Client: Check for shell integration when initializing platform plugin

This makes QWaylandDisplay::initialize return a boolean and moves the
QWaylandIntegration's failure check out of constructor as
QWaylandIntegration::shellIntegration is a virtual method, this also
removes the out-of-date comments about processEvents as it's no more
used in QWaylandDisplay::forceRoundTrip.

Fixes: QTBUG-102457
Pick-to: 6.5
Change-Id: I3c8f1d9fd195326b587b45318443c2beee1ebfc2
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: David Edmundson <davidedmundson@kde.org>

1 files changed, 7 insertions, 11 deletions

diff --git a/src/client/qwaylandintegration.cpp b/src/client/qwaylandintegration.cpp
index d4724545f..5d21e1c79 100644
--- a/src/client/qwaylandintegration.cpp
+++ b/src/client/qwaylandintegration.cpp
@@ -83,10 +83,6 @@ QWaylandIntegration::QWaylandIntegration()
 #endif
 {
     mDisplay.reset(new QWaylandDisplay(this));
-    if (!mDisplay->isInitialized()) {
-        mFailed = true;
-        return;
-    }
 
     QWaylandWindow::fixedToplevelPositions =
             !qEnvironmentVariableIsSet("QT_WAYLAND_DISABLE_FIXED_POSITIONS");
@@ -99,6 +95,11 @@ QWaylandIntegration::~QWaylandIntegration()
     sInstance = nullptr;
 }
 
+bool QWaylandIntegration::init()
+{
+    return mDisplay->initialize();
+}
+
 QPlatformNativeInterface * QWaylandIntegration::nativeInterface() const
 {
     return mNativeInterface.data();
@@ -168,7 +169,7 @@ QPlatformNativeInterface *QWaylandIntegration::createPlatformNativeInterface()
 // Support platform specific initialization
 void QWaylandIntegration::initializePlatform()
 {
-    mDisplay->initialize();
+    mDisplay->initEventThread();
 
     mNativeInterface.reset(createPlatformNativeInterface());
     initializeInputDeviceIntegration();
@@ -184,14 +185,9 @@ void QWaylandIntegration::initializePlatform()
 
 void QWaylandIntegration::initialize()
 {
-    mDisplay->initEventThread();
-
-    // Call this after initializing event thread for QWaylandDisplay::forceRoundTrip()
     initializePlatform();
 
-    // But the aboutToBlock() and awake() should be connected after initializePlatform().
-    // Otherwise the connected flushRequests() may consumes up all events before processEvents starts to wait,
-    // so that processEvents(QEventLoop::WaitForMoreEvents) may be blocked in the forceRoundTrip().
+    // Call this after initializing event thread for QWaylandDisplay::flushRequests()
     QAbstractEventDispatcher *dispatcher = QGuiApplicationPrivate::eventDispatcher;
     QObject::connect(dispatcher, SIGNAL(aboutToBlock()), mDisplay.data(), SLOT(flushRequests()));
     QObject::connect(dispatcher, SIGNAL(awake()), mDisplay.data(), SLOT(flushRequests()));