source: Dev/trunk/src/client/dijit/form/_ComboBoxMenu.js

define([
        "dojo/_base/declare", // declare
        "dojo/dom-class", // domClass.add domClass.remove
        "dojo/dom-style", // domStyle.get
        "dojo/keys", // keys.DOWN_ARROW keys.PAGE_DOWN keys.PAGE_UP keys.UP_ARROW
        "../_WidgetBase",
        "../_TemplatedMixin",
        "./_ComboBoxMenuMixin",
        "./_ListMouseMixin"
], function(declare, domClass, domStyle, keys,
                        _WidgetBase, _TemplatedMixin, _ComboBoxMenuMixin, _ListMouseMixin){


        // module:
        //              dijit/form/_ComboBoxMenu

        return declare("dijit.form._ComboBoxMenu",[_WidgetBase, _TemplatedMixin, _ListMouseMixin, _ComboBoxMenuMixin], {
                // summary:
                //              Focus-less menu for internal use in `dijit/form/ComboBox`
                //              Abstract methods that must be defined externally:
                //
                //              - onChange: item was explicitly chosen (mousedown somewhere on the menu and mouseup somewhere on the menu)
                //              - onPage: next(1) or previous(-1) button pressed
                // tags:
                //              private

                // TODO for 2.0 or earlier: stop putting stuff inside this.containerNode.   Switch to using this.domNode
                // or a different attach point.    See _TemplatedMixin::searchContainerNode.
                templateString: "<div class='dijitReset dijitMenu' data-dojo-attach-point='containerNode' style='overflow: auto; overflow-x: hidden;' role='listbox'>"
                                +"<div class='dijitMenuItem dijitMenuPreviousButton' data-dojo-attach-point='previousButton' role='option'></div>"
                                +"<div class='dijitMenuItem dijitMenuNextButton' data-dojo-attach-point='nextButton' role='option'></div>"
                                +"</div>",

                baseClass: "dijitComboBoxMenu",

                postCreate: function(){
                        this.inherited(arguments);
                        if(!this.isLeftToRight()){
                                domClass.add(this.previousButton, "dijitMenuItemRtl");
                                domClass.add(this.nextButton, "dijitMenuItemRtl");
                        }
                        this.containerNode.setAttribute("role","listbox");
                },

                _createMenuItem: function(){
                        // note: not using domConstruct.create() because need to specify document
                        var item = this.ownerDocument.createElement("div");
                        item.className = "dijitReset dijitMenuItem" +(this.isLeftToRight() ? "" : " dijitMenuItemRtl");
                        item.setAttribute("role", "option");
                        return item;
                },

                onHover: function(/*DomNode*/ node){
                        // summary:
                        //              Add hover CSS
                        domClass.add(node, "dijitMenuItemHover");
                },

                onUnhover: function(/*DomNode*/ node){
                        // summary:
                        //              Remove hover CSS
                        domClass.remove(node, "dijitMenuItemHover");
                },

                onSelect: function(/*DomNode*/ node){
                        // summary:
                        //              Add selected CSS
                        domClass.add(node, "dijitMenuItemSelected");
                },

                onDeselect: function(/*DomNode*/ node){
                        // summary:
                        //              Remove selected CSS
                        domClass.remove(node, "dijitMenuItemSelected");
                },

                _page: function(/*Boolean*/ up){
                        // summary:
                        //              Handles page-up and page-down keypresses

                        var scrollamount = 0;
                        var oldscroll = this.domNode.scrollTop;
                        var height = domStyle.get(this.domNode, "height");
                        // if no item is highlighted, highlight the first option
                        if(!this.getHighlightedOption()){
                                this.selectNextNode();
                        }
                        while(scrollamount<height){
                                var highlighted_option = this.getHighlightedOption();
                                if(up){
                                        // stop at option 1
                                        if(!highlighted_option.previousSibling ||
                                                highlighted_option.previousSibling.style.display == "none"){
                                                break;
                                        }
                                        this.selectPreviousNode();
                                }else{
                                        // stop at last option
                                        if(!highlighted_option.nextSibling ||
                                                highlighted_option.nextSibling.style.display == "none"){
                                                break;
                                        }
                                        this.selectNextNode();
                                }
                                // going backwards
                                var newscroll = this.domNode.scrollTop;
                                scrollamount += (newscroll-oldscroll)*(up ? -1:1);
                                oldscroll = newscroll;
                        }
                },

                handleKey: function(evt){
                        // summary:
                        //              Handle keystroke event forwarded from ComboBox, returning false if it's
                        //              a keystroke I recognize and process, true otherwise.
                        switch(evt.keyCode){
                                case keys.DOWN_ARROW:
                                        this.selectNextNode();
                                        return false;
                                case keys.PAGE_DOWN:
                                        this._page(false);
                                        return false;
                                case keys.UP_ARROW:
                                        this.selectPreviousNode();
                                        return false;
                                case keys.PAGE_UP:
                                        this._page(true);
                                        return false;
                                default:
                                        return true;
                        }
                }
        });
});