/*
This file is part of Ext JS 4.2

Copyright (c) 2011-2013 Sencha Inc

Contact:  http://www.sencha.com/contact

GNU General Public License Usage
This file may be used under the terms of the GNU General Public License version 3.0 as
published by the Free Software Foundation and appearing in the file LICENSE included in the
packaging of this file.

Please review the following information to ensure the GNU General Public License version 3.0
requirements will be met: http://www.gnu.org/copyleft/gpl.html.

If you are unsure which license is appropriate for your use, please contact the sales department
at http://www.sencha.com/contact.

Build date: 2013-05-16 14:36:50 (f9be68accb407158ba2b1be2c226a6ce1f649314)
*/
/**
 * This class manages animation for a specific {@link #target}. The animation allows
 * animation of various properties on the target, such as size, position, color and others.
 *
 * ## Starting Conditions
 *
 * The starting conditions for the animation are provided by the {@link #from} configuration.
 * Any/all of the properties in the {@link #from} configuration can be specified. If a particular
 * property is not defined, the starting value for that property will be read directly from the target.
 *
 * ## End Conditions
 *
 * The ending conditions for the animation are provided by the {@link #to} configuration. These mark
 * the final values once the animations has finished. The values in the {@link #from} can mirror
 * those in the {@link #to} configuration to provide a starting point.
 *
 * ## Other Options
 *
 *  - {@link #duration}: Specifies the time period of the animation.
 *  - {@link #easing}: Specifies the easing of the animation.
 *  - {@link #iterations}: Allows the animation to repeat a number of times.
 *  - {@link #alternate}: Used in conjunction with {@link #iterations}, reverses the direction every second iteration.
 *
 * ## Example Code
 *
 *     @example
 *     var myComponent = Ext.create('Ext.Component', {
 *         renderTo: document.body,
 *         width: 200,
 *         height: 200,
 *         style: 'border: 1px solid red;'
 *     });
 *
 *     Ext.create('Ext.fx.Anim', {
 *         target: myComponent,
 *         duration: 1000,
 *         from: {
 *             width: 400 //starting width 400
 *         },
 *         to: {
 *             width: 300, //end width 300
 *             height: 300 // end height 300
 *         }
 *     });
 */
Ext.define('Ext.fx.Anim', {

    /* Begin Definitions */

    mixins: {
        observable: 'Ext.util.Observable'
    },

    requires: ['Ext.fx.Manager', 'Ext.fx.Animator', 'Ext.fx.Easing', 'Ext.fx.CubicBezier', 'Ext.fx.PropertyHandler'],

    /* End Definitions */

    /**
     * @property {Boolean} isAnimation
     * `true` in this class to identify an object as an instantiated Anim, or subclass thereof.
     */
    isAnimation: true,

    /**
     * @cfg {Function} callback
     * A function to be run after the animation has completed.
     */

    /**
     * @cfg {Function} scope
     * The scope that the {@link #callback} function will be called with
     */

    /**
     * @cfg {Number} duration
     * Time in milliseconds for a single animation to last. If the {@link #iterations} property is
     * specified, then each animate will take the same duration for each iteration.
     */
    duration: 250,

    /**
     * @cfg {Number} delay
     * Time to delay before starting the animation.
     */
    delay: 0,

    /* @private used to track a delayed starting time */
    delayStart: 0,

    /**
     * @cfg {Boolean} dynamic
     * Currently only for Component Animation: Only set a component's outer element size bypassing layouts.
     * Set to true to do full layouts for every frame of the animation.
     */
    dynamic: false,

    /**
     * @cfg {String} easing
     * This describes how the intermediate values used during a transition will be calculated.
     * It allows for a transition to change speed over its duration.
     *
     * - backIn
     * - backOut
     * - bounceIn
     * - bounceOut
     * - ease
     * - easeIn
     * - easeOut
     * - easeInOut
     * - elasticIn
     * - elasticOut
     * - cubic-bezier(x1, y1, x2, y2)
     *
     * Note that cubic-bezier will create a custom easing curve following the CSS3 [transition-timing-function][0]
     * specification.  The four values specify points P1 and P2 of the curve as (x1, y1, x2, y2). All values must
     * be in the range [0, 1] or the definition is invalid.
     *
     * [0]: http://www.w3.org/TR/css3-transitions/#transition-timing-function_tag
     */
    easing: 'ease',

    /**
     * @cfg {Object} keyframes
     * Animation keyframes follow the CSS3 Animation configuration pattern. 'from' is always considered '0%' and 'to'
     * is considered '100%'. **Every keyframe declaration must have a keyframe rule for 0% and 100%, possibly defined using
     * "from" or "to".**  A keyframe declaration without these keyframe selectors is invalid and will not be available for
     * animation.  The keyframe declaration for a keyframe rule consists of properties and values. Properties that are unable to
     * be animated are ignored in these rules, with the exception of 'easing' which can be changed at each keyframe. For example:
     *
     *     keyframes : {
     *         '0%': {
     *             left: 100
     *         },
     *         '40%': {
     *             left: 150
     *         },
     *         '60%': {
     *             left: 75
     *         },
     *         '100%': {
     *             left: 100
     *         }
     *     }
     */

    /**
     * @private
     */
    damper: 1,

    /**
     * @private
     */
    bezierRE: /^(?:cubic-)?bezier\(([^,]+),([^,]+),([^,]+),([^\)]+)\)/,

    /**
     * Run the animation from the end to the beginning
     * Defaults to false.
     * @cfg {Boolean} reverse
     */
    reverse: false,

    /**
     * Flag to determine if the animation has started
     * @property running
     * @type Boolean
     */
    running: false,

    /**
     * Flag to determine if the animation is paused. Only set this to true if you need to
     * keep the Anim instance around to be unpaused later; otherwise call {@link #end}.
     * @property paused
     * @type Boolean
     */
    paused: false,

    /**
     * @cfg {Number} iterations
     * Number of times to execute the animation.
     */
    iterations: 1,

    /**
     * @cfg {Boolean} alternate
     * Used in conjunction with iterations to reverse the animation each time an iteration completes.
     */
    alternate: false,

    /**
     * Current iteration the animation is running.
     * @property currentIteration
     * @type Number
     */
    currentIteration: 0,

    /**
     * Starting time of the animation.
     * @property startTime
     * @type Date
     */
    startTime: 0,

    /**
     * Contains a cache of the interpolators to be used.
     * @private
     * @property propHandlers
     * @type Object
     */

    /**
     * @cfg {String/Object} target
     * The {@link Ext.fx.target.Target} to apply the animation to.  This should only be specified when creating an Ext.fx.Anim directly.
     * The target does not need to be a {@link Ext.fx.target.Target} instance, it can be the underlying object. For example, you can
     * pass a Component, Element or Sprite as the target and the Anim will create the appropriate {@link Ext.fx.target.Target} object
     * automatically.
     */

    /**
     * @cfg {Object} from
     * An object containing property/value pairs for the beginning of the animation.  If not specified, the current state of the
     * Ext.fx.target will be used. For example:
     *
     *     from: {
     *         opacity: 0,       // Transparent
     *         color: '#ffffff', // White
     *         left: 0
     *     }
     *
     */

    /**
     * @cfg {Object} to (required)
     * An object containing property/value pairs for the end of the animation. For example:
     *
     *     to: {
     *         opacity: 1,       // Opaque
     *         color: '#00ff00', // Green
     *         left: 500
     *     }
     *
     */
    
    // @private
    frameCount: 0,

    // @private
    constructor: function(config) {
        var me = this,
            curve;
            
        config = config || {};
        // If keyframes are passed, they really want an Animator instead.
        if (config.keyframes) {
            return new Ext.fx.Animator(config);
        }
        Ext.apply(me, config);
        if (me.from === undefined) {
            me.from = {};
        }
        me.propHandlers = {};
        me.config = config;
        me.target = Ext.fx.Manager.createTarget(me.target);
        me.easingFn = Ext.fx.Easing[me.easing];
        me.target.dynamic = me.dynamic;

        // If not a pre-defined curve, try a cubic-bezier
        if (!me.easingFn) {
            me.easingFn = String(me.easing).match(me.bezierRE);
            if (me.easingFn && me.easingFn.length == 5) {
                curve = me.easingFn;
                me.easingFn = Ext.fx.CubicBezier.cubicBezier(+curve[1], +curve[2], +curve[3], +curve[4]);
            }
        }
        me.id = Ext.id(null, 'ext-anim-');
        me.addEvents(
            /**
             * @event beforeanimate
             * Fires before the animation starts. A handler can return false to cancel the animation.
             * @param {Ext.fx.Anim} this
             */
            'beforeanimate',
             /**
              * @event afteranimate
              * Fires when the animation is complete.
              * @param {Ext.fx.Anim} this
              * @param {Date} startTime
              */
            'afteranimate',
             /**
              * @event lastframe
              * Fires when the animation's last frame has been set.
              * @param {Ext.fx.Anim} this
              * @param {Date} startTime
              */
            'lastframe'
        );
        me.mixins.observable.constructor.call(me);
        Ext.fx.Manager.addAnim(me);
    },

    /**
     * @private
     * Helper to the target
     */
    setAttr: function(attr, value) {
        return Ext.fx.Manager.items.get(this.id).setAttr(this.target, attr, value);
    },

    /**
     * @private
     * Set up the initial currentAttrs hash.
     */
    initAttrs: function() {
        var me = this,
            from = me.from,
            to = me.to,
            initialFrom = me.initialFrom || {},
            out = {},
            start, end, propHandler, attr;

        for (attr in to) {
            if (to.hasOwnProperty(attr)) {
                start = me.target.getAttr(attr, from[attr]);
                end = to[attr];
                // Use default (numeric) property handler
                if (!Ext.fx.PropertyHandler[attr]) {
                    if (Ext.isObject(end)) {
                        propHandler = me.propHandlers[attr] = Ext.fx.PropertyHandler.object;
                    } else {
                        propHandler = me.propHandlers[attr] = Ext.fx.PropertyHandler.defaultHandler;
                    }
                }
                // Use custom handler
                else {
                    propHandler = me.propHandlers[attr] = Ext.fx.PropertyHandler[attr];
                }
                out[attr] = propHandler.get(start, end, me.damper, initialFrom[attr], attr);
            }
        }
        me.currentAttrs = out;
    },

    /**
     * @private
     * Fires beforeanimate and sets the running flag.
     */
    start: function(startTime) {
        var me = this,
            delay = me.delay,
            delayStart = me.delayStart,
            delayDelta;
        
        if (delay) {
            if (!delayStart) {
                me.delayStart = startTime;
                return;
            }
            else {
                delayDelta = startTime - delayStart;
                if (delayDelta < delay) {
                    return;
                }
                else {
                    // Compensate for frame delay;
                    startTime = new Date(delayStart.getTime() + delay);
                }
            }
        }
        if (me.fireEvent('beforeanimate', me) !== false) {
            me.startTime = startTime;
            if (!me.paused && !me.currentAttrs) {
                me.initAttrs();
            }
            me.running = true;
            me.frameCount = 0;
        }
    },

    /**
     * @private
     * Calculate attribute value at the passed timestamp.
     * @returns a hash of the new attributes.
     */
    runAnim: function(elapsedTime) {
        var me = this,
            attrs = me.currentAttrs,
            duration = me.duration,
            easingFn = me.easingFn,
            propHandlers = me.propHandlers,
            ret = {},
            easing, values, attr, lastFrame;

        if (elapsedTime >= duration) {
            elapsedTime = duration;
            lastFrame = true;
        }
        if (me.reverse) {
            elapsedTime = duration - elapsedTime;
        }

        for (attr in attrs) {
            if (attrs.hasOwnProperty(attr)) {
                values = attrs[attr];
                easing = lastFrame ? 1 : easingFn(elapsedTime / duration);
                ret[attr] = propHandlers[attr].set(values, easing);
            }
        }
        me.frameCount++;
            
        return ret;
    },

    /**
     * @private
     * Perform lastFrame cleanup and handle iterations
     * @returns a hash of the new attributes.
     */
    lastFrame: function() {
        var me = this,
            iter = me.iterations,
            iterCount = me.currentIteration;

        iterCount++;
        if (iterCount < iter) {
            if (me.alternate) {
                me.reverse = !me.reverse;
            }
            me.startTime = new Date();
            me.currentIteration = iterCount;
            // Turn off paused for CSS3 Transitions
            me.paused = false;
        }
        else {
            me.currentIteration = 0;
            me.end();
            me.fireEvent('lastframe', me, me.startTime);
        }
    },

    endWasCalled: 0,

    /**
     * Fire afteranimate event and end the animation. Usually called automatically when the
     * animation reaches its final frame, but can also be called manually to pre-emptively
     * stop and destroy the running animation.
     */
    end: function() {
        if (this.endWasCalled++) {
            return;
        }
        var me = this;
        me.startTime = 0;
        me.paused = false;
        me.running = false;
        Ext.fx.Manager.removeAnim(me);
        me.fireEvent('afteranimate', me, me.startTime);
        Ext.callback(me.callback, me.scope, [me, me.startTime]);
    },
    
    isReady: function() {
        return this.paused === false && this.running === false && this.iterations > 0;
    },
    
    isRunning: function() {
        return this.paused === false && this.running === true && this.isAnimator !== true;
    }
});
// Set flag to indicate that Fx is available. Class might not be available immediately.
Ext.enableFx = true;
