startEndPoint.showOnDiagram(diagram);
endEndPoint.showOnDiagram(diagram);
int connectorX = diagram.boundaryPanel.getWidgetLeft(startEndPoint) - diagram.boundaryPanel.getAbsoluteLeft();
int connectorY = diagram.boundaryPanel.getWidgetTop(startEndPoint) - diagram.boundaryPanel.getAbsoluteTop();
diagram.onDiagramAdd(new DiagramAddEvent(this, connectorX, connectorY));
}