QtPrintSupport: convert some index-based into C++11 range-for loops

Also reserve a QList in QPrinter::supportedPaperSources().

Change-Id: I94d24b81d7adcad2b28d36efdbef5a8726412f1a
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

src/printsupport/dialogs/qprintpreviewdialog.cpp

@@ -250,8 +250,8 @@ void QPrintPreviewDialogPrivate::init(QPrinter *_printer)
     zoomEditor->setValidator(new ZoomFactorValidator(1, 1000, 1, zoomEditor));
     zoomFactor->setLineEdit(zoomEditor);
     static const short factorsX2[] = { 25, 50, 100, 200, 250, 300, 400, 800, 1600 };
-    for (int i = 0; i < int(sizeof(factorsX2) / sizeof(factorsX2[0])); ++i)
-        zoomFactor->addItem(QPrintPreviewDialog::tr("%1%").arg(factorsX2[i] / 2.0));
+    for (auto factorX2 : factorsX2)
+        zoomFactor->addItem(QPrintPreviewDialog::tr("%1%").arg(factorX2 / 2.0));
     QObject::connect(zoomFactor->lineEdit(), SIGNAL(editingFinished()),
                      q, SLOT(_q_zoomFactorChanged()));
     QObject::connect(zoomFactor, SIGNAL(currentIndexChanged(int)),

src/printsupport/kernel/qpaintengine_alpha.cpp

@@ -336,8 +336,8 @@ void QAlphaPaintEngine::flushAndInit(bool init)
         d->resetState(painter());
 
         // fill in the alpha images
-        for (int i=0; i<rects.size(); ++i)
-            d->drawAlphaImage(rects.at(i));
+        for (const auto &rect : qAsConst(rects))
+            d->drawAlphaImage(rect);
 
         d->m_alphargn = QRegion();
 

src/printsupport/kernel/qprintdevice.cpp

@@ -283,10 +283,10 @@ void QPrintDevice::format(QDebug debug) const
               << ", defaultColorMode="<< defaultColorMode();
 #    ifndef QT_NO_MIMETYPE
         const QList<QMimeType> mimeTypes = supportedMimeTypes();
-        if (const int mimeTypeCount = mimeTypes.size()) {
+        if (!mimeTypes.isEmpty()) {
             debug << ", supportedMimeTypes=(";
-            for (int i = 0; i < mimeTypeCount; ++i)
-                debug << " \"" << mimeTypes.at(i).name() << '"';
+            for (const auto &mimeType : mimeTypes)
+                debug << " \"" << mimeType.name() << '"';
             debug << ')';
         }
 #    endif // !QT_NO_MIMETYPE

src/printsupport/kernel/qprinter.cpp

@@ -1946,13 +1946,12 @@ int QPrinter::winPageSize() const
 QList<int> QPrinter::supportedResolutions() const
 {
     Q_D(const QPrinter);
-    QList<QVariant> varlist
+    const QList<QVariant> varlist
         = d->printEngine->property(QPrintEngine::PPK_SupportedResolutions).toList();
     QList<int> intlist;
-    const int numSupportedResolutions = varlist.size();
-    intlist.reserve(numSupportedResolutions);
-    for (int i = 0; i < numSupportedResolutions; ++i)
-        intlist << varlist.at(i).toInt();
+    intlist.reserve(varlist.size());
+    for (auto var : varlist)
+        intlist << var.toInt();
     return intlist;
 }
 
@@ -2015,10 +2014,11 @@ QList<QPrinter::PaperSource> QPrinter::supportedPaperSources() const
     Q_D(const QPrinter);
     QVariant v = d->printEngine->property(QPrintEngine::PPK_PaperSources);
 
-    QList<QVariant> variant_list = v.toList();
+    const QList<QVariant> variant_list = v.toList();
     QList<QPrinter::PaperSource> int_list;
-    for (int i=0; i<variant_list.size(); ++i)
-        int_list << (QPrinter::PaperSource) variant_list.at(i).toInt();
+    int_list.reserve(variant_list.size());
+    for (const auto &variant : variant_list)
+        int_list << QPrinter::PaperSource(variant.toInt());
 
     return int_list;
 }

src/printsupport/widgets/qprintpreviewwidget.cpp

@@ -295,9 +295,9 @@ int QPrintPreviewWidgetPrivate::calcCurrentPage()
     int maxArea = 0;
     int newPage = curPage;
     QRect viewRect = graphicsView->viewport()->rect();
-    QList<QGraphicsItem*> items = graphicsView->items(viewRect);
-    for (int i=0; i<items.size(); ++i) {
-        PageItem* pg = static_cast<PageItem*>(items.at(i));
+    const QList<QGraphicsItem*> items = graphicsView->items(viewRect);
+    for (auto *item : items) {
+        PageItem* pg = static_cast<PageItem*>(item);
         QRect overlap = graphicsView->mapFromScene(pg->sceneBoundingRect()).boundingRect() & viewRect;
         int area = overlap.width() * overlap.height();
         if (area > maxArea) {
@@ -335,17 +335,17 @@ void QPrintPreviewWidgetPrivate::init()
 void QPrintPreviewWidgetPrivate::populateScene()
 {
     // remove old pages
-    for (int i = 0; i < pages.size(); i++)
-        scene->removeItem(pages.at(i));
+    for (auto *page : qAsConst(pages))
+        scene->removeItem(page);
     qDeleteAll(pages);
     pages.clear();
 
-    int numPages = pictures.count();
     QSize paperSize = printer->pageLayout().fullRectPixels(printer->resolution()).size();
     QRect pageRect = printer->pageLayout().paintRectPixels(printer->resolution());
 
-    for (int i = 0; i < numPages; i++) {
-        PageItem* item = new PageItem(i+1, pictures.at(i), paperSize, pageRect);
+    int page = 1;
+    for (auto *picture : qAsConst(pictures)) {
+        PageItem* item = new PageItem(page++, picture, paperSize, pageRect);
         scene->addItem(item);
         pages.append(item);
     }