source: Dev/trunk/src/client/dojox/drawing/manager/Undo.js

define(["dojo", "../util/oo"],//, "../defaults"], 
function(dojo, oo){

//dojox.drawing.manager.Undo = 
return oo.declare(
        function(options){
                this.keys = options.keys;
                this.undostack = [];
                this.redostack = [];
                dojo.connect(this.keys, "onKeyDown", this, "onKeyDown");
        },
        {
                // summary:
                //              Handles the Undo in drawing.
                //              NOTE: Only partially implemented!!! There is very
                //              little actual undo functionality!

                onKeyDown: function(evt){
                        if(!evt.cmmd && !evt.ctrl){ return; }
                        
                        if(evt.keyCode==90 && !evt.shift){
                                this.undo();
                        }else if((evt.keyCode == 90 && evt.shift) || evt.keyCode==89){
                                this.redo();
                        }
                        
                },
                add: function(stack){
                        //console.log("undo add", stack)
                        stack.args = dojo.mixin({}, stack.args);
                        this.undostack.push(stack);
                },
                apply: function(scope, method, args){
                        dojo.hitch(scope, method)(args);
                },
                undo: function(){
                        
                        var o = this.undostack.pop();
                        console.log("undo!", o);
                        if(!o){ return; }
                        
                        o.before();
                        
                        this.redostack.push(o);
                },
                redo: function(){
                        console.log("redo!");
                        var o = this.redostack.pop();
                        if(!o){ return; }
                        if(o.after){
                                o.after();
                        }else{
                                o.before(); ///??????
                        }
                        
                        this.undostack.push(o);
                }
        }
);
});