jquery.cycle2.autoheight.js

/*! Cycle2 autoheight plugin; Copyright (c) M.Alsup, 2012; version: 20130304 */
(function($) {
"use strict";

$.extend($.fn.cycle.defaults, {
    autoHeight: 0 // setting this option to false disables autoHeight logic
});    

$(document).on( 'cycle-initialized', function( e, opts ) {
    var autoHeight = opts.autoHeight;
    var t = $.type( autoHeight );
    var resizeThrottle = null;
    var ratio;

    if ( t !== 'string' && t !== 'number' )
        return;

    // bind events
    opts.container.on( 'cycle-slide-added cycle-slide-removed', initAutoHeight );
    opts.container.on( 'cycle-destroyed', onDestroy );

    if ( autoHeight == 'container' ) {
        opts.container.on( 'cycle-before', onBefore );
    }
    else if ( t === 'string' && /\d+\:\d+/.test( autoHeight ) ) { 
        // use ratio
        ratio = autoHeight.match(/(\d+)\:(\d+)/);
        ratio = ratio[1] / ratio[2];
        opts._autoHeightRatio = ratio;
    }

    // if autoHeight is a number then we don't need to recalculate the sentinel
    // index on resize
    if ( t !== 'number' ) {
        // bind unique resize handler per slideshow (so it can be 'off-ed' in onDestroy)
        opts._autoHeightOnResize = function () {
            clearTimeout( resizeThrottle );
            resizeThrottle = setTimeout( onResize, 50 );
        };

        $(window).on( 'resize orientationchange', opts._autoHeightOnResize );
    }

    setTimeout( onResize, 30 );

    function onResize() {
        initAutoHeight( e, opts );
    }
});

function initAutoHeight( e, opts ) {
    var clone, height, sentinelIndex;
    var autoHeight = opts.autoHeight;

    if ( autoHeight == 'container' ) {
        height = $( opts.slides[ opts.currSlide ] ).outerHeight();
        opts.container.height( height );
    }
    else if ( opts._autoHeightRatio ) { 
        opts.container.height( opts.container.width() / opts._autoHeightRatio );
    }
    else if ( autoHeight === 'calc' || ( $.type( autoHeight ) == 'number' && autoHeight >= 0 ) ) {
        if ( autoHeight === 'calc' )
            sentinelIndex = calcSentinelIndex( e, opts );
        else if ( autoHeight >= opts.slides.length )
            sentinelIndex = 0;
        else 
            sentinelIndex = autoHeight;

        // only recreate sentinel if index is different
        if ( sentinelIndex == opts._sentinelIndex )
            return;

        opts._sentinelIndex = sentinelIndex;
        if ( opts._sentinel )
            opts._sentinel.remove();

        // clone existing slide as sentinel
        clone = $( opts.slides[ sentinelIndex ].cloneNode(true) );
        
        // #50; remove special attributes from cloned content
        clone.removeAttr( 'id name rel' ).find( '[id],[name],[rel]' ).removeAttr( 'id name rel' );

        clone.css({
            position: 'static',
            visibility: 'hidden',
            display: 'block'
        }).prependTo( opts.container ).addClass('cycle-sentinel cycle-slide').removeClass('cycle-slide-active');
        clone.find( '*' ).css( 'visibility', 'hidden' );

        opts._sentinel = clone;
    }
}    

function calcSentinelIndex( e, opts ) {
    var index = 0, max = -1;

    // calculate tallest slide index
    opts.slides.each(function(i) {
        var h = $(this).height();
        if ( h > max ) {
            max = h;
            index = i;
        }
    });
    return index;
}

function onBefore( e, opts, outgoing, incoming, forward ) {
    var h = $(incoming).outerHeight();
    var duration = opts.sync ? opts.speed / 2 : opts.speed;
    opts.container.animate( { height: h }, duration );
}

function onDestroy( e, opts ) {
    if ( opts._autoHeightOnResize ) {
        $(window).off( 'resize orientationchange', opts._autoHeightOnResize );
        opts._autoHeightOnResize = null;
    }
    opts.container.off( 'cycle-slide-added cycle-slide-removed', initAutoHeight );
    opts.container.off( 'cycle-destroyed', onDestroy );
    opts.container.off( 'cycle-before', onBefore );

    if ( opts._sentinel ) {
        opts._sentinel.remove();
        opts._sentinel = null;
    }
}

})(jQuery);