QtWidgets: replace some index-based for loops with C++11 range-for

This needs to be handled a bit carefully, because Qt containers
will detach upon being iteratoed over using range-for.

In the cases of this patch, that cannot happen, because all
containers are marked as const (either by this patch or before).

Separate patches will deal with other situations.

Apart from being more readable, range-for loops are also the
most efficient for loop.

This patch shaves almost 2K of text size off an optimized Linux
AMD64 GCC 4.9 build.

Change-Id: I53810c7b25420b4fd449d20c90c07503c5e76a66
Reviewed-by: Edward Welbourne <edward.welbourne@theqtcompany.com>
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

3 files changed, 12 insertions, 16 deletions

diff --git a/src/widgets/accessible/qaccessiblewidget.cpp b/src/widgets/accessible/qaccessiblewidget.cpp
index ed5b6f86fd..e540980a14 100644
--- a/src/widgets/accessible/qaccessiblewidget.cpp
+++ b/src/widgets/accessible/qaccessiblewidget.cpp
@@ -53,10 +53,9 @@ QT_BEGIN_NAMESPACE
 
 static QList<QWidget*> childWidgets(const QWidget *widget)
 {
-    QList<QObject*> list = widget->children();
     QList<QWidget*> widgets;
-    for (int i = 0; i < list.size(); ++i) {
-        QWidget *w = qobject_cast<QWidget *>(list.at(i));
+    for (QObject *o : widget->children()) {
+        QWidget *w = qobject_cast<QWidget *>(o);
         if (w && !w->isWindow()
             && !qobject_cast<QFocusFrame*>(w)
 #if !defined(QT_NO_MENU)
@@ -77,9 +76,8 @@ static QString buddyString(const QWidget *widget)
     if (!parent)
         return QString();
 #ifndef QT_NO_SHORTCUT
-    QObjectList ol = parent->children();
-    for (int i = 0; i < ol.size(); ++i) {
-        QLabel *label = qobject_cast<QLabel*>(ol.at(i));
+    for (QObject *o : parent->children()) {
+        QLabel *label = qobject_cast<QLabel*>(o);
         if (label && label->buddy() == widget)
             return label->text();
     }
@@ -302,8 +300,8 @@ QAccessibleWidget::relations(QAccessible::Relation match /*= QAccessible::AllRel
             // ideally we would go through all objects and check, but that
             // will be too expensive
             const QList<QWidget*> kids = childWidgets(parent);
-            for (int i = 0; i < kids.count(); ++i) {
-                if (QLabel *labelSibling = qobject_cast<QLabel*>(kids.at(i))) {
+            for (QWidget *kid : kids) {
+                if (QLabel *labelSibling = qobject_cast<QLabel*>(kid)) {
                     if (labelSibling->buddy() == widget()) {
                         QAccessibleInterface *iface = QAccessible::queryAccessibleInterface(labelSibling);
                         rels.append(qMakePair(iface, rel));
diff --git a/src/widgets/accessible/qaccessiblewidgets.cpp b/src/widgets/accessible/qaccessiblewidgets.cpp
index a4f433e65a..9bbc01b5cc 100644
--- a/src/widgets/accessible/qaccessiblewidgets.cpp
+++ b/src/widgets/accessible/qaccessiblewidgets.cpp
@@ -71,10 +71,9 @@ QList<QWidget*> childWidgets(const QWidget *widget)
 {
     if (widget == 0)
         return QList<QWidget*>();
-    QList<QObject*> list = widget->children();
     QList<QWidget*> widgets;
-    for (int i = 0; i < list.size(); ++i) {
-        QWidget *w = qobject_cast<QWidget *>(list.at(i));
+    for (QObject *o : widget->children()) {
+        QWidget *w = qobject_cast<QWidget *>(o);
         if (!w)
             continue;
         QString objectName = w->objectName();
@@ -1056,10 +1055,9 @@ QAccessibleInterface *QAccessibleMainWindow::childAt(int x, int y) const
     if (!QRect(gp.x(), gp.y(), w->width(), w->height()).contains(x, y))
         return 0;
 
-    QWidgetList kids = childWidgets(mainWindow());
+    const QWidgetList kids = childWidgets(mainWindow());
     QPoint rp = mainWindow()->mapFromGlobal(QPoint(x, y));
-    for (int i = 0; i < kids.size(); ++i) {
-        QWidget *child = kids.at(i);
+    for (QWidget *child : kids) {
         if (!child->isWindow() && !child->isHidden() && child->geometry().contains(rp)) {
             return QAccessible::queryAccessibleInterface(child);
         }
diff --git a/src/widgets/accessible/simplewidgets.cpp b/src/widgets/accessible/simplewidgets.cpp
index 065c618cf7..e77839cc12 100644
--- a/src/widgets/accessible/simplewidgets.cpp
+++ b/src/widgets/accessible/simplewidgets.cpp
@@ -570,8 +570,8 @@ QAccessibleGroupBox::relations(QAccessible::Relation match /* = QAccessible::All
 
     if ((match & QAccessible::Labelled) && (!groupBox()->title().isEmpty())) {
         const QList<QWidget*> kids = childWidgets(widget());
-        for (int i = 0; i < kids.count(); ++i) {
-            QAccessibleInterface *iface = QAccessible::queryAccessibleInterface(kids.at(i));
+        for (QWidget *kid : kids) {
+            QAccessibleInterface *iface = QAccessible::queryAccessibleInterface(kid);
             if (iface)
                 rels.append(qMakePair(iface, QAccessible::Relation(QAccessible::Labelled)));
         }