QtWidgets: use new QRegion::begin()/end() instead of rect()

Saves ~600b in text size on optimized GCC 5.3 Linux AMD64 builds.

Change-Id: Ib542a128982fc53638780945014d903f2cbee9c3
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

1 files changed, 4 insertions, 5 deletions

diff --git a/src/widgets/itemviews/qtreeview.cpp b/src/widgets/itemviews/qtreeview.cpp
index 95f14bec78..3568d937ff 100644
--- a/src/widgets/itemviews/qtreeview.cpp
+++ b/src/widgets/itemviews/qtreeview.cpp
@@ -1473,13 +1473,12 @@ void QTreeView::drawTree(QPainter *painter, const QRegion &region) const
     QPoint hoverPos = d->viewport->mapFromGlobal(QCursor::pos());
     d->hoverBranch = d->itemDecorationAt(hoverPos);
 
-    QVector<QRect> rects = region.rects();
     QVector<int> drawn;
-    bool multipleRects = (rects.size() > 1);
-    for (int a = 0; a < rects.size(); ++a) {
+    bool multipleRects = (region.rectCount() > 1);
+    for (const QRect &a : region) {
         const QRect area = (multipleRects
-                            ? QRect(0, rects.at(a).y(), viewportWidth, rects.at(a).height())
-                            : rects.at(a));
+                            ? QRect(0, a.y(), viewportWidth, a.height())
+                            : a);
         d->leftAndRight = d->startAndEndColumns(area);
 
         int i = firstVisibleItem; // the first item at the top of the viewport