// Constructor
extransit.MenuManager = function() {

    this.openItems = [];
    this.closingItems = [];
    this.currentlyOpen = '';
};

// Inherit
extransit.MenuManager.prototype = new Object();

// Constants

extransit.MenuManager.prototype.STATE_IDLE = 0;


// Public functions

/** Open a navigation menu.
 */
extransit.MenuManager.prototype.open = function(parent, items) {

    if (this.currentlyOpen == parent) {   // Clicked on the open menu

        // Close it, no more action

        // Put the currently open menu in the "closing program"
        this.closingItems = this.openItems;
        this.openItems = [];

        setTimeout(function() {
            menuManager.progress();
        }, 50);

        this.currentlyOpen = '';

        this.grayOut(false);

        return;
    }
    else { // Clicked on a non-open menu

        // Safely close any closing menu (if the user clicked in a new menu before the previous was closed)
        jQuery.each(this.closingItems, function(index, value) {

            jQuery('#' + value.id).hide();
        });

        // Put the currently open menu in the "closing program"
        this.closingItems = this.openItems;
        this.openItems = [];

        this.currentlyOpen = parent;

        this.grayOut(true);
    }

    var self = this;

    var factory = new extransit.LinearItemFactory();

    factory.init(parent, items);

    // Populate with aminatable menu items
    while (factory.hasNext()) {

        self.openItems.push(factory.next());        
    }

    // Fire up the animation
    setTimeout(function() {
        menuManager.progress();
    }, 50);

    // Show the opening menu
    jQuery.each(this.openItems, function(index, value) {

        jQuery('#' + value.id).show();
    });
};

/**
 * Animation progress.
 */
extransit.MenuManager.prototype.progress = function() {

    var ready = true;

    // Move the opening items towards their target pos
    jQuery.each(this.openItems, function(index, value) {

        var dX = (value.tX - value.x) / 4.0;
        var dY = (value.tY - value.y) / 4.0;

        value.x += dX;
        value.y += dY;

        value.node.style.left = value.x;
        value.node.style.top = value.y;

        if (Math.abs(dX) > 0.5 || Math.abs(dY) > 0.5) ready = false;
    });

    // Move the closing items towards their initial pos
    jQuery.each(this.closingItems, function(index, value) {

        var dX = (value.iX - value.x) / 8.0;
        var dY = (value.iY - value.y) / 8.0;

        value.x += dX;
        value.y += dY;

        value.node.style.left = value.x;
        value.node.style.top = value.y;

        if (Math.abs(dX) < 5.0 && Math.abs(dY) < 5.0) {

            jQuery('#' + value.id).hide();
        }
        else {

            ready = false;
        }
    });

    if (ready) {

        // Extra close of all closing items
        jQuery.each(this.closingItems, function(index, value) {

            jQuery('#' + value.id).hide();
        });
    }
    else {

        // Need more animation
        setTimeout(function() {
            menuManager.progress();
        }, 50)
    }

};


extransit.MenuManager.prototype.grayOut = function(vis, options) {

    if (true) return;

    // Pass true to gray out screen, false to ungray
    // options are optional.  This is a JSON object with the following (optional) properties
    // opacity:0-100         // Lower number = less grayout higher = more of a blackout
    // zindex: #             // HTML elements with a higher zindex appear on top of the gray out
    // bgcolor: (#xxxxxx)    // Standard RGB Hex color code
    // grayOut(true, {'zindex':'50', 'bgcolor':'#0000FF', 'opacity':'70'});
    // Because options is JSON opacity/zindex/bgcolor are all optional and can appear
    // in any order.  Pass only the properties you need to set.
    var options = options || {};
    var zindex = options.zindex || 50;
    var opacity = options.opacity || 25;
    var opaque = (opacity / 100);
    var bgcolor = options.bgcolor || '#000000';
    var dark = document.getElementById('darkenScreenObject');
    if (!dark) {
        // The dark layer doesn't exist, it's never been created.  So we'll
        // create it here and apply some basic styles.
        // If you are getting errors in IE see: http://support.microsoft.com/default.aspx/kb/927917
        var tbody = document.getElementsByTagName("body")[0];
        var tnode = document.createElement('div');           // Create the layer.
        tnode.style.position = 'absolute';                 // Position absolutely
        tnode.style.top = '0px';                           // In the top
        tnode.style.left = '0px';                          // Left corner of the page
        tnode.style.overflow = 'hidden';                   // Try to avoid making scroll bars
        tnode.style.display = 'none';                      // Start out Hidden
        tnode.id = 'darkenScreenObject';                   // Name it so we can find it later
        tbody.appendChild(tnode);                            // Add it to the web page
        dark = document.getElementById('darkenScreenObject');  // Get the object.
    }
    if (vis) {
        // Calculate the page width and height
        if (document.body && ( document.body.scrollWidth || document.body.scrollHeight )) {
            var pageWidth = document.body.scrollWidth + 'px';
            var pageHeight = document.body.scrollHeight + 'px';
        } else if (document.body.offsetWidth) {
            var pageWidth = document.body.offsetWidth + 'px';
            var pageHeight = document.body.offsetHeight + 'px';
        } else {
            var pageWidth = '100%';
            var pageHeight = '100%';
        }
        //set the shader to cover the entire page and make it visible.
        dark.style.opacity = opaque;
        dark.style.MozOpacity = opaque;
        dark.style.filter = 'alpha(opacity=' + opacity + ')';
        dark.style.zIndex = zindex;
        dark.style.backgroundColor = bgcolor;
        dark.style.width = pageWidth;
        dark.style.height = pageHeight;
        dark.style.display = 'block';
    } else {
        dark.style.display = 'none';
    }
}



// http://www.hunlock.com/blogs/Snippets:_Howto_Grey-Out_The_Screen