testlib: Add test function for simulating wheel events

Change-Id: I28fe4dff7db92fb58922948a3eec460df315318c
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

src/gui/kernel/qwindowsysteminterface.cpp

@@ -1205,6 +1205,13 @@ Q_GUI_EXPORT bool qt_sendShortcutOverrideEvent(QObject *o, ulong timestamp, int
 #endif
 }
 
+Q_GUI_EXPORT void qt_handleWheelEvent(QWindow *window, const QPointF &local, const QPointF &global,
+                                      QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods,
+                                      Qt::ScrollPhase phase)
+{
+    QWindowSystemInterface::handleWheelEvent(window, local, global, pixelDelta, angleDelta, mods, phase);
+}
+
 namespace QTest
 {
     Q_GUI_EXPORT QPointingDevice * createTouchDevice(QInputDevice::DeviceType devType,

src/testlib/CMakeLists.txt

@@ -55,6 +55,7 @@ qt_internal_add_module(Test
         qtestsystem.h
         qtesttable.cpp qtesttable_p.h
         qtesttouch.h
+        qtestwheel.h
         qttestglobal.h
         qxmltestlogger.cpp qxmltestlogger_p.h
     DEFINES

src/testlib/qtest_gui.h

@@ -17,6 +17,7 @@
 #include <QtTest/qtestevent.h>
 #include <QtTest/qtestmouse.h>
 #include <QtTest/qtesttouch.h>
+#include <QtTest/qtestwheel.h>
 #include <QtTest/qtestkeyboard.h>
 
 #include <QtGui/qcolor.h>

src/testlib/qtestcase.qdoc

@@ -1363,6 +1363,17 @@
     moving the mouse pointer.
 */
 
+/*! \fn void QTest::wheelEvent(QWindow *window, QPointF pos, QPoint angleDelta, QPoint pixelDelta = QPoint(0, 0), Qt::KeyboardModifiers stateKey = Qt::NoModifier, Qt::ScrollPhase phase = Qt::NoScrollPhase)
+    \since 6.8
+
+    Simulates a wheel event within \a window at position \a pos in local
+    window coordinates. \a angleDelta contains the wheel rotation angle.
+    A positive value means forward rotation, and a negative one means backward.
+    \a pixelDelta contains the scrolling distance in pixels on screen. This value can be null.
+    The keyboard states at the time of the event are specified by \a stateKey.
+    The scrolling phase of the event is specified by \a phase.
+*/
+
 /*!
     \fn template <typename T1, typename T2> char *QTest::toString(const std::pair<T1, T2> &pair)
     \overload

src/testlib/qtestwheel.h

@@ -0,0 +1,72 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QTESTWHEEL_H
+#define QTESTWHEEL_H
+
+#if 0
+// inform syncqt
+#pragma qt_no_master_include
+#endif
+
+#include <QtTest/qttestglobal.h>
+#include <QtTest/qtestassert.h>
+#include <QtTest/qtestsystem.h>
+#include <QtTest/qtestspontaneevent.h>
+#include <QtCore/qpoint.h>
+#include <QtCore/qstring.h>
+#include <QtCore/qpointer.h>
+#include <QtGui/qevent.h>
+#include <QtGui/qwindow.h>
+
+#include <QtCore/QDebug>
+
+QT_BEGIN_NAMESPACE
+
+Q_GUI_EXPORT void qt_handleWheelEvent(QWindow *window, const QPointF &local,
+                                      const QPointF &global, QPoint pixelDelta,
+                                      QPoint angleDelta, Qt::KeyboardModifiers mods, Qt::ScrollPhase phase);
+
+namespace QTest
+{
+    /*! \internal
+        This function creates a mouse wheel event and calls
+        QWindowSystemInterface::handleWheelEvent().
+        \a window is the window that should be receiving the event and \a pos
+        provides the location of the event in the window's local coordinates.
+        \a angleDelta contains the wheel rotation angle, while \a pixelDelta
+        contains the scrolling distance in pixels on screen.
+        The keyboard states at the time of the event are specified by \a stateKey.
+        The scrolling phase of the event is specified by \a phase.
+    */
+    [[maybe_unused]] static void wheelEvent(QWindow *window, QPointF pos,
+                                            QPoint angleDelta, QPoint pixelDelta = QPoint(0, 0),
+                                            Qt::KeyboardModifiers stateKey = Qt::NoModifier,
+                                            Qt::ScrollPhase phase = Qt::NoScrollPhase)
+    {
+        QTEST_ASSERT(window);
+
+        // pos is in window local coordinates
+        const QSize windowSize = window->geometry().size();
+        if (windowSize.width() <= pos.x() || windowSize.height() <= pos.y()) {
+            qWarning("Mouse event at %d, %d occurs outside target window (%dx%d).",
+                        static_cast<int>(pos.x()), static_cast<int>(pos.y()), windowSize.width(), windowSize.height());
+        }
+
+        if (pos.isNull())
+            pos = QPoint(window->width() / 2, window->height() / 2);
+
+        QPointF global = window->mapToGlobal(pos);
+        QPointer<QWindow> w(window);
+
+        if (angleDelta.isNull() && pixelDelta.isNull())
+            qWarning("No angle or pixel delta specified.");
+
+        qt_handleWheelEvent(w, pos, global, pixelDelta, angleDelta, stateKey, phase);
+        qApp->processEvents();
+    }
+}
+
+QT_END_NAMESPACE
+
+#endif // QTESTWHEEL_H