QSignalInspector

Implements spying on all signals of a QObject instance.

QSignalInspector is very similar to QSignalSpy but it records the emission of all signals of a class. Internally, QSignalInspector uses one QSignalSpy for each of the signals.

Example

#include "MyObject.h"
#include "QSignalInspector.hpp"
#include <QTextStream>
#include <QCoreApplication>
#include <cstdio>

int main(int argc, char **argv)
{
	QCoreApplication app(argc, argv);

	// Setup object to be inspected
	MyQObject object;
	QSignalInspector inspector(&object);

	QObject::connect(&object, SIGNAL(finished()), &app, SLOT(quit()));
	object.start();
	app.exec();

	// Print the recorded signals
	QTextStream out(stdout);
	QSignalInspector::ConstIterator iter;
	for (iter = inspector.begin(); iter != inspector.end(); ++iter)
	{
		QSignalEmissionEvent emission = *iter;
		QStringList parameters;
		QList<QVariant>::ConstIterator paramIter;

		for (paramIter = emission.parameters.begin(); paramIter != emission.parameters.end(); ++paramIter)
			parameters << paramIter->toString();

		out << emission.signal.name() << "(" << parameters.join(", ") << ")" << endl;
	}

	return 0;
}

Usage

QSignalInspector(const QObject* object, bool includeParentClassSignals = true)

Creates a QSignalInspector recording the signal emissions of object.

Parameters
object - The object whose signals should be recorded.
includeParentClassSignals - If true, the signals of all parent classes of object are recorded as well. If false, only those signals are recorded that are declared by the last class in the inheritance hierarchy of object.

Then use the QSignalInspector as a QList<QSignalEmissionEvent> to retrieve the information about the emissions:

QSignalInspector mySignalInspector(&objectToBeWatched);

// Trigger emissions of signals ...

QSignalInspector::ConstIterator iter;
for (iter = mySignalInspector.constBegin(); iter != mySignalInspector.constEnd(); ++iter)
{
	const QSignalEmissionEvent event = *iter;
	// Do something with event ...
}

Where QSignalEmissionEvent is a simple struct:

/*! Struct representing one emission of a signal.
 */
struct QSignalEmissionEvent
{
	QMetaMethod signal;         //!< The QMetaMethod of the signal that was emitted.
	QDateTime timestamp;        //!< The time when the signal was emitted.
	QList<QVariant> parameters; //!< The parameter values of the emission.
};

Requirements

• Qt 4.8 or later

License

Copyright (c) 2018 Jochen Ulrich

Licensed under MIT license.