private boolean canDelete(Object theLangObj) {
boolean result = true;
LanguageObject parent = (LanguageObject) contentProvider.getParent(theLangObj);
if (parent == null) {
// object is root. can only delete if not undefined
result = !isUndefined(theLangObj);
} else if (parent instanceof Function) {
// all function arguments except converstion type constants can be deleted
if (theLangObj instanceof Constant) {
result = !BuilderUtils.isConversionType((Constant) theLangObj);
}
} else if (parent instanceof NotCriteria) {
// get compound criteria and ask again
NotCriteria notCrit = (NotCriteria) parent;
Criteria criteria = notCrit.getCriteria();
// NotCriteria must contain either another NotCriteria or a CompoundCriteria
while (!(criteria instanceof CompoundCriteria)) {
// must be a NotCriteria
criteria = ((NotCriteria) criteria).getCriteria();
result = canDelete(criteria);
}
}
return result;
}
@Override
public void visit(NotCriteria obj) {
preVisitVisitor(obj);
visitNode(obj.getCriteria());
postVisitVisitor(obj);
}
private void delete(Object theLangObj) {
if (canDelete(theLangObj)) {
boolean doSelect = true;
//
// set the parent object to reflect the change in it's child. parent can't be undefined.
//
Object newSelection = StructuredSelection.EMPTY;
LanguageObject parent = (LanguageObject) contentProvider.getParent(theLangObj);
if (parent == null) {
// object being delete is root language object
setLanguageObject(null); // resets undefined count
refresh(true);
newSelection = contentProvider.getRoot();
expandToLevel(newSelection, ALL_LEVELS);
} else if (parent instanceof Function) {
// set the arg to null in parent
int index = contentProvider.getChildIndex(theLangObj);
Expression[] args = ((Function) parent).getArgs();
args[index] = null;
refresh(true);
newSelection = contentProvider.getChildAt(index, parent);
} else if (parent instanceof Criteria) {
if (contentProvider.getChildCount(parent) > 1) {
CompoundCriteria compoundCriteria = null;
// parent is either a compound criteria or not criteria
if (parent instanceof CompoundCriteria) {
compoundCriteria = (CompoundCriteria) parent;
} else { // NotCriteria
NotCriteria notCrit = (NotCriteria) parent;
Criteria criteria = notCrit.getCriteria();
// NotCriteria must contain either another NotCriteria or a CompoundCriteria
while (!(criteria instanceof CompoundCriteria)) {
// must be a NotCriteria
criteria = ((NotCriteria) criteria).getCriteria();
}
compoundCriteria = (CompoundCriteria) criteria;
}
List crits = compoundCriteria.getCriteria();
int index = contentProvider.getChildIndex(theLangObj);
// CompoundCriteria has to have at least 2 criteria to be compound. if it has more than 2
// just delete the selected obj. if there are exactly 2 criteria than this special
// processing block occurs.
if (contentProvider.getChildCount(parent) == 2) {
int siblingIndex = (index == 0) ? 1 : 0;
// if deleting this node would leave just an undefined node under the parent, delete
// parent
if (isUndefined(contentProvider.getChildAt(siblingIndex, parent))) {
delete(parent);
} else {
// sibling is not undefined
// if deleting an undefined node, delete from parent. this will leave one node
// under the parent.
if (isUndefined(theLangObj)) {
crits.remove(index);
// selection taken care of below in block checking for size of 1
} else {
// replace deleted node with undefined node
crits.set(index, (Criteria) null);
refresh(true);
newSelection = contentProvider.getChildAt(index, parent);
}
}
} else {
// just remove from parent
crits.remove(index);
refresh(true);
newSelection = parent;
}
if (crits.size() == 1) {
// need to modify parent node with the child (refresh done there)
modifyLanguageObject(
parent, (LanguageObject) contentProvider.getChildAt(0, parent), false);
doSelect = false; // modify does select
}
}
}
if (doSelect) {
final Object selection = newSelection;
Display.getDefault()
.asyncExec(
new Runnable() {
public void run() {
setSelection(new StructuredSelection(selection));
}
});
}
}
}