/*
DOM Component Library - Copyright 2005 Six Apart
$Id: Component.js 212 2007-06-11 17:08:49Z ddavis $

Copyright (c) 2005, Six Apart Ltd.
All rights reserved.

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 * <br/><br/>
 * <hr><br/><br/>
 * Class <code>Component</code> class.<br/><br/>
 * @object-prop <code>sentinels</code> <code>Array</code>  A collection of 
 *              hidden html input fields that bestow tabbability and modality upon components.<br/>
 * @object-prop <code>ativatable</code> <code>boolean</code> Whether or not this component could
 *              be made active -- see below.<br/>
 * @object-prop <code>ative</code> <code>boolean</code> Whether or not this component is active -- active 
 *              components are managed by <code>App</code>.<br/>
 * @object-prop <code>modal</code> <code>boolean</code> Whether or not this component is modal 
 *              (is the only part of the application that may be currently interacted with by the user)
 *               -- modal components are managed by <code>App</code>.<br/>
 * @object-prop <code>focusableTagNames</code> <code>Object</code>A dictionary of names of html tags that are 
 *              allowed focus under the 'active' state and under modality.  Used for controlling focus.<br/>
 * <br/><hr/>
 * Class <code>Modal</code>  The modal pop-up superclass.<br/>
 * @inherits-from <code>Component</code>.<br/>
 * <hr/>
 * Class <code>Transient</code>  A transient modal pop-up, such as a list or color picker.<br/>
 * @inherits-from <code>Modal</code>.<br/>
 * @listens-to <code>onkeypress</code> <br/>
 * <hr/>
 * Class <code>Modal-Message</code>  A  modal pop-up message, such as a confirm dialog.<br/>
 * @inherits-from <code>Modal</code>.<br/>
 * @listens-to <code>onkeypress</code> <br/>
 * <hr/>
 * Class <code>ModalMask</code>  The event-blocking mask that preserves the modality of modals 
 *        from clicking outside their boundaries.<br/>
 * <br/><br/>
 */

Component = new Class( Observable, Autolayout, {
    useClosures: false,
    
    
    init: function() {
        arguments.callee.applySuper( this, arguments );
        this.initObject.apply( this, arguments );
        this.initSentinels();
        this.initEventListeners();
        this.initComponents();
    },
    
    
    destroy: function() {
        arguments.callee.applySuper( this, arguments );
        this.destroyComponents();
        this.destroyEventListeners();
        this.destroyObject();
    },
    
    
    initObject: function( element ) {
        this.element = DOM.getElement( element );
        if( !this.element )
            throw typeof element == "string"
                ? "no element: " + element
                : "no element";
        this.name = element;
        this.parent = null;
        this.components = [];
        this.sentinels = null;
        this.active = false;
    },
    
    
    destroyObject: function( element ) {
        this.components = null;
        this.sentinels = null;
        this.parent = null;
        this.element = null;
        this.name = null;
    },
    
    
    /* events */
    
    initEventListeners: function() {
        this.addEventListener( this.element, "mouseover", "eventMouseOver" );
        this.addEventListener( this.element, "mouseout", "eventMouseOut" );
        this.addEventListener( this.element, "mousemove", "eventMouseMove" );
        this.addEventListener( this.element, "mousedown", "eventMouseDown" );
        this.addEventListener( this.element, "mouseup", "eventMouseUp" );
        this.addEventListener( this.element, "click", "eventClick" );
        this.addEventListener( this.element, "dblclick", "eventDoubleClick" );
        this.addEventListener( this.element, "contextmenu", "eventContextMenu" );
        this.addEventListener( this.element, "keydown", "eventKeyDown" );
        this.addEventListener( this.element, "keyup", "eventKeyUp" );
        this.addEventListener( this.element, "keypress", "eventKeyPress" );
        this.addEventListener( this.element, "focus", "eventFocus", true ); // FIXME: why are these capturing?
        this.addEventListener( this.element, "blur", "eventBlur", true ); // FIXME: why are these capturing?
        this.addEventListener( this.element, "focusin", "eventFocusIn" );
        this.addEventListener( this.element, "focusout", "eventFocusOut" );
    },
    

    destroyEventListeners: function() {},
    
    
    addEventListener: function( object, eventName, methodName, useCapture ) {
        if ( !this[ methodName ] || this[ methodName ] === Function.stub ) /* XXX - purge instances of Function.stub */
            return;
        DOM.addEventListener( object, eventName, 
            (this.useClosures
                ? this.getEventListener( methodName )
                : this.getIndirectEventListener( methodName ) ),
            useCapture );
    },

    
    removeEventListener: function( object, eventName, methodName, useCapture ) {
        var listener = this.useClosures
            ? this.getEventListener( methodName )
            : this.getIndirectEventListener( methodName );
        DOM.removeEventListener( object, eventName, listener, useCapture );
    },
    

    matchCommand: /(?:^|\s)command-(\S+)(?:\s|$)/,


    getMouseEventCommand: function( event, rootElement ) {
        var ancestors = DOM.getAncestors( event.target, true );
        var cmdattr = app.NAMESPACE + ":command";
        for( var i = 0; i < ancestors.length; i++ ) {
            try {
                /* check the new NAMESPACE:command attribute first */
                var result = ancestors[ i ].getAttribute( cmdattr );
                if ( !result ) {
                    result = this.matchCommand.exec( ancestors[ i ].className );
                    if ( result[ 1 ] )
                        result = result[ 1 ];
                }
                if ( result ) {
                    event.commandElement = ancestors[ i ];
                    /* foo-bar -> fooBar */
                    event.command = result.cssToJS(); 
                    return event.command;
                }
                if ( ancestors[ i ] == rootElement )
                    break;
            } catch( e ) {}
        }
    },


    /* event listeners */

    eventMouseDown : function( event ) {
        if( this.activatable ) 
            this.activate( event );
    },

    

    eventFocus: function( event ) {
        if( this.activatable ) 
            this.activate( event );
    },


    eventFocusIn: function( event ) {
        if( this.activatable ) 
            this.activate( event );
    },
    
    
    /* layout */
        
    reflow: function( event ) {
        this.applyAutolayouts( this.element );
        this.reflowComponents( event );
    },
    
    
    reflowComponents: function( event ) {
        this.components.forEach( function( component ) { component.reflow( event ); } );
    },
    
    
    /* components */
    
    initComponents: function() {},
    
    
    destroyComponents: function() {
        this.components.forEach( function( component ) { component.destroy(); } );
        this.components.length = 0;
    },
    
    
    addComponent: function( component ) {
        this.components.add( component );
        component.parent = this;
        component.reflow();
        return component;
    },
    
    
    removeComponent: function( component ) {
        this.components.remove( component );
        component.parent = null;
        return component;
    },
    

    /*  active component functionality (including modality) */
  
    activatable: false,
    modal: false,
    
    
    /**
     * class <code>Component</code>
     * Creates the invisible text input elements used as focus sinks for tabbability and modality 
     * (modal <code>div</code> "windows", etc).  These text input elements are arranged in a 
     * specific way so that, for modal components, they may trap tabbing events to keep tab focus
     * within the modal component.  When it receives focus, the last sentinal 'punts' focus 
     * back to the first sentinel.
     */    
    initSentinels: function() {
        if( !this.activatable || this.sentinels )
            return;
        
        this.sentinels = {
            captureStart: DOM.createInvisibleInput()
        };

        this.element.insertBefore( this.sentinels.captureStart, this.element.firstChild );
        
        if( !this.modal )
            return;
        
        extend( this.sentinels, {
            puntStart: DOM.createInvisibleInput(), 
            captureEnd: DOM.createInvisibleInput(),
            puntEnd: DOM.createInvisibleInput()
        } );

        this.element.insertBefore( this.sentinels.puntStart, this.element.firstChild );
        this.element.appendChild( this.sentinels.captureEnd );
        this.element.appendChild( this.sentinels.puntEnd );
    },


    /**
     * class <code>Component</code>
     * Create new sentinels.  This is necessary in case their html must be destroyed.
     */
    refreshSentinels: function() {
        this.sentinels = null;
        this.initSentinels();
    },


    /**
     * class <code>Component</code>     
     * Activate this component (can be either modal or 'plain' active).
     */
    activate: function( event ) {
        if( !this.activatable ) 
            return; 
        if( !window.app.setActiveComponent( this ) ) 
           return;
          
        this.active = true;
        this.captureFocus( event );
        DOM.addClassName( this.element, "active-component" );
        this.broadcastToObserversNB( "componentActivated", this );
    },


    /**
     * class <code>Component</code>
     * De-activate this component (can be either modal or 'plain' active).
     */
    deactivate: function() {
        this.active = false;
        DOM.removeClassName( this.element, "active-component" );
        this.broadcastToObserversNB( "componentDeactivated", this );
    },
    

    focusableTagNames: { // Note: All elements with 'mouse event commands' are focusable (see 'captureFocus').
        taginput: defined,
        tagtextarea: defined,
        tagbutton: defined,
        tagselect: defined,
        tagdiv: defined, // FF 1.5+ puts divs in the tabbing order. Added 2006-05-03: See case 27751 and case 34362.
        taga: defined, // 'anchor' tag.  Added 2006-05-03: See Case 27751.
        tagoption: defined,
        tagp: defined // case 36542
    },


    /** 
     * class <code>Component</code>
     * Capture and manage the focus on an activatable (optionally including modal) component.
     * The behavior differs for the various types of activatable component.
     * @param event <code>Event</code> The event that leads to focus (i.e., a tab or a click).
     */        
    captureFocus: function( event ) {
        if ( this.active && !this.modal )
            return;
        var tagName = ( defined( event ) && event.target.tagName )
            ? "tag" + event.target.tagName.toLowerCase()
            : null;
        var command;
        if ( tagName && event ) 
           command = this.getMouseEventCommand( event ); // Avoid scrolling out from over command elements.
        // Set the tabbing focus on the sentinel, unless the user wants it on another form or command element: 
        if( !tagName || ( this.focusableTagNames[ tagName ] !== defined ) && !command ) {
            try {
                this.sentinels.captureStart.focus();
                event.stop(); // Force the action to stop at the focus set above.
                if( defined( this.sentinels.captureStart.focusIn ) )
                    this.sentinels.captureStart.focusIn();
            } catch ( e ) {}
        }

        if( !defined( event ) || !this.modal )
            return;
        /*-
         * As of Firefox 1.5.0.6 at least, bug where key events could not be heard from divs has been fixed.
         * Workaround code for this put in on 2006-05-03 and removed 2006-08-24.  See case 27751 and case 34362.
         */
        try {
            if( event.target === this.sentinels.puntEnd )
                this.sentinels.captureStart.focus();
            else if( event.target === this.sentinels.puntStart )
                this.sentinels.captureEnd.focus();
        } catch( e ) {}
    },
    

    /* misc */
    
    hide: function() {
        DOM.removeClassName( this.element, "visible" );
        DOM.addClassName( this.element, "hidden" );
    },
    
    
    show: function() {
        DOM.removeClassName( this.element, "hidden" );
        DOM.addClassName( this.element, "visible" );
        this.reflow();
    }
} );


/* modal subclass */

Modal = new Class( Component, {
    activatable: true,
    modal: true,
    isOpen: false,
    
    /* execution */
    
    open: function( data, callback ) {
        if ( !this.transitory ) 
            window.scrollTo( 0, 0 );
        this.data = defined( data ) ? data : {};
        this.callback = callback;
        this.active = false;
        this.isOpen = true;
        window.app.addModal( this );        
    },
    
    
    close: function( data ) {
        window.app.removeModal( this );
        this.isOpen = false;
        if( this.callback )
            this.callback( data, this );
        this.callback = null;
        this.data = null;
    },
    

    eventClick: function( event ) {
        if ( event.shiftKey ) 
            event.stop();
    },

    
    eventKeyPress: function( event ) {
        switch( event.keyCode ) {
            case 27:
                this.close( false );
        }
    }
} );


/* transient subclass */

Transient = new Class( Modal, {
    transitory: true,
    
    /* events */
    
    /**
     * Class: <code>Transient</code><br>
     * This method allows a <ocde>Transient</code> to disappear on keypress of 'esc'..
     * @param event <code>Event</code>  A prepared (processed by the custom js framework) <code>Event</code> object.
     */
    eventKeyPress: function( event ) {
        switch( event.keyCode ) {
            case 27:
                this.close( false ); 
        }
    },
    

    /**
     * Returns the command from the event, via <code>getMouseEventCommand</code>.
     * @param event  <code>Event</code> A prepared event object.
     */
    eventClick: function( event ) {
        this.close( this.getMouseEventCommand( event ) );
        return event.stop();
    },
    
    
    eventContextMenu: function( event ) {
        return event.stop();
    },

    
    open: function( data, callback, targetElement ) {
        this.targetElement = targetElement;
        return arguments.callee.applySuper( this, arguments );
    }
} );


Component.Delegator = {
    
    DEFAULT_NAMESPACE: "core",

    setupDelegates: function( object ) {
        /* this needs more testing before enabling
        if ( object && !object.delegateParent )
            object.delegateParent = this;
        */
        
        if ( !this.delegateListeners )
            this.delegateListeners = {};
            
        if ( !this.delegates )
            this.delegates = {};

        if ( !defined( this.NAMESPACE ) )
            this.NAMESPACE = ( window.app && app.NAMESPACE )
                ? app.NAMESPACE : this.DEFAULT_NAMESPACE;
    },
    

    addEventListener: function( object, eventName, methodName, useCapture ) {
        DOM.addEventListener( object, eventName, 
            (this.useClosures
                ? this.getEventListener( methodName )
                : this.getIndirectEventListener( methodName ) ),
            useCapture );
    },


    /* delegate functions */
    setDelegate: function( name, object ) {
        this.setupDelegates( object );
        this.delegates[ name ] = object;
        return object;
    },
    
    
    setDelegateListener: function( eventName, delegateName ) {
        this.setupDelegates();
        this.delegateListeners[ eventName ] = delegateName;
    },
    
    
    delegateEvent: function( event, eventName ) {
        var delegate = DOM.getMouseEventAttribute( event, this.NAMESPACE + ":delegate" );
            
        if ( !delegate ) {
            if ( this.delegateListeners && this.delegateListeners.hasOwnProperty( eventName ) )
                delegate = this.delegateListeners[ eventName ];
            else
                return undefined;
        } else
            delegate = delegate.cssToJS();
        
        if ( this.delegates && this.delegates.hasOwnProperty( delegate ) && this.delegates[ delegate ][ eventName ] )
            return this.delegates[ delegate ][ eventName ]( event, this );
    },
    
    
    getIndirectEventListener: function( methodName ) {
        if( !this.indirectEventListeners )
            this.indirectEventListeners = {};
        var method = this[ methodName ];
        var indirectIndex = this.getIndirectIndex();
        if( !this.indirectEventListeners[ methodName ] ) {
            return this.indirectEventListeners[ methodName ] = new Function( "event",
                "if ( window.indirectObjects === undefined ) return;" +
                "try { event = Event.prep( event ); } catch( e ) {}" +
                "var o = window.indirectObjects[" + indirectIndex + "];" +
                "if ( !o ) return;" +
                "var r = o.delegateEvent( event, '" + methodName +
                "' ); if ( r ) return r; if ( o[ '" + methodName +
                "' ] ) return o['" + methodName + "'].call( o, event );" );
        }
        
        return this.indirectEventListeners[ methodName ];
    }
};
