/*

YUI 3.10.3 (build 2fb5187)

Copyright 2013 Yahoo! Inc. All rights reserved.

Licensed under the BSD License.

http://yuilibrary.com/license/

*/

YUI.add('slider-value-range', function (Y, NAME) {

/**

 * Adds value support for Slider as a range of integers between a configured

 * minimum and maximum value.  For use with <code>Y.Base.build(..)</code> to

 * add the plumbing to <code>Y.SliderBase</code>.

 *

 * @module slider

 * @submodule slider-value-range

 */

// Constants for compression or performance

var MIN       = 'min',

    MAX       = 'max',

    VALUE     = 'value',

//     MINORSTEP = 'minorStep',

//     MAJORSTEP = 'majorStep',

    round = Math.round;

/**

 * One class of value algorithm that can be built onto SliderBase.  By default,

 * values range between 0 and 100, but you can configure these on the

 * built Slider class by setting the <code>min</code> and <code>max</code>

 * configurations.  Set the initial value (will cause the thumb to move to the

 * appropriate location on the rail) in configuration as well if appropriate.

 *

 * @class SliderValueRange

 */

function SliderValueRange() {

    this._initSliderValueRange();

}

Y.SliderValueRange = Y.mix( SliderValueRange, {

    // Prototype properties and methods that will be added onto host class

    prototype: {

        /**

         * Factor used to translate value -> position -> value.

         *

         * @property _factor

         * @type {Number}

         * @protected

         */

        _factor: 1,

        /**

         * Stub for construction logic.  Override if extending this class and

         * you need to set something up during the initializer phase.

         *

         * @method _initSliderValueRange

         * @protected

         */

        _initSliderValueRange: function () {},

        /**

         * Override of stub method in SliderBase that is called at the end of

         * its bindUI stage of render().  Subscribes to internal events to

         * trigger UI and related state updates.

         *

         * @method _bindValueLogic

         * @protected

         */

        _bindValueLogic: function () {

            this.after( {

                minChange  : this._afterMinChange,

                maxChange  : this._afterMaxChange,

                valueChange: this._afterValueChange

            } );

        },

        /**

         * Move the thumb to appropriate position if necessary.  Also resets

         * the cached offsets and recalculates the conversion factor to

         * translate position to value.

         *

         * @method _syncThumbPosition

         * @protected

         */

        _syncThumbPosition: function () {

            this._calculateFactor();

            this._setPosition( this.get( VALUE ) );

        },

        /**

         * Calculates and caches

         * (range between max and min) / (rail length)

         * for fast runtime calculation of position -> value.

         *

         * @method _calculateFactor

         * @protected

         */

        _calculateFactor: function () {

            var length    = this.get( 'length' ),

                thumbSize = this.thumb.getStyle( this._key.dim ),

                min       = this.get( MIN ),

                max       = this.get( MAX );

            // The default thumb width is based on Sam skin's thumb dimension.

            // This attempts to allow for rendering off-DOM, then attaching

            // without the need to call syncUI().  It is still recommended

            // to call syncUI() in these cases though, just to be sure.

            length = parseFloat( length ) || 150;

            thumbSize = parseFloat( thumbSize ) || 15;

            this._factor = ( max - min ) / ( length - thumbSize );

            Y.log("Calculating factor(~" + this._factor.toFixed(3) + " = (max(" + max + ") - min(" + min + ")) / (length(" + length + ") - thumb size(" + thumbSize + "))","info","slider");

        },

        /**

         * Dispatch the new position of the thumb into the value setting

         * operations.

         *

         * @method _defThumbMoveFn

         * @param e { EventFacade } The host's thumbMove event

         * @protected

         */

        _defThumbMoveFn: function ( e ) {

            // To prevent set('value', x) from looping back around

            if (e.source !== 'set') {

                this.set(VALUE, this._offsetToValue(e.offset));

            }

        },

        /**

         * <p>Converts a pixel position into a value.  Calculates current

         * thumb offset from the leading edge of the rail multiplied by the

         * ratio of <code>(max - min) / (constraining dim)</code>.</p>

         *

         * <p>Override this if you want to use a different value mapping

         * algorithm.</p>

         *

         * @method _offsetToValue

         * @param offset { Number } X or Y pixel offset

         * @return { mixed } Value corresponding to the provided pixel offset

         * @protected

         */

        _offsetToValue: function ( offset ) {

            var value = round( offset * this._factor ) + this.get( MIN );

            Y.log("Offset: " + offset + " => Value: " + value, "info", "slider");

            return round( this._nearestValue( value ) );

        },

        /**

         * Converts a value into a pixel offset for use in positioning

         * the thumb according to the reverse of the

         * <code>_offsetToValue( xy )</code> operation.

         *

         * @method _valueToOffset

         * @param val { Number } The value to map to pixel X or Y position

         * @return { Number } The pixel offset 

         * @protected

         */

        _valueToOffset: function ( value ) {

            var offset = round( ( value - this.get( MIN ) ) / this._factor );

            Y.log("Value: " + value + " => Offset: " + offset, "info", "slider");

            return offset;

        },

        /**

         * Returns the current value.  Override this if you want to introduce

         * output formatting. Otherwise equivalent to slider.get( "value" );

         *

         * @method getValue

         * @return {Number}

         */

        getValue: function () {

            return this.get( VALUE );

        },

        /**

         * Updates the current value.  Override this if you want to introduce

         * input value parsing or preprocessing.  Otherwise equivalent to

         * slider.set( "value", v );

         *

         * @method setValue

         * @param val {Number} The new value

         * @return {Slider}

         * @chainable

         */

        setValue: function ( val ) {

            return this.set( VALUE, val );

        },

        /**

         * Update position according to new min value.  If the new min results

         * in the current value being out of range, the value is set to the

         * closer of min or max.

         *

         * @method _afterMinChange

         * @param e { EventFacade } The <code>min</code> attribute change event.

         * @protected

         */

        _afterMinChange: function ( e ) {

            this._verifyValue();

            this._syncThumbPosition();

        },

        /**

         * Update position according to new max value.  If the new max results

         * in the current value being out of range, the value is set to the

         * closer of min or max.

         *

         * @method _afterMaxChange

         * @param e { EventFacade } The <code>max</code> attribute change event.

         * @protected

         */

        _afterMaxChange: function ( e ) {

            this._verifyValue();

            this._syncThumbPosition();

        },

        /**

         * Verifies that the current value is within the min - max range.  If

         * not, value is set to either min or max, depending on which is

         * closer.

         *

         * @method _verifyValue

         * @protected

         */

        _verifyValue: function () {

            var value   = this.get( VALUE ),

                nearest = this._nearestValue( value );

            if ( value !== nearest ) {

                // @TODO Can/should valueChange, minChange, etc be queued

                // events? To make dd.set( 'min', n ); execute after minChange

                // subscribers before on/after valueChange subscribers.

                this.set( VALUE, nearest );

            }

        },

        /**

         * Propagate change to the thumb position unless the change originated

         * from the thumbMove event.

         *

         * @method _afterValueChange

         * @param e { EventFacade } The <code>valueChange</code> event.

         * @protected

         */

        _afterValueChange: function ( e ) {

            var val = e.newVal;

            Y.log("Positioning thumb after set('value',x)","info","slider");

            this._setPosition( val, { source: 'set' } );

        },

        /**

         * Positions the thumb and its ARIA attributes in accordance with the 

         * translated value.

         *

         * @method _setPosition

         * @param value {Number} Value to translate to a pixel position

         * @param [options] {Object} Details object to pass to `_uiMoveThumb`

         * @protected

         */

        _setPosition: function ( value, options ) {

            this._uiMoveThumb( this._valueToOffset( value ), options );

            this.thumb.set('aria-valuenow', value);

            this.thumb.set('aria-valuetext', value);

        },

        /**

         * Validates new values assigned to <code>min</code> attribute.  Numbers

         * are acceptable.  Override this to enforce different rules.

         *

         * @method _validateNewMin

         * @param value {Any} Value assigned to <code>min</code> attribute.

         * @return {Boolean} True for numbers.  False otherwise.

         * @protected

         */

        _validateNewMin: function ( value ) {

            return Y.Lang.isNumber( value );

        },

        /**

         * Validates new values assigned to <code>max</code> attribute.  Numbers

         * are acceptable.  Override this to enforce different rules.

         *

         * @method _validateNewMax

         * @param value { mixed } Value assigned to <code>max</code> attribute.

         * @return { Boolean } True for numbers.  False otherwise.

         * @protected

         */

        _validateNewMax: function ( value ) {

            return Y.Lang.isNumber( value );

        },

        /**

         * Restricts new values assigned to <code>value</code> attribute to be

         * between the configured <code>min</code> and <code>max</code>.

         * Rounds to nearest integer value.

         *

         * @method _setNewValue

         * @param value { Number } Value assigned to <code>value</code> attribute

         * @return { Number } Normalized and constrained value

         * @protected

         */

        _setNewValue: function ( value ) {

            return round( this._nearestValue( value ) );

        },

        /**

         * Returns the nearest valid value to the value input.  If the provided

         * value is outside the min - max range, accounting for min > max

         * scenarios, the nearest of either min or max is returned.  Otherwise,

         * the provided value is returned.

         *

         * @method _nearestValue

         * @param value { mixed } Value to test against current min - max range

         * @return { Number } Current min, max, or value if within range

         * @protected

         */

        _nearestValue: function ( value ) {

            var min = this.get( MIN ),

                max = this.get( MAX ),

                tmp;

            // Account for reverse value range (min > max)

            tmp = ( max > min ) ? max : min;

            min = ( max > min ) ? min : max;

            max = tmp;

            return ( value < min ) ?

                    min :

                    ( value > max ) ?

                        max :

                        value;

        }

    },

    /**

     * Attributes that will be added onto host class.

     *

     * @property ATTRS

     * @type {Object}

     * @static

     * @protected

     */

    ATTRS: {

        /**

         * The value associated with the farthest top, left position of the

         * rail.  Can be greater than the configured <code>max</code> if you

         * want values to increase from right-to-left or bottom-to-top.

         *

         * @attribute min

         * @type { Number }

         * @default 0

         */

        min: {

            value    : 0,

            validator: '_validateNewMin'

        },

        /**

         * The value associated with the farthest bottom, right position of

         * the rail.  Can be less than the configured <code>min</code> if

         * you want values to increase from right-to-left or bottom-to-top.

         *

         * @attribute max

         * @type { Number }

         * @default 100

         */

        max: {

            value    : 100,

            validator: '_validateNewMax'

        },

        /**

         * amount to increment/decrement the Slider value

         * when the arrow up/down/left/right keys are pressed

         *

         * @attribute minorStep

         * @type {Number}

         * @default 1

         */

        minorStep : {

            value: 1

        },

        /**

         * amount to increment/decrement the Slider value

         * when the page up/down keys are pressed

         *

         * @attribute majorStep

         * @type {Number}

         * @default 10

         */

        majorStep : {

            value: 10

        },

        /**

         * The value associated with the thumb's current position on the

         * rail. Defaults to the value inferred from the thumb's current

         * position. Specifying value in the constructor will move the

         * thumb to the position that corresponds to the supplied value.

         *

         * @attribute value

         * @type { Number }

         * @default (inferred from current thumb position)

         */

        value: {

            value : 0,

            setter: '_setNewValue'

        }

    }

}, true );

}, '3.10.3', {"requires": ["slider-base"]});