Move delivery of update requests into QPlatformWindow

Having deliverUpdateRequest in QWindowPrivate was a bit awkward and
asymmetric to the QPlatformWindow::requestUpdate() API. Keeping
them together follows the existing pattern of plumbing things
through the platform window, and also allows us to move away
from platform plugins relying on QWindowPrivate implementation
details.

Change-Id: Ib131ccdd1c2bdd6ff1c8d95facbc3f6f88a1abcf
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

src/gui/kernel/qplatformwindow.cpp

@@ -724,7 +724,7 @@ QRect QPlatformWindow::initialGeometry(const QWindow *w,
 
     QPlatformWindow subclasses can re-implement this function to
     provide display refresh synchronized updates. The event
-    should be delivered using QWindowPrivate::deliverUpdateRequest()
+    should be delivered using QPlatformWindow::deliverUpdateRequest()
     to not get out of sync with the the internal state of QWindow.
 
     The default implementation posts an UpdateRequest event to the
@@ -743,11 +743,27 @@ void QPlatformWindow::requestUpdate()
     }
 
     QWindow *w = window();
-    QWindowPrivate *wp = (QWindowPrivate *) QObjectPrivate::get(w);
+    QWindowPrivate *wp = qt_window_private(w);
     Q_ASSERT(wp->updateTimer == 0);
     wp->updateTimer = w->startTimer(timeout, Qt::PreciseTimer);
 }
 
+/*!
+    Delivers an QEvent::UpdateRequest event to the window.
+
+    QPlatformWindow subclasses can re-implement this function to
+    provide e.g. logging or tracing of the delivery, but should
+    always call the base class function.
+*/
+void QPlatformWindow::deliverUpdateRequest()
+{
+    QWindow *w = window();
+    QWindowPrivate *wp = qt_window_private(w);
+    wp->updateRequestPending = false;
+    QEvent request(QEvent::UpdateRequest);
+    QCoreApplication::sendEvent(w, &request);
+}
+
 /*!
     Returns the QWindow minimum size.
 */

src/gui/kernel/qplatformwindow.h

@@ -144,6 +144,7 @@ public:
         const QRect &initialGeometry, int defaultWidth, int defaultHeight);
 
     virtual void requestUpdate();
+    virtual void deliverUpdateRequest();
 
     // Window property accessors. Platform plugins should use these
     // instead of accessing QWindow directly.

src/gui/kernel/qwindow.cpp

@@ -2333,7 +2333,8 @@ bool QWindow::event(QEvent *ev)
         if (static_cast<QTimerEvent *>(ev)->timerId() == d->updateTimer) {
             killTimer(d->updateTimer);
             d->updateTimer = 0;
-            d->deliverUpdateRequest();
+            if (d->platformWindow)
+                d->platformWindow->deliverUpdateRequest();
         } else {
             QObject::event(ev);
         }
@@ -2357,14 +2358,6 @@ bool QWindow::event(QEvent *ev)
     return true;
 }
 
-void QWindowPrivate::deliverUpdateRequest()
-{
-    Q_Q(QWindow);
-    updateRequestPending = false;
-    QEvent request(QEvent::UpdateRequest);
-    QCoreApplication::sendEvent(q, &request);
-}
-
 /*!
     Schedules a QEvent::UpdateRequest event to be delivered to this window.
 

src/gui/kernel/qwindow_p.h

@@ -124,8 +124,6 @@ public:
     bool applyCursor();
 #endif
 
-    void deliverUpdateRequest();
-
     QPoint globalPosition() const;
 
     QWindow *topLevelWindow() const;

src/plugins/platforms/cocoa/qnsview_drawing.mm

@@ -120,7 +120,7 @@
     if (m_updateRequested) {
         Q_ASSERT(windowPrivate->updateRequestPending);
         qCDebug(lcQpaWindow) << "Delivering update request to" << m_platformWindow->window();
-        windowPrivate->deliverUpdateRequest();
+        m_platformWindow->deliverUpdateRequest();
         m_updateRequested = false;
     } else {
         m_platformWindow->handleExposeEvent(dirtyRegion);

src/plugins/platforms/ios/qiosscreen.mm

@@ -390,14 +390,19 @@ void QIOSScreen::deliverUpdateRequests() const
 
     QList<QWindow*> windows = QGuiApplication::allWindows();
     for (int i = 0; i < windows.size(); ++i) {
-        if (platformScreenForWindow(windows.at(i)) != this)
+        QWindow *window = windows.at(i);
+        if (platformScreenForWindow(window) != this)
             continue;
 
-        QWindowPrivate *wp = static_cast<QWindowPrivate *>(QObjectPrivate::get(windows.at(i)));
+        QWindowPrivate *wp = qt_window_private(window);
         if (!wp->updateRequestPending)
             continue;
 
-        wp->deliverUpdateRequest();
+        QPlatformWindow *platformWindow = window->handle();
+        if (!platformWindow)
+            continue;
+
+        platformWindow->deliverUpdateRequest();
 
         // Another update request was triggered, keep the display link running
         if (wp->updateRequestPending)