dragdropscripts.js

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    _enterTarget : function(dragSource, dropTarget) {
        // Monitor DOM changes.
        this._prepareForDomChanges();
        dropTarget.onDragEnterTarget(dragSource.get_dragMode(), dragSource.get_dragDataType(), dragSource.getDragData(this._activeContext));
        this._recoverFromDomChanges();
    },
    
    _leaveTarget : function(dragSource, dropTarget) {
        // Monitor DOM changes.
        this._prepareForDomChanges();
        dropTarget.onDragLeaveTarget(dragSource.get_dragMode(), dragSource.get_dragDataType(), dragSource.getDragData(this._activeContext));
        this._recoverFromDomChanges();
    },
    
    _findPotentialTarget : function(dragSource, dragVisual) {
        var ev = window._event;

        if (this._dropTargets == null) {
            return null;
        }
        
        var type = dragSource.get_dragDataType();
        var mode = dragSource.get_dragMode();
        var data = dragSource.getDragData(this._activeContext);

        // Get the current cursor location.
        var scrollOffset = this.getScrollOffset(document.body, /* recursive */ true);
        var x = ev.clientX + scrollOffset.x;
        var y = ev.clientY + scrollOffset.y;
        var cursorRect = { x: x - this._radius, y: y - this._radius, width: this._radius * 2, height: this._radius * 2 };
        
        // Find any targets near the current cursor location.
        var targetRect;
        for (var i = 0; i < this._dropTargets.length; i++) {
            targetRect = $common.getBounds(this._dropTargets[i].get_dropTargetElement());
            if ($common.overlaps(cursorRect, targetRect) && this._dropTargets[i].canDrop(mode, type, data)) {
                return this._dropTargets[i];
            }
        }
        
        return null;
    },
    
    _prepareForDomChanges : function() {
        this._oldOffset = $common.getLocation(this._activeDragVisual);
    },
    
    _recoverFromDomChanges : function() {
        var newOffset = $common.getLocation(this._activeDragVisual);
        if (this._oldOffset.x != newOffset.x || this._oldOffset.y != newOffset.y) {
            this._activeDragVisual.startingPoint = this.subtractPoints(this._activeDragVisual.startingPoint, this.subtractPoints(this._oldOffset, newOffset));
            scrollOffset = this.getScrollOffset(this._activeDragVisual, /* recursive */ true);
            var position = this.addPoints(this.subtractPoints(document._lastPosition, this._activeDragVisual.startingPoint), scrollOffset);
            $common.setLocation(this._activeDragVisual, position);
        }
    },
    
    addPoints : function(p1, p2) {
        return { x: p1.x + p2.x, y: p1.y + p2.y };
    },
    
    subtractPoints : function(p1, p2) {
        return { x: p1.x - p2.x, y: p1.y - p2.y };
    },
    
    // -- Drag and drop helper methods.
    getScrollOffset : function(element, recursive) {
        var left = element.scrollLeft;
        var top = element.scrollTop;
        if (recursive) {
            var parent = element.parentNode;
            while (parent != null && parent.scrollLeft != null) {
                left += parent.scrollLeft;
                top += parent.scrollTop;
                // Don't include anything below the body.
                if (parent == document.body && (left != 0 && top != 0))
                    break;
                parent = parent.parentNode;
            }
        }
        return { x: left, y: top };
    },
    
    getBrowserRectangle : function() {
        var width = window.innerWidth;
        var height = window.innerHeight;
        if (width == null) {
            width = document.body.clientWidth;
        }
        if (height == null) {
            height = document.body.clientHeight;
        }
        
        return { x: 0, y: 0, width: width, height: height };
    },
    
    getNextSibling : function(item) {
        for (item = item.nextSibling; item != null; item = item.nextSibling) {
            if (item.innerHTML != null) {
                return item;
            }
        }
        return null;
    },
    
    hasParent : function(element) {
        return (element.parentNode != null && element.parentNode.tagName != null);
    }
}
AjaxControlToolkit.IEDragDropManager.registerClass('AjaxControlToolkit.IEDragDropManager', Sys.Component);

AjaxControlToolkit.IEDragDropManager._getDataObjectsForDropTarget = function(dropTarget) {
    if (dropTarget == null) {
        return [];
    }
    var ev = window._event;
    var dataObjects = [];
    var dataTypes = [ "URL", "Text" ];
    var data;
    for (var i = 0; i < dataTypes.length; i++) {
        var dt = ev.dataTransfer;
        if(!dt && ev.rawEvent) dt = ev.rawEvent.dataTransfer;
        data = dt.getData(dataTypes[i]);
        if (dropTarget.canDrop(AjaxControlToolkit.DragMode.Copy, dataTypes[i], data)) {
            if (data) {
                Array.add(dataObjects, { type : dataTypes[i], value : data });
            }
        }
    }

    return dataObjects;
}


AjaxControlToolkit.GenericDragDropManager = function() {
    AjaxControlToolkit.GenericDragDropManager.initializeBase(this);
    
    this._dropTargets = null;
    // Radius of the cursor used to determine what drop target we 
    // are hovering. Anything below the cursor's zone may be a 
    // potential drop target.
    this._scrollEdgeConst = 40;
    this._scrollByConst = 10;
    this._scroller = null;
    this._scrollDeltaX = 0;
    this._scrollDeltaY = 0;
    this._activeDragVisual = null;
    this._activeContext = null;
    this._activeDragSource = null;
    this._oldOffset = null;
    this._potentialTarget = null;
    this._mouseUpHandler = null;
    this._mouseMoveHandler = null;
    this._keyPressHandler = null;
    this._scrollerTickHandler = null;
}
AjaxControlToolkit.GenericDragDropManager.prototype = {
   
    initialize : function() {
        AjaxControlToolkit.GenericDragDropManager.callBaseMethod(this, "initialize");
        this._mouseUpHandler = Function.createDelegate(this, this._onMouseUp);
        this._mouseMoveHandler = Function.createDelegate(this, this._onMouseMove);
        this._keyPressHandler = Function.createDelegate(this, this._onKeyPress);
        this._scrollerTickHandler = Function.createDelegate(this, this._onScrollerTick);
        if (Sys.Browser.agent === Sys.Browser.Safari) {
            AjaxControlToolkit.GenericDragDropManager.__loadSafariCompatLayer(this);
        }
        this._scroller = new Sys.Timer();
        this._scroller.set_interval(10);
        this._scroller.add_tick(this._scrollerTickHandler);
    },

    startDragDrop : function(dragSource, dragVisual, context) {
        this._activeDragSource = dragSource;
        this._activeDragVisual = dragVisual;
        this._activeContext = context;
        
        AjaxControlToolkit.GenericDragDropManager.callBaseMethod(this, "startDragDrop", [dragSource, dragVisual, context]);
    },
    
    _stopDragDrop : function(cancelled) {
        this._scroller.set_enabled(false);
        
        AjaxControlToolkit.GenericDragDropManager.callBaseMethod(this, "_stopDragDrop", [cancelled]);
    },
    
    _drag : function(isInitialDrag) {
        AjaxControlToolkit.GenericDragDropManager.callBaseMethod(this, "_drag", [isInitialDrag]);
        
        this._autoScroll();
    },
    
    _wireEvents : function() {
        $addHandler(document, "mouseup", this._mouseUpHandler);
        $addHandler(document, "mousemove", this._mouseMoveHandler);
        $addHandler(document, "keypress", this._keyPressHandler);
    },
    
    _unwireEvents : function() {
        $removeHandler(document, "keypress", this._keyPressHandler);
        $removeHandler(document, "mousemove", this._mouseMoveHandler);
        $removeHandler(document, "mouseup", this._mouseUpHandler);
    },
    
    _wireDropTargetEvents : function(dropTarget) {
        //
    },
    
    _unwireDropTargetEvents : function(dropTarget) {
        //
    },
    
    _onMouseUp : function(e) {
        window._event = e;
        this._stopDragDrop(false);
    },
    
    _onMouseMove : function(e) {
        window._event = e;
        this._drag();
    },
    
    _onKeyPress : function(e) {
        window._event = e;
        // Escape.
        var k = e.keyCode ? e.keyCode : e.rawEvent.keyCode;
        if (k == 27) {
            this._stopDragDrop(/* cancel */ true);
        }
    },
    
    _autoScroll : function() {
        var ev = window._event;
        var browserRect = this.getBrowserRectangle();
        if (browserRect.width > 0) {
            this._scrollDeltaX = this._scrollDeltaY = 0;
            if (ev.clientX < browserRect.x + this._scrollEdgeConst) this._scrollDeltaX = -this._scrollByConst;
            else if (ev.clientX > browserRect.width - this._scrollEdgeConst) this._scrollDeltaX = this._scrollByConst;
            if (ev.clientY < browserRect.y + this._scrollEdgeConst) this._scrollDeltaY = -this._scrollByConst;
            else if (ev.clientY > browserRect.height - this._scrollEdgeConst) this._scrollDeltaY = this._scrollByConst;
            if (this._scrollDeltaX != 0 || this._scrollDeltaY != 0) {
                this._scroller.set_enabled(true);
            }
            else {
                this._scroller.set_enabled(false);
            }
        }
    },
    
    _onScrollerTick : function() {
        var oldLeft = document.body.scrollLeft;
        var oldTop = document.body.scrollTop;
        window.scrollBy(this._scrollDeltaX, this._scrollDeltaY);
        var newLeft = document.body.scrollLeft;
        var newTop = document.body.scrollTop;
        
        var dragVisual = this._activeDragVisual;
        var position = { x: parseInt(dragVisual.style.left) + (newLeft - oldLeft), y: parseInt(dragVisual.style.top) + (newTop - oldTop) };
        $common.setLocation(dragVisual, position);
    }
}
AjaxControlToolkit.GenericDragDropManager.registerClass('AjaxControlToolkit.GenericDragDropManager', AjaxControlToolkit.IEDragDropManager);


if (Sys.Browser.agent === Sys.Browser.Safari) {
    AjaxControlToolkit.GenericDragDropManager.__loadSafariCompatLayer = function(ddm) {
        ddm._getScrollOffset = ddm.getScrollOffset;

        ddm.getScrollOffset = function(element, recursive) {
            return { x: 0, y: 0 };
        }

        ddm._getBrowserRectangle = ddm.getBrowserRectangle;

        ddm.getBrowserRectangle = function() {
            var browserRect = ddm._getBrowserRectangle();
            
            var offset = ddm._getScrollOffset(document.body, true);
            return { x: browserRect.x + offset.x, y: browserRect.y + offset.y,
                width: browserRect.width + offset.x, height: browserRect.height + offset.y };
        }
    }
}