InteractionDiagramModel<SVGInteraction, SVGInstance> interactionDiagramModel;
private void updateExtents() {
for (Figure f : getFigures()) {
if (!f.equals(background)) {
Double figureBounds = f.getBounds();
Double newExtents = new Double();
Double currentExtents = background.getBounds();
// TODO: cleanup re-extenting
newExtents.width = (((currentExtents.x - newExtents.x) + currentExtents.width) < ((figureBounds.x - newExtents.x)
+ figureBounds.width + (2 * SVGConstants.DEFAULT_DRAWING_MARGINE))) ? ((figureBounds.x - newExtents.x)
+ figureBounds.width + (2 * SVGConstants.DEFAULT_DRAWING_MARGINE))
: ((currentExtents.x - newExtents.x) + currentExtents.width);