source: Dev/trunk/src/client/dijit/_base/focus.js

define([
        "dojo/_base/array", // array.forEach
        "dojo/dom", // dom.isDescendant
        "dojo/_base/lang", // lang.isArray
        "dojo/topic", // publish
        "dojo/_base/window", // win.doc win.doc.selection win.global win.global.getSelection win.withGlobal
        "../focus",
        "../selection",
        "../main"       // for exporting symbols to dijit
], function(array, dom, lang, topic, win, focus, selection, dijit){

        // module:
        //              dijit/_base/focus

        var exports = {
                // summary:
                //              Deprecated module to monitor currently focused node and stack of currently focused widgets.
                //              New code should access dijit/focus directly.

                // _curFocus: DomNode
                //              Currently focused item on screen
                _curFocus: null,

                // _prevFocus: DomNode
                //              Previously focused item on screen
                _prevFocus: null,

                isCollapsed: function(){
                        // summary:
                        //              Returns true if there is no text selected
                        return dijit.getBookmark().isCollapsed;
                },

                getBookmark: function(){
                        // summary:
                        //              Retrieves a bookmark that can be used with moveToBookmark to return to the same range
                        var sel = win.global == window ? selection : new selection.SelectionManager(win.global);
                        return sel.getBookmark();
                },

                moveToBookmark: function(/*Object*/ bookmark){
                        // summary:
                        //              Moves current selection to a bookmark
                        // bookmark:
                        //              This should be a returned object from dijit.getBookmark()

                        var sel = win.global == window ? selection : new selection.SelectionManager(win.global);
                        return sel.moveToBookmark(bookmark);
                },

                getFocus: function(/*Widget?*/ menu, /*Window?*/ openedForWindow){
                        // summary:
                        //              Called as getFocus(), this returns an Object showing the current focus
                        //              and selected text.
                        //
                        //              Called as getFocus(widget), where widget is a (widget representing) a button
                        //              that was just pressed, it returns where focus was before that button
                        //              was pressed.   (Pressing the button may have either shifted focus to the button,
                        //              or removed focus altogether.)   In this case the selected text is not returned,
                        //              since it can't be accurately determined.
                        //
                        // menu: dijit/_WidgetBase|{domNode: DomNode} structure
                        //              The button that was just pressed.  If focus has disappeared or moved
                        //              to this button, returns the previous focus.  In this case the bookmark
                        //              information is already lost, and null is returned.
                        //
                        // openedForWindow:
                        //              iframe in which menu was opened
                        //
                        // returns:
                        //              A handle to restore focus/selection, to be passed to `dijit.focus`
                        var node = !focus.curNode || (menu && dom.isDescendant(focus.curNode, menu.domNode)) ? dijit._prevFocus : focus.curNode;
                        return {
                                node: node,
                                bookmark: node && (node == focus.curNode) && win.withGlobal(openedForWindow || win.global, dijit.getBookmark),
                                openedForWindow: openedForWindow
                        }; // Object
                },

                // _activeStack: dijit/_WidgetBase[]
                //              List of currently active widgets (focused widget and it's ancestors)
                _activeStack: [],

                registerIframe: function(/*DomNode*/ iframe){
                        // summary:
                        //              Registers listeners on the specified iframe so that any click
                        //              or focus event on that iframe (or anything in it) is reported
                        //              as a focus/click event on the `<iframe>` itself.
                        // description:
                        //              Currently only used by editor.
                        // returns:
                        //              Handle to pass to unregisterIframe()
                        return focus.registerIframe(iframe);
                },

                unregisterIframe: function(/*Object*/ handle){
                        // summary:
                        //              Unregisters listeners on the specified iframe created by registerIframe.
                        //              After calling be sure to delete or null out the handle itself.
                        // handle:
                        //              Handle returned by registerIframe()

                        handle && handle.remove();
                },

                registerWin: function(/*Window?*/targetWindow, /*DomNode?*/ effectiveNode){
                        // summary:
                        //              Registers listeners on the specified window (either the main
                        //              window or an iframe's window) to detect when the user has clicked somewhere
                        //              or focused somewhere.
                        // description:
                        //              Users should call registerIframe() instead of this method.
                        // targetWindow:
                        //              If specified this is the window associated with the iframe,
                        //              i.e. iframe.contentWindow.
                        // effectiveNode:
                        //              If specified, report any focus events inside targetWindow as
                        //              an event on effectiveNode, rather than on evt.target.
                        // returns:
                        //              Handle to pass to unregisterWin()

                        return focus.registerWin(targetWindow, effectiveNode);
                },

                unregisterWin: function(/*Handle*/ handle){
                        // summary:
                        //              Unregisters listeners on the specified window (either the main
                        //              window or an iframe's window) according to handle returned from registerWin().
                        //              After calling be sure to delete or null out the handle itself.

                        handle && handle.remove();
                }
        };

        // Override focus singleton's focus function so that dijit.focus()
        // has backwards compatible behavior of restoring selection (although
        // probably no one is using that).
        focus.focus = function(/*Object|DomNode */ handle){
                // summary:
                //              Sets the focused node and the selection according to argument.
                //              To set focus to an iframe's content, pass in the iframe itself.
                // handle:
                //              object returned by get(), or a DomNode

                if(!handle){ return; }

                var node = "node" in handle ? handle.node : handle,             // because handle is either DomNode or a composite object
                        bookmark = handle.bookmark,
                        openedForWindow = handle.openedForWindow,
                        collapsed = bookmark ? bookmark.isCollapsed : false;

                // Set the focus
                // Note that for iframe's we need to use the <iframe> to follow the parentNode chain,
                // but we need to set focus to iframe.contentWindow
                if(node){
                        var focusNode = (node.tagName.toLowerCase() == "iframe") ? node.contentWindow : node;
                        if(focusNode && focusNode.focus){
                                try{
                                        // Gecko throws sometimes if setting focus is impossible,
                                        // node not displayed or something like that
                                        focusNode.focus();
                                }catch(e){/*quiet*/}
                        }
                        focus._onFocusNode(node);
                }

                // set the selection
                // do not need to restore if current selection is not empty
                // (use keyboard to select a menu item) or if previous selection was collapsed
                // as it may cause focus shift (Esp in IE).
                if(bookmark && win.withGlobal(openedForWindow || win.global, dijit.isCollapsed) && !collapsed){
                        if(openedForWindow){
                                openedForWindow.focus();
                        }
                        try{
                                win.withGlobal(openedForWindow || win.global, dijit.moveToBookmark, null, [bookmark]);
                        }catch(e2){
                                /*squelch IE internal error, see http://trac.dojotoolkit.org/ticket/1984 */
                        }
                }
        };

        // For back compatibility, monitor changes to focused node and active widget stack,
        // publishing events and copying changes from focus manager variables into dijit (top level) variables
        focus.watch("curNode", function(name, oldVal, newVal){
                dijit._curFocus = newVal;
                dijit._prevFocus = oldVal;
                if(newVal){
                        topic.publish("focusNode", newVal);     // publish
                }
        });
        focus.watch("activeStack", function(name, oldVal, newVal){
                dijit._activeStack = newVal;
        });

        focus.on("widget-blur", function(widget, by){
                topic.publish("widgetBlur", widget, by);        // publish
        });
        focus.on("widget-focus", function(widget, by){
                topic.publish("widgetFocus", widget, by);       // publish
        });

        lang.mixin(dijit, exports);

        /*===== return exports; =====*/
        return dijit;   // for back compat :-(
});