Add globalRemove to QWaylandClientExtension

Adds support for handling of removal of the relevant global to
QtWaylandClientExtension. The user is responsible for destroying the object
once it becomes inactive to match the behavior on destruction.
Two signals for globals and their removal are added to QWaylandDisplay
to make it a bit nicer to use in a more "Qt-way". The addRregistryListener
function is kept for now until other places are ported.

Change-Id: I4ccbaa32e18a5ae15871aa23639e2b4a372cc34e
Reviewed-by: David Edmundson <davidedmundson@kde.org>

4 files changed, 48 insertions, 21 deletions

diff --git a/src/client/global/qwaylandclientextension.cpp b/src/client/global/qwaylandclientextension.cpp
index f0bc950ce..200dad072 100644
--- a/src/client/global/qwaylandclientextension.cpp
+++ b/src/client/global/qwaylandclientextension.cpp
@@ -1,6 +1,7 @@
 /****************************************************************************
 **
 ** Copyright (C) 2017 Erik Larsson.
+** Copyright (C) 2021 David Redondo <qt@david-redondo.de>
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtWaylandCompositor module of the Qt Toolkit.
@@ -48,6 +49,8 @@
 
 QT_BEGIN_NAMESPACE
 
+using RegistryGlobal = QtWaylandClient::QWaylandDisplay::RegistryGlobal;
+
 QWaylandClientExtensionPrivate::QWaylandClientExtensionPrivate()
 {
     // Keep the possibility to use a custom waylandIntegration as a plugin,
@@ -60,23 +63,41 @@ QWaylandClientExtensionPrivate::QWaylandClientExtensionPrivate()
         qWarning() << "This application requires a Wayland platform plugin";
 }
 
-void QWaylandClientExtensionPrivate::handleRegistryGlobal(void *data, ::wl_registry *registry, uint32_t id,
-                                                          const QString &interface, uint32_t version)
+void QWaylandClientExtensionPrivate::globalAdded(const RegistryGlobal &global)
+{
+    Q_Q(QWaylandClientExtension);
+    if (!active && global.interface == QLatin1String(q->extensionInterface()->name)) {
+        q->bind(global.registry, global.id, global.version);
+        active = true;
+        emit q->activeChanged();
+    }
+}
+
+void QWaylandClientExtensionPrivate::globalRemoved(const RegistryGlobal &global)
 {
-    QWaylandClientExtension *extension = static_cast<QWaylandClientExtension *>(data);
-    if (interface == QLatin1String(extension->extensionInterface()->name) && !extension->d_func()->active) {
-        extension->bind(registry, id, version);
-        extension->d_func()->active = true;
-        emit extension->activeChanged();
+    Q_Q(QWaylandClientExtension);
+    if (active && global.interface == QLatin1String(q->extensionInterface()->name)) {
+        active = false;
+        emit q->activeChanged();
     }
 }
 
 void QWaylandClientExtension::initialize()
 {
     Q_D(QWaylandClientExtension);
-    if (!d->registered) {
-        d->waylandIntegration->display()->addRegistryListener(&QWaylandClientExtensionPrivate::handleRegistryGlobal, this);
-        d->registered = true;
+    if (d->active) {
+        return;
+    }
+    const QtWaylandClient::QWaylandDisplay *display = d->waylandIntegration->display();
+    const auto globals = display->globals();
+    auto global =
+            std::find_if(globals.cbegin(), globals.cend(), [this](const RegistryGlobal &global) {
+                return global.interface == QLatin1String(extensionInterface()->name);
+            });
+    if (global != globals.cend()) {
+        bind(global->registry, global->id, global->version);
+        d->active = true;
+        emit activeChanged();
     }
 }
 
@@ -85,17 +106,17 @@ QWaylandClientExtension::QWaylandClientExtension(const int ver)
 {
     Q_D(QWaylandClientExtension);
     d->version = ver;
-
-    // The registry listener uses virtual functions and we don't want it to be called from
-    // the constructor.
+    auto display = d->waylandIntegration->display();
+    QObjectPrivate::connect(display, &QtWaylandClient::QWaylandDisplay::globalAdded, d,
+                            &QWaylandClientExtensionPrivate::globalAdded);
+    QObjectPrivate::connect(display, &QtWaylandClient::QWaylandDisplay::globalRemoved, d,
+                            &QWaylandClientExtensionPrivate::globalRemoved);
+    // This function uses virtual functions and we don't want it to be called from the constructor.
     QMetaObject::invokeMethod(this, "initialize", Qt::QueuedConnection);
 }
 
 QWaylandClientExtension::~QWaylandClientExtension()
 {
-    Q_D(QWaylandClientExtension);
-    if (d->registered && !QCoreApplication::closingDown())
-        d->waylandIntegration->display()->removeListener(&QWaylandClientExtensionPrivate::handleRegistryGlobal, this);
 }
 
 QtWaylandClient::QWaylandIntegration *QWaylandClientExtension::integration() const
diff --git a/src/client/global/qwaylandclientextension_p.h b/src/client/global/qwaylandclientextension_p.h
index 9091efbe5..621c14b77 100644
--- a/src/client/global/qwaylandclientextension_p.h
+++ b/src/client/global/qwaylandclientextension_p.h
@@ -53,22 +53,23 @@
 
 #include <QtCore/private/qobject_p.h>
 #include <QtWaylandClient/QWaylandClientExtension>
+#include <QtWaylandClient/private/qwaylanddisplay_p.h>
 #include <QtWaylandClient/private/qwaylandintegration_p.h>
 
 QT_BEGIN_NAMESPACE
 
 class Q_WAYLAND_CLIENT_EXPORT QWaylandClientExtensionPrivate : public QObjectPrivate
 {
-    Q_DECLARE_PUBLIC(QWaylandClientExtension)
 public:
+    Q_DECLARE_PUBLIC(QWaylandClientExtension)
     QWaylandClientExtensionPrivate();
-    static void handleRegistryGlobal(void *data, ::wl_registry *registry, uint32_t id,
-                                     const QString &interface, uint32_t version);
+
+    void globalAdded(const QtWaylandClient::QWaylandDisplay::RegistryGlobal &global);
+    void globalRemoved(const QtWaylandClient::QWaylandDisplay::RegistryGlobal &global);
 
     QtWaylandClient::QWaylandIntegration *waylandIntegration = nullptr;
     int version = -1;
     bool active = false;
-    bool registered = false;
 };
 
 class Q_WAYLAND_CLIENT_EXPORT QWaylandClientExtensionTemplatePrivate : public QWaylandClientExtensionPrivate
diff --git a/src/client/qwaylanddisplay.cpp b/src/client/qwaylanddisplay.cpp
index f8cb75e95..79c68a932 100644
--- a/src/client/qwaylanddisplay.cpp
+++ b/src/client/qwaylanddisplay.cpp
@@ -634,6 +634,7 @@ void QWaylandDisplay::registry_global(uint32_t id, const QString &interface, uin
     }
 
     mGlobals.append(RegistryGlobal(id, interface, version, registry));
+    emit globalAdded(mGlobals.back());
 
     const auto copy = mRegistryListeners; // be prepared for listeners unregistering on notification
     for (Listener l : copy)
@@ -690,7 +691,7 @@ void QWaylandDisplay::registry_global_remove(uint32_t id)
                     inputDevice->setTextInputMethod(nullptr);
                 mWaylandIntegration->reconfigureInputContext();
             }
-            mGlobals.removeAt(i);
+            emit globalRemoved(mGlobals.takeAt(i));
             break;
         }
     }
diff --git a/src/client/qwaylanddisplay_p.h b/src/client/qwaylanddisplay_p.h
index cf123cba3..5a83c3241 100644
--- a/src/client/qwaylanddisplay_p.h
+++ b/src/client/qwaylanddisplay_p.h
@@ -228,6 +228,10 @@ public slots:
     void blockingReadEvents();
     void flushRequests();
 
+signals:
+    void globalAdded(const RegistryGlobal &global);
+    void globalRemoved(const RegistryGlobal &global);
+
 private:
     void handleWaylandSync();
     void requestWaylandSync();