include/QtTest/qsignalspy.h

0001 // Copyright (C) 2016 The Qt Company Ltd.
0002 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
0003
0004 #ifndef QSIGNALSPY_H
0005 #define QSIGNALSPY_H
0006
0007 #include <QtCore/qbytearray.h>
0008 #include <QtCore/qlist.h>
0009 #include <QtCore/qobject.h>
0010 #include <QtCore/qmetaobject.h>
0011 #include <QtTest/qtesteventloop.h>
0012 #include <QtCore/qvariant.h>
0013 #include <QtCore/qmutex.h>
0014
0015 QT_BEGIN_NAMESPACE
0016
0017
0018 class QVariant;
0019
0020 class QSignalSpy: public QObject, public QList<QList<QVariant> >
0021 {
0022 public:
0023     explicit QSignalSpy(const QObject *obj, const char *aSignal)
0024     {
0025         if (!isObjectValid(obj))
0026             return;
0027
0028         if (!aSignal) {
0029             qWarning("QSignalSpy: Null signal name is not valid");
0030             return;
0031         }
0032
0033         if (((aSignal[0] - '0') & 0x03) != QSIGNAL_CODE) {
0034             qWarning("QSignalSpy: Not a valid signal, use the SIGNAL macro");
0035             return;
0036         }
0037
0038         const QByteArray ba = QMetaObject::normalizedSignature(aSignal + 1);
0039         const QMetaObject * const mo = obj->metaObject();
0040         const int sigIndex = mo->indexOfMethod(ba.constData());
0041         if (sigIndex < 0) {
0042             qWarning("QSignalSpy: No such signal: '%s'", ba.constData());
0043             return;
0044         }
0045
0046         initArgs(mo->method(sigIndex), obj);
0047         if (!connectToSignal(obj, sigIndex))
0048             return;
0049
0050         sig = ba;
0051     }
0052
0053 #ifdef Q_QDOC
0054     template <typename PointerToMemberFunction>
0055     QSignalSpy(const QObject *object, PointerToMemberFunction signal);
0056 #else
0057     template <typename Func>
0058     QSignalSpy(const typename QtPrivate::FunctionPointer<Func>::Object *obj, Func signal0)
0059     {
0060         if (!isObjectValid(obj))
0061             return;
0062
0063         if (!signal0) {
0064             qWarning("QSignalSpy: Null signal pointer is not valid");
0065             return;
0066         }
0067
0068         const QMetaObject * const mo = obj->metaObject();
0069         const QMetaMethod signalMetaMethod = QMetaMethod::fromSignal(signal0);
0070         const int sigIndex = signalMetaMethod.methodIndex();
0071
0072         if (!isSignalMetaMethodValid(signalMetaMethod))
0073             return;
0074
0075         initArgs(mo->method(sigIndex), obj);
0076         if (!connectToSignal(obj, sigIndex))
0077             return;
0078
0079         sig = signalMetaMethod.methodSignature();
0080     }
0081 #endif // Q_QDOC
0082
0083     QSignalSpy(const QObject *obj, const QMetaMethod &signal)
0084     {
0085         if (isObjectValid(obj) && isSignalMetaMethodValid(signal)) {
0086             initArgs(signal, obj);
0087             if (!connectToSignal(obj, signal.methodIndex()))
0088                 return;
0089
0090             sig = signal.methodSignature();
0091         }
0092     }
0093
0094     inline bool isValid() const { return !sig.isEmpty(); }
0095     inline QByteArray signal() const { return sig; }
0096
0097     bool wait(int timeout)
0098     { return wait(std::chrono::milliseconds{timeout}); }
0099
0100     bool wait(std::chrono::milliseconds timeout = std::chrono::seconds{5})
0101     {
0102         QMutexLocker locker(&m_mutex);
0103         Q_ASSERT(!m_waiting);
0104         const qsizetype origCount = size();
0105         m_waiting = true;
0106         locker.unlock();
0107
0108         m_loop.enterLoop(timeout);
0109
0110         locker.relock();
0111         m_waiting = false;
0112         return size() > origCount;
0113     }
0114
0115     int qt_metacall(QMetaObject::Call call, int methodId, void **a) override
0116     {
0117         methodId = QObject::qt_metacall(call, methodId, a);
0118         if (methodId < 0)
0119             return methodId;
0120
0121         if (call == QMetaObject::InvokeMetaMethod) {
0122             if (methodId == 0) {
0123                 appendArgs(a);
0124             }
0125             --methodId;
0126         }
0127         return methodId;
0128     }
0129
0130 private:
0131     bool connectToSignal(const QObject *sender, int sigIndex)
0132     {
0133         static const int memberOffset = QObject::staticMetaObject.methodCount();
0134         const bool connected = QMetaObject::connect(
0135             sender, sigIndex, this, memberOffset, Qt::DirectConnection, nullptr);
0136
0137         if (!connected)
0138             qWarning("QSignalSpy: QMetaObject::connect returned false. Unable to connect.");
0139
0140         return connected;
0141     }
0142
0143     static bool isSignalMetaMethodValid(const QMetaMethod &signal)
0144     {
0145         const bool valid = signal.isValid() && signal.methodType() == QMetaMethod::Signal;
0146
0147         if (!valid)
0148             qWarning("QSignalSpy: Not a valid signal: '%s'", signal.methodSignature().constData());
0149
0150         return valid;
0151     }
0152
0153     static bool isObjectValid(const QObject *object)
0154     {
0155         const bool valid = !!object;
0156
0157         if (!valid)
0158             qWarning("QSignalSpy: Cannot spy on a null object");
0159
0160         return valid;
0161     }
0162
0163     void initArgs(const QMetaMethod &member, const QObject *obj)
0164     {
0165         QMutexLocker locker(&m_mutex);
0166         args.reserve(member.parameterCount());
0167         for (int i = 0; i < member.parameterCount(); ++i) {
0168             QMetaType tp = member.parameterMetaType(i);
0169             if (!tp.isValid() && obj) {
0170                 locker.unlock();
0171                 void *argv[] = { &tp, &i };
0172                 QMetaObject::metacall(const_cast<QObject*>(obj),
0173                                       QMetaObject::RegisterMethodArgumentMetaType,
0174                                       member.methodIndex(), argv);
0175                 locker.relock();
0176             }
0177             if (!tp.isValid()) {
0178                 qWarning("QSignalSpy: Unable to handle parameter '%s' of type '%s' of method '%s',"
0179                          " use qRegisterMetaType to register it.",
0180                          member.parameterNames().at(i).constData(),
0181                          member.parameterTypes().at(i).constData(),
0182                          member.name().constData());
0183             }
0184             args << tp.id();
0185         }
0186     }
0187
0188     void appendArgs(void **a)
0189     {
0190         QMutexLocker locker(&m_mutex);
0191         QList<QVariant> list;
0192         list.reserve(args.size());
0193         for (qsizetype i = 0; i < args.size(); ++i) {
0194             const QMetaType::Type type = static_cast<QMetaType::Type>(args.at(i));
0195             if (type == QMetaType::QVariant)
0196                 list << *reinterpret_cast<QVariant *>(a[i + 1]);
0197             else
0198                 list << QVariant(QMetaType(type), a[i + 1]);
0199         }
0200         append(std::move(list));
0201
0202         if (m_waiting) {
0203             locker.unlock();
0204             m_loop.exitLoop();
0205         }
0206     }
0207
0208     // the full, normalized signal name
0209     QByteArray sig;
0210     // holds the QMetaType types for the argument list of the signal
0211     QList<int> args;
0212
0213     QTestEventLoop m_loop;
0214     bool m_waiting = false;
0215     static inline QMutex m_mutex; // protects m_waiting, args and the QList base class, between appendArgs() and wait()
0216 };
0217
0218 QT_END_NAMESPACE
0219
0220 #endif