ddcore.js

一个struts和extjs得源码

        /**
         * the DragDrop object that is currently being dragged
         * @property dragCurrent
         * @type DragDrop
         * @private
         * @static
         **/
        dragCurrent: null,

        /**
         * the DragDrop object(s) that are being hovered over
         * @property dragOvers
         * @type Array
         * @private
         * @static
         */
        dragOvers: {},

        /**
         * the X distance between the cursor and the object being dragged
         * @property deltaX
         * @type int
         * @private
         * @static
         */
        deltaX: 0,

        /**
         * the Y distance between the cursor and the object being dragged
         * @property deltaY
         * @type int
         * @private
         * @static
         */
        deltaY: 0,

        /**
         * Flag to determine if we should prevent the default behavior of the
         * events we define. By default this is true, but this can be set to
         * false if you need the default behavior (not recommended)
         * @property preventDefault
         * @type boolean
         * @static
         */
        preventDefault: true,

        /**
         * Flag to determine if we should stop the propagation of the events
         * we generate. This is true by default but you may want to set it to
         * false if the html element contains other features that require the
         * mouse click.
         * @property stopPropagation
         * @type boolean
         * @static
         */
        stopPropagation: true,

        /**
         * Internal flag that is set to true when drag and drop has been
         * intialized
         * @property initialized
         * @private
         * @static
         */
        initialized: false,

        /**
         * All drag and drop can be disabled.
         * @property locked
         * @private
         * @static
         */
        locked: false,

        /**
         * Called the first time an element is registered.
         * @method init
         * @private
         * @static
         */
        init: function() {
            this.initialized = true;
        },

        /**
         * In point mode, drag and drop interaction is defined by the
         * location of the cursor during the drag/drop
         * @property POINT
         * @type int
         * @static
         */
        POINT: 0,

        /**
         * In intersect mode, drag and drop interaction is defined by the
         * overlap of two or more drag and drop objects.
         * @property INTERSECT
         * @type int
         * @static
         */
        INTERSECT: 1,

        /**
         * The current drag and drop mode.  Default: POINT
         * @property mode
         * @type int
         * @static
         */
        mode: 0,

        /**
         * Runs method on all drag and drop objects
         * @method _execOnAll
         * @private
         * @static
         */
        _execOnAll: function(sMethod, args) {
            for (var i in this.ids) {
                for (var j in this.ids[i]) {
                    var oDD = this.ids[i][j];
                    if (! this.isTypeOfDD(oDD)) {
                        continue;
                    }
                    oDD[sMethod].apply(oDD, args);
                }
            }
        },

        /**
         * Drag and drop initialization.  Sets up the global event handlers
         * @method _onLoad
         * @private
         * @static
         */
        _onLoad: function() {

            this.init();


            Event.on(document, "mouseup",   this.handleMouseUp, this, true);
            Event.on(document, "mousemove", this.handleMouseMove, this, true);
            Event.on(window,   "unload",    this._onUnload, this, true);
            Event.on(window,   "resize",    this._onResize, this, true);
            // Event.on(window,   "mouseout",    this._test);

        },

        /**
         * Reset constraints on all drag and drop objs
         * @method _onResize
         * @private
         * @static
         */
        _onResize: function(e) {
            this._execOnAll("resetConstraints", []);
        },

        /**
         * Lock all drag and drop functionality
         * @method lock
         * @static
         */
        lock: function() { this.locked = true; },

        /**
         * Unlock all drag and drop functionality
         * @method unlock
         * @static
         */
        unlock: function() { this.locked = false; },

        /**
         * Is drag and drop locked?
         * @method isLocked
         * @return {boolean} True if drag and drop is locked, false otherwise.
         * @static
         */
        isLocked: function() { return this.locked; },

        /**
         * Location cache that is set for all drag drop objects when a drag is
         * initiated, cleared when the drag is finished.
         * @property locationCache
         * @private
         * @static
         */
        locationCache: {},

        /**
         * Set useCache to false if you want to force object the lookup of each
         * drag and drop linked element constantly during a drag.
         * @property useCache
         * @type boolean
         * @static
         */
        useCache: true,

        /**
         * The number of pixels that the mouse needs to move after the
         * mousedown before the drag is initiated.  Default=3;
         * @property clickPixelThresh
         * @type int
         * @static
         */
        clickPixelThresh: 3,

        /**
         * The number of milliseconds after the mousedown event to initiate the
         * drag if we don't get a mouseup event. Default=1000
         * @property clickTimeThresh
         * @type int
         * @static
         */
        clickTimeThresh: 350,

        /**
         * Flag that indicates that either the drag pixel threshold or the
         * mousdown time threshold has been met
         * @property dragThreshMet
         * @type boolean
         * @private
         * @static
         */
        dragThreshMet: false,

        /**
         * Timeout used for the click time threshold
         * @property clickTimeout
         * @type Object
         * @private
         * @static
         */
        clickTimeout: null,

        /**
         * The X position of the mousedown event stored for later use when a
         * drag threshold is met.
         * @property startX
         * @type int
         * @private
         * @static
         */
        startX: 0,

        /**
         * The Y position of the mousedown event stored for later use when a
         * drag threshold is met.
         * @property startY
         * @type int
         * @private
         * @static
         */
        startY: 0,

        /**
         * Each DragDrop instance must be registered with the DragDropMgr.
         * This is executed in DragDrop.init()
         * @method regDragDrop
         * @param {DragDrop} oDD the DragDrop object to register
         * @param {String} sGroup the name of the group this element belongs to
         * @static
         */
        regDragDrop: function(oDD, sGroup) {
            if (!this.initialized) { this.init(); }

            if (!this.ids[sGroup]) {
                this.ids[sGroup] = {};
            }
            this.ids[sGroup][oDD.id] = oDD;
        },

        /**
         * Removes the supplied dd instance from the supplied group. Executed
         * by DragDrop.removeFromGroup, so don't call this function directly.
         * @method removeDDFromGroup
         * @private
         * @static
         */
        removeDDFromGroup: function(oDD, sGroup) {
            if (!this.ids[sGroup]) {
                this.ids[sGroup] = {};
            }

            var obj = this.ids[sGroup];
            if (obj && obj[oDD.id]) {
                delete obj[oDD.id];
            }
        },

        /**
         * Unregisters a drag and drop item.  This is executed in
         * DragDrop.unreg, use that method instead of calling this directly.
         * @method _remove
         * @private
         * @static
         */
        _remove: function(oDD) {
            for (var g in oDD.groups) {
                if (g && this.ids[g] && this.ids[g][oDD.id]) {
                    delete this.ids[g][oDD.id];
                }
            }
            delete this.handleIds[oDD.id];
        },

        /**
         * Each DragDrop handle element must be registered.  This is done
         * automatically when executing DragDrop.setHandleElId()
         * @method regHandle
         * @param {String} sDDId the DragDrop id this element is a handle for
         * @param {String} sHandleId the id of the element that is the drag
         * handle
         * @static
         */
        regHandle: function(sDDId, sHandleId) {
            if (!this.handleIds[sDDId]) {
                this.handleIds[sDDId] = {};
            }
            this.handleIds[sDDId][sHandleId] = sHandleId;
        },

        /**
         * Utility function to determine if a given element has been
         * registered as a drag drop item.
         * @method isDragDrop
         * @param {String} id the element id to check
         * @return {boolean} true if this element is a DragDrop item,
         * false otherwise
         * @static
         */
        isDragDrop: function(id) {
            return ( this.getDDById(id) ) ? true : false;
        },

        /**
         * Returns the drag and drop instances that are in all groups the
         * passed in instance belongs to.
         * @method getRelated
         * @param {DragDrop} p_oDD the obj to get related data for
         * @param {boolean} bTargetsOnly if true, only return targetable objs
         * @return {DragDrop[]} the related instances
         * @static
         */
        getRelated: function(p_oDD, bTargetsOnly) {
            var oDDs = [];
            for (var i in p_oDD.groups) {
                for (j in this.ids[i]) {
                    var dd = this.ids[i][j];
                    if (! this.isTypeOfDD(dd)) {
                        continue;
                    }
                    if (!bTargetsOnly || dd.isTarget) {
                        oDDs[oDDs.length] = dd;
                    }
                }
            }

            return oDDs;
        },

        /**
         * Returns true if the specified dd target is a legal target for
         * the specifice drag obj
         * @method isLegalTarget
         * @param {DragDrop} the drag obj
         * @param {DragDrop} the target
         * @return {boolean} true if the target is a legal target for the
         * dd obj
         * @static
         */
        isLegalTarget: function (oDD, oTargetDD) {
            var targets = this.getRelated(oDD, true);
            for (var i=0, len=targets.length;i<len;++i) {
                if (targets[i].id == oTargetDD.id) {
                    return true;
                }
            }

            return false;
        },

        /**
         * My goal is to be able to transparently determine if an object is
         * typeof DragDrop, and the exact subclass of DragDrop.  typeof
         * returns "object", oDD.constructor.toString() always returns
         * "DragDrop" and not the name of the subclass.  So for now it just
         * evaluates a well-known variable in DragDrop.
         * @method isTypeOfDD
         * @param {Object} the object to evaluate
         * @return {boolean} true if typeof oDD = DragDrop
         * @static
         */
        isTypeOfDD: function (oDD) {
            return (oDD && oDD.__ygDragDrop);
        },

        /**
         * Utility function to determine if a given element has been
         * registered as a drag drop handle for the given Drag Drop object.
         * @method isHandle
         * @param {String} id the element id to check
         * @return {boolean} true if this element is a DragDrop handle, false
         * otherwise
         * @static
         */
        isHandle: function(sDDId, sHandleId) {
            return ( this.handleIds[sDDId] &&
                            this.handleIds[sDDId][sHandleId] );