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, 16 insertions, 18 deletions

diff --git a/src/widgets/dialogs/qfiledialog.cpp b/src/widgets/dialogs/qfiledialog.cpp
index 1f832abf78..1bf5691837 100644
--- a/src/widgets/dialogs/qfiledialog.cpp
+++ b/src/widgets/dialogs/qfiledialog.cpp
@@ -2587,7 +2587,7 @@ void QFileDialog::accept()
         return;
     }
 
-    QStringList files = selectedFiles();
+    const QStringList files = selectedFiles();
     if (files.isEmpty())
         return;
     QString lineEditText = d->lineEdit()->text();
@@ -2657,10 +2657,10 @@ void QFileDialog::accept()
 
     case ExistingFile:
     case ExistingFiles:
-        for (int i = 0; i < files.count(); ++i) {
-            QFileInfo info(files.at(i));
+        for (const auto &file : files) {
+            QFileInfo info(file);
             if (!info.exists())
-                info = QFileInfo(d->getEnvironmentVariable(files.at(i)));
+                info = QFileInfo(d->getEnvironmentVariable(file));
             if (!info.exists()) {
 #ifndef QT_NO_MESSAGEBOX
                 QString message = tr("%1\nFile not found.\nPlease verify the "
@@ -3444,15 +3444,13 @@ void QFileDialogPrivate::_q_autoCompleteFileName(const QString &text)
         return;
     }
 
-    QStringList multipleFiles = typedFiles();
+    const QStringList multipleFiles = typedFiles();
     if (multipleFiles.count() > 0) {
         QModelIndexList oldFiles = qFileDialogUi->listView->selectionModel()->selectedRows();
         QModelIndexList newFiles;
-        for (int i = 0; i < multipleFiles.count(); ++i) {
-            QModelIndex idx = model->index(multipleFiles.at(i));
-            if (oldFiles.contains(idx))
-                oldFiles.removeAll(idx);
-            else
+        for (const auto &file : multipleFiles) {
+            QModelIndex idx = model->index(file);
+            if (oldFiles.removeAll(idx) == 0)
                 newFiles.append(idx);
         }
         for (int i = 0; i < newFiles.count(); ++i)
@@ -3479,7 +3477,7 @@ void QFileDialogPrivate::_q_updateOkButton()
     bool enableButton = true;
     bool isOpenDirectory = false;
 
-    QStringList files = q->selectedFiles();
+    const QStringList files = q->selectedFiles();
     QString lineEditText = lineEdit()->text();
 
     if (lineEditText.startsWith(QLatin1String("//")) || lineEditText.startsWith(QLatin1Char('\\'))) {
@@ -3538,10 +3536,10 @@ void QFileDialogPrivate::_q_updateOkButton()
         }
         case QFileDialog::ExistingFile:
         case QFileDialog::ExistingFiles:
-            for (int i = 0; i < files.count(); ++i) {
-                QModelIndex idx = model->index(files.at(i));
+            for (const auto &file : files) {
+                QModelIndex idx = model->index(file);
                 if (!idx.isValid())
-                    idx = model->index(getEnvironmentVariable(files.at(i)));
+                    idx = model->index(getEnvironmentVariable(file));
                 if (!idx.isValid()) {
                     enableButton = false;
                     break;
@@ -3682,14 +3680,14 @@ void QFileDialogPrivate::_q_useNameFilter(int index)
 void QFileDialogPrivate::_q_selectionChanged()
 {
     const QFileDialog::FileMode fileMode = q_func()->fileMode();
-    QModelIndexList indexes = qFileDialogUi->listView->selectionModel()->selectedRows();
+    const QModelIndexList indexes = qFileDialogUi->listView->selectionModel()->selectedRows();
     bool stripDirs = (fileMode != QFileDialog::DirectoryOnly && fileMode != QFileDialog::Directory);
 
     QStringList allFiles;
-    for (int i = 0; i < indexes.count(); ++i) {
-        if (stripDirs && model->isDir(mapToSource(indexes.at(i))))
+    for (const auto &index : indexes) {
+        if (stripDirs && model->isDir(mapToSource(index)))
             continue;
-        allFiles.append(indexes.at(i).data().toString());
+        allFiles.append(index.data().toString());
     }
     if (allFiles.count() > 1)
         for (int i = 0; i < allFiles.count(); ++i) {