Merge remote-tracking branch 'origin/5.6' into 5.7

Conflicts:
	src/widgets/itemviews/qabstractitemview.cpp
	src/widgets/itemviews/qabstractitemview_p.h

Change-Id: I54589b1365103cb1749186af92aab03a49c94b64

11 files changed, 136 insertions, 103 deletions

diff --git a/src/widgets/dialogs/qdialog.cpp b/src/widgets/dialogs/qdialog.cpp
index 8f3072e41c..bfc943966f 100644
--- a/src/widgets/dialogs/qdialog.cpp
+++ b/src/widgets/dialogs/qdialog.cpp
@@ -874,8 +874,10 @@ void QDialog::adjustPosition(QWidget* w)
     // QTBUG-52735: Manually set the correct target screen since scaling in a
     // subsequent call to QWindow::resize() may otherwise use the wrong factor
     // if the screen changed notification is still in an event queue.
-    if (QWindow *window = windowHandle())
-        window->setScreen(QGuiApplication::screens().at(scrn));
+    if (scrn >= 0) {
+        if (QWindow *window = windowHandle())
+            window->setScreen(QGuiApplication::screens().at(scrn));
+    }
 
     move(p);
 }
diff --git a/src/widgets/itemviews/qabstractitemdelegate.cpp b/src/widgets/itemviews/qabstractitemdelegate.cpp
index 6ed019f4a8..5e3b74f7b7 100644
--- a/src/widgets/itemviews/qabstractitemdelegate.cpp
+++ b/src/widgets/itemviews/qabstractitemdelegate.cpp
@@ -376,6 +376,7 @@ bool QAbstractItemDelegate::helpEvent(QHelpEvent *event,
                                       const QStyleOptionViewItem &option,
                                       const QModelIndex &index)
 {
+    Q_D(QAbstractItemDelegate);
     Q_UNUSED(option);
 
     if (!event || !view)
@@ -384,9 +385,10 @@ bool QAbstractItemDelegate::helpEvent(QHelpEvent *event,
 #ifndef QT_NO_TOOLTIP
     case QEvent::ToolTip: {
         QHelpEvent *he = static_cast<QHelpEvent*>(event);
-        QVariant tooltip = index.data(Qt::ToolTipRole);
-        if (tooltip.canConvert<QString>()) {
-            QToolTip::showText(he->globalPos(), tooltip.toString(), view);
+        const int precision = inherits("QItemDelegate") ? 10 : 6; // keep in sync with DBL_DIG in qitemdelegate.cpp
+        const QString tooltip = d->textForRole(Qt::ToolTipRole, index.data(Qt::ToolTipRole), option.locale, precision);
+        if (!tooltip.isEmpty()) {
+            QToolTip::showText(he->globalPos(), tooltip, view);
             return true;
         }
         break;}
@@ -398,9 +400,10 @@ bool QAbstractItemDelegate::helpEvent(QHelpEvent *event,
         break; }
     case QEvent::WhatsThis: {
         QHelpEvent *he = static_cast<QHelpEvent*>(event);
-        QVariant whatsthis = index.data(Qt::WhatsThisRole);
-        if (whatsthis.canConvert<QString>()) {
-            QWhatsThis::showText(he->globalPos(), whatsthis.toString(), view);
+        const int precision = inherits("QItemDelegate") ? 10 : 6; // keep in sync with DBL_DIG in qitemdelegate.cpp
+        const QString whatsthis = d->textForRole(Qt::WhatsThisRole, index.data(Qt::WhatsThisRole), option.locale, precision);
+        if (!whatsthis.isEmpty()) {
+            QWhatsThis::showText(he->globalPos(), whatsthis, view);
             return true;
         }
         break ; }
@@ -543,6 +546,46 @@ bool QAbstractItemDelegatePrivate::tryFixup(QWidget *editor)
     return true;
 }
 
+QString QAbstractItemDelegatePrivate::textForRole(Qt::ItemDataRole role, const QVariant &value, const QLocale &locale, int precision) const
+{
+    const QLocale::FormatType formatType = (role == Qt::DisplayRole) ? QLocale::ShortFormat : QLocale::LongFormat;
+    QString text;
+    switch (value.userType()) {
+    case QMetaType::Float:
+        text = locale.toString(value.toFloat());
+        break;
+    case QVariant::Double:
+        text = locale.toString(value.toDouble(), 'g', precision);
+        break;
+    case QVariant::Int:
+    case QVariant::LongLong:
+        text = locale.toString(value.toLongLong());
+        break;
+    case QVariant::UInt:
+    case QVariant::ULongLong:
+        text = locale.toString(value.toULongLong());
+        break;
+    case QVariant::Date:
+        text = locale.toString(value.toDate(), formatType);
+        break;
+    case QVariant::Time:
+        text = locale.toString(value.toTime(), formatType);
+        break;
+    case QVariant::DateTime: {
+        const QDateTime dateTime = value.toDateTime();
+        text = locale.toString(dateTime.date(), formatType)
+             + QLatin1Char(' ')
+             + locale.toString(dateTime.time(), formatType);
+        break; }
+    default:
+        text = value.toString();
+        if (role == Qt::DisplayRole)
+            text.replace(QLatin1Char('\n'), QChar::LineSeparator);
+        break;
+    }
+    return text;
+}
+
 void QAbstractItemDelegatePrivate::_q_commitDataAndCloseEditor(QWidget *editor)
 {
     Q_Q(QAbstractItemDelegate);
diff --git a/src/widgets/itemviews/qabstractitemdelegate_p.h b/src/widgets/itemviews/qabstractitemdelegate_p.h
index 2fd38bdfd7..958737dd01 100644
--- a/src/widgets/itemviews/qabstractitemdelegate_p.h
+++ b/src/widgets/itemviews/qabstractitemdelegate_p.h
@@ -58,7 +58,7 @@
 
 QT_BEGIN_NAMESPACE
 
-class QAbstractItemDelegatePrivate : public QObjectPrivate
+class Q_AUTOTEST_EXPORT QAbstractItemDelegatePrivate : public QObjectPrivate
 {
     Q_DECLARE_PUBLIC(QAbstractItemDelegate)
 public:
@@ -66,6 +66,7 @@ public:
 
     bool editorEventFilter(QObject *object, QEvent *event);
     bool tryFixup(QWidget *editor);
+    QString textForRole(Qt::ItemDataRole role, const QVariant &value, const QLocale &locale, int precision = 6) const;
     void _q_commitDataAndCloseEditor(QWidget *editor);
 };
 
diff --git a/src/widgets/itemviews/qabstractitemview.cpp b/src/widgets/itemviews/qabstractitemview.cpp
index e67f8d83fb..83b9b7716d 100644
--- a/src/widgets/itemviews/qabstractitemview.cpp
+++ b/src/widgets/itemviews/qabstractitemview.cpp
@@ -4325,6 +4325,12 @@ const QEditorInfo & QAbstractItemViewPrivate::editorForIndex(const QModelIndex &
     return it.value();
 }
 
+bool QAbstractItemViewPrivate::hasEditor(const QModelIndex &index) const
+{
+    // Search's implicit cast (QModelIndex to QPersistentModelIndex) is slow; use cheap pre-test to avoid when we can.
+    return !indexEditorHash.isEmpty() && indexEditorHash.contains(index);
+}
+
 QModelIndex QAbstractItemViewPrivate::indexForEditor(QWidget *editor) const
 {
     // do not try to search to avoid slow implicit cast from QModelIndex to QPersistentModelIndex
diff --git a/src/widgets/itemviews/qabstractitemview_p.h b/src/widgets/itemviews/qabstractitemview_p.h
index 60ae1559b1..fcbe25d735 100644
--- a/src/widgets/itemviews/qabstractitemview_p.h
+++ b/src/widgets/itemviews/qabstractitemview_p.h
@@ -276,10 +276,7 @@ public:
     }
 
     const QEditorInfo &editorForIndex(const QModelIndex &index) const;
-    inline bool hasEditor(const QModelIndex &index) const {
-        // Search's implicit cast (QModelIndex to QPersistentModelIndex) is slow; use cheap pre-test to avoid when we can.
-        return !indexEditorHash.isEmpty() && indexEditorHash.contains(index);
-    }
+    bool hasEditor(const QModelIndex &index) const;
 
     QModelIndex indexForEditor(QWidget *editor) const;
     void addEditor(const QModelIndex &index, QWidget *editor, bool isStatic);
diff --git a/src/widgets/itemviews/qitemdelegate.cpp b/src/widgets/itemviews/qitemdelegate.cpp
index 194bd22493..747d5db782 100644
--- a/src/widgets/itemviews/qitemdelegate.cpp
+++ b/src/widgets/itemviews/qitemdelegate.cpp
@@ -67,6 +67,7 @@
 
 #include <limits.h>
 
+// keep in sync with QAbstractItemDelegate::helpEvent()
 #ifndef DBL_DIG
 #  define DBL_DIG 10
 #endif
@@ -102,7 +103,7 @@ public:
             return text;
         }
 
-    static QString valueToText(const QVariant &value, const QStyleOptionViewItem &option);
+    QString valueToText(const QVariant &value, const QStyleOptionViewItem &option) const;
 
     QItemEditorFactory *f;
     bool clipPainting;
@@ -332,40 +333,9 @@ void QItemDelegate::setClipping(bool clip)
     d->clipPainting = clip;
 }
 
-QString QItemDelegatePrivate::valueToText(const QVariant &value, const QStyleOptionViewItem &option)
+QString QItemDelegatePrivate::valueToText(const QVariant &value, const QStyleOptionViewItem &option) const
 {
-    QString text;
-    switch (value.userType()) {
-        case QMetaType::Float:
-            text = option.locale.toString(value.toFloat(), 'g');
-            break;
-        case QVariant::Double:
-            text = option.locale.toString(value.toDouble(), 'g', DBL_DIG);
-            break;
-        case QVariant::Int:
-        case QVariant::LongLong:
-            text = option.locale.toString(value.toLongLong());
-            break;
-        case QVariant::UInt:
-        case QVariant::ULongLong:
-            text = option.locale.toString(value.toULongLong());
-            break;
-        case QVariant::Date:
-            text = option.locale.toString(value.toDate(), QLocale::ShortFormat);
-            break;
-        case QVariant::Time:
-            text = option.locale.toString(value.toTime(), QLocale::ShortFormat);
-            break;
-        case QVariant::DateTime:
-            text = option.locale.toString(value.toDateTime().date(), QLocale::ShortFormat);
-            text += QLatin1Char(' ');
-            text += option.locale.toString(value.toDateTime().time(), QLocale::ShortFormat);
-            break;
-        default:
-            text = replaceNewLine(value.toString());
-            break;
-    }
-    return text;
+    return textForRole(Qt::DisplayRole, value, option.locale, DBL_DIG);
 }
 
 /*!
@@ -434,7 +404,7 @@ void QItemDelegate::paint(QPainter *painter,
     QRect displayRect;
     value = index.data(Qt::DisplayRole);
     if (value.isValid() && !value.isNull()) {
-        text = QItemDelegatePrivate::valueToText(value, opt);
+        text = d->valueToText(value, opt);
         displayRect = textRectangle(painter, d->textLayoutBounds(opt), opt.font, text);
     }
 
@@ -1061,7 +1031,7 @@ QRect QItemDelegate::rect(const QStyleOptionViewItem &option,
             return QRect(QPoint(0, 0), option.decorationSize);
         case QVariant::String:
         default: {
-            QString text = QItemDelegatePrivate::valueToText(value, option);
+            const QString text = d->valueToText(value, option);
             value = index.data(Qt::FontRole);
             QFont fnt = qvariant_cast<QFont>(value).resolve(option.font);
             return textRectangle(0, d->textLayoutBounds(option), fnt, text); }
diff --git a/src/widgets/itemviews/qstyleditemdelegate.cpp b/src/widgets/itemviews/qstyleditemdelegate.cpp
index 162ef826da..bab8436dce 100644
--- a/src/widgets/itemviews/qstyleditemdelegate.cpp
+++ b/src/widgets/itemviews/qstyleditemdelegate.cpp
@@ -261,41 +261,7 @@ QStyledItemDelegate::~QStyledItemDelegate()
 */
 QString QStyledItemDelegate::displayText(const QVariant &value, const QLocale& locale) const
 {
-    QString text;
-    switch (value.userType()) {
-    case QMetaType::Float:
-    case QVariant::Double:
-        text = locale.toString(value.toReal());
-        break;
-    case QVariant::Int:
-    case QVariant::LongLong:
-        text = locale.toString(value.toLongLong());
-        break;
-    case QVariant::UInt:
-    case QVariant::ULongLong:
-        text = locale.toString(value.toULongLong());
-        break;
-    case QVariant::Date:
-        text = locale.toString(value.toDate(), QLocale::ShortFormat);
-        break;
-    case QVariant::Time:
-        text = locale.toString(value.toTime(), QLocale::ShortFormat);
-        break;
-    case QVariant::DateTime:
-        text = locale.toString(value.toDateTime().date(), QLocale::ShortFormat);
-        text += QLatin1Char(' ');
-        text += locale.toString(value.toDateTime().time(), QLocale::ShortFormat);
-        break;
-    default:
-        // convert new lines into line separators
-        text = value.toString();
-        for (int i = 0; i < text.count(); ++i) {
-            if (text.at(i) == QLatin1Char('\n'))
-                text[i] = QChar::LineSeparator;
-        }
-        break;
-    }
-    return text;
+    return d_func()->textForRole(Qt::DisplayRole, value, locale);
 }
 
 /*!
diff --git a/src/widgets/styles/qwindowsstyle.cpp b/src/widgets/styles/qwindowsstyle.cpp
index 3eca9aef7f..075cb3719f 100644
--- a/src/widgets/styles/qwindowsstyle.cpp
+++ b/src/widgets/styles/qwindowsstyle.cpp
@@ -65,8 +65,12 @@
 #include "qlistview.h"
 #include <private/qmath_p.h>
 #include <qmath.h>
+#include <QtGui/qscreen.h>
+#include <QtGui/qwindow.h>
 #include <qpa/qplatformtheme.h>
+#include <qpa/qplatformscreen.h>
 #include <private/qguiapplication_p.h>
+#include <private/qhighdpiscaling_p.h>
 
 #include <private/qstylehelper_p.h>
 #include <private/qstyleanimation_p.h>
@@ -402,6 +406,47 @@ int QWindowsStylePrivate::fixedPixelMetric(QStyle::PixelMetric pm)
     return QWindowsStylePrivate::InvalidMetric;
 }
 
+static QWindow *windowOf(const QWidget *w)
+{
+    QWindow *result = Q_NULLPTR;
+    if (w) {
+        result = w->windowHandle();
+        if (!result) {
+            if (const QWidget *np = w->nativeParentWidget())
+                result = np->windowHandle();
+        }
+    }
+    return result;
+}
+
+static QScreen *screenOf(const QWidget *w)
+{
+    if (const QWindow *window = windowOf(w))
+        return window->screen();
+    return QGuiApplication::primaryScreen();
+}
+
+// Calculate the overall scale factor to obtain Qt Device Independent
+// Pixels from a native Windows size. Divide by devicePixelRatio
+// and account for secondary screens with differing logical DPI.
+qreal QWindowsStylePrivate::nativeMetricScaleFactor(const QWidget *widget)
+{
+    if (!QHighDpiScaling::isActive())
+        return 1;
+    qreal result = qreal(1) / QWindowsStylePrivate::devicePixelRatio(widget);
+    if (QGuiApplicationPrivate::screen_list.size() > 1) {
+        const QScreen *primaryScreen = QGuiApplication::primaryScreen();
+        const QScreen *screen = screenOf(widget);
+        if (screen != primaryScreen) {
+            const qreal primaryLogicalDpi = primaryScreen->handle()->logicalDpi().first;
+            const qreal logicalDpi = screen->handle()->logicalDpi().first;
+            if (!qFuzzyCompare(primaryLogicalDpi, logicalDpi))
+                result *= logicalDpi / primaryLogicalDpi;
+        }
+    }
+    return result;
+}
+
 /*!
   \reimp
 */
@@ -409,7 +454,7 @@ int QWindowsStyle::pixelMetric(PixelMetric pm, const QStyleOption *opt, const QW
 {
     int ret = QWindowsStylePrivate::pixelMetricFromSystemDp(pm, opt, widget);
     if (ret != QWindowsStylePrivate::InvalidMetric)
-        return qRound(qreal(ret) / QWindowsStylePrivate::devicePixelRatio(widget));
+        return qRound(qreal(ret) * QWindowsStylePrivate::nativeMetricScaleFactor(widget));
 
     ret = QWindowsStylePrivate::fixedPixelMetric(pm);
     if (ret != QWindowsStylePrivate::InvalidMetric)
diff --git a/src/widgets/styles/qwindowsstyle_p_p.h b/src/widgets/styles/qwindowsstyle_p_p.h
index e6c44f401e..f034255837 100644
--- a/src/widgets/styles/qwindowsstyle_p_p.h
+++ b/src/widgets/styles/qwindowsstyle_p_p.h
@@ -72,6 +72,7 @@ public:
     static int fixedPixelMetric(QStyle::PixelMetric pm);
     static qreal devicePixelRatio(const QWidget *widget = 0)
         { return widget ? widget->devicePixelRatioF() : QWindowsStylePrivate::appDevicePixelRatio(); }
+    static qreal nativeMetricScaleFactor(const QWidget *widget = Q_NULLPTR);
 
     bool hasSeenAlt(const QWidget *widget) const;
     bool altDown() const { return alt_down; }
@@ -104,3 +105,4 @@ QT_END_NAMESPACE
 #endif // QT_NO_STYLE_WINDOWS
 
 #endif //QWINDOWSSTYLE_P_P_H
+;
diff --git a/src/widgets/styles/qwindowsvistastyle.cpp b/src/widgets/styles/qwindowsvistastyle.cpp
index 5c227b9d5d..1f4598ea14 100644
--- a/src/widgets/styles/qwindowsvistastyle.cpp
+++ b/src/widgets/styles/qwindowsvistastyle.cpp
@@ -432,7 +432,7 @@ void QWindowsVistaStyle::drawPrimitive(PrimitiveElement element, const QStyleOpt
                 XPThemeData themeSize = theme;
                 themeSize.partId = TVP_HOTGLYPH;
                 themeSize.stateId = GLPS_OPENED;
-                const QSizeF size = themeSize.size() / QWindowsXPStylePrivate::devicePixelRatio(widget);
+                const QSizeF size = themeSize.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget);
                 decoration_size = qRound(qMax(size.width(), size.height()));
             }
             int mid_h = option->rect.x() + option->rect.width() / 2;
@@ -994,7 +994,7 @@ void QWindowsVistaStyle::drawControl(ControlElement element, const QStyleOption
                 XPThemeData theme(widget, 0, QWindowsXPStylePrivate::ToolBarTheme,
                                   TP_DROPDOWNBUTTON);
                 if (theme.isValid()) {
-                    const QSizeF size = theme.size() / QWindowsXPStylePrivate::devicePixelRatio(widget);
+                    const QSizeF size = theme.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget);
                     if (!size.isEmpty()) {
                         mbiw = qRound(size.width());
                         mbih = qRound(size.height());
@@ -1190,8 +1190,8 @@ void QWindowsVistaStyle::drawControl(ControlElement element, const QStyleOption
                 XPThemeData themeSize = theme;
                 themeSize.partId = MENU_POPUPCHECK;
                 themeSize.stateId = 0;
-                const QSizeF size = themeSize.size() / QWindowsXPStylePrivate::devicePixelRatio(widget);
-                const QMarginsF margins = themeSize.margins() / QWindowsXPStylePrivate::devicePixelRatio(widget);
+                const QSizeF size = themeSize.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget);
+                const QMarginsF margins = themeSize.margins() * QWindowsStylePrivate::nativeMetricScaleFactor(widget);
                 checkcol = qMax(menuitem->maxIconWidth, qRound(gutterWidth + size.width() + margins.left() + margins.right()));
             }
             QRect rect = option->rect;
@@ -1216,7 +1216,7 @@ void QWindowsVistaStyle::drawControl(ControlElement element, const QStyleOption
 
             if (menuitem->menuItemType == QStyleOptionMenuItem::Separator) {
                 int yoff = y-2 + h / 2;
-                const int separatorSize = 6 / QWindowsXPStylePrivate::devicePixelRatio(widget);
+                const int separatorSize = qRound(qreal(6) * QWindowsStylePrivate::nativeMetricScaleFactor(widget));
                 QPoint p1 = QPoint(x + checkcol, yoff);
                 QPoint p2 = QPoint(x + w + separatorSize, yoff);
                 stateId = MBI_HOT;
@@ -1249,8 +1249,8 @@ void QWindowsVistaStyle::drawControl(ControlElement element, const QStyleOption
                 XPThemeData themeSize = theme;
                 themeSize.partId = MENU_POPUPCHECK;
                 themeSize.stateId = 0;
-                const QSizeF size = themeSize.size() / QWindowsXPStylePrivate::devicePixelRatio(widget);
-                const QMarginsF margins = themeSize.margins() / QWindowsXPStylePrivate::devicePixelRatio(widget);
+                const QSizeF size = themeSize.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget);
+                const QMarginsF margins = themeSize.margins() * QWindowsStylePrivate::nativeMetricScaleFactor(widget);
                 QRect checkRect(0, 0, qRound(size.width() + margins.left() + margins.right()),
                                 qRound(size.height() + margins.bottom() + margins.top()));
                 checkRect.moveCenter(vCheckRect.center());
@@ -1862,8 +1862,8 @@ QSize QWindowsVistaStyle::sizeFromContents(ContentsType type, const QStyleOption
             XPThemeData themeSize = theme;
             themeSize.partId = MENU_POPUPCHECK;
             themeSize.stateId = 0;
-            const QSizeF size = themeSize.size() / QWindowsXPStylePrivate::devicePixelRatio(widget);
-            const QMarginsF margins = themeSize.margins() / QWindowsXPStylePrivate::devicePixelRatio(widget);
+            const QSizeF size = themeSize.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget);
+            const QMarginsF margins = themeSize.margins() * QWindowsStylePrivate::nativeMetricScaleFactor(widget);
             minimumHeight = qMax(qRound(size.height() + margins.bottom() + margins.top()), sz.height());
             sz.rwidth() += qRound(size.width() + margins.left() + margins.right());
         }
@@ -1973,7 +1973,7 @@ QRect QWindowsVistaStyle::subElementRect(SubElement element, const QStyleOption
             int arrowWidth = 13;
             int arrowHeight = 5;
             if (theme.isValid()) {
-                const QSizeF size = theme.size() / QWindowsXPStylePrivate::devicePixelRatio(widget);
+                const QSizeF size = theme.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget);
                 if (!size.isEmpty()) {
                     arrowWidth = qRound(size.width());
                     arrowHeight = qRound(size.height());
@@ -2456,7 +2456,7 @@ QIcon QWindowsVistaStyle::standardIcon(StandardPixmap standardIcon,
                               QWindowsXPStylePrivate::ButtonTheme,
                               BP_COMMANDLINKGLYPH, CMDLGS_NORMAL);
             if (theme.isValid()) {
-                const QSize size = (theme.size() / QWindowsXPStylePrivate::devicePixelRatio(widget)).toSize();
+                const QSize size = (theme.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget)).toSize();
                 QIcon linkGlyph;
                 QPixmap pm(size);
                 pm.fill(Qt::transparent);
diff --git a/src/widgets/styles/qwindowsxpstyle.cpp b/src/widgets/styles/qwindowsxpstyle.cpp
index 900597cdab..ed4271505b 100644
--- a/src/widgets/styles/qwindowsxpstyle.cpp
+++ b/src/widgets/styles/qwindowsxpstyle.cpp
@@ -489,7 +489,7 @@ const QPixmap *QWindowsXPStylePrivate::tabBody(QWidget *widget)
 {
     if (!tabbody) {
         XPThemeData theme(0, 0, QWindowsXPStylePrivate::TabTheme, TABP_BODY);
-        const QSize size = (theme.size() / QWindowsXPStylePrivate::devicePixelRatio(widget)).toSize();
+        const QSize size = (theme.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget)).toSize();
 
         tabbody = new QPixmap(size.width(), QApplication::desktop()->screenGeometry().height());
         QPainter painter(tabbody);
@@ -3457,7 +3457,7 @@ int QWindowsXPStyle::pixelMetric(PixelMetric pm, const QStyleOption *option, con
 
     int res = QWindowsXPStylePrivate::pixelMetricFromSystemDp(pm, option, widget);
     if (res != QWindowsStylePrivate::InvalidMetric)
-        return qRound(qreal(res) / QWindowsStylePrivate::devicePixelRatio(widget));
+        return qRound(qreal(res) * QWindowsStylePrivate::nativeMetricScaleFactor(widget));
 
     res = 0;
     switch (pm) {
@@ -3603,9 +3603,10 @@ QRect QWindowsXPStyle::subControlRect(ComplexControl cc, const QStyleOptionCompl
             const int height = tb->rect.height();
             const int width = tb->rect.width();
             const int buttonMargin = int(QStyleHelper::dpiScaled(4));
-            int buttonHeight = qRound(qreal(GetSystemMetrics(SM_CYSIZE)) / QWindowsStylePrivate::devicePixelRatio(widget))
+            const qreal factor = QWindowsStylePrivate::nativeMetricScaleFactor(widget);
+            int buttonHeight = qRound(qreal(GetSystemMetrics(SM_CYSIZE)) * factor)
                 - buttonMargin;
-            int buttonWidth = qRound(qreal(GetSystemMetrics(SM_CXSIZE)) / QWindowsStylePrivate::devicePixelRatio(widget))
+            int buttonWidth = qRound(qreal(GetSystemMetrics(SM_CXSIZE)) * factor)
                 - buttonMargin;
             const int delta = buttonWidth + 2;
             int controlTop = option->rect.bottom() - buttonHeight - 2;
@@ -3975,7 +3976,7 @@ QPixmap QWindowsXPStyle::standardPixmap(StandardPixmap standardPixmap, const QSt
             if (widget && widget->isWindow()) {
                 XPThemeData theme(widget, 0, QWindowsXPStylePrivate::WindowTheme, WP_SMALLCLOSEBUTTON, CBS_NORMAL);
                 if (theme.isValid()) {
-                    const QSize size = (theme.size() / QWindowsXPStylePrivate::devicePixelRatio(widget)).toSize();
+                    const QSize size = (theme.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget)).toSize();
                     return QIcon(QWindowsStyle::standardPixmap(standardPixmap, option, widget)).pixmap(size);
                 }
             }
@@ -4009,7 +4010,7 @@ QIcon QWindowsXPStyle::standardIcon(StandardPixmap standardIcon,
                 XPThemeData theme(0, 0, QWindowsXPStylePrivate::WindowTheme,
                                   WP_MAXBUTTON, MAXBS_NORMAL);
                 if (theme.isValid()) {
-                    const QSize size = (themeSize.size() / QWindowsXPStylePrivate::devicePixelRatio(widget)).toSize();
+                    const QSize size = (themeSize.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget)).toSize();
                     QPixmap pm(size);
                     pm.fill(Qt::transparent);
                     QPainter p(&pm);
@@ -4043,7 +4044,7 @@ QIcon QWindowsXPStyle::standardIcon(StandardPixmap standardIcon,
                 XPThemeData theme(0, 0, QWindowsXPStylePrivate::WindowTheme,
                                   WP_SMALLCLOSEBUTTON, CBS_NORMAL);
                 if (theme.isValid()) {
-                    const QSize size = (theme.size() / QWindowsXPStylePrivate::devicePixelRatio(widget)).toSize();
+                    const QSize size = (theme.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget)).toSize();
                     QPixmap pm(size);
                     pm.fill(Qt::transparent);
                     QPainter p(&pm);