Windows: Add checks to usages of QWindow::screen().

Default to primary screen and handle situations where the screen
is null consistently. Remove unused QWindowsScreen::screenOf() method.

Task-number: QTBUG-48288
Change-Id: I91b3c2331521d9d3be8ac77606ee820cd35ebb0f
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

4 files changed, 21 insertions, 19 deletions

diff --git a/src/plugins/platforms/windows/qwindowsmousehandler.cpp b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
index 4ab861a960..90cb6fe195 100644
--- a/src/plugins/platforms/windows/qwindowsmousehandler.cpp
+++ b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
@@ -477,7 +477,12 @@ bool QWindowsMouseHandler::translateTouchEvent(QWindow *window, HWND,
     typedef QList<QWindowSystemInterface::TouchPoint> QTouchPointList;
 
     Q_ASSERT(m_touchDevice);
-    const QRect screenGeometry = window->screen()->geometry();
+    const QScreen *screen = window->screen();
+    if (!screen)
+        screen = QGuiApplication::primaryScreen();
+    if (!screen)
+        return true;
+    const QRect screenGeometry = screen->geometry();
 
     const int winTouchPointCount = msg.wParam;
     QScopedArrayPointer<TOUCHINPUT> winTouchInputs(new TOUCHINPUT[winTouchPointCount]);
@@ -569,7 +574,12 @@ bool QWindowsMouseHandler::translateGestureEvent(QWindow *window, HWND hwnd,
     if (gi.dwID != GID_DIRECTMANIPULATION)
         return true;
     static QPoint lastTouchPos;
-    const QRect screenGeometry = window->screen()->geometry();
+    const QScreen *screen = window->screen();
+    if (!screen)
+        screen = QGuiApplication::primaryScreen();
+    if (!screen)
+        return true;
+    const QRect screenGeometry = screen->geometry();
     QWindowSystemInterface::TouchPoint touchPoint;
     static QWindowSystemInterface::TouchPoint touchPoint2;
     touchPoint.id = 0;//gi.dwInstanceID;
diff --git a/src/plugins/platforms/windows/qwindowsscreen.cpp b/src/plugins/platforms/windows/qwindowsscreen.cpp
index 391735a035..e6abfb2403 100644
--- a/src/plugins/platforms/windows/qwindowsscreen.cpp
+++ b/src/plugins/platforms/windows/qwindowsscreen.cpp
@@ -276,18 +276,6 @@ QWindow *QWindowsScreen::windowAt(const QPoint &screenPoint, unsigned flags)
     return result;
 }
 
-QWindowsScreen *QWindowsScreen::screenOf(const QWindow *w)
-{
-    if (w)
-        if (const QScreen *s = w->screen())
-            if (QPlatformScreen *pscr = s->handle())
-                return static_cast<QWindowsScreen *>(pscr);
-    if (const QScreen *ps = QGuiApplication::primaryScreen())
-        if (QPlatformScreen *ppscr = ps->handle())
-            return static_cast<QWindowsScreen *>(ppscr);
-    return 0;
-}
-
 qreal QWindowsScreen::pixelDensity() const
 {
     const qreal physicalDpi = m_data.geometry.width() / m_data.physicalSizeMM.width() * qreal(25.4);
diff --git a/src/plugins/platforms/windows/qwindowsscreen.h b/src/plugins/platforms/windows/qwindowsscreen.h
index 67e7ff644b..bc8fbf553b 100644
--- a/src/plugins/platforms/windows/qwindowsscreen.h
+++ b/src/plugins/platforms/windows/qwindowsscreen.h
@@ -79,8 +79,6 @@ public:
 
     explicit QWindowsScreen(const QWindowsScreenData &data);
 
-    static QWindowsScreen *screenOf(const QWindow *w = 0);
-
     QRect geometry() const Q_DECL_OVERRIDE { return m_data.geometry; }
     QRect availableGeometry() const Q_DECL_OVERRIDE { return m_data.availableGeometry; }
     int depth() const Q_DECL_OVERRIDE { return m_data.depth; }
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 531836015c..abfddcfed6 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -1637,8 +1637,12 @@ void QWindowsWindow::setWindowState(Qt::WindowState state)
 bool QWindowsWindow::isFullScreen_sys() const
 {
     const QWindow *w = window();
-    return w->isTopLevel()
-        && geometry_sys() == QHighDpi::toNativePixels(w->screen()->geometry(), w);
+    if (!w->isTopLevel())
+        return false;
+    const QScreen *screen = w->screen();
+    if (!screen)
+        screen = QGuiApplication::primaryScreen();
+    return screen && geometry_sys() == QHighDpi::toNativePixels(screen->geometry(), w);
 }
 
 /*!
@@ -1708,7 +1712,9 @@ void QWindowsWindow::setWindowState_sys(Qt::WindowState newState)
             // Use geometry of QWindow::screen() within creation or the virtual screen the
             // window is in (QTBUG-31166, QTBUG-30724).
             const QScreen *screen = window()->screen();
-            const QRect r = QHighDpi::toNativePixels(screen->geometry(), window());
+            if (!screen)
+                screen = QGuiApplication::primaryScreen();
+            const QRect r = screen ? QHighDpi::toNativePixels(screen->geometry(), window()) : m_savedFrameGeometry;
             const UINT swpf = SWP_FRAMECHANGED | SWP_NOACTIVATE;
             const bool wasSync = testFlag(SynchronousGeometryChangeEvent);
             setFlag(SynchronousGeometryChangeEvent);