Stop Grid Commit on fail validation

Created a CustomField that I add for the Grid edit mode

column.setEditorField(new MyField()); that is a TextField with a validator

textField.addValidator(new RegexpValidator("...", true, "FAIL")); Failing validation does not stop the Grid of commiting.
Do I need to do something in

grid.getEditorFieldGroup().addCommitHandler(new FieldGroup.CommitHandler() {
    public void preCommit(FieldGroup.CommitEvent commitEvent) throws FieldGroup.CommitException {
    }//end preCommit

    public void postCommit(FieldGroup.CommitEvent commitEvent) throws FieldGroup.CommitException {
    }//end postCommit

Do not know if this is the correct approach, but manage to do it in

for(Field<?> f:commitEvent.getFieldBinder().getFields()){ And then checking the values throwing CommitException on error

throw new CommitException("INVALID VALUE!!!");