Limit size of UndoRedo stack?

dcuny

How can I limit the size of the UndoRedo stack?

I see it's possible to clear the entire UndoRedohistory with clear_history(), and get size of the stack via get_history_count().

But there doesn't see to be any way to limit the number of items in the stack.

I'm working on an editor where there's the possibility of a lot of data to be stored in UndoRedo, so it would be helpful to have some sort of control of this instead of the application locking up once the user exhausts the available memory.

dcuny

Looking at the source code, there is a _pop_history_tail() call that removes a single item from the history.

clear_history() is implemented using this method.

However, it doesn't appear that _pop_history_tail() is exposed to the end user. 🙁

dcuny

I'm not seeing anything in the source code that does something comparable.

But it seems that it wouldn't be difficult to implement:

void UndoRedo::clip_history(bool p_increase_version, int undo_limit) {
	ERR_FAIL_COND(action_level > 0);
	_discard_redo();

	while (actions.size() > undo_limit) {
		_pop_history_tail();
	}

	if (p_increase_version) {
		version++;
		emit_signal(SNAME("version_changed"));
	}
}

Having this at the tail end of UndoRedo::commit_action so it automatically maintained the stack size would make things even easier.

dcuny

I guess it's time to head over to GitHub and post a code change request...