iv class=CToolTip id="tt1551"><div class=CVariable><blockquote><table border=0 cellspacing=0 cellpadding=0 class="Prototype"><tr><td class="prettyprint">mxGraphHandler.prototype.highlightEnabled</td></tr></table></blockquote>Specifies if drop targets under the mouse should be enabled. </div></div><div class=CToolTip id="tt1552"><div class=CVariable><blockquote><table border=0 cellspacing=0 cellpadding=0 class="Prototype"><tr><td class="prettyprint">mxUndoManager.prototype.history</td></tr></table></blockquo