source: Dev/trunk/src/client/dijit/_FocusMixin.js

define([
        "./focus",
        "./_WidgetBase",
        "dojo/_base/declare", // declare
        "dojo/_base/lang" // lang.extend
], function(focus, _WidgetBase, declare, lang){

        // module:
        //              dijit/_FocusMixin

        // We don't know where _FocusMixin will occur in the inheritance chain, but we need the _onFocus()/_onBlur() below
        // to be last in the inheritance chain, so mixin to _WidgetBase.
        lang.extend(_WidgetBase, {
                // focused: [readonly] Boolean
                //              This widget or a widget it contains has focus, or is "active" because
                //              it was recently clicked.
                focused: false,

                onFocus: function(){
                        // summary:
                        //              Called when the widget becomes "active" because
                        //              it or a widget inside of it either has focus, or has recently
                        //              been clicked.
                        // tags:
                        //              callback
                },

                onBlur: function(){
                        // summary:
                        //              Called when the widget stops being "active" because
                        //              focus moved to something outside of it, or the user
                        //              clicked somewhere outside of it, or the widget was
                        //              hidden.
                        // tags:
                        //              callback
                },

                _onFocus: function(){
                        // summary:
                        //              This is where widgets do processing for when they are active,
                        //              such as changing CSS classes.  See onFocus() for more details.
                        // tags:
                        //              protected
                        this.onFocus();
                },

                _onBlur: function(){
                        // summary:
                        //              This is where widgets do processing for when they stop being active,
                        //              such as changing CSS classes.  See onBlur() for more details.
                        // tags:
                        //              protected
                        this.onBlur();
                }
        });

        return declare("dijit._FocusMixin", null, {
                // summary:
                //              Mixin to widget to provide _onFocus() and _onBlur() methods that
                //              fire when a widget or its descendants get/lose focus

                // flag that I want _onFocus()/_onBlur() notifications from focus manager
                _focusManager: focus
        });

});