QStyle/QWidget: Avoid repetitive invocation of QStyleHelper::dpiScaled()

Store the result of QStyleHelper::dpiScaled() or functions dependent on it
in a variable, preparing the addition of a DPI parameter.

Task-number: QTBUG-45055
Change-Id: Ic70d65b590793c29a4b1f7a7a5312dd169517fc5
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

2 files changed, 8 insertions, 6 deletions

diff --git a/src/widgets/dialogs/qwizard.cpp b/src/widgets/dialogs/qwizard.cpp
index c692a0f8db..f428114bbe 100644
--- a/src/widgets/dialogs/qwizard.cpp
+++ b/src/widgets/dialogs/qwizard.cpp
@@ -1595,23 +1595,25 @@ bool QWizardPrivate::handleAeroStyleChange()
     bool vistaMargins = false;
 
     if (isVistaThemeEnabled()) {
+        const int topOffset = vistaHelper->topOffset();
+        const int topPadding = vistaHelper->topPadding();
         if (isVistaThemeEnabled(QVistaHelper::VistaAero)) {
             if (isWindow) {
                 vistaHelper->setDWMTitleBar(QVistaHelper::ExtendedTitleBar);
                 q->installEventFilter(vistaHelper);
             }
             q->setMouseTracking(true);
-            antiFlickerWidget->move(0, vistaHelper->titleBarSize() + vistaHelper->topOffset());
+            antiFlickerWidget->move(0, vistaHelper->titleBarSize() + topOffset);
             vistaHelper->backButton()->move(
-                0, vistaHelper->topOffset() // ### should ideally work without the '+ 1'
-                - qMin(vistaHelper->topOffset(), vistaHelper->topPadding() + 1));
+                0, topOffset // ### should ideally work without the '+ 1'
+                - qMin(topOffset, topPadding + 1));
             vistaMargins = true;
             vistaHelper->backButton()->show();
         } else {
             if (isWindow)
                 vistaHelper->setDWMTitleBar(QVistaHelper::NormalTitleBar);
             q->setMouseTracking(true);
-            antiFlickerWidget->move(0, vistaHelper->topOffset());
+            antiFlickerWidget->move(0, topOffset);
             vistaHelper->backButton()->move(0, -1); // ### should ideally work with (0, 0)
         }
         if (isWindow)
diff --git a/src/widgets/dialogs/qwizard_win.cpp b/src/widgets/dialogs/qwizard_win.cpp
index 4986bbc75f..95f8f6a878 100644
--- a/src/widgets/dialogs/qwizard_win.cpp
+++ b/src/widgets/dialogs/qwizard_win.cpp
@@ -293,9 +293,9 @@ void QVistaHelper::drawTitleBar(QPainter *painter)
     int glowOffset = 0;
 
     if (vistaState() == VistaAero) {
-        textHeight += 2 * glowSize();
-        textWidth += 2 * glowSize();
         glowOffset = glowSize();
+        textHeight += 2 * glowOffset;
+        textWidth += 2 * glowOffset;
     }
 
     const int titleLeft = (wizard->layoutDirection() == Qt::LeftToRight