ddcore.js

一个struts和extjs得源码

        },

        /**
         * Returns the DragDrop instance for a given id
         * @method getDDById
         * @param {String} id the id of the DragDrop object
         * @return {DragDrop} the drag drop object, null if it is not found
         * @static
         */
        getDDById: function(id) {
            for (var i in this.ids) {
                if (this.ids[i][id]) {
                    return this.ids[i][id];
                }
            }
            return null;
        },

        /**
         * Fired after a registered DragDrop object gets the mousedown event.
         * Sets up the events required to track the object being dragged
         * @method handleMouseDown
         * @param {Event} e the event
         * @param oDD the DragDrop object being dragged
         * @private
         * @static
         */
        handleMouseDown: function(e, oDD) {
            if(Ext.QuickTips){
                Ext.QuickTips.disable();
            }
            if(this.dragCurrent){
                // the original browser mouseup wasn't handled (e.g. outside FF browser window)
                // so clean up first to avoid breaking the next drag
                this.handleMouseUp(e);
            }
            
            this.currentTarget = e.getTarget();
            this.dragCurrent = oDD;

            var el = oDD.getEl();

            // track start position
            this.startX = e.getPageX();
            this.startY = e.getPageY();

            this.deltaX = this.startX - el.offsetLeft;
            this.deltaY = this.startY - el.offsetTop;

            this.dragThreshMet = false;

            this.clickTimeout = setTimeout(
                    function() {
                        var DDM = Ext.dd.DDM;
                        DDM.startDrag(DDM.startX, DDM.startY);
                    },
                    this.clickTimeThresh );
        },

        /**
         * Fired when either the drag pixel threshol or the mousedown hold
         * time threshold has been met.
         * @method startDrag
         * @param x {int} the X position of the original mousedown
         * @param y {int} the Y position of the original mousedown
         * @static
         */
        startDrag: function(x, y) {
            clearTimeout(this.clickTimeout);
            if (this.dragCurrent) {
                this.dragCurrent.b4StartDrag(x, y);
                this.dragCurrent.startDrag(x, y);
            }
            this.dragThreshMet = true;
        },

        /**
         * Internal function to handle the mouseup event.  Will be invoked
         * from the context of the document.
         * @method handleMouseUp
         * @param {Event} e the event
         * @private
         * @static
         */
        handleMouseUp: function(e) {

            if(Ext.QuickTips){
                Ext.QuickTips.enable();
            }
            if (! this.dragCurrent) {
                return;
            }

            clearTimeout(this.clickTimeout);

            if (this.dragThreshMet) {
                this.fireEvents(e, true);
            } else {
            }

            this.stopDrag(e);

            this.stopEvent(e);
        },

        /**
         * Utility to stop event propagation and event default, if these
         * features are turned on.
         * @method stopEvent
         * @param {Event} e the event as returned by this.getEvent()
         * @static
         */
        stopEvent: function(e){
            if(this.stopPropagation) {
                e.stopPropagation();
            }

            if (this.preventDefault) {
                e.preventDefault();
            }
        },

        /**
         * Internal function to clean up event handlers after the drag
         * operation is complete
         * @method stopDrag
         * @param {Event} e the event
         * @private
         * @static
         */
        stopDrag: function(e) {
            // Fire the drag end event for the item that was dragged
            if (this.dragCurrent) {
                if (this.dragThreshMet) {
                    this.dragCurrent.b4EndDrag(e);
                    this.dragCurrent.endDrag(e);
                }

                this.dragCurrent.onMouseUp(e);
            }

            this.dragCurrent = null;
            this.dragOvers = {};
        },

        /**
         * Internal function to handle the mousemove event.  Will be invoked
         * from the context of the html element.
         *
         * @TODO figure out what we can do about mouse events lost when the
         * user drags objects beyond the window boundary.  Currently we can
         * detect this in internet explorer by verifying that the mouse is
         * down during the mousemove event.  Firefox doesn't give us the
         * button state on the mousemove event.
         * @method handleMouseMove
         * @param {Event} e the event
         * @private
         * @static
         */
        handleMouseMove: function(e) {
            if (! this.dragCurrent) {
                return true;
            }

            // var button = e.which || e.button;

            // check for IE mouseup outside of page boundary
            if (Ext.isIE && (e.button !== 0 && e.button !== 1 && e.button !== 2)) {
                this.stopEvent(e);
                return this.handleMouseUp(e);
            }

            if (!this.dragThreshMet) {
                var diffX = Math.abs(this.startX - e.getPageX());
                var diffY = Math.abs(this.startY - e.getPageY());
                if (diffX > this.clickPixelThresh ||
                            diffY > this.clickPixelThresh) {
                    this.startDrag(this.startX, this.startY);
                }
            }

            if (this.dragThreshMet) {
                this.dragCurrent.b4Drag(e);
                this.dragCurrent.onDrag(e);
                if(!this.dragCurrent.moveOnly){
                    this.fireEvents(e, false);
                }
            }

            this.stopEvent(e);

            return true;
        },

        /**
         * Iterates over all of the DragDrop elements to find ones we are
         * hovering over or dropping on
         * @method fireEvents
         * @param {Event} e the event
         * @param {boolean} isDrop is this a drop op or a mouseover op?
         * @private
         * @static
         */
        fireEvents: function(e, isDrop) {
            var dc = this.dragCurrent;

            // If the user did the mouse up outside of the window, we could
            // get here even though we have ended the drag.
            if (!dc || dc.isLocked()) {
                return;
            }

            var pt = e.getPoint();

            // cache the previous dragOver array
            var oldOvers = [];

            var outEvts   = [];
            var overEvts  = [];
            var dropEvts  = [];
            var enterEvts = [];

            // Check to see if the object(s) we were hovering over is no longer
            // being hovered over so we can fire the onDragOut event
            for (var i in this.dragOvers) {

                var ddo = this.dragOvers[i];

                if (! this.isTypeOfDD(ddo)) {
                    continue;
                }

                if (! this.isOverTarget(pt, ddo, this.mode)) {
                    outEvts.push( ddo );
                }

                oldOvers[i] = true;
                delete this.dragOvers[i];
            }

            for (var sGroup in dc.groups) {

                if ("string" != typeof sGroup) {
                    continue;
                }

                for (i in this.ids[sGroup]) {
                    var oDD = this.ids[sGroup][i];
                    if (! this.isTypeOfDD(oDD)) {
                        continue;
                    }

                    if (oDD.isTarget && !oDD.isLocked() && oDD != dc) {
                        if (this.isOverTarget(pt, oDD, this.mode)) {
                            // look for drop interactions
                            if (isDrop) {
                                dropEvts.push( oDD );
                            // look for drag enter and drag over interactions
                            } else {

                                // initial drag over: dragEnter fires
                                if (!oldOvers[oDD.id]) {
                                    enterEvts.push( oDD );
                                // subsequent drag overs: dragOver fires
                                } else {
                                    overEvts.push( oDD );
                                }

                                this.dragOvers[oDD.id] = oDD;
                            }
                        }
                    }
                }
            }

            if (this.mode) {
                if (outEvts.length) {
                    dc.b4DragOut(e, outEvts);
                    dc.onDragOut(e, outEvts);
                }

                if (enterEvts.length) {
                    dc.onDragEnter(e, enterEvts);
                }

                if (overEvts.length) {
                    dc.b4DragOver(e, overEvts);
                    dc.onDragOver(e, overEvts);
                }

                if (dropEvts.length) {
                    dc.b4DragDrop(e, dropEvts);
                    dc.onDragDrop(e, dropEvts);
                }

            } else {
                // fire dragout events
                var len = 0;
                for (i=0, len=outEvts.length; i<len; ++i) {
                    dc.b4DragOut(e, outEvts[i].id);
                    dc.onDragOut(e, outEvts[i].id);
                }

                // fire enter events
                for (i=0,len=enterEvts.length; i<len; ++i) {
                    // dc.b4DragEnter(e, oDD.id);
                    dc.onDragEnter(e, enterEvts[i].id);
                }

                // fire over events
                for (i=0,len=overEvts.length; i<len; ++i) {
                    dc.b4DragOver(e, overEvts[i].id);
                    dc.onDragOver(e, overEvts[i].id);
                }

                // fire drop events
                for (i=0, len=dropEvts.length; i<len; ++i) {
                    dc.b4DragDrop(e, dropEvts[i].id);
                    dc.onDragDrop(e, dropEvts[i].id);
                }

            }

            // notify about a drop that did not find a target
            if (isDrop && !dropEvts.length) {
                dc.onInvalidDrop(e);
            }

        },

        /**
         * Helper function for getting the best match from the list of drag
         * and drop objects returned by the drag and drop events when we are
         * in INTERSECT mode.  It returns either the first object that the
         * cursor is over, or the object that has the greatest overlap with
         * the dragged element.
         * @method getBestMatch
         * @param  {DragDrop[]} dds The array of drag and drop objects
         * targeted
         * @return {DragDrop}       The best single match
         * @static
         */
        getBestMatch: function(dds) {
            var winner = null;
            // Return null if the input is not what we expect
            //if (!dds || !dds.length || dds.length == 0) {
               // winner = null;
            // If there is only one item, it wins
            //} else if (dds.length == 1) {

            var len = dds.length;

            if (len == 1) {
                winner = dds[0];
            } else {
                // Loop through the targeted items
                for (var i=0; i<len; ++i) {
                    var dd = dds[i];
                    // If the cursor is over the object, it wins.  If the
                    // cursor is over multiple matches, the first one we come
                    // to wins.
                    if (dd.cursorIsOver) {
                        winner = dd;
                        break;
                    // Otherwise the object with the most overlap wins
                    } else {
                        if (!winner ||
                            winner.overlap.getArea() < dd.overlap.getArea()) {
                            winner = dd;
                        }
                    }
                }
            }

            return winner;
        },

        /**
         * Refreshes the cache of the top-left and bottom-right points of the
         * drag and drop objects in the specified group(s).  This is in the
         * format that is stored in the drag and drop instance, so typical
         * usage is:
         * <code>
         * Ext.dd.DragDropMgr.refreshCache(ddinstance.groups);
         * </code>
         * Alternatively:
         * <code>
         * Ext.dd.DragDropMgr.refreshCache({group1:true, group2:true});
         * </code>
         * @TODO this really should be an indexed array.  Alternatively this
         * method could accept both.
         * @method refreshCache
         * @param {Object} groups an associative array of groups to refresh
         * @static
         */
        refreshCache: function(groups) {
            for (var sGroup in groups) {
                if ("string" != typeof sGroup) {
                    continue;
                }
                for (var i in this.ids[sGroup]) {
                    var oDD = this.ids[sGroup][i];

                    if (this.isTypeOfDD(oDD)) {
                    // if (this.isTypeOfDD(oDD) && oDD.isTarget) {
                        var