dragdrop.js

SugarCRM5.1 开源PHP客户关系管理系统

            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) {
                YAHOO.util.Event.stopPropagation(e);
            }

            if (this.preventDefault) {
                YAHOO.util.Event.preventDefault(e);
            }
        },

        /** 
         * 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 (YAHOO.util.Event.isIE && !e.button) {
                this.stopEvent(e);
                return this.handleMouseUp(e);
            }

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

            if (this.dragThreshMet) {
                this.dragCurrent.b4Drag(e);
                this.dragCurrent.onDrag(e);
                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 x = YAHOO.util.Event.getPageX(e);
            var y = YAHOO.util.Event.getPageY(e);
            var pt = new YAHOO.util.Point(x,y);

            // 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;

            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 (this.mode == this.INTERSECT && dd.cursorIsOver) {
                        winner = dd;
                        break;
                    // Otherwise the object with the most overlap wins
                    } else {
                        if (!winner || !winner.overlap || (dd.overlap &&
                            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>
         * YAHOO.util.DragDropMgr.refreshCache(ddinstance.groups);
         * </code>
         * Alternatively:
         * <code>
         * YAHOO.util.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 loc = this.getLocation(oDD);
                        if (loc) {
                            this.locationCache[oDD.id] = loc;
                        } else {
                            delete this.locationCache[oDD.id];
                            // this will unregister the drag and drop object if
                            // the element is not in a usable state
                            // oDD.unreg();
                        }
                    }
                }
            }
        },

        /**
         * This checks to make sure an element exists and is in the DOM.  The
         * main purpose is to handle cases where innerHTML is used to remove
         * drag and drop objects from the DOM.  IE provides an 'unspecified
         * error' when trying to access the offsetParent of such an element
         * @method verifyEl
         * @param {HTMLElement} el the element to check
         * @return {boolean} true if the element looks usable
         * @static
         */
        verifyEl: function(el) {
            try {
                if (el) {
                    var parent = el.offsetParent;
                    if (parent) {
                        return true;
                    }
                }
            } catch(e) {
            }

            return false;
        },
        
        /**
         * Returns a Region object containing the drag and drop element's position
         * and size, including the padding configured for it
         * @method getLocation
         * @param {DragDrop} oDD the drag and drop object to get the 
         *                       location for
         * @return {YAHOO.util.Region} a Region object representing the total area
         *                             the element occupies, including any padding
         *                             the instance is configured for.
         * @static
         */
        getLocation: function(oDD) {
            if (! this.isTypeOfDD(oDD)) {
                return null;
            }

            var el = oDD.getEl(), pos, x1, x2, y1, y2, t, r, b, l;

            try {
                pos= YAHOO.util.Dom.getXY(el);
            } catch (e) { }

            if (!pos) {
                return null;
            }

            x1 = pos[0];
            x2 = x1 + el.offsetWidth;
            y1 = pos[1];
            y2 = y1 + el.offsetHeight;

            t = y1 - oDD.padding[0];
            r = x2 + oDD.padding[1];
            b = y2 + oDD.padding[2];
            l = x1 - oDD.padding[3];

            return new YAHOO.util.Region( t, r, b, l );
        },

        /**
         * Checks the cursor location to see if it over the target
         * @method isOverTarget
         * @param {YAHOO.util.Point} pt The point to evaluate
         * @param {DragDrop} oTarget the DragDrop object we are inspecting
         * @return {boolean} true if the mouse is over the target
         * @private
         * @static
         */
        isOverTarget: function(pt, oTarget, intersect) {
            // use cache if available
            var loc = this.locationCache[oTarget.id];
            if (!loc || !this.useCache) {
                loc = this.getLocation(oTarget);
                this.locationCache[oTarget.id] = loc;

            }

            if (!loc) {
                return false;
            }

            oTarget.cursorIsOver = loc.contains( pt );