QtGui: use reserve to optimize memory allocation.

Change-Id: I34a571b67840557de19ab496cadebd698c7f4f6a
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

2 files changed, 3 insertions, 1 deletions

diff --git a/src/gui/kernel/qhighdpiscaling_p.h b/src/gui/kernel/qhighdpiscaling_p.h
index 60e8dcf562..fe71de6c27 100644
--- a/src/gui/kernel/qhighdpiscaling_p.h
+++ b/src/gui/kernel/qhighdpiscaling_p.h
@@ -473,6 +473,7 @@ QVector<T> fromNativePixels(const QVector<T> &pixelValues, const QWindow *window
         return pixelValues;
 
     QVector<T> pointValues;
+    pointValues.reserve(pixelValues.size());
     for (const T &pixelValue : pixelValues)
         pointValues.append(pixelValue / QHighDpiScaling::factor(window));
     return pointValues;
@@ -486,6 +487,7 @@ QVector<T> toNativePixels(const QVector<T> &pointValues, const QWindow *window)
         return pointValues;
 
     QVector<T> pixelValues;
+    pixelValues.reserve(pointValues.size());
     for (const T &pointValue : pointValues)
         pixelValues.append(pointValue * QHighDpiScaling::factor(window));
     return pixelValues;
diff --git a/src/gui/kernel/qwindowsysteminterface.cpp b/src/gui/kernel/qwindowsysteminterface.cpp
index c76721f89b..39bc161a7c 100644
--- a/src/gui/kernel/qwindowsysteminterface.cpp
+++ b/src/gui/kernel/qwindowsysteminterface.cpp
@@ -928,7 +928,7 @@ static QWindowSystemInterface::TouchPoint touchPoint(const QTouchEvent::TouchPoi
 static QList<struct QWindowSystemInterface::TouchPoint> touchPointList(const QList<QTouchEvent::TouchPoint>& pointList)
 {
     QList<struct QWindowSystemInterface::TouchPoint> newList;
-
+    newList.reserve(pointList.size());
     for (const QTouchEvent::TouchPoint &p : pointList)
         newList.append(touchPoint(p));