/** @see org.eclipse.gef.commands.Command#canExecute() */
@Override
public boolean canExecute() {
boolean returnValue = true;
if (foreignEntity.equals(primaryEntity)) {
returnValue = false;
} else {
if (primaryEntity == null) {
return false;
} else {
// Check for existence of relationship already
List<ERDAssociation> relationships = primaryEntity.getPrimaryKeyRelationships();
for (int i = 0; i < relationships.size(); i++) {
ERDAssociation currentRelationship = relationships.get(i);
if (currentRelationship.getForeignKeyEntity().equals(foreignEntity)) {
returnValue = false;
break;
}
}
}
}
return returnValue;
}
/** @see org.eclipse.gef.commands.Command#redo() */
@Override
public void redo() {
foreignEntity.addForeignKeyRelationship(association, true);
primaryEntity.addPrimaryKeyRelationship(association, true);
}
/** Undo version of command */
@Override
public void undo() {
foreignEntity.removeForeignKeyRelationship(association, true);
primaryEntity.removePrimaryKeyRelationship(association, true);
}