source: Dev/trunk/src/client/dojo/dnd/Moveable.js

define([
        "../_base/array", "../_base/declare", "../_base/lang",
        "../dom", "../dom-class", "../Evented", "../on", "../topic", "../touch", "./common", "./Mover", "../_base/window"
], function(array, declare, lang, dom, domClass, Evented, on, topic, touch, dnd, Mover, win){

// module:
//              dojo/dnd/Moveable


var Moveable = declare("dojo.dnd.Moveable", [Evented], {
        // summary:
        //              an object, which makes a node movable

        // object attributes (for markup)
        handle: "",
        delay: 0,
        skip: false,

        constructor: function(node, params){
                // node: Node
                //              a node (or node's id) to be moved
                // params: Moveable.__MoveableArgs?
                //              optional parameters
                this.node = dom.byId(node);
                if(!params){ params = {}; }
                this.handle = params.handle ? dom.byId(params.handle) : null;
                if(!this.handle){ this.handle = this.node; }
                this.delay = params.delay > 0 ? params.delay : 0;
                this.skip  = params.skip;
                this.mover = params.mover ? params.mover : Mover;
                this.events = [
                        on(this.handle, touch.press, lang.hitch(this, "onMouseDown")),
                        // cancel text selection and text dragging
                        on(this.handle, "dragstart",   lang.hitch(this, "onSelectStart")),
                        on(this.handle, "selectstart",   lang.hitch(this, "onSelectStart"))
                ];
        },

        // markup methods
        markupFactory: function(params, node, Ctor){
                return new Ctor(node, params);
        },

        // methods
        destroy: function(){
                // summary:
                //              stops watching for possible move, deletes all references, so the object can be garbage-collected
                array.forEach(this.events, function(handle){ handle.remove(); });
                this.events = this.node = this.handle = null;
        },

        // mouse event processors
        onMouseDown: function(e){
                // summary:
                //              event processor for onmousedown/ontouchstart, creates a Mover for the node
                // e: Event
                //              mouse/touch event
                if(this.skip && dnd.isFormElement(e)){ return; }
                if(this.delay){
                        this.events.push(
                                on(this.handle, touch.move, lang.hitch(this, "onMouseMove")),
                                on(this.handle, touch.release, lang.hitch(this, "onMouseUp"))
                        );
                        this._lastX = e.pageX;
                        this._lastY = e.pageY;
                }else{
                        this.onDragDetected(e);
                }
                e.stopPropagation();
                e.preventDefault();
        },
        onMouseMove: function(e){
                // summary:
                //              event processor for onmousemove/ontouchmove, used only for delayed drags
                // e: Event
                //              mouse/touch event
                if(Math.abs(e.pageX - this._lastX) > this.delay || Math.abs(e.pageY - this._lastY) > this.delay){
                        this.onMouseUp(e);
                        this.onDragDetected(e);
                }
                e.stopPropagation();
                e.preventDefault();
        },
        onMouseUp: function(e){
                // summary:
                //              event processor for onmouseup, used only for delayed drags
                // e: Event
                //              mouse event
                for(var i = 0; i < 2; ++i){
                        this.events.pop().remove();
                }
                e.stopPropagation();
                e.preventDefault();
        },
        onSelectStart: function(e){
                // summary:
                //              event processor for onselectevent and ondragevent
                // e: Event
                //              mouse event
                if(!this.skip || !dnd.isFormElement(e)){
                        e.stopPropagation();
                        e.preventDefault();
                }
        },

        // local events
        onDragDetected: function(/*Event*/ e){
                // summary:
                //              called when the drag is detected;
                //              responsible for creation of the mover
                new this.mover(this.node, e, this);
        },
        onMoveStart: function(/*Mover*/ mover){
                // summary:
                //              called before every move operation
                topic.publish("/dnd/move/start", mover);
                domClass.add(win.body(), "dojoMove");
                domClass.add(this.node, "dojoMoveItem");
        },
        onMoveStop: function(/*Mover*/ mover){
                // summary:
                //              called after every move operation
                topic.publish("/dnd/move/stop", mover);
                domClass.remove(win.body(), "dojoMove");
                domClass.remove(this.node, "dojoMoveItem");
        },
        onFirstMove: function(/*===== mover, e =====*/){
                // summary:
                //              called during the very first move notification;
                //              can be used to initialize coordinates, can be overwritten.
                // mover: Mover
                // e: Event

                // default implementation does nothing
        },
        onMove: function(mover, leftTop /*=====, e =====*/){
                // summary:
                //              called during every move notification;
                //              should actually move the node; can be overwritten.
                // mover: Mover
                // leftTop: Object
                // e: Event
                this.onMoving(mover, leftTop);
                var s = mover.node.style;
                s.left = leftTop.l + "px";
                s.top  = leftTop.t + "px";
                this.onMoved(mover, leftTop);
        },
        onMoving: function(/*===== mover, leftTop =====*/){
                // summary:
                //              called before every incremental move; can be overwritten.
                // mover: Mover
                // leftTop: Object

                // default implementation does nothing
        },
        onMoved: function(/*===== mover, leftTop =====*/){
                // summary:
                //              called after every incremental move; can be overwritten.
                // mover: Mover
                // leftTop: Object

                // default implementation does nothing
        }
});

/*=====
Moveable.__MoveableArgs = declare([], {
        // handle: Node||String
        //              A node (or node's id), which is used as a mouse handle.
        //              If omitted, the node itself is used as a handle.
        handle: null,

        // delay: Number
        //              delay move by this number of pixels
        delay: 0,

        // skip: Boolean
        //              skip move of form elements
        skip: false,

        // mover: Object
        //              a constructor of custom Mover
        mover: dnd.Mover
});
=====*/

return Moveable;
});