QSignalBlocker Class

Exception-safe wrapper around QObject::blockSignals(). More...

Header: #include <QSignalBlocker>
qmake: QT += core
Since: Qt 5.3

This class was introduced in Qt 5.3.

Note: All functions in this class are reentrant.

Detailed Description

QSignalBlocker can be used wherever you would otherwise use a pair of calls to blockSignals(). It blocks signals in its constructor and in the destructor it resets the state to what it was before the constructor ran.


  {
  const QSignalBlocker blocker(someQObject);
  // no signals here
  }

is thus equivalent to


  const bool wasBlocked = someQObject->blockSignals(true);
  // no signals here
  someQObject->blockSignals(wasBlocked);

except the code using QSignalBlocker is safe in the face of exceptions.

See also QMutexLocker and QEventLoopLocker.