public static boolean processAddition( final MTrimBar trimBar, MTrimContribution contribution, List<MTrimElement> contributions, HashSet<String> existingToolbarIds) { int idx = getIndex(trimBar, contribution.getPositionInParent()); if (idx == -1) { return false; } for (MTrimElement item : contribution.getChildren()) { if (item instanceof MToolBar && existingToolbarIds.contains(item.getElementId())) { // skip this, it's already there continue; } MTrimElement copy = (MTrimElement) EcoreUtil.copy((EObject) item); if (DEBUG) { trace("addTrimContribution " + copy, trimBar.getWidget(), trimBar); // $NON-NLS-1$ } trimBar.getChildren().add(idx++, copy); contributions.add(copy); if (copy instanceof MToolBar && copy.getElementId() != null) { existingToolbarIds.add(copy.getElementId()); } } return true; }