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

define([
        "dojo/_base/declare", // declare
        "dojo/keys", // keys
        "../focus", // focus.focus()
        "./DropDownButton",
        "dojo/text!./templates/ComboButton.html"
], function(declare, keys, focus, DropDownButton, template){

        // module:
        //              dijit/form/ComboButton

        return declare("dijit.form.ComboButton", DropDownButton, {
                // summary:
                //              A combination button and drop-down button.
                //              Users can click one side to "press" the button, or click an arrow
                //              icon to display the drop down.
                //
                // example:
                // |    <button data-dojo-type="dijit/form/ComboButton" onClick="...">
                // |            <span>Hello world</span>
                // |            <div data-dojo-type="dijit/Menu">...</div>
                // |    </button>
                //
                // example:
                // |    var button1 = new ComboButton({label: "hello world", onClick: foo, dropDown: "myMenu"});
                // |    dojo.body().appendChild(button1.domNode);
                //

                templateString: template,

                // Map widget attributes to DOMNode attributes.
                _setIdAttr: "", // override _FormWidgetMixin which puts id on the focusNode
                _setTabIndexAttr: ["focusNode", "titleNode"],
                _setTitleAttr: "titleNode",

                // optionsTitle: String
                //              Text that describes the options menu (accessibility)
                optionsTitle: "",

                baseClass: "dijitComboButton",

                // Set classes like dijitButtonContentsHover or dijitArrowButtonActive depending on
                // mouse action over specified node
                cssStateNodes: {
                        "buttonNode": "dijitButtonNode",
                        "titleNode": "dijitButtonContents",
                        "_popupStateNode": "dijitDownArrowButton"
                },

                _focusedNode: null,

                _onButtonKeyDown: function(/*Event*/ evt){
                        // summary:
                        //              Handler for right arrow key when focus is on left part of button
                        if(evt.keyCode == keys[this.isLeftToRight() ? "RIGHT_ARROW" : "LEFT_ARROW"]){
                                focus.focus(this._popupStateNode);
                                evt.stopPropagation();
                                evt.preventDefault();
                        }
                },

                _onArrowKeyDown: function(/*Event*/ evt){
                        // summary:
                        //              Handler for left arrow key when focus is on right part of button
                        if(evt.keyCode == keys[this.isLeftToRight() ? "LEFT_ARROW" : "RIGHT_ARROW"]){
                                focus.focus(this.titleNode);
                                evt.stopPropagation();
                                evt.preventDefault();
                        }
                },

                focus: function(/*String*/ position){
                        // summary:
                        //              Focuses this widget to according to position, if specified,
                        //              otherwise on arrow node
                        // position:
                        //              "start" or "end"
                        if(!this.disabled){
                                focus.focus(position == "start" ? this.titleNode : this._popupStateNode);
                        }
                }
        });
});