Mon 21 Jul 22:43:21 CEST 2025

js/ui/mxgraph/src/js/handler/mxCellTracker.js

@@ -0,0 +1,145 @@
+/**
+ * Copyright (c) 2006-2015, JGraph Ltd
+ * Copyright (c) 2006-2015, Gaudenz Alder
+ */
+/**
+ * Class: mxCellTracker
+ * 
+ * Event handler that highlights cells. Inherits from <mxCellMarker>.
+ * 
+ * Example:
+ * 
+ * (code)
+ * new mxCellTracker(graph, '#00FF00');
+ * (end)
+ * 
+ * For detecting dragEnter, dragOver and dragLeave on cells, the following
+ * code can be used:
+ * 
+ * (code)
+ * graph.addMouseListener(
+ * {
+ *   cell: null,
+ *   mouseDown: function(sender, me) { },
+ *   mouseMove: function(sender, me)
+ *   {
+ *     var tmp = me.getCell();
+ *     
+ *     if (tmp != this.cell)
+ *     {
+ *       if (this.cell != null)
+ *       {
+ *         this.dragLeave(me.getEvent(), this.cell);
+ *       }
+ *       
+ *       this.cell = tmp;
+ *       
+ *       if (this.cell != null)
+ *       {
+ *         this.dragEnter(me.getEvent(), this.cell);
+ *       }
+ *     }
+ *     
+ *     if (this.cell != null)
+ *     {
+ *       this.dragOver(me.getEvent(), this.cell);
+ *     }
+ *   },
+ *   mouseUp: function(sender, me) { },
+ *   dragEnter: function(evt, cell)
+ *   {
+ *     mxLog.debug('dragEnter', cell.value);
+ *   },
+ *   dragOver: function(evt, cell)
+ *   {
+ *     mxLog.debug('dragOver', cell.value);
+ *   },
+ *   dragLeave: function(evt, cell)
+ *   {
+ *     mxLog.debug('dragLeave', cell.value);
+ *   }
+ * });
+ * (end)
+ * 
+ * Constructor: mxCellTracker
+ * 
+ * Constructs an event handler that highlights cells.
+ * 
+ * Parameters:
+ * 
+ * graph - Reference to the enclosing <mxGraph>.
+ * color - Color of the highlight. Default is blue.
+ * funct - Optional JavaScript function that is used to override
+ * <mxCellMarker.getCell>.
+ */
+function mxCellTracker(graph, color, funct)
+{
+	mxCellMarker.call(this, graph, color);
+
+	this.graph.addMouseListener(this);
+	
+	if (funct != null)
+	{
+		this.getCell = funct;
+	}
+	
+	// Automatic deallocation of memory
+	if (mxClient.IS_IE)
+	{
+		mxEvent.addListener(window, 'unload', mxUtils.bind(this, function()
+		{
+			this.destroy();
+		}));
+	}
+};
+
+/**
+ * Extends mxCellMarker.
+ */
+mxUtils.extend(mxCellTracker, mxCellMarker);
+
+/**
+ * Function: mouseDown
+ * 
+ * Ignores the event. The event is not consumed.
+ */
+mxCellTracker.prototype.mouseDown = function(sender, me) { };
+
+/**
+ * Function: mouseMove
+ * 
+ * Handles the event by highlighting the cell under the mousepointer if it
+ * is over the hotspot region of the cell.
+ */
+mxCellTracker.prototype.mouseMove = function(sender, me)
+{
+	if (this.isEnabled())
+	{
+		this.process(me);
+	}
+};
+
+/**
+ * Function: mouseUp
+ * 
+ * Handles the event by reseting the highlight.
+ */
+mxCellTracker.prototype.mouseUp = function(sender, me) { };
+
+/**
+ * Function: destroy
+ * 
+ * Destroys the object and all its resources and DOM nodes. This doesn't
+ * normally need to be called. It is called automatically when the window
+ * unloads.
+ */
+mxCellTracker.prototype.destroy = function()
+{
+	if (!this.destroyed)
+	{
+		this.destroyed = true;
+
+		this.graph.removeMouseListener(this);
+		mxCellMarker.prototype.destroy.apply(this);
+	}
+};