// Functions for handling the disclosure buttons.
var GSDisclosureButton = function () {
    /* GroupServer Disclosure Button Module.
    
        In general, A disclosure button is used to hide non-essential data 
        from the user. Error messages, and collapsing-tree views of folders
        are two common examples. While their presentation may vary, the 
        buttons are present in the widget sets used by Microsoft Windows, 
        Apple Aqua, GNOME, and KDE.
        
        In GroupServer, disclosure buttons are mostly used to hide the
        bottom-quoting and signatures at the end of posts. However, the 
        system is generic, and can be used to hide arbitrary information.
        If the correct markup is followed, the JavaScript code will add the
        event-handlers to show or hide the information, as appropriate.
        
        In addition to the event handler, an arrow is added to each button,
        which indicates the state of the disclosure widget. The arrow
        points to the right when the information is hidden, and points down
        when the data is shown.
        
        XHTML MARKUP
            
          The markup for disclosure buttons mostly contains of two div
          elements, a paragraph, and an anchor.
          
          <div class="disclosureWidget">
            <p>
              <a class="disclosureButton">Foo</a>
            </p>
            <div class="disclosureShowHide" style="display: none;">
              Foo bar wibble blarg&#8230;
            </div>
          </div>
          
          Classes are used to mark the essential components of the 
          disclosure widget:
            * The main div, that contain the entire disclosure widget,
            * The button uses to show, or hide, the information, and
            * A div to hold the  information.
          ID attributes can be added to the components of the disclosure 
          widget, and additional callbacks can be added, to launch an AJAX
          query.
        
        FUNCTIONS
        
          "init"       Add an arrow and a click-callback to all disclosure
                       widgets. Launched after the document is "ready".
          "show_all"   Show the contents of all the disclosure widgets.
          "hide_all"   Hide the contents of all the disclosure widgets.
          "toggle_all" Show the contents of all the hidden disclosure
                       widgets, and hide the conents of all the shown 
                       disclosure widgets. (The 'click' event is sent to
                       all the disclosure widgets.)
                   
        DEPENDENCIES
          
          jQuery is used to implement the GroupServer disclosure button.
          However, the "jQuery()" call (rather than "$()") is used 
          throughout, to avoid conflicts with Prototype.
    */

    // Private variables
    // Arrows
    var hiddenArrow = "\u25b6";
    var shownArrow = "\u25bc";
    var speed = 'fast';
    // Elements of the disclosure widgets
    var dw = ".disclosureWidget";
    var db = ".disclosureButton";
    var dsh = ".disclosureShowHide";
    
    // Private methods
    var buttonClicked = function () {
        html = jQuery(this).html()
        coreHTML = html.substring(2, html.length);
        arrow = html.substring(0, 1);
        showHideWidget = jQuery(this).parents(dw).find(dsh)
        
        if ( arrow == hiddenArrow ) {
            jQuery(this).html(shownArrow+" "+coreHTML);
        } else {
            jQuery(this).html(hiddenArrow+" "+coreHTML);
        }
        showHideWidget.slideToggle(speed);
    }
    
    var show = function (button) {
        var html = jQuery(this).html();
        var coreHTML = html.substring(2, html.length);
        jQuery(this).html(shownArrow+" "+coreHTML);
        
        jQuery(this).parents(dw).find(dsh).slideDown(speed);
    }

    var hide = function (button) {
        var html = jQuery(this).html();
        var coreHTML = html.substring(2, html.length);
        jQuery(this).html(hiddenArrow+" "+coreHTML);
        
        jQuery(this).parents(dw).find(dsh).slideUp(speed);
    }
    
    var prepare = function (button) {
        var visible = false;
        visible = jQuery(this).parents(dw).find(dsh).css('display') != 'none';
        if (visible) {
          jQuery(this).prepend(shownArrow+" ");
        } else {
          jQuery(this).prepend(hiddenArrow+" ");
        }
        jQuery(this).removeAttr('href').css("cursor","pointer");
    }
    
    // Public methods and properties
    return {
        init: function () {
            jQuery(db).each( prepare ).click( buttonClicked );
        },
        toggle_all: function() {
            jQuery(db).click();
        },
        show_all: function () {
            jQuery(db).each(show);
        },
        hide_all: function () {
            jQuery(db).each(hide);
        }
    };
}(); // GSDisclosureButton

jQuery(document).ready( function () {
    GSDisclosureButton.init(); 
});