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C++ MessagePtr::setUndoState方法代码示例

本文整理汇总了C++中MessagePtr::setUndoState方法的典型用法代码示例。如果您正苦于以下问题:C++ MessagePtr::setUndoState方法的具体用法?C++ MessagePtr::setUndoState怎么用?C++ MessagePtr::setUndoState使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在MessagePtr的用法示例。

在下文中一共展示了MessagePtr::setUndoState方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于我们的系统推荐出更棒的C++代码示例。

示例1: handleUndoCommand

bool Client::handleUndoCommand(protocol::Undo &undo)
{
	// First check if user context override is used
	if(undo.overrideId()) {
		undo.setContextId(undo.overrideId());
	}

	// Undo history is limited to last UNDO_HISTORY_LIMIT undopoints
	// or the latest snapshot point, whichever comes first
	// Clients usually store more than that, but to ensure a consistent
	// experience, we enforce the limit here.

	if(undo.points()>0) {
		// Undo mode: iterator towards the beginning of the history,
		// marking not-undone UndoPoints as undone.
		int limit = protocol::UNDO_HISTORY_LIMIT;
		int pos = _session->mainstream().end()-1;
		int points = 0;
		while(limit>0 && points<undo.points() && _session->mainstream().isValidIndex(pos)) {
			MessagePtr msg = _session->mainstream().at(pos);

			if(msg->type() == protocol::MSG_SNAPSHOTPOINT)
				break;

			if(msg->type() == protocol::MSG_UNDOPOINT) {
				--limit;
				if(msg->contextId() == undo.contextId() && msg->undoState()==protocol::DONE) {
					msg->setUndoState(protocol::UNDONE);
					++points;
				}
			}
			--pos;
		}

		// Did we undo anything?
		if(points==0)
			return false;

		// Number of undoable actions may be less than expected, but undo what we got.
		undo.setPoints(points);
		return true;
	} else if(undo.points()<0) {
		// Redo mode: find the start of the latest undo sequence, then mark
		// (points) UndoPoints as redone.
		int redostart = _session->mainstream().end();
		int limit = protocol::UNDO_HISTORY_LIMIT;
		int pos = _session->mainstream().end();
		while(_session->mainstream().isValidIndex(--pos) && limit>0) {
			protocol::MessagePtr msg = _session->mainstream().at(pos);
			if(msg->type() == protocol::MSG_UNDOPOINT) {
				--limit;
				if(msg->contextId() == undo.contextId()) {
					if(msg->undoState() != protocol::DONE)
						redostart = pos;
					else
						break;
				}
			}
		}

		// There may be nothing to redo
		if(redostart == _session->mainstream().end())
			return false;

		pos = redostart;

		// Mark undone actions as done again
		int actions = -undo.points() + 1;
		int points = 0;
		while(pos < _session->mainstream().end()) {
			protocol::MessagePtr msg = _session->mainstream().at(pos);
			if(msg->contextId() == undo.contextId() && msg->type() == protocol::MSG_UNDOPOINT) {
				if(msg->undoState() == protocol::UNDONE) {
					if(--actions==0)
						break;

					msg->setUndoState(protocol::DONE);
					++points;
				}
			}
			++pos;
		}

		// Did we redo anything
		if(points==0)
			return false;

		undo.setPoints(-points);
		return true;
	} else {
		// points==0 is invalid
		return false;
	}
}
开发者ID:gotomypc,项目名称:Drawpile,代码行数:94,代码来源:client.cpp



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