eglfs: change the condition to destroy the openglcompositor

With an openglcompositor, only first QEglFSWindow is set
with a flag, HasNativeWindow and when it is destroyed,
the openglcompositor is destroyed, too.
For now, when using openglcompositor, Qt will not check
HasNativeWindow for its nativeWindow because it is not
possible to add a HasNativeWindow flag in an existing
window. And the openglcompositor will be destroyed after
the all the QEglFSWindows are closed.

Fixes: QTBUG-129576
Pick-to: 6.8 6.5
Change-Id: I620a904a03d29e8db1738d9392f716b3ebf5b553
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

src/opengl/qopenglcompositor.cpp

@@ -273,9 +273,9 @@ void QOpenGLCompositor::addWindow(QOpenGLCompositorWindow *window)
 
 void QOpenGLCompositor::removeWindow(QOpenGLCompositorWindow *window)
 {
-    m_windows.removeOne(window);
-    if (!m_windows.isEmpty())
-        emit topWindowChanged(m_windows.last());
+    bool couldChangeTopWindow = (m_windows.size() > 1) ? (window == m_windows.constLast()) : false;
+    if (m_windows.removeOne(window) && couldChangeTopWindow)
+        emit topWindowChanged(m_windows.constLast());
 }
 
 void QOpenGLCompositor::moveToTop(QOpenGLCompositorWindow *window)

src/plugins/platforms/eglfs/api/qeglfswindow.cpp

@@ -129,29 +129,42 @@ void QEglFSWindow::destroy()
     if (!m_flags.testFlag(Created))
         return; // already destroyed
 
-#ifndef QT_NO_OPENGL
-    QOpenGLCompositor::instance()->removeWindow(this);
-#endif
-
     QEglFSScreen *screen = this->screen();
-    if (m_flags.testFlag(HasNativeWindow)) {
 #ifndef QT_NO_OPENGL
+    QOpenGLCompositor *compositor = QOpenGLCompositor::instance();
+    compositor->removeWindow(this);
+    if (compositor->targetWindow() == window()) {
         QEglFSCursor *cursor = qobject_cast<QEglFSCursor *>(screen->cursor());
         if (cursor)
             cursor->resetResources();
-#endif
+
         if (screen->primarySurface() == m_surface)
             screen->setPrimarySurface(EGL_NO_SURFACE);
 
         invalidateSurface();
 
-#ifndef QT_NO_OPENGL
-        QOpenGLCompositor::destroy();
-        if (qt_gl_global_share_context() == m_rasterCompositingContext)
-            qt_gl_set_global_share_context(nullptr);
-        delete m_rasterCompositingContext;
-#endif
+        if (compositor->windows().isEmpty()) {
+            compositor->destroy();
+            if (qt_gl_global_share_context() == m_rasterCompositingContext)
+                qt_gl_set_global_share_context(nullptr);
+            delete m_rasterCompositingContext;
+        } else {
+            auto topWindow = static_cast<QEglFSWindow *>(compositor->windows().last());
+            // Make fullscreen
+            topWindow->setGeometry(screen->rawGeometry());
+            topWindow->resetSurface();
+            screen->setPrimarySurface(topWindow->surface());
+            compositor->setTargetWindow(topWindow->sourceWindow(), screen->rawGeometry());
+        }
+    }
+#else
+    if (m_flags.testFlag(HasNativeWindow)) {
+        if (screen->primarySurface() == m_surface)
+            screen->setPrimarySurface(EGL_NO_SURFACE);
+
+        invalidateSurface();
     }
+#endif
 
     m_flags = { };
 }
@@ -179,7 +192,6 @@ void QEglFSWindow::invalidateSurface()
         if (screen()->primarySurface() == m_surface)
             screen()->setPrimarySurface(EGL_NO_SURFACE);
 
-
         m_surface = EGL_NO_SURFACE;
         m_flags = m_flags & ~Created;
     }