source: Dev/trunk/src/client/dojox/mdnd/AutoScroll.js

define(["dojo/_base/kernel",
        "dojo/_base/declare",
        "dojo/_base/lang",
        "dojo/_base/connect",
        "dojo/_base/sniff",
        "dojo/ready",
        "dojo/_base/window"
],function(dojo, declare, lang, connect, sniff, ready){
        var as = declare(
                "dojox.mdnd.AutoScroll",
                null,
        {
                // summary:
                //              Activate scrolling while dragging a widget.
        
                // interval: Integer
                //              default mouse move offset
                interval: 3,
        
                // recursiveTimer: Integer
                recursiveTimer: 10,
        
                // marginMouse: Integer
                //              Default mouse margin
                marginMouse: 50,
        
                constructor: function(){
                        //console.log("dojox.mdnd.AutoScroll ::: constructor ");
                        this.resizeHandler = connect.connect(dojo.global,"onresize", this, function(){
                                this.getViewport();
                        });
                        ready(lang.hitch(this, "init"));
                },
        
                init: function(){
                        //console.log("dojox.mdnd.AutoScroll ::: init ");
                        this._html = (sniff("webkit"))? dojo.body() : dojo.body().parentNode;
                        this.getViewport();
                },
        
                getViewport:function(){
                        // summary:
                        //              Set the visible part of the window. Varies accordion to Navigator.
        
                        //console.log("dojox.mdnd.AutoScroll ::: getViewport ");
                        var d = dojo.doc, dd = d.documentElement, w = window, b = dojo.body();
                        if(dojo.isMozilla){
                                this._v = { 'w': dd.clientWidth, 'h': w.innerHeight };  // Object
                        }
                        else if(!dojo.isOpera && w.innerWidth){
                                this._v = { 'w': w.innerWidth, 'h': w.innerHeight };            // Object
                        }
                        else if(!dojo.isOpera && dd && dd.clientWidth){
                                this._v = { 'w': dd.clientWidth, 'h': dd.clientHeight };        // Object
                        }
                        else if(b.clientWidth){
                                this._v = { 'w': b.clientWidth, 'h': b.clientHeight };  // Object
                        }
                },
        
                setAutoScrollNode: function(/*Node*/node){
                        // summary:
                        //              set the node which is dragged
                        // node:
                        //              node to scroll
        
                        //console.log("dojox.mdnd.AutoScroll ::: setAutoScrollNode ");
                        this._node = node;
                },
        
                setAutoScrollMaxPage: function(){
                        // summary:
                        //              Set the hightest heigh and width authorized scroll.
        
                        //console.log("dojox.mdnd.AutoScroll ::: setAutoScrollMaxPage ");
                        this._yMax = this._html.scrollHeight;
                        this._xMax = this._html.scrollWidth;
                },
        
                checkAutoScroll: function(/*Event*/e){
                        // summary:
                        //              Check if an autoScroll have to be launched.
        
                        //console.log("dojox.mdnd.AutoScroll ::: checkAutoScroll");
                        if(this._autoScrollActive){
                                this.stopAutoScroll();
                        }
                        this._y = e.pageY;
                        this._x = e.pageX;
                        if(e.clientX < this.marginMouse){
                                this._autoScrollActive = true;
                                this._autoScrollLeft(e);
                        }
                        else if(e.clientX > this._v.w - this.marginMouse){
                                this._autoScrollActive = true;
                                this._autoScrollRight(e);
                        }
                        if(e.clientY < this.marginMouse){
                                this._autoScrollActive = true;
                                this._autoScrollUp(e);
                                
                        }
                        else if(e.clientY > this._v.h - this.marginMouse){
                                this._autoScrollActive = true;
                                this._autoScrollDown();
                        }
                },
        
                _autoScrollDown: function(){
                        // summary:
                        //              Manage the down autoscroll.
                        // tags:
                        //              protected
        
                        //console.log("dojox.mdnd.AutoScroll ::: _autoScrollDown ");
                        if(this._timer){
                                clearTimeout(this._timer);
                        }
                        if(this._autoScrollActive && this._y + this.marginMouse < this._yMax){
                                this._html.scrollTop += this.interval;
                                this._node.style.top = (parseInt(this._node.style.top) + this.interval) + "px";
                                this._y += this.interval;
                                this._timer = setTimeout(lang.hitch(this, "_autoScrollDown"), this.recursiveTimer);
                        }
                },
        
                _autoScrollUp: function(){
                        // summary:
                        //              Manage the up autoscroll.
                        // tags:
                        //              protected
        
                        //console.log("dojox.mdnd.AutoScroll ::: _autoScrollUp ");
                        if(this._timer){
                                clearTimeout(this._timer);
                        }
                        if(this._autoScrollActive && this._y - this.marginMouse > 0){
                                this._html.scrollTop -= this.interval;
                                this._node.style.top = (parseInt(this._node.style.top) - this.interval) + "px";
                                this._y -= this.interval;
                                this._timer = setTimeout(lang.hitch(this, "_autoScrollUp"),this.recursiveTimer);
                        }
                },
        
                _autoScrollRight: function(){
                        // summary:
                        //              Manage the right autoscroll.
                        // tags:
                        //              protected
        
                        //console.log("dojox.mdnd.AutoScroll ::: _autoScrollRight ");
                        if(this._timer){
                                clearTimeout(this._timer);
                        }
                        if(this._autoScrollActive && this._x + this.marginMouse < this._xMax){
                                this._html.scrollLeft += this.interval;
                                this._node.style.left = (parseInt(this._node.style.left) + this.interval) + "px";
                                this._x += this.interval;
                                this._timer = setTimeout(lang.hitch(this, "_autoScrollRight"), this.recursiveTimer);
                        }
                },
        
                _autoScrollLeft: function(/*Event*/e){
                        // summary:
                        //              Manage the left autoscroll.
                        // tags:
                        //              protected
        
                        //console.log("dojox.mdnd.AutoScroll ::: _autoScrollLeft ");
                        if(this._timer){
                                clearTimeout(this._timer);
                        }
                        if(this._autoScrollActive && this._x - this.marginMouse > 0){
                                this._html.scrollLeft -= this.interval;
                                this._node.style.left = (parseInt(this._node.style.left) - this.interval) + "px";
                                this._x -= this.interval;
                                this._timer = setTimeout(lang.hitch(this, "_autoScrollLeft"),this.recursiveTimer);
                        }
                },
        
                stopAutoScroll: function(){
                        // summary:
                        //              Stop the autoscroll.
                        
                        //console.log("dojox.mdnd.AutoScroll ::: stopAutoScroll ");
                        if(this._timer){
                                clearTimeout(this._timer);
                        }
                        this._autoScrollActive = false;
                },
        
                destroy: function(){
                        //console.log("dojox.mdnd.AutoScroll ::: destroy ");
                        connect.disconnect(this.resizeHandler);
                }
        });
        
        dojox.mdnd.autoScroll = null;
        
        dojox.mdnd.autoScroll = new dojox.mdnd.AutoScroll();
        return as;
});