in rico.js [1171:1184]
_updateDropZonesHover: function(e) {
var n = this.dropZones.length;
for ( var i = 0 ; i < n ; i++ ) {
if ( ! this._mousePointInDropZone( e, this.dropZones[i] ) )
this.dropZones[i].hideHover();
}
for ( var i = 0 ; i < n ; i++ ) {
if ( this._mousePointInDropZone( e, this.dropZones[i] ) ) {
if ( this.dropZones[i].canAccept(this.currentDragObjects) )
this.dropZones[i].showHover();
}
}
},