暂时阻止两个 QObject 之间的信号

我想一般性地暂时阻止两个之间的信号QObjects不修改其他信号/槽的行为，也不知道它们的上下文。

就像是QObject::blockSignals(布尔) http://qt-project.org/doc/qt-4.8/qobject.html#blockSignals，但只作用于两者之间QObjects.

也就是说，实现以下SignalBlocker::blockSignals(bool)功能：

class SignalBlocker {

public:
  SignalBlocker(QObject *sender, QObject *receiver) :
    mSender(sender), mReceiver(receiver) {}
  void blockSignals(bool block);

private:
  QObject *mSender, *mReceiver;
}

可以通过断开并重新连接对象来实现，但首先必须存储信号/槽列表。 内省方法似乎不足以实现这一目标（我查看了QMetaObject and QSignalSpy没有成功）。

QT 没有能力仅禁用信号槽对。尝试这个解决方法：

struct SignalDisabler
{
    SignalDisabler(const QObject *sender, const char *signal, const QObject *receiver, const char *member)
        : sender(sender)
        , signal(signal)
        , receiver(receiver)
        , member(member)
    {
        QObject::disconnect(sender, signal, receiver, member);
    }

    ~SignalDisabler()
    {
        QObject::connect(sender, signal, receiver, member);
    }

    const QObject *sender;
    const char *signal;
    const QObject *receiver;
    const char *member;
};