attr, val + unit);
    },                        
    
    /**
     * Returns current value of the attribute.
     * @method getAttribute
     * @param {String} attr The name of the attribute.
     * @return {Number} val The current value of the attribute.
     */
    getAttribute: function(attr) {
        var el = this.getEl();
        var val = Y.Dom.getStyle(el, attr);

        if (val !== 'auto' && !this.patterns.offsetUnit.test(val)) {
            return parseFloat(val);
        }
        
        var a = this.patterns.offsetAttribute.exec(attr) || [];
        var pos = !!( a[3] ); // top or left
        var box = !!( a[2] ); // width or height
        
        // use offsets for width/height and abs pos top/left
        if ( box || (Y.Dom.getStyle(el, 'position') == 'absolute' && pos) ) {
            val = el['offset' + a[0].charAt(0).toUpperCase() + a[0].substr(1)];
        } else { // default to zero for other 'auto'
            val = 0;
        }

        return val;
    },
    
    /**
     * Returns the unit to use when none is supplied.
     * @method getDefaultUnit
     * @param {attr} attr The name of the attribute.
     * @return {String} The default unit to be used.
     */
    getDefaultUnit: function(attr) {
         if ( this.patterns.defaultUnit.test(attr) ) {
            return 'px';
         }
         
         return '';
    },
        
    /**
     * Sets the actual values to be used during the animation.  Should only be needed for subclass use.
     * @method setRuntimeAttribute
     * @param {Object} attr The attribute object
     * @private 
     */
    setRuntimeAttribute: function(attr) {
        var start;
        var end;
        var attributes = this.attributes;

        this.runtimeAttributes[attr] = {};
        
        var isset = function(prop) {
            return (typeof prop !== 'undefined');
        };
        
        if ( !isset(attributes[attr]['to']) && !isset(attributes[attr]['by']) ) {
            return false; // note return; nothing to animate to
        }
        
        start = ( isset(attributes[attr]['from']) ) ? attributes[attr]['from'] : this.getAttribute(attr);

        // To beats by, per SMIL 2.1 spec
        if ( isset(attributes[attr]['to']) ) {
            end = attributes[attr]['to'];
        } else if ( isset(attributes[attr]['by']) ) {
            if (start.constructor == Array) {
                end = [];
                for (var i = 0, len = start.length; i < len; ++i) {
                    end[i] = start[i] + attributes[attr]['by'][i] * 1; // times 1 to cast "by" 
                }
            } else {
                end = start + attributes[attr]['by'] * 1;
            }
        }
        
        this.runtimeAttributes[attr].start = start;
        this.runtimeAttributes[attr].end = end;

        // set units if needed
        this.runtimeAttributes[attr].unit = ( isset(attributes[attr].unit) ) ?
                attributes[attr]['unit'] : this.getDefaultUnit(attr);
        return true;
    },

    /**
     * Constructor for Anim instance.
     * @method init
     * @param {String | HTMLElement} el Reference to the element that will be animated
     * @param {Object} attributes The attribute(s) to be animated.  
     * Each attribute is an object with at minimum a "to" or "by" member defined.  
     * Additional optional members are "from" (defaults to current value), "units" (defaults to "px").  
     * All attribute names use camelCase.
     * @param {Number} duration (optional, defaults to 1 second) Length of animation (frames or seconds), defaults to time-based
     * @param {Function} method (optional, defaults to YAHOO.util.Easing.easeNone) Computes the values that are applied to the attributes per frame (generally a YAHOO.util.Easing method)
     */ 
    init: function(el, attributes, duration, method) {
        /**
         * Whether or not the animation is running.
         * @property isAnimated
         * @private
         * @type Boolean
         */
        var isAnimated = false;
        
        /**
         * A Date object that is created when the animation begins.
         * @property startTime
         * @private
         * @type Date
         */
        var startTime = null;
        
        /**
         * The number of frames this animation was able to execute.
         * @property actualFrames
         * @private
         * @type Int
         */
        var actualFrames = 0; 

        /**
         * The element to be animated.
         * @property el
         * @private
         * @type HTMLElement
         */
        el = Y.Dom.get(el);
        
        /**
         * The collection of attributes to be animated.  
         * Each attribute must have at least a "to" or "by" defined in order to animate.  
         * If "to" is supplied, the animation will end with the attribute at that value.  
         * If "by" is supplied, the animation will end at that value plus its starting value. 
         * If both are supplied, "to" is used, and "by" is ignored. 
         * Optional additional member include "from" (the value the attribute should start animating from, defaults to current value), and "unit" (the units to apply to the values).
         * @property attributes
         * @type Object
         */
        this.attributes = attributes || {};
        
        /**
         * The length of the animation.  Defaults to "1" (second).
         * @property duration
         * @type Number
         */
        this.duration = !YAHOO.lang.isUndefined(duration) ? duration : 1;
        
        /**
         * The method that will provide values to the attribute(s) during the animation. 
         * Defaults to "YAHOO.util.Easing.easeNone".
         * @property method
         * @type Function
         */
        this.method = method || Y.Easing.easeNone;

        /**
         * Whether or not the duration should be treated as seconds.
         * Defaults to true.
         * @property useSeconds
         * @type Boolean
         */
        this.useSeconds = true; // default to seconds
        
        /**
         * The location of the current animation on the timeline.
         * In time-based animations, this is used by AnimMgr to ensure the animation finishes on time.
         * @property currentFrame
         * @type Int
         */
        this.currentFrame = 0;
        
        /**
         * The total number of frames to be executed.
         * In time-based animations, this is used by AnimMgr to ensure the animation finishes on time.
         * @property totalFrames
         * @type Int
         */
        this.totalFrames = Y.AnimMgr.fps;
        
        /**
         * Changes the animated element
         * @method setEl
         */
        this.setEl = function(element) {
            el = Y.Dom.get(element);
        };
        
        /**
         * Returns a reference to the animated element.
         * @method getEl
         * @return {HTMLElement}
         */
        this.getEl = function() { return el; };
        
        /**
         * Checks whether the element is currently animated.
         * @method isAnimated
         * @return {Boolean} current value of isAnimated.     
         */
        this.isAnimated = function() {
            return isAnimated;
        };
        
        /**
         * Returns the animation start time.
         * @method getStartTime
         * @return {Date} current value of startTime.      
         */
        this.getStartTime = function() {
            return startTime;
        };        
        
        this.runtimeAttributes = {};
        
        var logger = {};
        logger.log = function() {YAHOO.log.apply(window, arguments)};
        
        logger.log('creating new instance of ' + this);
        
        /**
         * Starts the animation by registering it with the animation manager. 
         * @method animate  
         */
        this.animate = function() {
            if ( this.isAnimated() ) {
                return false;
            }
            
            this.currentFrame = 0;
            
            this.totalFrames = ( this.useSeconds ) ? Math.ceil(Y.AnimMgr.fps * this.duration) : this.duration;
    
            if (this.duration === 0 && this.useSeconds) { // jump to last frame if zero second duration 
                this.totalFrames = 1; 
            }
            Y.AnimMgr.registerElement(this);
            return true;
        };
          
        /**
         * Stops the animation.  Normally called by AnimMgr when animation completes.
         * @method stop
         * @param {Boolean} finish (optional) If true, animation will jump to final frame.
         */ 
        this.stop = function(finish) {