QPoint/F: add transposed()

For symmetry with QSize and QRect and because there were some users in Qt.

Port those users.

[ChangeLog][QtCore][QPoint/QPointF] Added transposed().

Change-Id: If4f23dbcf7d67983a6b1885e0d1d538115b49e2b
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

4 files changed, 31 insertions, 4 deletions

diff --git a/src/corelib/tools/qpoint.cpp b/src/corelib/tools/qpoint.cpp
index e98eaac4fc..432fb33297 100644
--- a/src/corelib/tools/qpoint.cpp
+++ b/src/corelib/tools/qpoint.cpp
@@ -138,6 +138,17 @@ QT_BEGIN_NAMESPACE
     \sa y(), setX()
 */
 
+/*!
+    \fn QPoint::transposed() const
+    \since 5.14
+
+    Returns a point with x and y coordinates exchanged:
+    \code
+    QPoint{1, 2}.transposed() // {2, 1}
+    \endcode
+
+    \sa x(), y(), setX(), setY()
+*/
 
 /*!
     \fn int &QPoint::rx()
@@ -583,6 +594,18 @@ QDebug operator<<(QDebug dbg, const QPointF &p)
 */
 
 /*!
+    \fn QPointF::transposed() const
+    \since 5.14
+
+    Returns a point with x and y coordinates exchanged:
+    \code
+    QPointF{1.0, 2.0}.transposed() // {2.0, 1.0}
+    \endcode
+
+    \sa x(), y(), setX(), setY()
+*/
+
+/*!
     \fn qreal& QPointF::rx()
 
     Returns a reference to the x coordinate of this point.
diff --git a/src/corelib/tools/qpoint.h b/src/corelib/tools/qpoint.h
index 34df673b93..fe952f95da 100644
--- a/src/corelib/tools/qpoint.h
+++ b/src/corelib/tools/qpoint.h
@@ -64,6 +64,8 @@ public:
 
     Q_DECL_CONSTEXPR inline int manhattanLength() const;
 
+    Q_DECL_CONSTEXPR QPoint transposed() const noexcept { return {yp, xp}; }
+
     Q_DECL_RELAXED_CONSTEXPR inline int &rx();
     Q_DECL_RELAXED_CONSTEXPR inline int &ry();
 
@@ -232,6 +234,8 @@ public:
     Q_DECL_RELAXED_CONSTEXPR inline void setX(qreal x);
     Q_DECL_RELAXED_CONSTEXPR inline void setY(qreal y);
 
+    Q_DECL_CONSTEXPR QPointF transposed() const noexcept { return {yp, xp}; }
+
     Q_DECL_RELAXED_CONSTEXPR inline qreal &rx();
     Q_DECL_RELAXED_CONSTEXPR inline qreal &ry();
 
diff --git a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
index bc09fe2f91..4639185416 100644
--- a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
@@ -997,8 +997,8 @@ void QXcbConnection::xi2HandleScrollEvent(void *event, ScrollingDevice &scrollin
                 QPoint global(fixed1616ToReal(xiDeviceEvent->root_x), fixed1616ToReal(xiDeviceEvent->root_y));
                 Qt::KeyboardModifiers modifiers = keyboard()->translateModifiers(xiDeviceEvent->mods.effective);
                 if (modifiers & Qt::AltModifier) {
-                    std::swap(angleDelta.rx(), angleDelta.ry());
-                    std::swap(rawDelta.rx(), rawDelta.ry());
+                    angleDelta = angleDelta.transposed();
+                    rawDelta = rawDelta.transposed();
                 }
                 qCDebug(lcQpaXInputEvents) << "scroll wheel @ window pos" << local << "delta px" << rawDelta << "angle" << angleDelta;
                 QWindowSystemInterface::handleWheelEvent(platformWindow->window(), xiDeviceEvent->time, local, global, rawDelta, angleDelta, modifiers);
@@ -1024,7 +1024,7 @@ void QXcbConnection::xi2HandleScrollEvent(void *event, ScrollingDevice &scrollin
                 QPoint global(fixed1616ToReal(xiDeviceEvent->root_x), fixed1616ToReal(xiDeviceEvent->root_y));
                 Qt::KeyboardModifiers modifiers = keyboard()->translateModifiers(xiDeviceEvent->mods.effective);
                 if (modifiers & Qt::AltModifier)
-                    std::swap(angleDelta.rx(), angleDelta.ry());
+                    angleDelta = angleDelta.transposed();
                 qCDebug(lcQpaXInputEvents) << "scroll wheel (button" << xiDeviceEvent->detail << ") @ window pos" << local << "delta angle" << angleDelta;
                 QWindowSystemInterface::handleWheelEvent(platformWindow->window(), xiDeviceEvent->time, local, global, QPoint(), angleDelta, modifiers);
             }
diff --git a/src/plugins/platforms/xcb/qxcbwindow.cpp b/src/plugins/platforms/xcb/qxcbwindow.cpp
index 1d1a4eea1c..97da420798 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbwindow.cpp
@@ -1908,7 +1908,7 @@ void QXcbWindow::handleButtonPressEvent(int event_x, int event_y, int root_x, in
             else if (detail == 7)
                 angleDelta.setX(-120);
             if (modifiers & Qt::AltModifier)
-                std::swap(angleDelta.rx(), angleDelta.ry());
+                angleDelta = angleDelta.transposed();
             QWindowSystemInterface::handleWheelEvent(window(), timestamp, local, global, QPoint(), angleDelta, modifiers);
 #if QT_CONFIG(xcb_xinput)
         }