Quick tests: Introduce QQmlMessageHandler.

Add QQmlMessageHandler class that can be used to record messages
into a QStringList. It also makes sure that the old message
handler is reinstalled if the test fails.

Task-number: QTBUG-28611
Change-Id: I0fff7bc11e188cf47178d9573e5f2eead693bc10
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

2 files changed, 50 insertions, 0 deletions

diff --git a/tests/auto/shared/util.cpp b/tests/auto/shared/util.cpp
index 57c016a16a..eaefb1f9d6 100644
--- a/tests/auto/shared/util.cpp
+++ b/tests/auto/shared/util.cpp
@@ -46,6 +46,8 @@
 #include <QtQml/QQmlContext>
 #include <QtQml/QQmlEngine>
 #include <QtCore/QTextStream>
+#include <QtCore/QDebug>
+#include <QtCore/QMutexLocker>
 
 QQmlDataTest *QQmlDataTest::m_instance = 0;
 
@@ -107,3 +109,30 @@ QByteArray QQmlDataTest::msgComponentError(const QQmlComponent &c,
     }
     return result.toLocal8Bit();
 }
+
+Q_GLOBAL_STATIC(QMutex, qQmlTestMessageHandlerMutex)
+
+QQmlTestMessageHandler *QQmlTestMessageHandler::m_instance = 0;
+
+void QQmlTestMessageHandler::messageHandler(QtMsgType, const QMessageLogContext &, const QString &message)
+{
+    QMutexLocker locker(qQmlTestMessageHandlerMutex());
+    if (QQmlTestMessageHandler::m_instance)
+        QQmlTestMessageHandler::m_instance->m_messages.push_back(message);
+}
+
+QQmlTestMessageHandler::QQmlTestMessageHandler()
+{
+    QMutexLocker locker(qQmlTestMessageHandlerMutex());
+    Q_ASSERT(!QQmlTestMessageHandler::m_instance);
+    QQmlTestMessageHandler::m_instance = this;
+    m_oldHandler = qInstallMessageHandler(messageHandler);
+}
+
+QQmlTestMessageHandler::~QQmlTestMessageHandler()
+{
+    QMutexLocker locker(qQmlTestMessageHandlerMutex());
+    Q_ASSERT(QQmlTestMessageHandler::m_instance);
+    qInstallMessageHandler(m_oldHandler);
+    QQmlTestMessageHandler::m_instance = 0;
+}
diff --git a/tests/auto/shared/util.h b/tests/auto/shared/util.h
index 4a5c9176c6..eff54b30d9 100644
--- a/tests/auto/shared/util.h
+++ b/tests/auto/shared/util.h
@@ -45,6 +45,7 @@
 #include <QtCore/QDir>
 #include <QtCore/QUrl>
 #include <QtCore/QCoreApplication>
+#include <QtCore/QStringList>
 #include <QtTest/QTest>
 
 QT_FORWARD_DECLARE_CLASS(QQmlComponent)
@@ -87,4 +88,24 @@ private:
     QString m_directory;
 };
 
+class QQmlTestMessageHandler
+{
+    Q_DISABLE_COPY(QQmlTestMessageHandler)
+public:
+    QQmlTestMessageHandler();
+    ~QQmlTestMessageHandler();
+
+    const QStringList &messages() const { return m_messages; }
+    const QString messageString() const { return m_messages.join(QLatin1Char('\n')); }
+
+    void clear() { m_messages.clear(); }
+
+private:
+    static void messageHandler(QtMsgType, const QMessageLogContext &, const QString &message);
+
+    static QQmlTestMessageHandler *m_instance;
+    QStringList m_messages;
+    QtMessageHandler m_oldHandler;
+};
+
 #endif // QQMLTESTUTILS_H