this.split.el.hide();
        }
        if(this.config.animate && skipAnim !== true){
            this.fireEvent("invalidated", this);
            this.animateCollapse();
        }else{
            this.el.setLocation(-20000,-20000);
            this.el.hide();
            this.collapsedEl.show();
            this.fireEvent("collapsed", this);
            this.fireEvent("invalidated", this);
        }
    },

    animateCollapse : function(){
        // overridden
    },

    /**
     * Expands this region if it was previously collapsed.
     * @param {Ext.EventObject} e The event that triggered the expand (or null if calling manually)
     * @param {Boolean} skipAnim (optional) true to expand the element without animation (if animate is true)
     */
    expand : function(e, skipAnim){
        if(e) e.stopPropagation();
        if(!this.collapsed || this.el.hasActiveFx()) return;
        if(this.isSlid){
            this.afterSlideIn();
            skipAnim = true;
        }
        this.collapsed = false;
        if(this.config.animate && skipAnim !== true){
            this.animateExpand();
        }else{
            this.el.show();
            if(this.split){
                this.split.el.show();
            }
            this.collapsedEl.setLocation(-2000,-2000);
            this.collapsedEl.hide();
            this.fireEvent("invalidated", this);
            this.fireEvent("expanded", this);
        }
    },

    animateExpand : function(){
        // overridden
    },

    initTabs : function(){
        this.bodyEl.setStyle("overflow", "hidden");
        var ts = new Ext.TabPanel(this.bodyEl.dom, {
            tabPosition: this.bottomTabs ? 'bottom' : 'top',
            disableTooltips: this.config.disableTabTips
        });
        if(this.config.hideTabs){
            ts.stripWrap.setDisplayed(false);
        }
        this.tabs = ts;
        ts.resizeTabs = this.config.resizeTabs === true;
        ts.minTabWidth = this.config.minTabWidth || 40;
        ts.maxTabWidth = this.config.maxTabWidth || 250;
        ts.preferredTabWidth = this.config.preferredTabWidth || 150;
        ts.monitorResize = false;
        ts.bodyEl.setStyle("overflow", this.config.autoScroll ? "auto" : "hidden");
        ts.bodyEl.addClass('x-layout-tabs-body');
        this.panels.each(this.initPanelAsTab, this);
    },

    initPanelAsTab : function(panel){
        var ti = this.tabs.addTab(panel.getEl().id, panel.getTitle(), null,
                    this.config.closeOnTab && panel.isClosable());
        if(panel.tabTip !== undefined){
            ti.setTooltip(panel.tabTip);
        }
        ti.on("activate", function(){
              this.setActivePanel(panel);
        }, this);
        if(this.config.closeOnTab){
            ti.on("beforeclose", function(t, e){
                e.cancel = true;
                this.remove(panel);
            }, this);
        }
        return ti;
    },

    updatePanelTitle : function(panel, title){
        if(this.activePanel == panel){
            this.updateTitle(title);
        }
        if(this.tabs){
            var ti = this.tabs.getTab(panel.getEl().id);
            ti.setText(title);
            if(panel.tabTip !== undefined){
                ti.setTooltip(panel.tabTip);
            }
        }
    },

    updateTitle : function(title){
        if(this.titleTextEl && !this.config.title){
            this.titleTextEl.innerHTML = (typeof title != "undefined" && title.length > 0 ? title : " ");
        }
    },

    setActivePanel : function(panel){
        panel = this.getPanel(panel);
        if(this.activePanel && this.activePanel != panel){
            this.activePanel.setActiveState(false);
        }
        this.activePanel = panel;
        panel.setActiveState(true);
        if(this.panelSize){
            panel.setSize(this.panelSize.width, this.panelSize.height);
        }
        if(this.closeBtn){
            this.closeBtn.setVisible(!this.config.closeOnTab && !this.isSlid && panel.isClosable());
        }
        this.updateTitle(panel.getTitle());
        if(this.tabs){
            this.fireEvent("invalidated", this);
        }
        this.fireEvent("panelactivated", this, panel);
    },

    /**
     * Shows the specified panel.
     * @param {Number/String/ContentPanel} panelId The panel's index, id or the panel itself
     * @return {Ext.ContentPanel} The shown panel, or null if a panel could not be found from panelId
     */
    showPanel : function(panel){
        if(panel = this.getPanel(panel)){
            if(this.tabs){
                var tab = this.tabs.getTab(panel.getEl().id);
                if(tab.isHidden()){
                    this.tabs.unhideTab(tab.id);
                }
                tab.activate();
            }else{
                this.setActivePanel(panel);
            }
        }
        return panel;
    },

    /**
     * Get the active panel for this region.
     * @return {Ext.ContentPanel} The active panel or null
     */
    getActivePanel : function(){
        return this.activePanel;
    },

    validateVisibility : function(){
        if(this.panels.getCount() < 1){
            this.updateTitle("&#160;");
            this.closeBtn.hide();
            this.hide();
        }else{
            if(!this.isVisible()){
                this.show();
            }
        }
    },

    /**
     * Adds the passed ContentPanel(s) to this region.
     * @param {ContentPanel...} panel The ContentPanel(s) to add (you can pass more than one)
     * @return {Ext.ContentPanel} The panel added (if only one was added; null otherwise)
     */
    add : function(panel){
        if(arguments.length > 1){
            for(var i = 0, len = arguments.length; i < len; i++) {
                this.add(arguments[i]);
            }
            return null;
        }
        if(this.hasPanel(panel)){
            this.showPanel(panel);
            return panel;
        }
        panel.setRegion(this);
        this.panels.add(panel);
        if(this.panels.getCount() == 1 && !this.config.alwaysShowTabs){
            this.bodyEl.dom.appendChild(panel.getEl().dom);
            if(panel.background !== true){
                this.setActivePanel(panel);
            }
            this.fireEvent("paneladded", this, panel);
            return panel;
        }
        if(!this.tabs){
            this.initTabs();
        }else{
            this.initPanelAsTab(panel);
        }
        if(panel.background !== true){
            this.tabs.activate(panel.getEl().id);
        }
        this.fireEvent("paneladded", this, panel);
        return panel;
    },

    /**
     * Hides the tab for the specified panel.
     * @param {Number/String/ContentPanel} panel The panel's index, id or the panel itself
     */
    hidePanel : function(panel){
        if(this.tabs && (panel = this.getPanel(panel))){
            this.tabs.hideTab(panel.getEl().id);
        }
    },

    /**
     * Unhides the tab for a previously hidden panel.
     * @param {Number/String/ContentPanel} panel The panel's index, id or the panel itself
     */
    unhidePanel : function(panel){
        if(this.tabs && (panel = this.getPanel(panel))){
            this.tabs.unhideTab(panel.getEl().id);
        }
    },

    clearPanels : function(){
        while(this.panels.getCount() > 0){
             this.remove(this.panels.first());
        }
    },

    /**
     * Removes the specified panel. If preservePanel is not true (either here or in the config), the panel is destroyed.
     * @param {Number/String/ContentPanel} panel The panel's index, id or the panel itself
     * @param {Boolean} preservePanel Overrides the config preservePanel option
     * @return {Ext.ContentPanel} The panel that was removed
     */
    remove : function(panel, preservePanel){
        panel = this.getPanel(panel);
        if(!panel){
            return null;
        }
        var e = {};
        this.fireEvent("beforeremove", this, panel, e);
        if(e.cancel === true){
            return null;
        }
        preservePanel = (typeof preservePanel != "undefined" ? preservePanel : (this.config.preservePanels === true || panel.preserve === true));
        var panelId = panel.getId();
        this.panels.removeKey(panelId);
        if(preservePanel){
            document.body.appendChild(panel.getEl().dom);
        }
        if(this.tabs){
            this.tabs.removeTab(panel.getEl().id);
        }else if (!preservePanel){
            this.bodyEl.dom.removeChild(panel.getEl().dom);
        }
        if(this.panels.getCount() == 1 && this.tabs && !this.config.alwaysShowTabs){
            var p = this.panels.first();
            var tempEl = document.createElement("div"); // temp holder to keep IE from deleting the node
            tempEl.appendChild(p.getEl().dom);
            this.bodyEl.update("");
            this.bodyEl.dom.appendChild(p.getEl().dom);
            tempEl = null;
            this.updateTitle(p.getTitle());
            this.tabs = null;
            this.bodyEl.setStyle("overflow", this.config.autoScroll ? "auto" : "hidden");
            this.setActivePanel(p);
        }
        panel.setRegion(null);
        if(this.activePanel == panel){
            this.activePanel = null;
        }
        if(this.config.autoDestroy !== false && preservePanel !== true){
            try{panel.destroy();}catch(e){}
        }
        this.fireEvent("panelremoved", this, panel);
        return panel;
    },

    /**
     * Returns the TabPanel component used by this region
     * @return {Ext.TabPanel}
     */
    getTabs : function(){
        return this.tabs;
    },

    createTool : function(parentEl, className){
        var btn = Ext.DomHelper.append(parentEl, {tag: "div", cls: "x-layout-tools-button",
            children: [{tag: "div", cls: "x-layout-tools-button-inner " + className, html: "&#160;"}]}, true);
        btn.addClassOnOver("x-layout-tools-button-over");
        return btn;
    }
});