Windows styles: Add device pixel scaling for system metrics.

Metrics obtained from the system must be scaled down
when device pixel ration scaling is in effect. Factor out
functions to return the device pixel values which might still
be used for drawing.

Task-number: QTBUG-38993
Task-number: QTBUG-38858
Change-Id: I6b90629e4979436bbb46f8c1fa1ee2253ada7ece
Reviewed-by: Alessandro Portale <alessandro.portale@digia.com>

1 files changed, 97 insertions, 172 deletions

diff --git a/src/widgets/styles/qwindowsxpstyle.cpp b/src/widgets/styles/qwindowsxpstyle.cpp
index 2e3586db42..424a1f7234 100644
--- a/src/widgets/styles/qwindowsxpstyle.cpp
+++ b/src/widgets/styles/qwindowsxpstyle.cpp
@@ -411,22 +411,21 @@ HWND QWindowsXPStylePrivate::winId(const QWidget *widget)
     height of the screen. This way the theme engine doesn't need to
     scale the body for every time we ask for it. (Speed optimization)
 */
-const QPixmap *QWindowsXPStylePrivate::tabBody(QWidget *)
+const QPixmap *QWindowsXPStylePrivate::tabBody(QWidget *widget)
 {
     if (!tabbody) {
-        SIZE sz;
         XPThemeData theme(0, 0, QWindowsXPStylePrivate::TabTheme, TABP_BODY);
-        pGetThemePartSize(theme.handle(), qt_win_display_dc(), TABP_BODY, 0, 0, TS_TRUE, &sz);
+        const QSize size = theme.size() / QWindowsXPStylePrivate::devicePixelRatio(widget);
 
-        tabbody = new QPixmap(sz.cx, QApplication::desktop()->screenGeometry().height());
+        tabbody = new QPixmap(size.width(), QApplication::desktop()->screenGeometry().height());
         QPainter painter(tabbody);
-        theme.rect = QRect(0, 0, sz.cx, sz.cy);
+        theme.rect = QRect(QPoint(0, 0), size);
         drawBackground(theme);
         // We fill with the last line of the themedata, that
         // way we don't get a tiled pixmap inside big tabs
-        QPixmap temp(sz.cx, 1);
-        painter.drawPixmap(0, 0, temp, 0, sz.cy-1, -1, -1);
-        painter.drawTiledPixmap(0, sz.cy, sz.cx, tabbody->height()-sz.cy, temp);
+        QPixmap temp(size.width(), 1);
+        painter.drawPixmap(0, 0, temp, 0, size.height() - 1, -1, -1);
+        painter.drawTiledPixmap(0, size.height(), size.width(), tabbody->height() - size.height(), temp);
     }
     return tabbody;
 }
@@ -2002,25 +2001,24 @@ void QWindowsXPStyle::drawControl(ControlElement element, const QStyleOption *op
         {
             themeNumber = QWindowsXPStylePrivate::StatusTheme;
             partId = SP_GRIPPER;
-            SIZE sz;
             XPThemeData theme(0, p, themeNumber, partId, 0);
-            QWindowsXPStylePrivate::pGetThemePartSize(theme.handle(), 0, partId, 0, 0, TS_TRUE, &sz);
-            --sz.cy;
+            QSize size = theme.size() / QWindowsStylePrivate::devicePixelRatio(widget);
+            size.rheight()--;
             if (const QStyleOptionSizeGrip *sg = qstyleoption_cast<const QStyleOptionSizeGrip *>(option)) {
                 switch (sg->corner) {
                     case Qt::BottomRightCorner:
-                        rect = QRect(rect.right() - sz.cx, rect.bottom() - sz.cy, sz.cx, sz.cy);
+                        rect = QRect(QPoint(rect.right() - size.width(), rect.bottom() - size.height()), size);
                         break;
                     case Qt::BottomLeftCorner:
-                        rect = QRect(rect.left() + 1, rect.bottom() - sz.cy, sz.cx, sz.cy);
+                        rect = QRect(QPoint(rect.left() + 1, rect.bottom() - size.height()), size);
                         hMirrored = true;
                         break;
                     case Qt::TopRightCorner:
-                        rect = QRect(rect.right() - sz.cx, rect.top() + 1, sz.cx, sz.cy);
+                        rect = QRect(QPoint(rect.right() - size.width(), rect.top() + 1), size);
                         vMirrored = true;
                         break;
                     case Qt::TopLeftCorner:
-                        rect = QRect(rect.left() + 1, rect.top() + 1, sz.cx, sz.cy);
+                        rect = QRect(rect.topLeft() + QPoint(1, 1), size);
                         hMirrored = vMirrored = true;
                 }
             }
@@ -2075,10 +2073,9 @@ void QWindowsXPStyle::drawControl(ControlElement element, const QStyleOption *op
                                   QWindowsXPStylePrivate::ToolBarTheme,
                                   TP_SPLITBUTTONDROPDOWN);
                 if (theme.isValid()) {
-                    SIZE size;
-                    QWindowsXPStylePrivate::pGetThemePartSize(theme.handle(), 0, theme.partId, theme.stateId, 0, TS_TRUE, &size);
-                    mbiw = size.cx;
-                    mbih = size.cy;
+                    const QSize size = theme.size() / QWindowsStylePrivate::devicePixelRatio(widget);
+                    mbiw = size.width();
+                    mbih = size.height();
                 }
 
                 QRect ir = btn->rect;
@@ -2770,28 +2767,19 @@ void QWindowsXPStyle::drawComplexControl(ComplexControl cc, const QStyleOptionCo
                     const int swidth = theme.rect.width();
                     const int sheight = theme.rect.height();
 
-                    MARGINS contentsMargin;
-                    RECT rect = theme.toRECT(theme.rect);
-                    QWindowsXPStylePrivate::pGetThemeMargins(theme.handle(), 0, theme.partId, theme.stateId, TMT_SIZINGMARGINS, &rect, &contentsMargin);
+                    const QMargins contentsMargin = theme.margins(theme.rect, TMT_SIZINGMARGINS)
+                                                    / QWindowsStylePrivate::devicePixelRatio(widget);
 
-                    SIZE size;
                     theme.partId = flags & State_Horizontal ? SBP_GRIPPERHORZ : SBP_GRIPPERVERT;
-                    QWindowsXPStylePrivate::pGetThemePartSize(theme.handle(), 0, theme.partId, theme.stateId, 0, TS_TRUE, &size);
-                    int gw = size.cx, gh = size.cy;
-
-
-                    QRect gripperBounds;
-                    if (flags & State_Horizontal && ((swidth - contentsMargin.cxLeftWidth - contentsMargin.cxRightWidth) > gw)) {
-                        gripperBounds.setLeft(theme.rect.left() + swidth/2 - gw/2);
-                        gripperBounds.setTop(theme.rect.top() + sheight/2 - gh/2);
-                        gripperBounds.setWidth(gw);
-                        gripperBounds.setHeight(gh);
-                    } else if ((sheight - contentsMargin.cyTopHeight - contentsMargin.cyBottomHeight) > gh) {
-                        gripperBounds.setLeft(theme.rect.left() + swidth/2 - gw/2);
-                        gripperBounds.setTop(theme.rect.top() + sheight/2 - gh/2);
-                        gripperBounds.setWidth(gw);
-                        gripperBounds.setHeight(gh);
+                    const QSize size = theme.size() / QWindowsStylePrivate::devicePixelRatio(widget);
+                    QPoint gripperBoundsPos(0, 0);
+                    if ((flags & State_Horizontal
+                         && swidth - contentsMargin.left() - contentsMargin.right() > size.width())
+                        || sheight - contentsMargin.top() - contentsMargin.bottom() > size.height()) {
+                        gripperBoundsPos = QPoint(theme.rect.left() + (swidth - size.width()) / 2,
+                                                  theme.rect.top() + (sheight - size.height()) /2);
                     }
+                    const QRect gripperBounds(gripperBoundsPos, size);
 
                     // Draw gripper if there is enough space
                     if (!gripperBounds.isEmpty()) {
@@ -3113,9 +3101,7 @@ void QWindowsXPStyle::drawComplexControl(ComplexControl cc, const QStyleOptionCo
                     } else {
                         theme.partId = partId;
                         theme.stateId = stateId;
-                        SIZE sz;
-                        QWindowsXPStylePrivate::pGetThemePartSize(theme.handle(), qt_win_display_dc(), theme.partId, theme.stateId, 0, TS_TRUE, &sz);
-                        if (sz.cx == 0 || sz.cy == 0) {
+                        if (theme.size().isEmpty()) {
                             int iconSize = proxy()->pixelMetric(PM_SmallIconSize, tb, widget);
                             QPixmap pm = proxy()->standardIcon(SP_TitleBarMenuButton, tb, widget).pixmap(iconSize, iconSize);
                             p->save();
@@ -3330,23 +3316,63 @@ void QWindowsXPStyle::drawComplexControl(ComplexControl cc, const QStyleOptionCo
     }
 }
 
+static inline Qt::Orientation progressBarOrientation(const QStyleOption *option = 0)
+{
+    if (const QStyleOptionProgressBarV2 *pb2 = qstyleoption_cast<const QStyleOptionProgressBarV2 *>(option))
+        return pb2->orientation;
+    return Qt::Horizontal;
+}
+
+int QWindowsXPStylePrivate::pixelMetricFromSystemDp(QStyle::PixelMetric pm, const QStyleOption *option, const QWidget *widget)
+{
+    switch (pm) {
+    case QStyle::PM_IndicatorWidth:
+        return XPThemeData::themeSize(widget, 0, QWindowsXPStylePrivate::ButtonTheme, BP_CHECKBOX, CBS_UNCHECKEDNORMAL).width();
+    case QStyle::PM_IndicatorHeight:
+        return XPThemeData::themeSize(widget, 0, QWindowsXPStylePrivate::ButtonTheme, BP_CHECKBOX, CBS_UNCHECKEDNORMAL).height();
+    case QStyle::PM_ExclusiveIndicatorWidth:
+        return XPThemeData::themeSize(widget, 0, QWindowsXPStylePrivate::ButtonTheme, BP_RADIOBUTTON, RBS_UNCHECKEDNORMAL).width();
+    case QStyle::PM_ExclusiveIndicatorHeight:
+        return XPThemeData::themeSize(widget, 0, QWindowsXPStylePrivate::ButtonTheme, BP_RADIOBUTTON, RBS_UNCHECKEDNORMAL).height();
+    case QStyle::PM_ProgressBarChunkWidth:
+        return progressBarOrientation(option) == Qt::Horizontal
+            ? XPThemeData::themeSize(widget, 0, QWindowsXPStylePrivate::ProgressTheme, PP_CHUNK).width()
+            : XPThemeData::themeSize(widget, 0, QWindowsXPStylePrivate::ProgressTheme, PP_CHUNKVERT).height();
+    case QStyle::PM_SliderThickness:
+        return XPThemeData::themeSize(widget, 0, QWindowsXPStylePrivate::TrackBarTheme, TKP_THUMB).height();
+    case QStyle::PM_TitleBarHeight:
+        return widget && (widget->windowType() == Qt::Tool)
+            ? GetSystemMetrics(SM_CYSMCAPTION) + GetSystemMetrics(SM_CXSIZEFRAME)
+            : GetSystemMetrics(SM_CYCAPTION) + GetSystemMetrics(SM_CXSIZEFRAME);
+    case QStyle::PM_MdiSubWindowFrameWidth:
+        return XPThemeData::themeSize(widget, 0, QWindowsXPStylePrivate::WindowTheme, WP_FRAMELEFT, FS_ACTIVE).width();
+    case QStyle::PM_DockWidgetFrameWidth:
+        return XPThemeData::themeSize(widget, 0, QWindowsXPStylePrivate::WindowTheme, WP_SMALLFRAMERIGHT, FS_ACTIVE).width();
+    default:
+        break;
+    }
+    return QWindowsXPStylePrivate::InvalidMetric;
+}
+
 /*! \reimp */
 int QWindowsXPStyle::pixelMetric(PixelMetric pm, const QStyleOption *option, const QWidget *widget) const
 {
     if (!QWindowsXPStylePrivate::useXP())
         return QWindowsStyle::pixelMetric(pm, option, widget);
 
-    int res = 0;
+    int res = QWindowsXPStylePrivate::pixelMetricFromSystemDp(pm, option, widget);
+    if (res != QWindowsStylePrivate::InvalidMetric)
+        return res / QWindowsStylePrivate::devicePixelRatio(widget);
+
+    res = 0;
     switch (pm) {
     case PM_MenuBarPanelWidth:
+    case PM_ButtonDefaultIndicator:
         res = 0;
         break;
 
     case PM_DefaultFrameWidth:
-        if (qobject_cast<const QListView*>(widget))
-            res = 2;
-        else
-            res = 1;
+        res = qobject_cast<const QListView*>(widget) ? 2 : 1;
         break;
     case PM_MenuPanelWidth:
     case PM_SpinBoxFrameWidth:
@@ -3364,6 +3390,8 @@ int QWindowsXPStyle::pixelMetric(PixelMetric pm, const QStyleOption *option, con
             switch (tab->shape) {
             case QTabBar::RoundedNorth:
             case QTabBar::TriangularNorth:
+            case QTabBar::RoundedWest:
+            case QTabBar::TriangularWest:
                 res = 1;
                 break;
             case QTabBar::RoundedSouth:
@@ -3374,10 +3402,6 @@ int QWindowsXPStyle::pixelMetric(PixelMetric pm, const QStyleOption *option, con
             case QTabBar::TriangularEast:
                 res = 3;
                 break;
-            case QTabBar::RoundedWest:
-            case QTabBar::TriangularWest:
-                res = 1;
-                break;
             }
         }
         break;
@@ -3386,77 +3410,6 @@ int QWindowsXPStyle::pixelMetric(PixelMetric pm, const QStyleOption *option, con
         res = qMax(int(QStyleHelper::dpiScaled(5.)), QApplication::globalStrut().width());
         break;
 
-    case PM_IndicatorWidth:
-    case PM_IndicatorHeight:
-        {
-            XPThemeData theme(widget, 0, QWindowsXPStylePrivate::ButtonTheme, BP_CHECKBOX, CBS_UNCHECKEDNORMAL);
-            if (theme.isValid()) {
-                SIZE size;
-                QWindowsXPStylePrivate::pGetThemePartSize(theme.handle(), 0, theme.partId, theme.stateId, 0, TS_TRUE, &size);
-                res = (pm == PM_IndicatorWidth) ? size.cx : size.cy;
-            }
-        }
-        break;
-
-    case PM_ExclusiveIndicatorWidth:
-    case PM_ExclusiveIndicatorHeight:
-        {
-            XPThemeData theme(widget, 0, QWindowsXPStylePrivate::ButtonTheme, BP_RADIOBUTTON, RBS_UNCHECKEDNORMAL);
-            if (theme.isValid()) {
-                SIZE size;
-                QWindowsXPStylePrivate::pGetThemePartSize(theme.handle(), 0, theme.partId, theme.stateId, 0, TS_TRUE, &size);
-                res = (pm == PM_ExclusiveIndicatorWidth) ? size.cx : size.cy;
-            }
-        }
-        break;
-
-    case PM_ProgressBarChunkWidth:
-        {
-            Qt::Orientation orient = Qt::Horizontal;
-            if (const QStyleOptionProgressBarV2 *pb2 = qstyleoption_cast<const QStyleOptionProgressBarV2 *>(option))
-                orient = pb2->orientation;
-            XPThemeData theme(widget, 0, QWindowsXPStylePrivate::ProgressTheme,
-                              (orient == Qt::Horizontal) ? PP_CHUNK : PP_CHUNKVERT);
-            if (theme.isValid()) {
-                SIZE size;
-                QWindowsXPStylePrivate::pGetThemePartSize(theme.handle(), 0, theme.partId, theme.stateId, 0, TS_TRUE, &size);
-                res = (orient == Qt::Horizontal) ? size.cx : size.cy;
-            }
-        }
-        break;
-
-    case PM_SliderThickness:
-        {
-            XPThemeData theme(widget, 0, QWindowsXPStylePrivate::TrackBarTheme,
-                              TKP_THUMB);
-            if (theme.isValid()) {
-                SIZE size;
-                QWindowsXPStylePrivate::pGetThemePartSize(theme.handle(), 0, theme.partId, theme.stateId, 0, TS_TRUE, &size);
-                res = size.cy;
-            }
-        }
-        break;
-
-    case PM_TitleBarHeight:
-        {
-            if (widget && (widget->windowType() == Qt::Tool))
-                res = GetSystemMetrics(SM_CYSMCAPTION) + GetSystemMetrics(SM_CXSIZEFRAME);
-            else
-                res = GetSystemMetrics(SM_CYCAPTION) + GetSystemMetrics(SM_CXSIZEFRAME);
-        }
-        break;
-
-    case PM_MdiSubWindowFrameWidth:
-        {
-            XPThemeData theme(widget, 0, QWindowsXPStylePrivate::WindowTheme, WP_FRAMELEFT, FS_ACTIVE);
-            if (theme.isValid()) {
-                SIZE size;
-                QWindowsXPStylePrivate::pGetThemePartSize(theme.handle(), 0, WP_FRAMELEFT, FS_ACTIVE, 0, TS_TRUE, &size);
-                res = size.cx-1;
-            }
-        }
-        break;
-
     case PM_MdiSubWindowMinimizedWidth:
         res = 160;
         break;
@@ -3467,33 +3420,14 @@ int QWindowsXPStyle::pixelMetric(PixelMetric pm, const QStyleOption *option, con
         break;
 
 #endif // QT_NO_TOOLBAR
-    case PM_DockWidgetFrameWidth:
-    {
-        XPThemeData theme(widget, 0, QWindowsXPStylePrivate::WindowTheme, WP_SMALLFRAMERIGHT, FS_ACTIVE);
-        if (theme.isValid()) {
-            SIZE size;
-            QWindowsXPStylePrivate::pGetThemePartSize(theme.handle(), 0, theme.partId, theme.stateId, 0, TS_TRUE, &size);
-            res = size.cx;
-        }
-    }
-    break;
     case PM_DockWidgetSeparatorExtent:
-        res = int(QStyleHelper::dpiScaled(4.));
-        break;
     case PM_DockWidgetTitleMargin:
         res = int(QStyleHelper::dpiScaled(4.));
         break;
 
     case PM_ButtonShiftHorizontal:
     case PM_ButtonShiftVertical:
-        if (qstyleoption_cast<const QStyleOptionToolButton *>(option))
-            res = 1;
-        else
-            res = 0;
-        break;
-
-    case PM_ButtonDefaultIndicator:
-        res = 0;
+        res = qstyleoption_cast<const QStyleOptionToolButton *>(option) ? 1 : 0;
         break;
 
     default:
@@ -3573,8 +3507,11 @@ QRect QWindowsXPStyle::subControlRect(ComplexControl cc, const QStyleOptionCompl
             const bool isToolTitle = false;
             const int height = tb->rect.height();
             const int width = tb->rect.width();
-            int buttonHeight = GetSystemMetrics(SM_CYSIZE) - 4;
-            int buttonWidth = GetSystemMetrics(SM_CXSIZE) - 4;
+            const int buttonMargin = 4;
+            int buttonHeight = GetSystemMetrics(SM_CYSIZE) / QWindowsStylePrivate::devicePixelRatio(widget)
+                - buttonMargin;
+            int buttonWidth = GetSystemMetrics(SM_CXSIZE) / QWindowsStylePrivate::devicePixelRatio(widget)
+                - buttonMargin;
             const int delta = buttonWidth + 2;
             int controlTop = option->rect.bottom() - buttonHeight - 2;
             const int frameWidth = proxy()->pixelMetric(PM_MdiSubWindowFrameWidth, option, widget);
@@ -3766,20 +3703,12 @@ QSize QWindowsXPStyle::sizeFromContents(ContentsType ct, const QStyleOption *opt
     case CT_LineEdit:
     case CT_ComboBox:
         {
-            XPThemeData buttontheme(widget, 0, QWindowsXPStylePrivate::ButtonTheme);
-            HTHEME theme = buttontheme.handle();
-            MARGINS borderSize;
-            if (theme) {
-                int result = QWindowsXPStylePrivate::pGetThemeMargins(theme,
-                                              NULL,
-                                              BP_PUSHBUTTON,
-                                              PBS_NORMAL,
-                                              TMT_CONTENTMARGINS,
-                                              NULL,
-                                              &borderSize);
-                if (result == S_OK) {
-                    sz += QSize(borderSize.cxLeftWidth + borderSize.cxRightWidth - 2,
-                                borderSize.cyBottomHeight + borderSize.cyTopHeight - 2);
+            XPThemeData buttontheme(widget, 0, QWindowsXPStylePrivate::ButtonTheme, BP_PUSHBUTTON, PBS_NORMAL);
+            if (buttontheme.isValid()) {
+                const QMargins borderSize = buttontheme.margins() / QWindowsXPStylePrivate::devicePixelRatio(widget);
+                if (!borderSize.isNull()) {
+                    sz.rwidth() += borderSize.left() + borderSize.right() - 2;
+                    sz.rheight() += borderSize.bottom() + borderSize.top() - 2;
                 }
                 const int textMargins = 2*(proxy()->pixelMetric(PM_FocusFrameHMargin) + 1);
                 sz += QSize(qMax(pixelMetric(QStyle::PM_ScrollBarExtent, option, widget)
@@ -3949,9 +3878,8 @@ QPixmap QWindowsXPStyle::standardPixmap(StandardPixmap standardPixmap, const QSt
             if (widget && widget->isWindow()) {
                 XPThemeData theme(widget, 0, QWindowsXPStylePrivate::WindowTheme, WP_SMALLCLOSEBUTTON, CBS_NORMAL);
                 if (theme.isValid()) {
-                    SIZE sz;
-                    QWindowsXPStylePrivate::pGetThemePartSize(theme.handle(), 0, theme.partId, theme.stateId, 0, TS_TRUE, &sz);
-                    return QIcon(QWindowsStyle::standardPixmap(standardPixmap, option, widget)).pixmap(QSize(sz.cx, sz.cy));
+                    const QSize size = theme.size() / QWindowsXPStylePrivate::devicePixelRatio(widget);
+                    return QIcon(QWindowsStyle::standardPixmap(standardPixmap, option, widget)).pixmap(size);
                 }
             }
         }
@@ -3984,13 +3912,12 @@ QIcon QWindowsXPStyle::standardIcon(StandardPixmap standardIcon,
                 XPThemeData theme(0, 0, QWindowsXPStylePrivate::WindowTheme,
                                   WP_MAXBUTTON, MAXBS_NORMAL);
                 if (theme.isValid()) {
-                    SIZE size;
-                    QWindowsXPStylePrivate::pGetThemePartSize(themeSize.handle(), 0, themeSize.partId, themeSize.stateId, 0, TS_TRUE, &size);
-                    QPixmap pm = QPixmap(size.cx, size.cy);
+                    const QSize size = themeSize.size() / QWindowsXPStylePrivate::devicePixelRatio(widget);
+                    QPixmap pm(size);
                     pm.fill(Qt::transparent);
                     QPainter p(&pm);
                     theme.painter = &p;
-                    theme.rect = QRect(0, 0, size.cx, size.cy);
+                    theme.rect = QRect(QPoint(0, 0), size);
                     d->drawBackground(theme);
                     d->dockFloat.addPixmap(pm, QIcon::Normal, QIcon::Off);    // Normal
                     pm.fill(Qt::transparent);
@@ -4019,14 +3946,13 @@ QIcon QWindowsXPStyle::standardIcon(StandardPixmap standardIcon,
                 XPThemeData theme(0, 0, QWindowsXPStylePrivate::WindowTheme,
                                   WP_SMALLCLOSEBUTTON, CBS_NORMAL);
                 if (theme.isValid()) {
-                    SIZE size;
-                    QWindowsXPStylePrivate::pGetThemePartSize(theme.handle(), 0, theme.partId, theme.stateId, 0, TS_TRUE, &size);
-                    QPixmap pm = QPixmap(size.cx, size.cy);
+                    const QSize size = theme.size() / QWindowsXPStylePrivate::devicePixelRatio(widget);
+                    QPixmap pm(size);
                     pm.fill(Qt::transparent);
                     QPainter p(&pm);
                     theme.painter = &p;
                     theme.partId = WP_CLOSEBUTTON; // ####
-                    theme.rect = QRect(0, 0, size.cx, size.cy);
+                    theme.rect = QRect(QPoint(0, 0), size);
                     d->drawBackground(theme);
                     d->dockClose.addPixmap(pm, QIcon::Normal, QIcon::Off);    // Normal
                     pm.fill(Qt::transparent);
@@ -4056,13 +3982,12 @@ QIcon QWindowsXPStyle::standardIcon(StandardPixmap standardIcon,
                 XPThemeData theme(0, 0, QWindowsXPStylePrivate::WindowTheme,
                                   WP_RESTOREBUTTON, RBS_NORMAL);
                 if (theme.isValid()) {
-                    SIZE size;
-                    QWindowsXPStylePrivate::pGetThemePartSize(themeSize.handle(), 0, themeSize.partId, themeSize.stateId, 0, TS_TRUE, &size);
-                    QPixmap pm = QPixmap(size.cx, size.cy);
+                    const QSize size = themeSize.size() / QWindowsStylePrivate::devicePixelRatio(widget);
+                    QPixmap pm(size);
                     pm.fill(Qt::transparent);
                     QPainter p(&pm);
                     theme.painter = &p;
-                    theme.rect = QRect(0, 0, size.cx, size.cy);
+                    theme.rect = QRect(QPoint(0, 0), size);
                     d->drawBackground(theme);
                     d->dockFloat.addPixmap(pm, QIcon::Normal, QIcon::Off);    // Normal
                     pm.fill(Qt::transparent);