QtGui: eradicate Q_FOREACH loops [rvalues]

... by replacing them with C++11 range-for loops.

This is the simplest of the patch series: Q_FOREACH took a
copy, so we do, too. Except we don't, since we're just
catching the return value that comes out of the function
(RVO). We can't feed the rvalues into range-for, because
they are non-const and would thus detach.

Change-Id: I457942159015ff153bdfc6d5f031a3f0a0f6e9ac
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

src/gui/doc/snippets/code/src_gui_kernel_qapplication.cpp

@@ -89,7 +89,8 @@ QSize MyWidget::sizeHint() const
 //! [4]
 void showAllHiddenTopLevelWidgets()
 {
-    foreach (QWidget *widget, QApplication::topLevelWidgets()) {
+    const auto topLevelWidgets = QApplication::topLevelWidgets();
+    for (QWidget *widget : topLevelWidgets) {
         if (widget->isHidden())
             widget->show();
     }
@@ -100,7 +101,8 @@ void showAllHiddenTopLevelWidgets()
 //! [5]
 void updateAllWidgets()
 {
-    foreach (QWidget *widget, QApplication::allWidgets())
+    const auto topLevelWidgets = QApplication::topLevelWidgets();
+    for (QWidget *widget : topLevelWidgets)
         widget->update();
 }
 //! [5]

src/gui/kernel/qguiapplication.cpp

@@ -2714,7 +2714,8 @@ void QGuiApplicationPrivate::reportGeometryChange(QWindowSystemInterfacePrivate:
         emit s->availableGeometryChanged(s->availableGeometry());
 
     if (geometryChanged || availableGeometryChanged) {
-        foreach (QScreen* sibling, s->virtualSiblings())
+        const auto siblings = s->virtualSiblings();
+        for (QScreen* sibling : siblings)
             emit sibling->virtualGeometryChanged(sibling->virtualGeometry());
     }
 }

src/gui/kernel/qhighdpiscaling.cpp

@@ -267,7 +267,8 @@ void QHighDpiScaling::updateHighDpiScaling()
         return;
 
     if (m_usePixelDensity && !m_pixelDensityScalingActive) {
-        Q_FOREACH (QScreen *screen, QGuiApplication::screens()) {
+        const auto screens = QGuiApplication::screens();
+        for (QScreen *screen : screens) {
             if (!qFuzzyCompare(screenSubfactor(screen->handle()), qreal(1))) {
                 m_pixelDensityScalingActive = true;
                 break;
@@ -276,7 +277,8 @@ void QHighDpiScaling::updateHighDpiScaling()
     }
     if (qEnvironmentVariableIsSet(screenFactorsEnvVar)) {
         int i = 0;
-        Q_FOREACH (const QByteArray &spec, qgetenv(screenFactorsEnvVar).split(';')) {
+        const auto specs = qgetenv(screenFactorsEnvVar).split(';');
+        for (const QByteArray &spec : specs) {
             QScreen *screen = 0;
             int equalsPos = spec.lastIndexOf('=');
             double factor = 0;
@@ -287,7 +289,8 @@ void QHighDpiScaling::updateHighDpiScaling()
                 bool ok;
                 factor = f.toDouble(&ok);
                 if (ok) {
-                    Q_FOREACH (QScreen *s, QGuiApplication::screens()) {
+                    const auto screens = QGuiApplication::screens();
+                    for (QScreen *s : screens) {
                         if (s->name() == QString::fromLocal8Bit(name)) {
                             screen = s;
                             break;
@@ -327,7 +330,8 @@ void QHighDpiScaling::setGlobalFactor(qreal factor)
     m_globalScalingActive = !qFuzzyCompare(factor, qreal(1));
     m_factor = m_globalScalingActive ? factor : qreal(1);
     m_active = m_globalScalingActive || m_screenFactorSet || m_pixelDensityScalingActive;
-    Q_FOREACH (QScreen *screen, QGuiApplication::screens())
+    const auto screens = QGuiApplication::screens();
+    for (QScreen *screen : screens)
          screen->d_func()->updateHighDpi();
 }
 

src/gui/kernel/qhighdpiscaling_p.h

@@ -381,7 +381,8 @@ inline QRegion fromNativeLocalRegion(const QRegion &pixelRegion, const QWindow *
 
     qreal scaleFactor = QHighDpiScaling::factor(window);
     QRegion pointRegion;
-    foreach (const QRect &rect, pixelRegion.rects()) {
+    const auto rects = pixelRegion.rects();
+    for (const QRect &rect : rects) {
         pointRegion += QRect(fromNative(rect.topLeft(), scaleFactor),
                              fromNative(rect.size(), scaleFactor));
     }
@@ -395,7 +396,8 @@ inline QRegion toNativeLocalRegion(const QRegion &pointRegion, const QWindow *wi
 
     qreal scaleFactor = QHighDpiScaling::factor(window);
     QRegion pixelRegon;
-    foreach (const QRect &rect, pointRegion.rects()) {
+    const auto rects = pointRegion.rects();
+    for (const QRect &rect : rects) {
         pixelRegon += QRect(toNative(rect.topLeft(), scaleFactor),
                              toNative(rect.size(), scaleFactor));
     }

src/gui/kernel/qplatformscreen.cpp

@@ -111,7 +111,8 @@ QWindow *QPlatformScreen::topLevelAt(const QPoint & pos) const
 const QPlatformScreen *QPlatformScreen::screenForPosition(const QPoint &point) const
 {
     if (!geometry().contains(point)) {
-        Q_FOREACH (const QPlatformScreen* screen, virtualSiblings()) {
+        const auto screens = virtualSiblings();
+        for (const QPlatformScreen *screen : screens) {
             if (screen->geometry().contains(point))
                 return screen;
         }

src/gui/kernel/qplatformwindow.cpp

@@ -494,7 +494,8 @@ QPlatformScreen *QPlatformWindow::screenForGeometry(const QRect &newGeometry) co
     const QPoint center = newGeometry.isEmpty() ? newGeometry.topLeft() : newGeometry.center();
 
     if (!parent() && currentScreen && !currentScreen->geometry().contains(center)) {
-        Q_FOREACH (QPlatformScreen* screen, currentScreen->virtualSiblings()) {
+        const auto screens = currentScreen->virtualSiblings();
+        for (QPlatformScreen *screen : screens) {
             if (screen->geometry().contains(center))
                 return screen;
             if (screen->geometry().intersects(newGeometry))

src/gui/kernel/qscreen.cpp

@@ -122,7 +122,8 @@ QScreen::~QScreen()
     bool movingFromVirtualSibling = primaryScreen && primaryScreen->handle()->virtualSiblings().contains(handle());
 
     // Move any leftover windows to the primary screen
-    foreach (QWindow *window, QGuiApplication::allWindows()) {
+    const auto allWindows = QGuiApplication::allWindows();
+    for (QWindow *window : allWindows) {
         if (!window->isTopLevel() || window->screen() != this)
             continue;
 
@@ -399,7 +400,8 @@ QSize QScreen::virtualSize() const
 QRect QScreen::virtualGeometry() const
 {
     QRect result;
-    foreach (QScreen *screen, virtualSiblings())
+    const auto screens = virtualSiblings();
+    for (QScreen *screen : screens)
         result |= screen->geometry();
     return result;
 }
@@ -432,7 +434,8 @@ QSize QScreen::availableVirtualSize() const
 QRect QScreen::availableVirtualGeometry() const
 {
     QRect result;
-    foreach (QScreen *screen, virtualSiblings())
+    const auto screens = virtualSiblings();
+    for (QScreen *screen : screens)
         result |= screen->availableGeometry();
     return result;
 }

src/gui/kernel/qwindow.cpp

@@ -1509,7 +1509,8 @@ QScreen *QWindowPrivate::screenForGeometry(const QRect &newGeometry)
     QScreen *fallback = currentScreen;
     QPoint center = newGeometry.center();
     if (!q->parent() && currentScreen && !currentScreen->geometry().contains(center)) {
-        Q_FOREACH (QScreen* screen, currentScreen->virtualSiblings()) {
+        const auto screens = currentScreen->virtualSiblings();
+        for (QScreen* screen : screens) {
             if (screen->geometry().contains(center))
                 return screen;
             if (screen->geometry().intersects(newGeometry))

src/gui/opengl/qopengldebug.cpp

@@ -176,8 +176,8 @@ QT_BEGIN_NAMESPACE
 
     \code
 
-    QList<QOpenGLDebugMessage> messages = logger->loggedMessages();
-    foreach (const QOpenGLDebugMessage &message, messages)
+    const QList<QOpenGLDebugMessage> messages = logger->loggedMessages();
+    for (const QOpenGLDebugMessage &message : messages)
         qDebug() << message;
 
     \endcode