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>

1 files changed, 13 insertions, 15 deletions

diff --git a/src/widgets/dialogs/qfilesystemmodel.cpp b/src/widgets/dialogs/qfilesystemmodel.cpp
index 3c154c3dbb..c1d0ecf33b 100644
--- a/src/widgets/dialogs/qfilesystemmodel.cpp
+++ b/src/widgets/dialogs/qfilesystemmodel.cpp
@@ -1562,10 +1562,9 @@ void QFileSystemModel::setNameFilters(const QStringList &filters)
         d->bypassFilters.clear();
         // We guarantee that rootPath will stick around
         QPersistentModelIndex root(index(rootPath()));
-        QModelIndexList persistantList = persistentIndexList();
-        for (int i = 0; i < persistantList.count(); ++i) {
-            QFileSystemModelPrivate::QFileSystemNode *node;
-            node = d->node(persistantList.at(i));
+        const QModelIndexList persistentList = persistentIndexList();
+        for (const auto &persistentIndex : persistentList) {
+            QFileSystemModelPrivate::QFileSystemNode *node = d->node(persistentIndex);
             while (node) {
                 if (d->bypassFilters.contains(node))
                     break;
@@ -1579,9 +1578,8 @@ void QFileSystemModel::setNameFilters(const QStringList &filters)
     d->nameFilters.clear();
     const Qt::CaseSensitivity caseSensitive =
         (filter() & QDir::CaseSensitive) ? Qt::CaseSensitive : Qt::CaseInsensitive;
-    for (int i = 0; i < filters.size(); ++i) {
-        d->nameFilters << QRegExp(filters.at(i), caseSensitive, QRegExp::Wildcard);
-    }
+    for (const auto &filter : filters)
+        d->nameFilters << QRegExp(filter, caseSensitive, QRegExp::Wildcard);
     d->forceSort = true;
     d->delayedSort();
 #endif
@@ -1734,9 +1732,9 @@ void QFileSystemModelPrivate::addVisibleFiles(QFileSystemNode *parentNode, const
     if (parentNode->dirtyChildrenIndex == -1)
         parentNode->dirtyChildrenIndex = parentNode->visibleChildren.count();
 
-    for (int i = 0; i < newFiles.count(); ++i) {
-        parentNode->visibleChildren.append(newFiles.at(i));
-        parentNode->children.value(newFiles.at(i))->isVisible = true;
+    for (const auto &newFile : newFiles) {
+        parentNode->visibleChildren.append(newFile);
+        parentNode->children.value(newFile)->isVisible = true;
     }
     if (!indexHidden)
       q->endInsertRows();
@@ -1779,10 +1777,10 @@ void QFileSystemModelPrivate::_q_fileSystemChanged(const QString &path, const QV
     QStringList newFiles;
     QFileSystemModelPrivate::QFileSystemNode *parentNode = node(path, false);
     QModelIndex parentIndex = index(parentNode);
-    for (int i = 0; i < updates.count(); ++i) {
-        QString fileName = updates.at(i).first;
+    for (const auto &update : updates) {
+        QString fileName = update.first;
         Q_ASSERT(!fileName.isEmpty());
-        QExtendedInformation info = fileInfoGatherer.getInfo(updates.at(i).second);
+        QExtendedInformation info = fileInfoGatherer.getInfo(update.second);
         bool previouslyHere = parentNode->children.contains(fileName);
         if (!previouslyHere) {
             addNode(parentNode, fileName, info.fileInfo());
@@ -1971,8 +1969,8 @@ bool QFileSystemModelPrivate::passNameFilters(const QFileSystemNode *node) const
 
     // Check the name regularexpression filters
     if (!(node->isDir() && (filters & QDir::AllDirs))) {
-        for (int i = 0; i < nameFilters.size(); ++i) {
-            QRegExp copy = nameFilters.at(i);
+        for (const auto &nameFilter : nameFilters) {
+            QRegExp copy = nameFilter;
             if (copy.exactMatch(node->fileName))
                 return true;
         }