# Yahoo! UI Library

### dd 3.0.0b1

Yahoo! UI Library > dd > drag.js (source view)
Search:
Filters Show Private Show Protected Show Deprecated

        /**
         * The Drag & Drop Utility allows you to create a draggable interface efficiently, buffering you from browser-level abnormalities and enabling you to focus on the interesting logic surrounding your particular implementation. This component enables you to create a variety of standard draggable objects with just a few lines of code and then, using its extensive API, add your own specific implementation logic.
         * @module dd
         * @submodule dd-drag
         */
        /**
         * This class provides the ability to drag a Node.
         * @class Drag
         * @extends Base
         * @constructor
         * @namespace DD
         */

        var DDM = Y.DD.DDM,
            NODE = 'node',
            DRAGGING = 'dragging',
            DRAG_NODE = 'dragNode',
            OFFSET_HEIGHT = 'offsetHeight',
            OFFSET_WIDTH = 'offsetWidth',
            MOUSE_UP = 'mouseup',
            MOUSE_DOWN = 'mousedown',
            DRAG_START = 'dragstart',
            /**
            * @event drag:mouseDown
            * @description Handles the mousedown DOM event, checks to see if you have a valid handle then starts the drag timers.
            * @preventable _defMouseDownFn
            * @param {Event.Facade} ev The mousedown event.
            * @bubbles DDM
            * @type {Event.Custom}
            */
            EV_MOUSE_DOWN = 'drag:mouseDown',
            /**
            * @event drag:afterMouseDown
            * @description Fires after the mousedown event has been cleared.
            * @param {Event.Facade} ev The mousedown event.
            * @bubbles DDM
            * @type {Event.Custom}
            */
            EV_AFTER_MOUSE_DOWN = 'drag:afterMouseDown',
            /**
            * @event drag:removeHandle
            * @description Fires after a handle is removed.
            * @bubbles DDM
            * @type {Event.Custom}
            */
            EV_REMOVE_HANDLE = 'drag:removeHandle',
            /**
            * @event drag:addHandle
            * @description Fires after a handle is added.
            * @bubbles DDM
            * @type {Event.Custom}
            */
            EV_ADD_HANDLE = 'drag:addHandle',
            /**
            * @event drag:removeInvalid
            * @description Fires after an invalid selector is removed.
            * @bubbles DDM
            * @type {Event.Custom}
            */
            EV_REMOVE_INVALID = 'drag:removeInvalid',
            /**
            * @event drag:addInvalid
            * @description Fires after an invalid selector is added.
            * @bubbles DDM
            * @type {Event.Custom}
            */
            EV_ADD_INVALID = 'drag:addInvalid',
            /**
            * @event drag:start
            * @description Fires at the start of a drag operation.
            * @bubbles DDM
            * @type {Event.Custom}
            */
            EV_START = 'drag:start',
            /**
            * @event drag:end
            * @description Fires at the end of a drag operation.
            * @bubbles DDM
            * @type {Event.Custom}
            */
            EV_END = 'drag:end',
            /**
            * @event drag:drag
            * @description Fires every mousemove during a drag operation.
            * @bubbles DDM
            * @type {Event.Custom}
            */
            EV_DRAG = 'drag:drag',
            /**
            * @event drag:align
            * @preventable _defAlignFn
            * @description Fires when this node is aligned.
            * @bubbles DDM
            * @type {Event.Custom}
            */
            EV_ALIGN = 'drag:align',
            /**
            * @event drag:over
            * @description Fires when this node is over a Drop Target. (Fired from dd-drop)
            * @bubbles DDM
            * @type {Event.Custom}
            */
            /**
            * @event drag:enter
            * @description Fires when this node enters a Drop Target. (Fired from dd-drop)
            * @bubbles DDM
            * @type {Event.Custom}
            */
            /**
            * @event drag:exit
            * @description Fires when this node exits a Drop Target. (Fired from dd-drop)
            * @bubbles DDM
            * @type {Event.Custom}
            */
            /**
            * @event drag:drophit
            * @description Fires when this node is dropped on a valid Drop Target. (Fired from dd-ddm-drop)
            * @bubbles DDM
            * @type {Event.Custom}
            */
            /**
            * @event drag:dropmiss
            * @description Fires when this node is dropped on an invalid Drop Target. (Fired from dd-ddm-drop)
            * @bubbles DDM
            * @type {Event.Custom}
            */

        Drag = function() {
            this._lazyAddAttrs = false;
            Drag.superclass.constructor.apply(this, arguments);

            DDM._regDrag(this);
        };

        Drag.NAME = 'drag';

        Drag.ATTRS = {
            /**
            * @attribute node
            * @description Y.Node instanace to use as the element to initiate a drag operation
            * @type Node
            */
            node: {
                setter: function(node) {
                    var n = Y.get(node);
                    if (!n) {
                        Y.error('DD.Drag: Invalid Node Given: ' + node);
                    } else {
                        n = n.item(0);
                    }
                    return n;
                }
            },
            /**
            * @attribute dragNode
            * @description Y.Node instanace to use as the draggable element, defaults to node
            * @type Node
            */
            dragNode: {
                setter: function(node) {
                    var n = Y.Node.get(node);
                    if (!n) {
                        Y.error('DD.Drag: Invalid dragNode Given: ' + node);
                    }
                    return n;
                }
            },
            /**
            * @attribute offsetNode
            * @description Offset the drag element by the difference in cursor position: default true
            * @type Boolean
            */
            offsetNode: {
                value: true
            },
            /**
            * @attribute clickPixelThresh
            * @description The number of pixels to move to start a drag operation, default is 3.
            * @type Number
            */
            clickPixelThresh: {
                value: DDM.get('clickPixelThresh')
            },
            /**
            * @attribute clickTimeThresh
            * @description The number of milliseconds a mousedown has to pass to start a drag operation, default is 1000.
            * @type Number
            */
            clickTimeThresh: {
                value: DDM.get('clickTimeThresh')
            },
            /**
            * @attribute lock
            * @description Set to lock this drag element so that it can't be dragged: default false.
            * @type Boolean
            */
            lock: {
                value: false,
                setter: function(lock) {
                    if (lock) {
                        this.get(NODE).addClass(DDM.CSS_PREFIX + '-locked');
                    } else {
                        this.get(NODE).removeClass(DDM.CSS_PREFIX + '-locked');
                    }
                    return lock;
                }
            },
            /**
            * @attribute data
            * @description A payload holder to store arbitrary data about this drag object, can be used to store any value.
            * @type Mixed
            */
            data: {
                value: false
            },
            /**
            * @attribute move
            * @description If this is false, the drag element will not move with the cursor: default true. Can be used to "resize" the element.
            * @type Boolean
            */
            move: {
                value: true
            },
            /**
            * @attribute useShim
            * @description Use the protective shim on all drag operations: default true. Only works with dd-ddm, not dd-ddm-base.
            * @type Boolean
            */
            useShim: {
                value: true
            },
            /**
            * @attribute activeHandle
            * @description This config option is set by Drag to inform you of which handle fired the drag event (in the case that there are several handles): default false.
            * @type Node
            */
            activeHandle: {
                value: false
            },
            /**
            * @attribute primaryButtonOnly
            * @description By default a drag operation will only begin if the mousedown occurred with the primary mouse button. Setting this to false will allow for all mousedown events to trigger a drag.
            * @type Boolean
            */
            primaryButtonOnly: {
                value: true
            },
            /**
            * @attribute dragging
            * @description This attribute is not meant to be used by the implementor, it is meant to be used as an Event tracker so you can listen for it to change.
            * @type Boolean
            */
            dragging: {
                value: false
            },
            parent: {
                value: false
            },
            /**
            * @attribute target
            * @description This attribute only works if the dd-drop module has been loaded. It will make this node a drop target as well as draggable.
            * @type Boolean
            */
            target: {
                value: false,
                setter: function(config) {
                    this._handleTarget(config);
                    return config;
                }
            },
            /**
            * @attribute dragMode
            * @description This attribute only works if the dd-drop module is active. It will set the dragMode (point, intersect, strict) of this Drag instance.
            * @type String
            */
            dragMode: {
                value: null,
                setter: function(mode) {
                    return DDM._setDragMode(mode);
                }
            },
            /**
            * @attribute groups
            * @description Array of groups to add this drag into.
            * @type Array
            */
            groups: {
                value: ['default'],
                getter: function() {
                    if (!this._groups) {
                        this._groups = {};
                    }
                    var ret = [];
                    Y.each(this._groups, function(v, k) {
                        ret[ret.length] = k;
                    });
                    return ret;
                },
                setter: function(g) {
                    this._groups = {};
                    Y.each(g, function(v, k) {
                        this._groups[v] = true;
                    }, this);
                    return g;
                }
            },
            /**
            * @attribute handles
            * @description Array of valid handles to add. Adding something here will set all handles, even if previously added with addHandle
            * @type Array
            */
            handles: {
                value: null,
                setter: function(g) {
                    if (g) {
                        this._handles = {};
                        Y.each(g, function(v, k) {
                            this._handles[v] = true;
                        }, this);
                    } else {
                        this._handles = null;
                    }
                    return g;
                }
            },
            /**
            * @attribute bubbles
            * @description Controls the default bubble parent for this Drag instance. Default: Y.DD.DDM. Set to false to disable bubbling.
            * @type Object
            */
            bubbles: {
                writeOnce: true,
                value: Y.DD.DDM
            }
        };

        Y.extend(Drag, Y.Base, {
            /**
            * @method addToGroup
            * @description Add this Drag instance to a group, this should be used for on-the-fly group additions.
            * @param {String} g The group to add this Drag Instance to.
            * @return {Self}
            * @chainable
            */
            addToGroup: function(g) {
                this._groups[g] = true;
                DDM._activateTargets();
                return this;
            },
            /**
            * @method removeFromGroup
            * @description Remove this Drag instance from a group, this should be used for on-the-fly group removals.
            * @param {String} g The group to remove this Drag Instance from.
            * @return {Self}
            * @chainable
            */
            removeFromGroup: function(g) {
                delete this._groups[g];
                DDM._activateTargets();
                return this;
            },
            /**
            * @property target
            * @description This will be a reference to the Drop instance associated with this drag if the target: true config attribute is set..
            * @type {Object}
            */
            target: null,
            /**
            * @private
            * @method _handleTarget
            * @description Attribute handler for the target config attribute.
            * @param {Boolean/Object}
            * @return {Boolean/Object}
            */
            _handleTarget: function(config) {
                if (Y.DD.Drop) {
                    if (config === false) {
                        if (this.target) {
                            DDM._unregTarget(this.target);
                            this.target = null;
                        }
                        return false;
                    } else {
                        if (!Y.Lang.isObject(config)) {
                            config = {};
                        }
                        config.bubbles = ('bubbles' in config) ? config.bubbles : this.get('bubbles');
                        config.node = this.get(NODE);
                        config.groups = config.groups || this.get('groups');
                        this.target = new Y.DD.Drop(config);
                    }
                } else {
                    return false;
                }
            },
            /**
            * @private
            * @property _groups
            * @description Storage Array for the groups this drag belongs to.
            * @type {Array}
            */
            _groups: null,
            /**
            * @private
            * @method _createEvents
            * @description This method creates all the events for this Event Target and publishes them so we get Event Bubbling.
            */
            _createEvents: function() {

                this.publish(EV_MOUSE_DOWN, {
                    defaultFn: this._defMouseDownFn,
                    queuable: false,
                    emitFacade: true,
                    bubbles: true,
                    prefix: 'drag'
                });

                this.publish(EV_ALIGN, {
                    defaultFn: this._defAlignFn,
                    queuable: false,
                    emitFacade: true,
                    bubbles: true,
                    prefix: 'drag'
                });

                this.publish(EV_DRAG, {
                    defaultFn: this._defDragFn,
                    queuable: false,
                    emitFacade: true,
                    bubbles: true,
                    prefix: 'drag'
                });

                this.publish(EV_END, {
                    preventedFn: this._prevEndFn,
                    queuable: false,
                    emitFacade: true,
                    bubbles: true,
                    prefix: 'drag'
                });

                var ev = [
                    EV_AFTER_MOUSE_DOWN,
                    EV_REMOVE_HANDLE,
                    EV_ADD_HANDLE,
                    EV_REMOVE_INVALID,
                    EV_ADD_INVALID,
                    EV_START,
                    'drag:drophit',
                    'drag:dropmiss',
                    'drag:over',
                    'drag:enter',
                    'drag:exit'
                ];

                Y.each(ev, function(v, k) {
                    this.publish(v, {
                        type: v,
                        emitFacade: true,
                        bubbles: true,
                        preventable: false,
                        queuable: false,
                        prefix: 'drag'
                    });
                }, this);

                if (this.get('bubbles')) {
                    this.addTarget(this.get('bubbles'));
                }

            },
            /**
            * @private
            * @property _ev_md
            * @description A private reference to the mousedown DOM event
            * @type {Event.Facade}
            */
            _ev_md: null,
            /**
            * @private
            * @property _startTime
            * @description The getTime of the mousedown event. Not used, just here in case someone wants/needs to use it.
            * @type Date
            */
            _startTime: null,
            /**
            * @private
            * @property _endTime
            * @description The getTime of the mouseup event. Not used, just here in case someone wants/needs to use it.
            * @type Date
            */
            _endTime: null,
            /**
            * @private
            * @property _handles
            * @description A private hash of the valid drag handles
            * @type {Object}
            */
            _handles: null,
            /**
            * @private
            * @property _invalids
            * @description A private hash of the invalid selector strings
            * @type {Object}
            */
            _invalids: null,
            /**
            * @private
            * @property _invalidsDefault
            * @description A private hash of the default invalid selector strings: {'textarea': true, 'input': true, 'a': true, 'button': true}
            * @type {Object}
            */
            _invalidsDefault: {'textarea': true, 'input': true, 'a': true, 'button': true},
            /**
            * @private
            * @property _dragThreshMet
            * @description Private flag to see if the drag threshhold was met
            * @type {Boolean}
            */
            _dragThreshMet: null,
            /**
            * @private
            * @property _fromTimeout
            * @description Flag to determine if the drag operation came from a timeout
            * @type {Boolean}
            */
            _fromTimeout: null,
            /**
            * @private
            * @property _clickTimeout
            * @description Holder for the setTimeout call
            * @type {Boolean}
            */
            _clickTimeout: null,
            /**
            * @property deltaXY
            * @description The offset of the mouse position to the element's position
            * @type {Array}
            */
            deltaXY: null,
            /**
            * @property startXY
            * @description The initial mouse position
            * @type {Array}
            */
            startXY: null,
            /**
            * @property nodeXY
            * @description The initial element position
            * @type {Array}
            */
            nodeXY: null,
            /**
            * @property lastXY
            * @description The position of the element as it's moving (for offset calculations)
            * @type {Array}
            */
            lastXY: null,
            /**
            * @property actXY
            * @description The xy that the node will be set to. Changing this will alter the position as it's dragged.
            * @type {Array}
            */
            actXY: null,
            /**
            * @property realXY
            * @description The real xy position of the node.
            * @type {Array}
            */
            realXY: null,
            /**
            * @property mouseXY
            * @description The XY coords of the mousemove
            * @type {Array}
            */
            mouseXY: null,
            /**
            * @property region
            * @description A region object associated with this drag, used for checking regions while dragging.
            * @type Object
            */
            region: null,
            /**
            * @private
            * @method _handleMouseUp
            * @description Handler for the mouseup DOM event
            * @param {Event.Facade}
            */
            _handleMouseUp: function(ev) {
                this._fixIEMouseUp();
                if (DDM.activeDrag) {
                    DDM._end();
                }
            },
            /**
            * @private
            * @method _fixDragStart
            * @description The function we use as the ondragstart handler when we start a drag in Internet Explorer. This keeps IE from blowing up on images as drag handles.
            */
            _fixDragStart: function(e) {
                e.preventDefault();
            },
            /**
            * @private
            * @method _ieSelectFix
            * @description The function we use as the onselectstart handler when we start a drag in Internet Explorer
            */
            _ieSelectFix: function() {
                return false;
            },
            /**
            * @private
            * @property _ieSelectBack
            * @description We will hold a copy of the current "onselectstart" method on this property, and reset it after we are done using it.
            */
            _ieSelectBack: null,
            /**
            * @private
            * @method _fixIEMouseDown
            * @description This method copies the onselectstart listner on the document to the _ieSelectFix property
            */
            _fixIEMouseDown: function() {
                if (Y.UA.ie) {
                    this._ieSelectBack = Y.config.doc.body.onselectstart;
                    Y.config.doc.body.onselectstart = this._ieSelectFix;
                }
            },
            /**
            * @private
            * @method _fixIEMouseUp
            * @description This method copies the _ieSelectFix property back to the onselectstart listner on the document.
            */
            _fixIEMouseUp: function() {
                if (Y.UA.ie) {
                    Y.config.doc.body.onselectstart = this._ieSelectBack;
                }
            },
            /**
            * @private
            * @method _handleMouseDownEvent
            * @description Handler for the mousedown DOM event
            * @param {Event.Facade}
            */
            _handleMouseDownEvent: function(ev) {
                this.fire(EV_MOUSE_DOWN, { ev: ev });
            },
            /**
            * @private
            * @method _defMouseDownFn
            * @description Handler for the mousedown DOM event
            * @param {Event.Facade}
            */
            _defMouseDownFn: function(e) {
                var ev = e.ev;
                this._dragThreshMet = false;
                this._ev_md = ev;

                if (this.get('primaryButtonOnly') && ev.button > 1) {
                    return false;
                }
                if (this.validClick(ev)) {
                    this._fixIEMouseDown();
                    ev.halt();
                    this._setStartPosition([ev.pageX, ev.pageY]);

                    DDM.activeDrag = this;

                    this._clickTimeout = Y.later(this.get('clickTimeThresh'), this, this._timeoutCheck);
                }
                this.fire(EV_AFTER_MOUSE_DOWN, { ev: ev });
            },
            /**
            * @method validClick
            * @description Method first checks to see if we have handles, if so it validates the click against the handle. Then if it finds a valid handle, it checks it against the invalid handles list. Returns true if a good handle was used, false otherwise.
            * @param {Event.Facade}
            * @return {Boolean}
            */
            validClick: function(ev) {
                var r = false, n = false,
                tar = ev.target,
                hTest = null,
                els = null,
                set = false;
                if (this._handles) {
                    Y.each(this._handles, function(i, n) {
                        if (Y.Lang.isString(n)) {
                            //Am I this or am I inside this
                            if (tar.test(n + ', ' + n + ' *') && !hTest) {
                                hTest = n;
                                r = true;
                            }
                        }
                    });
                } else {
                    n = this.get(NODE)
                    if (n.contains(tar) || n.compareTo(tar)) {
                        r = true;
                    }
                }
                if (r) {
                    if (this._invalids) {
                        Y.each(this._invalids, function(i, n) {
                            if (Y.Lang.isString(n)) {
                                //Am I this or am I inside this
                                if (tar.test(n + ', ' + n + ' *')) {
                                    r = false;
                                }
                            }
                        });
                    }
                }
                if (r) {
                    if (hTest) {
                        els = ev.currentTarget.queryAll(hTest);
                        set = false;
                        els.each(function(n, i) {
                            if ((n.contains(tar) || n.compareTo(tar)) && !set) {
                                set = true;
                                this.set('activeHandle', n);
                            }
                        }, this);
                    } else {
                        this.set('activeHandle', this.get(NODE));
                    }
                }
                return r;
            },
            /**
            * @private
            * @method _setStartPosition
            * @description Sets the current position of the Element and calculates the offset
            * @param {Array} xy The XY coords to set the position to.
            */
            _setStartPosition: function(xy) {
                this.startXY = xy;

                this.nodeXY = this.lastXY = this.realXY = this.get(NODE).getXY();

                if (this.get('offsetNode')) {
                    this.deltaXY = [(this.startXY[0] - this.nodeXY[0]), (this.startXY[1] - this.nodeXY[1])];
                } else {
                    this.deltaXY = [0, 0];
                }
            },
            /**
            * @private
            * @method _timeoutCheck
            * @description The method passed to setTimeout to determine if the clickTimeThreshold was met.
            */
            _timeoutCheck: function() {
                if (!this.get('lock') && !this._dragThreshMet) {
                    this._fromTimeout = this._dragThreshMet = true;
                    this.start();
                    this._alignNode([this._ev_md.pageX, this._ev_md.pageY], true);
                }
            },
            /**
            * @method removeHandle
            * @description Remove a Selector added by addHandle
            * @param {String} str The selector for the handle to be removed.
            * @return {Self}
            * @chainable
            */
            removeHandle: function(str) {
                if (this._handles[str]) {
                    delete this._handles[str];
                    this.fire(EV_REMOVE_HANDLE, { handle: str });
                }
                return this;
            },
            /**
            * @method addHandle
            * @description Add a handle to a drag element. Drag only initiates when a mousedown happens on this element.
            * @param {String} str The selector to test for a valid handle. Must be a child of the element.
            * @return {Self}
            * @chainable
            */
            addHandle: function(str) {
                if (!this._handles) {
                    this._handles = {};
                }
                if (Y.Lang.isString(str)) {
                    this._handles[str] = true;
                    this.fire(EV_ADD_HANDLE, { handle: str });
                }
                return this;
            },
            /**
            * @method removeInvalid
            * @description Remove an invalid handle added by addInvalid
            * @param {String} str The invalid handle to remove from the internal list.
            * @return {Self}
            * @chainable
            */
            removeInvalid: function(str) {
                if (this._invalids[str]) {
                    this._invalids[str] = null;
                    delete this._invalids[str];
                    this.fire(EV_REMOVE_INVALID, { handle: str });
                }
                return this;
            },
            /**
            * @method addInvalid
            * @description Add a selector string to test the handle against. If the test passes the drag operation will not continue.
            * @param {String} str The selector to test against to determine if this is an invalid drag handle.
            * @return {Self}
            * @chainable
            */
            addInvalid: function(str) {
                if (Y.Lang.isString(str)) {
                    this._invalids[str] = true;
                    this.fire(EV_ADD_INVALID, { handle: str });
                }
                return this;
            },
            /**
            * @private
            * @method initializer
            * @description Internal init handler
            */
            initializer: function() {
                this.get(NODE).dd = this;

                if (!this.get(NODE).get('id')) {
                    var id = Y.stamp(this.get(NODE));
                    this.get(NODE).set('id', id);
                }

                this.actXY = [];

                this._invalids = Y.clone(this._invalidsDefault, true);

                this._createEvents();

                if (!this.get(DRAG_NODE)) {
                    this.set(DRAG_NODE, this.get(NODE));
                }
                this._prep();
                this._dragThreshMet = false;
                //Shouldn't have to do this..
                this.set('groups', this.get('groups'));
            },
            /**
            * @private
            * @method _prep
            * @description Attach event listners and add classname
            */
            _prep: function() {
                var node = this.get(NODE);
                node.addClass(DDM.CSS_PREFIX + '-draggable');
                node.on(MOUSE_DOWN, Y.bind(this._handleMouseDownEvent, this));
                node.on(MOUSE_UP, Y.bind(this._handleMouseUp, this));
                node.on(DRAG_START, Y.bind(this._fixDragStart, this));
            },
            /**
            * @private
            * @method _unprep
            * @description Detach event listeners and remove classname
            */
            _unprep: function() {
                var node = this.get(NODE);
                node.removeClass(DDM.CSS_PREFIX + '-draggable');
                node.detachAll();
            },
            /**
            * @method start
            * @description Starts the drag operation
            * @return {Self}
            * @chainable
            */
            start: function() {
                if (!this.get('lock') && !this.get(DRAGGING)) {
                    var node = this.get(NODE), ow = node.get(OFFSET_WIDTH), oh = node.get(OFFSET_HEIGHT);
                    this._startTime = (new Date()).getTime();

                    DDM._start(this.deltaXY, [oh, ow]);
                    node.addClass(DDM.CSS_PREFIX + '-dragging');
                    this.fire(EV_START, {
                        pageX: this.nodeXY[0],
                        pageY: this.nodeXY[1],
                        startTime: this._startTime
                    });
                    var xy = this.nodeXY;

                    this.region = {
                        '0': xy[0],
                        '1': xy[1],
                        area: 0,
                        top: xy[1],
                        right: xy[0] + ow,
                        bottom: xy[1] + oh,
                        left: xy[0]
                    };
                    this.set(DRAGGING, true);
                }
                return this;
            },
            /**
            * @method end
            * @description Ends the drag operation
            * @return {Self}
            * @chainable
            */
            end: function() {
                this._endTime = (new Date()).getTime();
                if (this._clickTimeout) {
                    this._clickTimeout.cancel();
                }
                this._dragThreshMet = false;
                this._fromTimeout = false;
                if (!this.get('lock') && this.get(DRAGGING)) {
                    this.fire(EV_END, {
                        pageX: this.lastXY[0],
                        pageY: this.lastXY[1],
                        startTime: this._startTime,
                        endTime: this._endTime
                    });
                }
                this.get(NODE).removeClass(DDM.CSS_PREFIX + '-dragging');
                this.set(DRAGGING, false);
                this.deltaXY = [0, 0];

                return this;
            },
            /**
            * @private
            * @method _prevEndFn
            * @description Handler for preventing the drag:end event. It will reset the node back to it's start position
            */
            _prevEndFn: function(e) {
                //Bug #1852577
                this.get(DRAG_NODE).setXY(this.nodeXY);
            },
            /**
            * @private
            * @method _align
            * @description Calculates the offsets and set's the XY that the element will move to.
            * @param {Array} xy The xy coords to align with.
            */
            _align: function(xy) {
                this.fire(EV_ALIGN, {pageX: xy[0], pageY: xy[1] });
            },
            /**
            * @private
            * @method _defAlignFn
            * @description Calculates the offsets and set's the XY that the element will move to.
            * @param {Event.Facade} e The drag:align event.
            */
            _defAlignFn: function(e) {
                this.actXY = [e.pageX - this.deltaXY[0], e.pageY - this.deltaXY[1]];
            },
            /**
            * @private
            * @method _alignNode
            * @description This method performs the alignment before the element move.
            * @param {Array} eXY The XY to move the element to, usually comes from the mousemove DOM event.
            */
            _alignNode: function(eXY) {
                this._align(eXY);
                this._moveNode();
            },
            /**
            * @private
            * @method _moveNode
            * @description This method performs the actual element move.
            */
            _moveNode: function(scroll) {
                //if (!this.get(DRAGGING)) {
                //    return;
                //}
                var diffXY = [], diffXY2 = [], startXY = this.nodeXY, xy = this.actXY;

                diffXY[0] = (xy[0] - this.lastXY[0]);
                diffXY[1] = (xy[1] - this.lastXY[1]);

                diffXY2[0] = (xy[0] - this.nodeXY[0]);
                diffXY2[1] = (xy[1] - this.nodeXY[1]);

                this.region = {
                    '0': xy[0],
                    '1': xy[1],
                    area: 0,
                    top: xy[1],
                    right: xy[0] + this.get(DRAG_NODE).get(OFFSET_WIDTH),
                    bottom: xy[1] + this.get(DRAG_NODE).get(OFFSET_HEIGHT),
                    left: xy[0]
                };

                this.fire(EV_DRAG, {
                    pageX: xy[0],
                    pageY: xy[1],
                    scroll: scroll,
                    info: {
                        start: startXY,
                        xy: xy,
                        delta: diffXY,
                        offset: diffXY2
                    }
                });

                this.lastXY = xy;
            },
            /**
            * @private
            * @method _defDragFn
            * @description Default function for drag:drag. Fired from _moveNode.
            * @param {Event.Facade} ev The drag:drag event
            */
            _defDragFn: function(e) {
                if (this.get('move')) {
                    if (e.scroll) {
                        e.scroll.node.set('scrollTop', e.scroll.top);
                        e.scroll.node.set('scrollLeft', e.scroll.left);
                    }
                    this.get(DRAG_NODE).setXY([e.pageX, e.pageY]);
                    this.realXY = [e.pageX, e.pageY];
                }
            },
            /**
            * @private
            * @method _move
            * @description Fired from DragDropMgr (DDM) on mousemove.
            * @param {Event.Facade} ev The mousemove DOM event
            */
            _move: function(ev) {
                if (this.get('lock')) {
                    return false;
                } else {
                    this.mouseXY = [ev.pageX, ev.pageY];
                    if (!this._dragThreshMet) {
                        var diffX = Math.abs(this.startXY[0] - ev.pageX),
                        diffY = Math.abs(this.startXY[1] - ev.pageY);
                        if (diffX > this.get('clickPixelThresh') || diffY > this.get('clickPixelThresh')) {
                            this._dragThreshMet = true;
                            this.start();
                            this._alignNode([ev.pageX, ev.pageY]);
                        }
                    } else {
                        if (this._clickTimeout) {
                            this._clickTimeout.cancel();
                        }
                        this._alignNode([ev.pageX, ev.pageY]);
                    }
                }
            },
            /**
            * @method stopDrag
            * @description Method will forcefully stop a drag operation. For example calling this from inside an ESC keypress handler will stop this drag.
            * @return {Self}
            * @chainable
            */
            stopDrag: function() {
                if (this.get(DRAGGING)) {
                    DDM._end();
                }
                return this;
            },
            /**
            * @private
            * @method destructor
            * @description Lifecycle destructor, unreg the drag from the DDM and remove listeners
            */
            destructor: function() {
                this._unprep();
                this.detachAll();
                if (this.target) {
                    this.target.destroy();
                }
                DDM._unregDrag(this);
            }
        });
        Y.namespace('DD');
        Y.DD.Drag = Drag;

Copyright © 2009 Yahoo! Inc. All rights reserved.