Send SurfaceCreated and SurfaceAboutToBeDestroyed events for wl_surface

Previously, the events were matching the life cycle of QWaylandWindow. This
commit changes it so the events are matching the life cycle of wl_surfaces
instead (a QWaylandWindow can outlive several wl_surfaces).

Some of these events were already sent in QWindowPrivate (the first and last).
Now we handle the cases where the wl_surface is destroyed and recreated due to
hiding/showing the window or when changing the role of the wl_surface.

Task-number: QTBUG-58423
Change-Id: Ie4a4e7dd529e1a41a2cf42e02cebb3c8aca4a4cc
Reviewed-by: Giulio Camuffo <giulio.camuffo@kdab.com>
Reviewed-by: Marco Martin <notmart@gmail.com>

2 files changed, 11 insertions, 4 deletions

diff --git a/src/client/qwaylandwindow.cpp b/src/client/qwaylandwindow.cpp
index 9b994508c..5bfa158ae 100644
--- a/src/client/qwaylandwindow.cpp
+++ b/src/client/qwaylandwindow.cpp
@@ -110,7 +110,7 @@ QWaylandWindow::~QWaylandWindow()
     delete mWindowDecoration;
 
     if (isInitialized())
-        reset();
+        reset(false);
 
     QList<QWaylandInputDevice *> inputDevices = mDisplay->inputDevices();
     for (int i = 0; i < inputDevices.size(); ++i)
@@ -132,8 +132,11 @@ void QWaylandWindow::initWindow()
     if (window()->type() == Qt::Desktop)
         return;
 
-    if (!isInitialized())
+    if (!isInitialized()) {
         initializeWlSurface();
+        QPlatformSurfaceEvent e(QPlatformSurfaceEvent::SurfaceCreated);
+        QGuiApplication::sendEvent(window(), &e);
+    }
 
     if (shouldCreateSubSurface()) {
         Q_ASSERT(!mSubSurfaceWindow);
@@ -240,8 +243,12 @@ bool QWaylandWindow::shouldCreateSubSurface() const
     return QPlatformWindow::parent() != Q_NULLPTR;
 }
 
-void QWaylandWindow::reset()
+void QWaylandWindow::reset(bool sendDestroyEvent)
 {
+    if (isInitialized() && sendDestroyEvent) {
+        QPlatformSurfaceEvent e(QPlatformSurfaceEvent::SurfaceAboutToBeDestroyed);
+        QGuiApplication::sendEvent(window(), &e);
+    }
     delete mShellSurface;
     mShellSurface = 0;
     delete mSubSurfaceWindow;
diff --git a/src/client/qwaylandwindow_p.h b/src/client/qwaylandwindow_p.h
index cc11b3c11..9f6ff5b4e 100644
--- a/src/client/qwaylandwindow_p.h
+++ b/src/client/qwaylandwindow_p.h
@@ -252,7 +252,7 @@ private:
     void initializeWlSurface();
     bool shouldCreateShellSurface() const;
     bool shouldCreateSubSurface() const;
-    void reset();
+    void reset(bool sendDestroyEvent = true);
     void sendExposeEvent(const QRect &rect);
 
     void handleMouseEventWithDecoration(QWaylandInputDevice *inputDevice, const QWaylandPointerEvent &e);