2 files changed, 18 insertions, 24 deletions

diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index 325989a5d6..a9813d5187 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -398,6 +398,7 @@ void QQuickWindow::physicalDpiChanged()
     d->lastReportedItemDevicePixelRatio = newPixelRatio;
     if (d->contentItem)
         updatePixelRatioHelper(d->contentItem, newPixelRatio);
+    d->forcePolish();
 }
 
 void QQuickWindow::handleFontDatabaseChanged()
@@ -406,23 +407,6 @@ void QQuickWindow::handleFontDatabaseChanged()
     d->pendingFontUpdate = true;
 }
 
-void QQuickWindow::handleScreenChanged(QScreen *screen)
-{
-    Q_D(QQuickWindow);
-    // we connected to the initial screen in QQuickWindowPrivate::init, but the screen changed
-    disconnect(d->physicalDpiChangedConnection);
-    if (screen) {
-        physicalDpiChanged();
-        // When physical DPI changes on the same screen, either the resolution or the device pixel
-        // ratio changed. We must check what it is. Device pixel ratio does not have its own
-        // ...Changed() signal. Reconnect, same as in QQuickWindowPrivate::init.
-        d->physicalDpiChangedConnection = connect(screen, &QScreen::physicalDotsPerInchChanged,
-                                                  this, &QQuickWindow::physicalDpiChanged);
-    }
-
-    d->forcePolish();
-}
-
 void forcePolishHelper(QQuickItem *item)
 {
     if (item->flags() & QQuickItem::ItemHasContents) {
@@ -434,6 +418,13 @@ void forcePolishHelper(QQuickItem *item)
         forcePolishHelper(items.at(i));
 }
 
+void QQuickWindow::handleScreenChanged(QScreen *screen)
+{
+    Q_D(QQuickWindow);
+    Q_UNUSED(screen);
+    d->forcePolish();
+}
+
 /*!
     Schedules polish events on all items in the scene.
 */
@@ -746,12 +737,8 @@ void QQuickWindowPrivate::init(QQuickWindow *c, QQuickRenderControl *control)
                      q,
                      &QQuickWindow::handleFontDatabaseChanged);
 
-    if (QScreen *screen = q->screen()) {
+    if (q->screen()) {
         lastReportedItemDevicePixelRatio = q->effectiveDevicePixelRatio();
-        // if the screen changes, then QQuickWindow::handleScreenChanged disconnects
-        // and connects to the new screen
-        physicalDpiChangedConnection = QObject::connect(screen, &QScreen::physicalDotsPerInchChanged,
-                                                        q, &QQuickWindow::physicalDpiChanged);
     }
 
     QSGContext *sg;
@@ -1555,6 +1542,8 @@ bool QQuickWindow::event(QEvent *event)
         d->inheritPalette(QGuiApplication::palette());
         if (d->contentItem)
             QCoreApplication::sendEvent(d->contentItem, event);
+    case QEvent::DevicePixelRatioChange:
+        physicalDpiChanged();
     default:
         break;
     }
diff --git a/src/quickwidgets/qquickwidget.cpp b/src/quickwidgets/qquickwidget.cpp
index 8a472a4f0a..2197ab834d 100644
--- a/src/quickwidgets/qquickwidget.cpp
+++ b/src/quickwidgets/qquickwidget.cpp
@@ -1681,15 +1681,20 @@ bool QQuickWidget::event(QEvent *e)
         QScreen *newScreen = screen();
         if (d->offscreenWindow)
             d->offscreenWindow->setScreen(newScreen);
-
+        break;
+    }
+    case QEvent::DevicePixelRatioChange:
         if (d->useSoftwareRenderer || d->outputTexture) {
             // This will check the size taking the devicePixelRatio into account
             // and recreate if needed.
             createFramebufferObject();
             d->render(true);
         }
+        if (d->offscreenWindow) {
+            QEvent dprChangeEvent(QEvent::DevicePixelRatioChange);
+            QGuiApplication::sendEvent(d->offscreenWindow, &dprChangeEvent);
+        }
         break;
-    }
     case QEvent::Show:
     case QEvent::Move:
         d->updatePosition();