Reduce QDesktopWidget API to bare minimum

The class is documented as obsolete, and the majority of APIs is marked
as deprecated. In this first phase, remove all explicitly deprecated
APIs and trivial implementations.

The test case is complete removed; what's left when code that uses any
of those deprecated methods is removed is not testing anything
meaningful.

For some methods, there is no practical replacement using QScreen yet,
and QDesktopWidget is still used in QWidget internals. Those require
refactoring to only use QScreen before the rest can be removed.

Change-Id: I8f7c968ec566820077221d37b817843758d51d49
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

23 files changed, 24 insertions, 766 deletions

diff --git a/src/widgets/dialogs/qcolordialog.cpp b/src/widgets/dialogs/qcolordialog.cpp
index 2d1bfa65d3..e5f2fd1c49 100644
--- a/src/widgets/dialogs/qcolordialog.cpp
+++ b/src/widgets/dialogs/qcolordialog.cpp
@@ -1706,7 +1706,7 @@ void QColorDialogPrivate::initWidgets()
 #else
     // small displays (e.g. PDAs) cannot fit the full color dialog,
     // so just use the color picker.
-    smallDisplay = (QDesktopWidgetPrivate::width() < 480 || QDesktopWidgetPrivate::height() < 350);
+    smallDisplay = (QGuiApplication::primaryScreen()->virtualGeometry().width() < 480 || QGuiApplication::primaryScreen()->virtualGeometry().height() < 350);
     const int lumSpace = topLay->spacing() / 2;
 #endif
 
diff --git a/src/widgets/dialogs/qdialog.cpp b/src/widgets/dialogs/qdialog.cpp
index d5daedef3e..14cfe6800c 100644
--- a/src/widgets/dialogs/qdialog.cpp
+++ b/src/widgets/dialogs/qdialog.cpp
@@ -884,7 +884,7 @@ void QDialog::adjustPosition(QWidget* w)
     QRect desk;
     if (w) {
         scrn = QDesktopWidgetPrivate::screenNumber(w);
-    } else if (QDesktopWidgetPrivate::isVirtualDesktop()) {
+    } else if (QGuiApplication::primaryScreen()->virtualSiblings().size() > 1) {
         scrn = QDesktopWidgetPrivate::screenNumber(QCursor::pos());
     } else {
         scrn = QDesktopWidgetPrivate::screenNumber(this);
diff --git a/src/widgets/dialogs/qwizard.cpp b/src/widgets/dialogs/qwizard.cpp
index d2bd84216c..c7aac8b9da 100644
--- a/src/widgets/dialogs/qwizard.cpp
+++ b/src/widgets/dialogs/qwizard.cpp
@@ -399,7 +399,7 @@ void QWizardHeader::setup(const QWizardLayoutInfo &info, const QString &title,
         /*
             There is no widthForHeight() function, so we simulate it with a loop.
         */
-        int candidateSubTitleWidth = qMin(512, 2 * QDesktopWidgetPrivate::width() / 3);
+        int candidateSubTitleWidth = qMin(512, 2 * QGuiApplication::primaryScreen()->virtualGeometry().width() / 3);
         int delta = candidateSubTitleWidth >> 1;
         while (delta > 0) {
             if (subTitleLabel->heightForWidth(candidateSubTitleWidth - delta)
diff --git a/src/widgets/graphicsview/qgraphicsview.cpp b/src/widgets/graphicsview/qgraphicsview.cpp
index ca14e03a72..30e386569a 100644
--- a/src/widgets/graphicsview/qgraphicsview.cpp
+++ b/src/widgets/graphicsview/qgraphicsview.cpp
@@ -1293,7 +1293,7 @@ QSize QGraphicsView::sizeHint() const
     if (d->scene) {
         QSizeF baseSize = d->matrix.mapRect(sceneRect()).size();
         baseSize += QSizeF(d->frameWidth * 2, d->frameWidth * 2);
-        return baseSize.boundedTo((3 * QDesktopWidgetPrivate::size()) / 4).toSize();
+        return baseSize.boundedTo((3 * QGuiApplication::primaryScreen()->virtualSize()) / 4).toSize();
     }
     return QAbstractScrollArea::sizeHint();
 }
diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index d7919c9414..6e17901677 100644
--- a/src/widgets/kernel/qapplication.cpp
+++ b/src/widgets/kernel/qapplication.cpp
@@ -2517,6 +2517,8 @@ void QApplicationPrivate::sendSyntheticEnterLeave(QWidget *widget)
 }
 
 /*!
+    \internal
+
     Returns the desktop widget (also called the root window).
 
     The desktop may be composed of multiple screens, so it would be incorrect,
diff --git a/src/widgets/kernel/qapplication.h b/src/widgets/kernel/qapplication.h
index 974c789e08..1903aa48dc 100644
--- a/src/widgets/kernel/qapplication.h
+++ b/src/widgets/kernel/qapplication.h
@@ -46,9 +46,6 @@
 #include <QtCore/qpoint.h>
 #include <QtCore/qsize.h>
 #include <QtGui/qcursor.h>
-#ifdef QT_INCLUDE_COMPAT
-# include <QtWidgets/qdesktopwidget.h>
-#endif
 #include <QtGui/qguiapplication.h>
 
 QT_BEGIN_NAMESPACE
diff --git a/src/widgets/kernel/qdesktopwidget.cpp b/src/widgets/kernel/qdesktopwidget.cpp
index 9f98af86e3..dd74fbf53e 100644
--- a/src/widgets/kernel/qdesktopwidget.cpp
+++ b/src/widgets/kernel/qdesktopwidget.cpp
@@ -71,11 +71,6 @@ int QDesktopScreenWidget::screenNumber() const
     return desktopWidgetP->screens.indexOf(const_cast<QDesktopScreenWidget *>(this));
 }
 
-const QRect QDesktopWidget::screenGeometry(const QWidget *widget) const
-{
-    return QDesktopWidgetPrivate::screenGeometry(widget);
-}
-
 const QRect QDesktopWidgetPrivate::screenGeometry(const QWidget *widget)
 {
     if (Q_UNLIKELY(!widget)) {
@@ -89,11 +84,6 @@ const QRect QDesktopWidgetPrivate::screenGeometry(const QWidget *widget)
     else return rect;
 }
 
-const QRect QDesktopWidget::availableGeometry(const QWidget *widget) const
-{
-    return QDesktopWidgetPrivate::availableGeometry(widget);
-}
-
 const QRect QDesktopWidgetPrivate::availableGeometry(const QWidget *widget)
 {
     if (Q_UNLIKELY(!widget)) {
@@ -122,7 +112,6 @@ void QDesktopWidgetPrivate::_q_updateScreens()
     Q_Q(QDesktopWidget);
     const QList<QScreen *> screenList = QGuiApplication::screens();
     const int targetLength = screenList.length();
-    bool screenCountChanged = false;
 
     // Re-build our screens list. This is the easiest way to later compute which signals to emit.
     // Create new screen widgets as necessary. While iterating, keep the old list in place so
@@ -147,11 +136,8 @@ void QDesktopWidgetPrivate::_q_updateScreens()
             screenWidget = new QDesktopScreenWidget(qScreen, screenGeometry);
             QObject::connect(qScreen, SIGNAL(geometryChanged(QRect)),
                              q, SLOT(_q_updateScreens()), Qt::QueuedConnection);
-            QObject::connect(qScreen, SIGNAL(availableGeometryChanged(QRect)),
-                             q, SLOT(_q_availableGeometryChanged()), Qt::QueuedConnection);
             QObject::connect(qScreen, SIGNAL(destroyed()),
                              q, SLOT(_q_updateScreens()), Qt::QueuedConnection);
-            screenCountChanged = true;
         }
         // record all the screens and the overall geometry.
         newScreens.push_back(screenWidget);
@@ -165,43 +151,9 @@ void QDesktopWidgetPrivate::_q_updateScreens()
 
     // Delete the QDesktopScreenWidget that are not used any more.
     foreach (QDesktopScreenWidget *screen, newScreens) {
-        if (!screens.contains(screen)) {
+        if (!screens.contains(screen))
             delete screen;
-            screenCountChanged = true;
-        }
     }
-
-    // Finally, emit the signals.
-    if (screenCountChanged) {
-        // Notice that we trigger screenCountChanged even if a screen was removed and another one added,
-        // in which case the total number of screens did not change. This is the only way for applications
-        // to notice that a screen was swapped out against another one.
-#if QT_DEPRECATED_SINCE(5, 11)
-QT_WARNING_PUSH
-QT_WARNING_DISABLE_DEPRECATED
-        emit q->screenCountChanged(targetLength);
-QT_WARNING_POP
-#endif
-    }
-#if QT_DEPRECATED_SINCE(5, 11)
-    foreach (int changedScreen, changedScreens)
-QT_WARNING_PUSH
-QT_WARNING_DISABLE_DEPRECATED
-        emit q->resized(changedScreen);
-QT_WARNING_POP
-#endif
-}
-
-void QDesktopWidgetPrivate::_q_availableGeometryChanged()
-{
-#if QT_DEPRECATED_SINCE(5, 11)
-    Q_Q(QDesktopWidget);
-    if (QScreen *screen = qobject_cast<QScreen *>(q->sender()))
-QT_WARNING_PUSH
-QT_WARNING_DISABLE_DEPRECATED
-        emit q->workAreaResized(QGuiApplication::screens().indexOf(screen));
-QT_WARNING_POP
-#endif
 }
 
 QDesktopWidget::QDesktopWidget()
@@ -211,70 +163,12 @@ QDesktopWidget::QDesktopWidget()
     setObjectName(QLatin1String("desktop"));
     d->_q_updateScreens();
     connect(qApp, SIGNAL(screenAdded(QScreen*)), this, SLOT(_q_updateScreens()));
-#if QT_DEPRECATED_SINCE(5, 11)
-    connect(qApp, SIGNAL(primaryScreenChanged(QScreen*)), this, SIGNAL(primaryScreenChanged()));
-#endif
 }
 
 QDesktopWidget::~QDesktopWidget()
 {
 }
 
-#if QT_DEPRECATED_SINCE(5, 11)
-bool QDesktopWidget::isVirtualDesktop() const
-{
-    return QDesktopWidgetPrivate::isVirtualDesktop();
-}
-#endif
-
-bool QDesktopWidgetPrivate::isVirtualDesktop()
-{
-    return QGuiApplication::primaryScreen()->virtualSiblings().size() > 1;
-}
-
-QRect QDesktopWidgetPrivate::geometry()
-{
-    return QGuiApplication::primaryScreen()->virtualGeometry();
-}
-
-QSize QDesktopWidgetPrivate::size()
-{
-    return geometry().size();
-}
-
-int QDesktopWidgetPrivate::width()
-{
-    return geometry().width();
-}
-
-int QDesktopWidgetPrivate::height()
-{
-    return geometry().height();
-}
-
-#if QT_DEPRECATED_SINCE(5, 11)
-int QDesktopWidget::primaryScreen() const
-{
-    return QDesktopWidgetPrivate::primaryScreen();
-}
-#endif
-
-int QDesktopWidgetPrivate::primaryScreen()
-{
-    return 0;
-}
-
-int QDesktopWidgetPrivate::numScreens()
-{
-    return qMax(QGuiApplication::screens().size(), 1);
-}
-
-#if QT_DEPRECATED_SINCE(5, 11)
-int QDesktopWidget::numScreens() const
-{
-    return QDesktopWidgetPrivate::numScreens();
-}
-
 QWidget *QDesktopWidget::screen(int screen)
 {
     Q_D(QDesktopWidget);
@@ -283,45 +177,27 @@ QWidget *QDesktopWidget::screen(int screen)
     return d->screens.at(screen);
 }
 
-const QRect QDesktopWidget::availableGeometry(int screenNo) const
-{
-    return QDesktopWidgetPrivate::availableGeometry(screenNo);
-}
-#endif
-
 const QRect QDesktopWidgetPrivate::availableGeometry(int screenNo)
 {
     const QScreen *screen = QDesktopWidgetPrivate::screen(screenNo);
     return screen ? screen->availableGeometry() : QRect();
 }
 
-#if QT_DEPRECATED_SINCE(5, 11)
-const QRect QDesktopWidget::screenGeometry(int screenNo) const
-{
-    return QDesktopWidgetPrivate::screenGeometry(screenNo);
-}
-#endif
-
 const QRect QDesktopWidgetPrivate::screenGeometry(int screenNo)
 {
     const QScreen *screen = QDesktopWidgetPrivate::screen(screenNo);
     return screen ? screen->geometry() : QRect();
 }
 
-int QDesktopWidget::screenNumber(const QWidget *w) const
-{
-    return QDesktopWidgetPrivate::screenNumber(w);
-}
-
 int QDesktopWidgetPrivate::screenNumber(const QWidget *w)
 {
     if (!w)
-        return primaryScreen();
+        return 0;
 
     const QList<QScreen *> allScreens = QGuiApplication::screens();
     QList<QScreen *> screens = allScreens;
     if (screens.isEmpty()) // This should never happen
-        return primaryScreen();
+        return 0;
 
     // If there is more than one virtual desktop
     if (screens.count() != screens.constFirst()->virtualSiblings().count()) {
@@ -352,17 +228,10 @@ int QDesktopWidgetPrivate::screenNumber(const QWidget *w)
     return allScreens.indexOf(widgetScreen);
 }
 
-#if QT_DEPRECATED_SINCE(5, 11)
-int QDesktopWidget::screenNumber(const QPoint &p) const
-{
-    return QDesktopWidgetPrivate::screenNumber(p);
-}
-#endif
-
 int QDesktopWidgetPrivate::screenNumber(const QPoint &p)
 {
     QScreen *screen = QGuiApplication::screenAt(p);
-    return screen ? QGuiApplication::screens().indexOf(screen) : primaryScreen();
+    return screen ? QGuiApplication::screens().indexOf(screen) : 0;
 }
 
 QScreen *QDesktopWidgetPrivate::screen(int screenNo)
@@ -375,10 +244,6 @@ QScreen *QDesktopWidgetPrivate::screen(int screenNo)
     return screens.at(screenNo);
 }
 
-void QDesktopWidget::resizeEvent(QResizeEvent *)
-{
-}
-
 QT_END_NAMESPACE
 
 #include "moc_qdesktopwidget.cpp"
diff --git a/src/widgets/kernel/qdesktopwidget.h b/src/widgets/kernel/qdesktopwidget.h
index e5c587984f..265f320b1f 100644
--- a/src/widgets/kernel/qdesktopwidget.h
+++ b/src/widgets/kernel/qdesktopwidget.h
@@ -52,78 +52,21 @@ class QDesktopWidgetPrivate;
 class Q_WIDGETS_EXPORT QDesktopWidget : public QWidget
 {
     Q_OBJECT
-#if QT_DEPRECATED_SINCE(5, 11)
-    Q_PROPERTY(bool virtualDesktop READ isVirtualDesktop)
-    Q_PROPERTY(int screenCount READ screenCount NOTIFY screenCountChanged)
-    Q_PROPERTY(int primaryScreen READ primaryScreen NOTIFY primaryScreenChanged)
-#endif
 public:
     QDesktopWidget();
     ~QDesktopWidget();
 
-    int screenNumber(const QWidget *widget = nullptr) const;
-    const QRect screenGeometry(const QWidget *widget) const;
-    const QRect availableGeometry(const QWidget *widget) const;
-
-#if QT_DEPRECATED_SINCE(5, 11)
-    QT_DEPRECATED_X("Use QScreen::virtualSiblings() of primary screen")  bool isVirtualDesktop() const;
-
-    QT_DEPRECATED_X("Use QGuiApplication::screens()") int numScreens() const;
-    QT_DEPRECATED_X("Use QGuiApplication::screens()") int screenCount() const;
-    QT_DEPRECATED_X("Use QGuiApplication::primaryScreen()") int primaryScreen() const;
-
-    QT_DEPRECATED_X("Use QGuiApplication::screenAt()") int screenNumber(const QPoint &) const;
-
     QT_DEPRECATED_X("Use QScreen") QWidget *screen(int screen = -1);
 
-    QT_DEPRECATED_X("Use QGuiApplication::screens()") const QRect screenGeometry(int screen = -1) const;
-    QT_DEPRECATED_X("Use QGuiApplication::screenAt()") const QRect screenGeometry(const QPoint &point) const
-    {
-QT_WARNING_PUSH
-QT_WARNING_DISABLE_DEPRECATED
-        return screenGeometry(screenNumber(point));
-QT_WARNING_POP
-    }
-
-    QT_DEPRECATED_X("Use QGuiApplication::screens()") const QRect availableGeometry(int screen = -1) const;
-    QT_DEPRECATED_X("Use QGuiApplication::screenAt()") const QRect availableGeometry(const QPoint &point) const
-    {
-QT_WARNING_PUSH
-QT_WARNING_DISABLE_DEPRECATED
-    return availableGeometry(screenNumber(point));
-QT_WARNING_POP
-    }
-
-Q_SIGNALS:
-    QT_DEPRECATED_X("Use QScreen::geometryChanged()") void resized(int);
-    QT_DEPRECATED_X("Use QScreen::availableGeometryChanged()") void workAreaResized(int);
-    QT_DEPRECATED_X("Use QGuiApplication::screenAdded/Removed()") void screenCountChanged(int);
-    QT_DEPRECATED_X("Use QGuiApplication::primaryScreenChanged()") void primaryScreenChanged();
-#endif
-
-protected:
-    void resizeEvent(QResizeEvent *e) override;
-
 private:
     Q_DISABLE_COPY(QDesktopWidget)
     Q_DECLARE_PRIVATE(QDesktopWidget)
     Q_PRIVATE_SLOT(d_func(), void _q_updateScreens())
-    Q_PRIVATE_SLOT(d_func(), void _q_availableGeometryChanged())
 
     friend class QApplication;
     friend class QApplicationPrivate;
 };
 
-#if QT_DEPRECATED_SINCE(5, 11)
-inline int QDesktopWidget::screenCount() const
-{
-QT_WARNING_PUSH
-QT_WARNING_DISABLE_DEPRECATED
-    return numScreens();
-QT_WARNING_POP
-}
-#endif
-
 QT_END_NAMESPACE
 
 #endif // QDESKTOPWIDGET_H
diff --git a/src/widgets/kernel/qdesktopwidget.qdoc b/src/widgets/kernel/qdesktopwidget.qdoc
deleted file mode 100644
index dd2d9535ae..0000000000
--- a/src/widgets/kernel/qdesktopwidget.qdoc
+++ /dev/null
@@ -1,336 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the documentation of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:FDL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Free Documentation License Usage
-** Alternatively, this file may be used under the terms of the GNU Free
-** Documentation License version 1.3 as published by the Free Software
-** Foundation and appearing in the file included in the packaging of
-** this file. Please review the following information to ensure
-** the GNU Free Documentation License version 1.3 requirements
-** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-/*!
-    \class QDesktopWidget
-    \brief The QDesktopWidget class provides access to screen information on multi-head systems.
-
-    \ingroup advanced
-    \ingroup desktop
-    \inmodule QtWidgets
-    \obsolete
-
-    Systems with more than one graphics card and monitor can manage the
-    physical screen space available either as multiple desktops, or as a
-    large virtual desktop.
-
-    This class provides information about the user's desktop, such as its
-    total size, number of screens, the geometry of each screen, and whether
-    they are configured as separate desktops or a single virtual desktop.
-
-    Widgets provided by Qt use this class to place tooltips, menus and
-    dialog boxes on the correct screen for their parent or application
-    widgets. Applications can use this class to obtain information that
-    can be used to save window positions, or to place child widgets and
-    dialogs on one particular screen.
-
-    \section1 Obtaining a Desktop Widget
-
-    The QApplication::desktop() function is used to get an instance of
-    QDesktopWidget.
-
-    The widget's screenGeometry() function provides information about the
-    geometry of the available screens with. The number of screens
-    available is returned by screenCount, and the screenCountChanged()
-    signal is emitted when screens are added or removed.
-    The screen number that a particular point or widget is located in
-    is returned by screenNumber().
-
-    \section1 Screen Geometry
-
-    To obtain the dimensions of a particular screen, call the screenGeometry()
-    function. On some desktop environments, not all of the screen is
-    available for applications to use; for example, an application dock or
-    menu bar may take up some space. Use the availableGeometry() function
-    to obtain the available area for applications.
-
-    QDesktopWidget also inherits the QWidget properties, width() and
-    height(), which specify the size of the desktop. However, for
-    desktops with multiple screens, the size of the desktop is the union
-    of all the screen sizes, so width() and height() should \e not be
-    used for computing the size of a widget to be placed on one of the
-    screens.
-
-    On systems that are configured to use the available screens as a
-    single, large virtual desktop, the virtualDesktop property will be
-    set to true. In this case, the widget's size is usually the size of
-    the bounding rectangle of all the screens.
-
-    \section1 Use of the Primary Screen
-
-    For an application, the screen where the main widget resides is the
-    primary screen. This is stored in the primaryScreen property.
-    All windows opened in the context of the application should be
-    constrained to the boundaries of the primary screen; for example,
-    it would be inconvenient if a dialog box popped up on a different
-    screen, or split over two screens.
-
-    \image qdesktopwidget.png Managing Multiple Screens
-
-    In the illustration above, Application One's primary screen is
-    screen 0, and App Two's primary screen is screen 1.
-
-    \sa QApplication, QApplication::desktop()
-*/
-
-/*!
-    \fn QDesktopWidget::QDesktopWidget()
-
-    \internal
-
-    Creates the desktop widget.
-
-    If the system supports a virtual desktop, this widget will have
-    the size of the virtual desktop; otherwise this widget will have
-    the size of the primary screen.
-
-    Instead of using QDesktopWidget directly, use QApplication::desktop().
-*/
-
-/*!
-    \fn QDesktopWidget::~QDesktopWidget()
-
-    \internal
-
-    Destroys the desktop widget and frees any allocated resources.
-*/
-
-/*!
-    \fn int QDesktopWidget::numScreens() const
-
-    Returns the number of available screens.
-
-    \obsolete
-
-    Use QGuiApplication::screens() instead.
-
-    \sa primaryScreen
-*/
-
-/*!
-    \fn QWidget *QDesktopWidget::screen(int screen)
-
-    Returns a widget that represents the screen with index \a screen
-    (a value of -1 means the default screen).
-
-    If the system uses a virtual desktop, the returned widget will
-    have the geometry of the entire virtual desktop; i.e., bounding
-    every \a screen.
-
-    \obsolete
-
-    Use QScreen instead.
-
-    \sa primaryScreen, screenCount, virtualDesktop
-*/
-
-/*!
-    \fn const QRect QDesktopWidget::availableGeometry(int screen) const
-
-     Returns the available geometry of the screen with index \a screen. What
-     is available will be subrect of screenGeometry() based on what the
-     platform decides is available (for example excludes the dock and menu bar
-     on \macos, or the task bar on Windows). The default screen is used if
-     \a screen is -1.
-
-    \obsolete
-
-    Use QGuiApplication::screens() instead.
-
-     \sa screenNumber(), screenGeometry(), QScreen::availableGeometry()
-*/
-
-/*!
-    \fn const QRect QDesktopWidget::availableGeometry(const QWidget *widget) const
-    \overload
-
-    Returns the available geometry of the screen which contains \a widget.
-
-    \sa screenGeometry()
-*/
-
-/*!
-    \fn const QRect QDesktopWidget::availableGeometry(const QPoint &p) const
-    \overload
-
-    Returns the available geometry of the screen which contains \a p.
-
-    \obsolete
-
-    Use QGuiApplication::screenAt() instead.
-
-    \sa screenGeometry()
-*/
-
-
-/*!
-    \fn const QRect QDesktopWidget::screenGeometry(int screen) const
-
-    Returns the geometry of the screen with index \a screen. The default
-    screen is used if \a screen is -1.
-
-    \obsolete
-
-    Use QGuiApplication::screens() instead.
-
-    \sa screenNumber()
-*/
-
-/*!
-    \fn const QRect QDesktopWidget::screenGeometry(const QWidget *widget) const
-    \overload
-
-    Returns the geometry of the screen which contains \a widget.
-*/
-
-/*!
-    \fn const QRect QDesktopWidget::screenGeometry(const QPoint &p) const
-    \overload
-
-    Returns the geometry of the screen which contains \a p.
-
-    \obsolete
-
-    Use QGuiApplication::screenAt() instead.
-*/
-
-
-/*!
-    \fn int QDesktopWidget::screenNumber(const QWidget *widget) const
-
-    Returns the index of the screen that contains the largest
-    part of \a widget, or -1 if the widget not on a screen.
-
-    \sa primaryScreen
-*/
-
-/*!
-    \fn int QDesktopWidget::screenNumber(const QPoint &point) const
-
-    \overload
-    Returns the index of the screen that contains the \a point, or the
-    screen which is the shortest distance from the \a point.
-
-    \obsolete
-
-    Use QGuiApplication::screenAt() instead.
-
-    \sa primaryScreen
-*/
-
-/*!
-    \fn void QDesktopWidget::resizeEvent(QResizeEvent *event)
-    \reimp
-    \internal
-*/
-
-/*!
-    \fn void QDesktopWidget::resized(int screen)
-
-    This signal is emitted when the size of \a screen changes.
-
-    \obsolete
-
-    Use QScreen::geometryChanged() instead.
-*/
-
-/*!
-    \fn void QDesktopWidget::workAreaResized(int screen)
-
-    This signal is emitted when the work area available on \a screen changes.
-
-    \obsolete
-
-    Use QScreen::availableGeometryChanged() instead.
-*/
-
-/*!
-    \property QDesktopWidget::screenCount
-    \brief the number of screens currently available on the system.
-
-    \obsolete
-
-    Use QGuiApplication::screens() instead.
-
-    \since 4.6
-*/
-
-/*!
-    \property QDesktopWidget::primaryScreen
-    \brief the index of the screen that is configured to be the primary screen
-    on the system.
-
-    \obsolete
-
-    Use QGuiApplication::primaryScreen() instead.
-*/
-
-/*!
-    \property QDesktopWidget::virtualDesktop
-
-    \brief if the system manages the available screens in a virtual desktop.
-
-    For virtual desktops, screen() will always return the same widget.
-    The size of the virtual desktop is the size of this desktop
-    widget.
-
-    \obsolete
-
-    Use QScreen::virtualSiblings() of primary screen instead.
-*/
-
-/*!
-    \fn void QDesktopWidget::screenCountChanged(int newCount)
-
-    \since 4.6
-
-    This signal is emitted when the number of screens changes to \a newCount.
-
-    \obsolete
-
-    Use QGuiApplication::screenAdded and QGuiApplication::screenRemoved() instead.
-
-    \sa screenCount
-*/
-
-
-/*!
-    \fn void QDesktopWidget::primaryScreenChanged()
-
-    \since 5.6
-
-    \brief This signal is emitted whenever the primary screen changes.
-
-    \note This doesn't mean the QDesktopWidget::primaryScreen index will
-    necessarily be different, but now it will refer to the new primary screen.
-
-    \obsolete
-
-    Use QGuiApplication::primaryScreenChanged() instead.
-
-    \sa primaryScreen, screenGeometry()
-*/
diff --git a/src/widgets/kernel/qdesktopwidget_p.h b/src/widgets/kernel/qdesktopwidget_p.h
index 63949055aa..b0ac13808d 100644
--- a/src/widgets/kernel/qdesktopwidget_p.h
+++ b/src/widgets/kernel/qdesktopwidget_p.h
@@ -84,19 +84,8 @@ class QDesktopWidgetPrivate : public QWidgetPrivate {
 public:
     ~QDesktopWidgetPrivate() { qDeleteAll(screens); }
     void _q_updateScreens();
-    void _q_availableGeometryChanged();
     QDesktopScreenWidget *widgetForScreen(QScreen *qScreen) const;
 
-    static bool isVirtualDesktop();
-
-    static QRect geometry();
-    static QSize size();
-    static int width();
-    static int height();
-
-    static int numScreens();
-    static int primaryScreen();
-
     static int screenNumber(const QWidget *widget = nullptr);
     static int screenNumber(const QPoint &);
 
diff --git a/src/widgets/kernel/qtooltip.cpp b/src/widgets/kernel/qtooltip.cpp
index eda3be0ba3..ca5025ef8f 100644
--- a/src/widgets/kernel/qtooltip.cpp
+++ b/src/widgets/kernel/qtooltip.cpp
@@ -373,7 +373,7 @@ bool QTipLabel::eventFilter(QObject *o, QEvent *e)
 
 int QTipLabel::getTipScreen(const QPoint &pos, QWidget *w)
 {
-    if (QDesktopWidgetPrivate::isVirtualDesktop())
+    if (QGuiApplication::primaryScreen()->virtualSiblings().size() > 1)
         return QDesktopWidgetPrivate::screenNumber(pos);
     else
         return QDesktopWidgetPrivate::screenNumber(w);
diff --git a/src/widgets/kernel/qwhatsthis.cpp b/src/widgets/kernel/qwhatsthis.cpp
index 8a632a395a..17824fba32 100644
--- a/src/widgets/kernel/qwhatsthis.cpp
+++ b/src/widgets/kernel/qwhatsthis.cpp
@@ -212,7 +212,7 @@ QWhatsThat::QWhatsThat(const QString& txt, QWidget* parent, QWidget *showTextFor
     }
     else
     {
-        int sw = QDesktopWidgetPrivate::width() / 3;
+        int sw = QGuiApplication::primaryScreen()->virtualGeometry().width() / 3;
         if (sw < 200)
             sw = 200;
         else if (sw > 300)
diff --git a/src/widgets/kernel/qwidget.cpp b/src/widgets/kernel/qwidget.cpp
index a1f5b9a26c..a217ef5352 100644
--- a/src/widgets/kernel/qwidget.cpp
+++ b/src/widgets/kernel/qwidget.cpp
@@ -7252,8 +7252,8 @@ bool QWidget::restoreGeometry(const QByteArray &geometry)
 
     // ### Qt 6 - Perhaps it makes sense to dumb down the restoreGeometry() logic, see QTBUG-69104
 
-    if (restoredScreenNumber >= QDesktopWidgetPrivate::numScreens())
-        restoredScreenNumber = QDesktopWidgetPrivate::primaryScreen();
+    if (restoredScreenNumber >= qMax(QGuiApplication::screens().size(), 1))
+        restoredScreenNumber = 0;
     const qreal screenWidthF = qreal(QDesktopWidgetPrivate::screenGeometry(restoredScreenNumber).width());
     // Sanity check bailing out when large variations of screen sizes occur due to
     // high DPI scaling or different levels of DPI awareness.
diff --git a/src/widgets/widgets/qdockarealayout.cpp b/src/widgets/widgets/qdockarealayout.cpp
index 693692d6c7..3d2396c4a6 100644
--- a/src/widgets/widgets/qdockarealayout.cpp
+++ b/src/widgets/widgets/qdockarealayout.cpp
@@ -3021,7 +3021,7 @@ QSize QDockAreaLayout::minimumSize() const
 QRect QDockAreaLayout::constrainedRect(QRect rect, QWidget* widget)
 {
     QRect desktop;
-    if (QDesktopWidgetPrivate::isVirtualDesktop())
+    if (QGuiApplication::primaryScreen()->virtualSiblings().size() > 1)
         desktop = QDesktopWidgetPrivate::screenGeometry(rect.topLeft());
     else
         desktop = QDesktopWidgetPrivate::screenGeometry(widget);
diff --git a/src/widgets/widgets/qmdiarea.cpp b/src/widgets/widgets/qmdiarea.cpp
index 713c5f3d75..e6fd021e4a 100644
--- a/src/widgets/widgets/qmdiarea.cpp
+++ b/src/widgets/widgets/qmdiarea.cpp
@@ -1744,7 +1744,7 @@ QSize QMdiArea::sizeHint() const
     }
     const int scaleFactor = 3 * (nestedCount + 1);
 
-    QSize desktopSize = QDesktopWidgetPrivate::size();
+    QSize desktopSize = QGuiApplication::primaryScreen()->virtualSize();
     QSize size(desktopSize.width() * 2 / scaleFactor, desktopSize.height() * 2 / scaleFactor);
     for (QMdiSubWindow *child : d_func()->childWindows) {
         if (!sanityCheck(child, "QMdiArea::sizeHint"))
diff --git a/src/widgets/widgets/qmenubar.cpp b/src/widgets/widgets/qmenubar.cpp
index 9122273d0d..b45a6b5b01 100644
--- a/src/widgets/widgets/qmenubar.cpp
+++ b/src/widgets/widgets/qmenubar.cpp
@@ -1625,7 +1625,7 @@ QSize QMenuBar::minimumSizeHint() const
     int fw = style()->pixelMetric(QStyle::PM_MenuBarPanelWidth, nullptr, this);
     int spaceBelowMenuBar = style()->styleHint(QStyle::SH_MainWindow_SpaceBelowMenuBar, nullptr, this);
     if(as_gui_menubar) {
-        int w = parentWidget() ? parentWidget()->width() : QDesktopWidgetPrivate::width();
+        int w = parentWidget() ? parentWidget()->width() : QGuiApplication::primaryScreen()->virtualGeometry().width();
         d->calcActionRects(w - (2 * fw), 0);
         for (int i = 0; ret.isNull() && i < d->actions.count(); ++i)
             ret = d->actionRects.at(i).size();
@@ -1675,7 +1675,7 @@ QSize QMenuBar::sizeHint() const
     int fw = style()->pixelMetric(QStyle::PM_MenuBarPanelWidth, nullptr, this);
     int spaceBelowMenuBar = style()->styleHint(QStyle::SH_MainWindow_SpaceBelowMenuBar, nullptr, this);
     if(as_gui_menubar) {
-        const int w = parentWidget() ? parentWidget()->width() : QDesktopWidgetPrivate::width();
+        const int w = parentWidget() ? parentWidget()->width() : QGuiApplication::primaryScreen()->virtualGeometry().width();
         d->calcActionRects(w - (2 * fw), 0);
         for (int i = 0; i < d->actionRects.count(); ++i) {
             const QRect &actionRect = d->actionRects.at(i);
diff --git a/src/widgets/widgets/qtabwidget.cpp b/src/widgets/widgets/qtabwidget.cpp
index 115a557e52..6f9e51cf4a 100644
--- a/src/widgets/widgets/qtabwidget.cpp
+++ b/src/widgets/widgets/qtabwidget.cpp
@@ -899,7 +899,7 @@ QSize QTabWidget::sizeHint() const
         if (usesScrollButtons())
             t = t.boundedTo(QSize(200,200));
         else
-            t = t.boundedTo(QDesktopWidgetPrivate::size());
+            t = t.boundedTo(QGuiApplication::primaryScreen()->virtualGeometry().size());
     }
 
     QSize sz = basicSize(d->pos == North || d->pos == South, lc, rc, s, t);
@@ -968,7 +968,7 @@ int QTabWidget::heightForWidth(int width) const
         if (usesScrollButtons())
             t = t.boundedTo(QSize(200,200));
         else
-            t = t.boundedTo(QDesktopWidgetPrivate::size());
+            t = t.boundedTo(QGuiApplication::primaryScreen()->virtualSize());
     }
 
     const bool tabIsHorizontal = (d->pos == North || d->pos == South);
diff --git a/src/widgets/widgets/qwidgetresizehandler.cpp b/src/widgets/widgets/qwidgetresizehandler.cpp
index 43aa4c7988..e012ca624d 100644
--- a/src/widgets/widgets/qwidgetresizehandler.cpp
+++ b/src/widgets/widgets/qwidgetresizehandler.cpp
@@ -336,7 +336,7 @@ void QWidgetResizeHandler::keyPressEvent(QKeyEvent * e)
     switch (e->key()) {
     case Qt::Key_Left:
         pos.rx() -= delta;
-        if (pos.x() <= QDesktopWidgetPrivate::geometry().left()) {
+        if (pos.x() <= QGuiApplication::primaryScreen()->virtualGeometry().left()) {
             if (mode == TopLeft || mode == BottomLeft) {
                 moveOffset.rx() += delta;
                 invertedMoveOffset.rx() += delta;
@@ -361,7 +361,7 @@ void QWidgetResizeHandler::keyPressEvent(QKeyEvent * e)
         break;
     case Qt::Key_Right:
         pos.rx() += delta;
-        if (pos.x() >= QDesktopWidgetPrivate::geometry().right()) {
+        if (pos.x() >= QGuiApplication::primaryScreen()->virtualGeometry().right()) {
             if (mode == TopRight || mode == BottomRight) {
                 moveOffset.rx() += delta;
                 invertedMoveOffset.rx() += delta;
@@ -386,7 +386,7 @@ void QWidgetResizeHandler::keyPressEvent(QKeyEvent * e)
         break;
     case Qt::Key_Up:
         pos.ry() -= delta;
-        if (pos.y() <= QDesktopWidgetPrivate::geometry().top()) {
+        if (pos.y() <= QGuiApplication::primaryScreen()->virtualGeometry().top()) {
             if (mode == TopLeft || mode == TopRight) {
                 moveOffset.ry() += delta;
                 invertedMoveOffset.ry() += delta;
@@ -411,7 +411,7 @@ void QWidgetResizeHandler::keyPressEvent(QKeyEvent * e)
         break;
     case Qt::Key_Down:
         pos.ry() += delta;
-        if (pos.y() >= QDesktopWidgetPrivate::geometry().bottom()) {
+        if (pos.y() >= QGuiApplication::primaryScreen()->virtualGeometry().bottom()) {
             if (mode == BottomLeft || mode == BottomRight) {
                 moveOffset.ry() += delta;
                 invertedMoveOffset.ry() += delta;
diff --git a/tests/auto/widgets/kernel/CMakeLists.txt b/tests/auto/widgets/kernel/CMakeLists.txt
index 51759264b2..ec32603585 100644
--- a/tests/auto/widgets/kernel/CMakeLists.txt
+++ b/tests/auto/widgets/kernel/CMakeLists.txt
@@ -4,7 +4,6 @@ add_subdirectory(qaction)
 add_subdirectory(qactiongroup)
 add_subdirectory(qapplication)
 add_subdirectory(qboxlayout)
-add_subdirectory(qdesktopwidget)
 add_subdirectory(qformlayout)
 add_subdirectory(qgridlayout)
 add_subdirectory(qlayout)
diff --git a/tests/auto/widgets/kernel/kernel.pro b/tests/auto/widgets/kernel/kernel.pro
index c66c1822b2..8fbaf948f2 100644
--- a/tests/auto/widgets/kernel/kernel.pro
+++ b/tests/auto/widgets/kernel/kernel.pro
@@ -2,7 +2,6 @@ TEMPLATE=subdirs
 SUBDIRS=\
    qapplication \
    qboxlayout \
-   qdesktopwidget \
    qformlayout \
    qgesturerecognizer \
    qgridlayout \
diff --git a/tests/auto/widgets/kernel/qdesktopwidget/CMakeLists.txt b/tests/auto/widgets/kernel/qdesktopwidget/CMakeLists.txt
deleted file mode 100644
index 79790049fe..0000000000
--- a/tests/auto/widgets/kernel/qdesktopwidget/CMakeLists.txt
+++ /dev/null
@@ -1,13 +0,0 @@
-# Generated from qdesktopwidget.pro.
-
-#####################################################################
-## tst_qdesktopwidget Test:
-#####################################################################
-
-add_qt_test(tst_qdesktopwidget
-    SOURCES
-        tst_qdesktopwidget.cpp
-    PUBLIC_LIBRARIES
-        Qt::Gui
-        Qt::Widgets
-)
diff --git a/tests/auto/widgets/kernel/qdesktopwidget/qdesktopwidget.pro b/tests/auto/widgets/kernel/qdesktopwidget/qdesktopwidget.pro
deleted file mode 100644
index 1ab155f22e..0000000000
--- a/tests/auto/widgets/kernel/qdesktopwidget/qdesktopwidget.pro
+++ /dev/null
@@ -1,4 +0,0 @@
-CONFIG += testcase
-TARGET = tst_qdesktopwidget
-QT += widgets testlib
-SOURCES += tst_qdesktopwidget.cpp
diff --git a/tests/auto/widgets/kernel/qdesktopwidget/tst_qdesktopwidget.cpp b/tests/auto/widgets/kernel/qdesktopwidget/tst_qdesktopwidget.cpp
deleted file mode 100644
index a29e8408a3..0000000000
--- a/tests/auto/widgets/kernel/qdesktopwidget/tst_qdesktopwidget.cpp
+++ /dev/null
@@ -1,183 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the test suite of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:GPL-EXCEPT$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 3 as published by the Free Software
-** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-
-#include <QtTest/QtTest>
-#include <QtWidgets/QDesktopWidget>
-#include <QtGui/QWindow>
-#include <QDebug>
-
-// the complete class is deprecated
-QT_WARNING_PUSH
-QT_WARNING_DISABLE_DEPRECATED
-class tst_QDesktopWidget : public QObject
-{
-    Q_OBJECT
-
-private slots:
-    void cleanup();
-
-#if QT_DEPRECATED_SINCE(5, 11)
-    void numScreens();
-    void primaryScreen();
-    void screenNumberForQPoint();
-#endif
-    void screenNumberForQWidget();
-    void availableGeometry();
-    void screenGeometry();
-    void topLevels();
-};
-
-void tst_QDesktopWidget::cleanup()
-{
-    QVERIFY(QApplication::topLevelWidgets().isEmpty());
-}
-
-#if QT_DEPRECATED_SINCE(5, 11)
-void tst_QDesktopWidget::numScreens()
-{
-    QDesktopWidget desktop;
-    QVERIFY(desktop.numScreens() > 0);
-}
-
-void tst_QDesktopWidget::primaryScreen()
-{
-    QDesktopWidget desktop;
-    QVERIFY(desktop.primaryScreen() >= 0);
-    QVERIFY(desktop.primaryScreen() < desktop.numScreens());
-}
-#endif
-
-void tst_QDesktopWidget::availableGeometry()
-{
-    QDesktopWidget desktop;
-    QTest::ignoreMessage(QtWarningMsg, "QDesktopWidget::availableGeometry(): Attempt "
-                                       "to get the available geometry of a null widget");
-    QRect r = desktop.availableGeometry(nullptr);
-    QVERIFY(r.isNull());
-
-#if QT_DEPRECATED_SINCE(5, 11)
-    QRect total;
-    QRect available;
-
-    for (int i = 0; i < desktop.screenCount(); ++i) {
-        total = desktop.screenGeometry(i);
-        available = desktop.availableGeometry(i);
-        QVERIFY(total.contains(available));
-    }
-
-    total = desktop.screenGeometry();
-    available = desktop.availableGeometry();
-    QVERIFY(total.contains(available));
-    QCOMPARE(desktop.availableGeometry(desktop.primaryScreen()), available);
-    QCOMPARE(desktop.screenGeometry(desktop.primaryScreen()), total);
-#endif
-}
-
-void tst_QDesktopWidget::screenNumberForQWidget()
-{
-    QDesktopWidget desktop;
-
-    QCOMPARE(desktop.screenNumber(nullptr), 0);
-
-    QWidget widget;
-    widget.show();
-    QVERIFY(QTest::qWaitForWindowExposed(&widget));
-    QVERIFY(widget.isVisible());
-
-    int widgetScreen = desktop.screenNumber(&widget);
-    QVERIFY(widgetScreen > -1);
-    QVERIFY(widgetScreen < QGuiApplication::screens().size());
-}
-
-#if QT_DEPRECATED_SINCE(5, 11)
-void tst_QDesktopWidget::screenNumberForQPoint()
-{
-    // make sure QDesktopWidget::screenNumber(QPoint) returns the correct screen
-    QDesktopWidget *desktopWidget = QApplication::desktop();
-    QRect allScreens;
-    for (int i = 0; i < desktopWidget->numScreens(); ++i) {
-        QRect screenGeometry = desktopWidget->screenGeometry(i);
-        QCOMPARE(desktopWidget->screenNumber(screenGeometry.center()), i);
-        allScreens |= screenGeometry;
-    }
-
-    // make sure QDesktopWidget::screenNumber(QPoint) returns a valid screen for points that aren't on any screen
-    int screen;
-    screen = desktopWidget->screenNumber(allScreens.topLeft() - QPoint(1, 1));
-
-    QVERIFY(screen >= 0 && screen < desktopWidget->numScreens());
-    screen = desktopWidget->screenNumber(allScreens.topRight() + QPoint(1, 1));
-    QVERIFY(screen >= 0 && screen < desktopWidget->numScreens());
-    screen = desktopWidget->screenNumber(allScreens.bottomLeft() - QPoint(1, 1));
-    QVERIFY(screen >= 0 && screen < desktopWidget->numScreens());
-    screen = desktopWidget->screenNumber(allScreens.bottomRight() + QPoint(1, 1));
-    QVERIFY(screen >= 0 && screen < desktopWidget->numScreens());
-}
-#endif
-
-void tst_QDesktopWidget::screenGeometry()
-{
-    QDesktopWidget *desktopWidget = QApplication::desktop();
-    QTest::ignoreMessage(QtWarningMsg, "QDesktopWidget::screenGeometry(): Attempt "
-                                       "to get the screen geometry of a null widget");
-    QRect r = desktopWidget->screenGeometry(nullptr);
-    QVERIFY(r.isNull());
-    QWidget widget;
-    widget.show();
-    QVERIFY(QTest::qWaitForWindowExposed(&widget));
-    r = desktopWidget->screenGeometry(&widget);
-
-#if QT_DEPRECATED_SINCE(5, 11)
-    QRect total;
-    QRect available;
-    for (int i = 0; i < desktopWidget->screenCount(); ++i) {
-        total = desktopWidget->screenGeometry(i);
-        available = desktopWidget->availableGeometry(i);
-    }
-#endif
-}
-
-void tst_QDesktopWidget::topLevels()
-{
-    // Desktop widgets/windows should not be listed as top-levels.
-    int topLevelDesktopWidgets = 0;
-    int topLevelDesktopWindows = 0;
-    foreach (const QWidget *w, QApplication::topLevelWidgets())
-        if (w->windowType() == Qt::Desktop)
-            topLevelDesktopWidgets++;
-    foreach (const QWindow *w, QGuiApplication::topLevelWindows())
-        if (w->type() == Qt::Desktop)
-            topLevelDesktopWindows++;
-    QCOMPARE(topLevelDesktopWidgets, 0);
-    QCOMPARE(topLevelDesktopWindows, 0);
-}
-QT_WARNING_POP
-
-QTEST_MAIN(tst_QDesktopWidget)
-#include "tst_qdesktopwidget.moc"