source: Dev/branches/rest-dojo-ui/client/dijit/_OnDijitClickMixin.js @ 274

define([
        "dojo/on",
        "dojo/_base/array", // array.forEach
        "dojo/keys", // keys.ENTER keys.SPACE
        "dojo/_base/declare", // declare
        "dojo/_base/sniff", // has("ie")
        "dojo/_base/unload", // unload.addOnWindowUnload
        "dojo/_base/window" // win.doc.addEventListener win.doc.attachEvent win.doc.detachEvent
], function(on, array, keys, declare, has, unload, win){

        // module:
        //              dijit/_OnDijitClickMixin
        // summary:
        //              Mixin so you can pass "ondijitclick" to this.connect() method,
        //              as a way to handle clicks by mouse, or by keyboard (SPACE/ENTER key)


        // Keep track of where the last keydown event was, to help avoid generating
        // spurious ondijitclick events when:
        // 1. focus is on a <button> or <a>
        // 2. user presses then releases the ENTER key
        // 3. onclick handler fires and shifts focus to another node, with an ondijitclick handler
        // 4. onkeyup event fires, causing the ondijitclick handler to fire
        var lastKeyDownNode = null;
        if(has("ie")){
                (function(){
                        var keydownCallback = function(evt){
                                lastKeyDownNode = evt.srcElement;
                        };
                        win.doc.attachEvent('onkeydown', keydownCallback);
                        unload.addOnWindowUnload(function(){
                                win.doc.detachEvent('onkeydown', keydownCallback);
                        });
                })();
        }else{
                win.doc.addEventListener('keydown', function(evt){
                        lastKeyDownNode = evt.target;
                }, true);
        }

        // Custom a11yclick (a.k.a. ondijitclick) event
        var a11yclick = function(node, listener){
                if(/input|button/i.test(node.nodeName)){
                        // pass through, the browser already generates click event on SPACE/ENTER key
                        return on(node, "click", listener);
                }else{
                        // Don't fire the click event unless both the keydown and keyup occur on this node.
                        // Avoids problems where focus shifted to this node or away from the node on keydown,
                        // either causing this node to process a stray keyup event, or causing another node
                        // to get a stray keyup event.

                        function clickKey(/*Event*/ e){
                                return (e.keyCode == keys.ENTER || e.keyCode == keys.SPACE) &&
                                                !e.ctrlKey && !e.shiftKey && !e.altKey && !e.metaKey;
                        }
                        var handles = [
                                on(node, "keypress", function(e){
                                        //console.log(this.id + ": onkeydown, e.target = ", e.target, ", lastKeyDownNode was ", lastKeyDownNode, ", equality is ", (e.target === lastKeyDownNode));
                                        if(clickKey(e)){
                                                // needed on IE for when focus changes between keydown and keyup - otherwise dropdown menus do not work
                                                lastKeyDownNode = e.target;

                                                // Prevent viewport scrolling on space key in IE<9.
                                                // (Reproducible on test_Button.html on any of the first dijit.form.Button examples)
                                                // Do this onkeypress rather than onkeydown because onkeydown.preventDefault() will
                                                // suppress the onkeypress event, breaking _HasDropDown
                                                e.preventDefault();
                                        }
                                }),

                                on(node, "keyup", function(e){
                                        //console.log(this.id + ": onkeyup, e.target = ", e.target, ", lastKeyDownNode was ", lastKeyDownNode, ", equality is ", (e.target === lastKeyDownNode));
                                        if(clickKey(e) && e.target == lastKeyDownNode){ // === breaks greasemonkey
                                                //need reset here or have problems in FF when focus returns to trigger element after closing popup/alert
                                                lastKeyDownNode = null;
                                                listener.call(this, e);
                                        }
                                }),

                                on(node, "click", function(e){
                                        // and connect for mouse clicks too (or touch-clicks on mobile)
                                        listener.call(this, e);
                                })
                        ];

                        return {
                                remove: function(){
                                        array.forEach(handles, function(h){ h.remove(); });
                                }
                        };
                }
        };

        return declare("dijit._OnDijitClickMixin", null, {
                connect: function(
                                /*Object|null*/ obj,
                                /*String|Function*/ event,
                                /*String|Function*/ method){
                        // summary:
                        //              Connects specified obj/event to specified method of this object
                        //              and registers for disconnect() on widget destroy.
                        // description:
                        //              Provide widget-specific analog to connect.connect, except with the
                        //              implicit use of this widget as the target object.
                        //              This version of connect also provides a special "ondijitclick"
                        //              event which triggers on a click or space or enter keyup.
                        //              Events connected with `this.connect` are disconnected upon
                        //              destruction.
                        // returns:
                        //              A handle that can be passed to `disconnect` in order to disconnect before
                        //              the widget is destroyed.
                        // example:
                        //      |       var btn = new dijit.form.Button();
                        //      |       // when foo.bar() is called, call the listener we're going to
                        //      |       // provide in the scope of btn
                        //      |       btn.connect(foo, "bar", function(){
                        //      |               console.debug(this.toString());
                        //      |       });
                        // tags:
                        //              protected

                        return this.inherited(arguments, [obj, event == "ondijitclick" ? a11yclick : event, method]);
                }
        });
});