testlib: Move qtestsystem helpers to their respective modules

Having the helpers in each respective module lets us implement the
helpers using private APIs without forcing the test to add private
dependencies.

It also makes it easier to test Qt using a third party testing
framework (for running the test suite), while still using the helpers
for ensuring tests behave expectedly.

Change-Id: I2a6ce24526ed345f3513548f11da05c7804c203f
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 92 insertions, 0 deletions

diff --git a/src/corelib/kernel/qtestsupport_core.h b/src/corelib/kernel/qtestsupport_core.h
new file mode 100644
index 0000000000..7fc0054580
--- /dev/null
+++ b/src/corelib/kernel/qtestsupport_core.h
@@ -0,0 +1,92 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtTest module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QTESTSUPPORT_CORE_H
+#define QTESTSUPPORT_CORE_H
+
+#include <QtCore/qcoreapplication.h>
+#include <QtCore/qdeadlinetimer.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace QTestPrivate {
+Q_CORE_EXPORT void qSleep(int ms);
+}
+
+namespace QTest {
+
+template <typename Functor>
+Q_REQUIRED_RESULT static bool qWaitFor(Functor predicate, int timeout = 5000)
+{
+    // We should not spin the event loop in case the predicate is already true,
+    // otherwise we might send new events that invalidate the predicate.
+    if (predicate())
+        return true;
+
+    // qWait() is expected to spin the event loop, even when called with a small
+    // timeout like 1ms, so we we can't use a simple while-loop here based on
+    // the deadline timer not having timed out. Use do-while instead.
+
+    int remaining = timeout;
+    QDeadlineTimer deadline(remaining, Qt::PreciseTimer);
+
+    do {
+        QCoreApplication::processEvents(QEventLoop::AllEvents, remaining);
+        QCoreApplication::sendPostedEvents(nullptr, QEvent::DeferredDelete);
+
+        remaining = deadline.remainingTime();
+        if (remaining > 0)
+            QTestPrivate::qSleep(qMin(10, remaining));
+
+        if (predicate())
+            return true;
+
+        remaining = deadline.remainingTime();
+    } while (remaining > 0);
+
+    return predicate(); // Last chance
+}
+
+Q_CORE_EXPORT void qWait(int ms);
+
+} // namespace QTest
+
+QT_END_NAMESPACE
+
+#endif