Accessibility Linux: Make dbus registration async

Change-Id: I74043be04f4ee17089353304fdc007a7f22cdea0
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Jan Arve Sæther <jan-arve.saether@digia.com>

src/platformsupport/linuxaccessibility/atspiadaptor.cpp

@@ -69,7 +69,7 @@ static bool isDebugging = false;
 #define qAtspiDebug              if (!::isDebugging); else qDebug
 
 AtSpiAdaptor::AtSpiAdaptor(DBusConnection *connection, QObject *parent)
-    : QDBusVirtualObject(parent), m_dbus(connection), initialized(false)
+    : QDBusVirtualObject(parent), m_dbus(connection)
     , sendFocus(0)
     , sendObject(0)
     , sendObject_active_descendant_changed(0)
@@ -132,6 +132,17 @@ AtSpiAdaptor::AtSpiAdaptor(DBusConnection *connection, QObject *parent)
 
     m_applicationAdaptor = new QSpiApplicationAdaptor(m_dbus->connection(), this);
     connect(m_applicationAdaptor, SIGNAL(windowActivated(QObject*,bool)), this, SLOT(windowActivated(QObject*,bool)));
+
+    updateEventListeners();
+    bool success = m_dbus->connection().connect(QLatin1String("org.a11y.atspi.Registry"), QLatin1String("/org/a11y/atspi/registry"),
+                                                QLatin1String("org.a11y.atspi.Registry"), QLatin1String("EventListenerRegistered"), this,
+                                                SLOT(eventListenerRegistered(QString,QString)));
+    success = success && m_dbus->connection().connect(QLatin1String("org.a11y.atspi.Registry"), QLatin1String("/org/a11y/atspi/registry"),
+                                                      QLatin1String("org.a11y.atspi.Registry"), QLatin1String("EventListenerDeregistered"), this,
+                                                      SLOT(eventListenerDeregistered(QString,QString)));
+#ifdef QT_ATSPI_DEBUG
+    qAtspiDebug() << "Registered event listener change listener: " << success;
+#endif
 }
 
 AtSpiAdaptor::~AtSpiAdaptor()
@@ -605,30 +616,6 @@ QString AtSpiAdaptor::introspect(const QString &path) const
     return xml;
 }
 
-/*!
-  When initialized we will send updates, not before this.
-
-  This function also checks which event listeners are registered in the at-spi registry.
-  */
-void AtSpiAdaptor::setInitialized(bool init)
-{
-    initialized = init;
-
-    if (!initialized)
-        return;
-
-    updateEventListeners();
-    bool success = m_dbus->connection().connect(QLatin1String("org.a11y.atspi.Registry"), QLatin1String("/org/a11y/atspi/registry"),
-                                               QLatin1String("org.a11y.atspi.Registry"), QLatin1String("EventListenerRegistered"), this,
-                                               SLOT(eventListenerRegistered(QString,QString)));
-    success = success && m_dbus->connection().connect(QLatin1String("org.a11y.atspi.Registry"), QLatin1String("/org/a11y/atspi/registry"),
-                                               QLatin1String("org.a11y.atspi.Registry"), QLatin1String("EventListenerDeregistered"), this,
-                                               SLOT(eventListenerDeregistered(QString,QString)));
-#ifdef QT_ATSPI_DEBUG
-    qAtspiDebug() << "Registered event listener change listener: " << success;
-#endif
-}
-
 void AtSpiAdaptor::setBitFlag(const QString &flag)
 {
     Q_ASSERT(flag.size());
@@ -918,9 +905,6 @@ void AtSpiAdaptor::notifyStateChange(const QAIPointer &interface, const QString
 */
 void AtSpiAdaptor::notify(QAccessibleEvent *event)
 {
-    if (!initialized)
-        return;
-
     switch (event->type()) {
     case QAccessible::ObjectCreated:
         if (sendObject || sendObject_children_changed)

src/platformsupport/linuxaccessibility/atspiadaptor_p.h

@@ -75,8 +75,8 @@ public:
     bool handleMessage(const QDBusMessage &message, const QDBusConnection &connection);
     void notify(QAccessibleEvent *event);
 
-    void setInitialized(bool init);
+    void init();
-
+    void checkInitializedAndEnabled();
 public Q_SLOTS:
     void eventListenerRegistered(const QString &bus, const QString &path);
     void eventListenerDeregistered(const QString &bus, const QString &path);
@@ -140,7 +140,6 @@ private:
 
     /// Assigned from the accessibility registry.
     int m_applicationId;
-    bool initialized;
 
     mutable QHash<quintptr, QPointer<QObject> > m_handledObjects;
 

src/platformsupport/linuxaccessibility/bridge.cpp

@@ -62,24 +62,16 @@ QT_BEGIN_NAMESPACE
 */
 
 QSpiAccessibleBridge::QSpiAccessibleBridge()
-    : cache(0)
+    : cache(0), dec(0), dbusAdaptor(0), m_enabled(false)
 {
     dbusConnection = new DBusConnection();
-    if (!dBusConnection().isConnected())
+    connect(dbusConnection, SIGNAL(enabledChanged(bool)), this, SLOT(enabledChanged(bool)));
-        qWarning() << "Could not connect to dbus.";
+}
 
-    qSpiInitializeStructTypes();
+void QSpiAccessibleBridge::enabledChanged(bool enabled)
-    initializeConstantMappings();
+{
-
+    m_enabled = enabled;
-    /* Create the cache of accessible objects */
+    updateStatus();
-    cache = new QSpiDBusCache(dBusConnection(), this);
-    dec = new DeviceEventControllerAdaptor(this);
-
-    dBusConnection().registerObject(QLatin1String(ATSPI_DBUS_PATH_DEC), this, QDBusConnection::ExportAdaptors);
-
-    dbusAdaptor = new AtSpiAdaptor(dbusConnection, this);
-    dBusConnection().registerVirtualObject(QLatin1String(QSPI_OBJECT_PATH_ACCESSIBLE), dbusAdaptor, QDBusConnection::SubPath);
-    dbusAdaptor->registerApplication();
 }
 
 QSpiAccessibleBridge::~QSpiAccessibleBridge()
@@ -92,15 +84,30 @@ QDBusConnection QSpiAccessibleBridge::dBusConnection() const
     return dbusConnection->connection();
 }
 
-void QSpiAccessibleBridge::setRootObject(QObject *obj)
+void QSpiAccessibleBridge::updateStatus()
 {
-    Q_UNUSED(obj);
+    // create the adaptor to handle everything if we are in enabled state
-    dbusAdaptor->setInitialized(true);
+    if (!dbusAdaptor && m_enabled) {
+        qSpiInitializeStructTypes();
+        initializeConstantMappings();
+
+        cache = new QSpiDBusCache(dbusConnection->connection(), this);
+        dec = new DeviceEventControllerAdaptor(this);
+
+        dbusConnection->connection().registerObject(QLatin1String(ATSPI_DBUS_PATH_DEC), this, QDBusConnection::ExportAdaptors);
+
+        dbusAdaptor = new AtSpiAdaptor(dbusConnection, this);
+        dbusConnection->connection().registerVirtualObject(QLatin1String(QSPI_OBJECT_PATH_ACCESSIBLE), dbusAdaptor, QDBusConnection::SubPath);
+        dbusAdaptor->registerApplication();
+    }
 }
 
 void QSpiAccessibleBridge::notifyAccessibilityUpdate(QAccessibleEvent *event)
 {
-    dbusAdaptor->notify(event);
+    if (!dbusAdaptor)
+        return;
+    if (m_enabled)
+        dbusAdaptor->notify(event);
 }
 
 struct RoleMapping {

src/platformsupport/linuxaccessibility/bridge_p.h

@@ -62,21 +62,22 @@ public:
     QSpiAccessibleBridge();
 
     virtual ~QSpiAccessibleBridge();
-    virtual void setRootObject(QObject *obj);
 
     virtual void notifyAccessibilityUpdate(QAccessibleEvent *event);
     QDBusConnection dBusConnection() const;
 
+public Q_SLOTS:
+    void enabledChanged(bool enabled);
+
 private:
     void initializeConstantMappings();
+    void updateStatus();
 
     QSpiDBusCache *cache;
     DeviceEventControllerAdaptor *dec;
-
     AtSpiAdaptor *dbusAdaptor;
-
     DBusConnection* dbusConnection;
-    bool initialized;
+    bool m_enabled;
 };
 
 QT_END_NAMESPACE

src/platformsupport/linuxaccessibility/dbusconnection.cpp

@@ -44,10 +44,16 @@
 #include "dbusconnection_p.h"
 
 #include <QtDBus/QDBusMessage>
+#include <QtDBus/QDBusServiceWatcher>
 #include <qdebug.h>
 
+#include <QDBusConnectionInterface>
+
 QT_BEGIN_NAMESPACE
 
+QString A11Y_SERVICE = QStringLiteral("org.a11y.Bus");
+QString A11Y_PATH = QStringLiteral("/org/a11y/bus");
+
 /*!
     \class DBusConnection
     \internal
@@ -55,53 +61,81 @@ QT_BEGIN_NAMESPACE
 
     This is usually a different bus from the session bus.
 */
-DBusConnection::DBusConnection()
+DBusConnection::DBusConnection(QObject *parent)
-    : dbusConnection(connectDBus())
+    : QObject(parent), m_a11yConnection(QString()), m_enabled(false)
-{}
-
-QDBusConnection DBusConnection::connectDBus()
 {
-    QString address = getAccessibilityBusAddress();
+    // Start monitoring if "org.a11y.Bus" is registered as DBus service.
-
-    if (!address.isEmpty()) {
-        QDBusConnection c = QDBusConnection::connectToBus(address, QStringLiteral("a11y"));
-        if (c.isConnected())
-            return c;
-        qWarning("Found Accessibility DBus address but cannot connect. Falling back to session bus.");
-    } else {
-        qWarning("Accessibility DBus not found. Falling back to session bus.");
-    }
-
     QDBusConnection c = QDBusConnection::sessionBus();
-    if (!c.isConnected()) {
+    dbusWatcher = new QDBusServiceWatcher(A11Y_SERVICE, c, QDBusServiceWatcher::WatchForRegistration, this);
-        qWarning("Could not connect to DBus.");
+    connect(dbusWatcher, SIGNAL(serviceRegistered(QString)), this, SLOT(serviceRegistered()));
-    }
+
-    return QDBusConnection::sessionBus();
+    // If it is registered already, setup a11y right away
+    if (c.interface()->isServiceRegistered(A11Y_SERVICE))
+        serviceRegistered();
 }
 
-QString DBusConnection::getAccessibilityBusAddress() const
+// We have the a11y registry on the session bus.
+// Subscribe to updates about a11y enabled state.
+// Find out the bus address
+void DBusConnection::serviceRegistered()
 {
+    // listen to enabled changes
     QDBusConnection c = QDBusConnection::sessionBus();
+    // FXIME check for changes of enabled state
+//    if (!c.connect(A11Y_SERVICE, A11Y_PATH, QStringLiteral("org.freedesktop.DBus.Properties"), QStringLiteral("PropertiesChanged"), this, SLOT(enabledStateChanged(QDBusVariant))))
+//        qWarning() << "Could not listen to accessibility enabled state changes.";
 
-    QDBusMessage m = QDBusMessage::createMethodCall(QLatin1String("org.a11y.Bus"),
+    // check if it's enabled right away
-                                                    QLatin1String("/org/a11y/bus"),
+    QDBusMessage enabledMessage = QDBusMessage::createMethodCall(A11Y_SERVICE, A11Y_PATH, QStringLiteral("org.freedesktop.DBus.Properties"), QStringLiteral("Get"));
-                                                    QLatin1String("org.a11y.Bus"), QLatin1String("GetAddress"));
+    QList<QVariant> args;
-    QDBusMessage reply = c.call(m);
+    args << QStringLiteral("org.a11y.Status") << QStringLiteral("IsEnabled");
-    if (reply.type() == QDBusMessage::ErrorMessage) {
+    enabledMessage.setArguments(args);
-        qWarning() << "Qt at-spi: error getting the accessibility dbus address: " << reply.errorMessage();
+    c.callWithCallback(enabledMessage, this, SLOT(enabledStateCallback(QDBusVariant)), SLOT(dbusError(QDBusError)));
-        return QString();
+}
+
+void DBusConnection::dbusError(const QDBusError &error)
+{
+    qWarning() << "Accessibility encountered a DBus error:" << error;
+}
+
+void DBusConnection::serviceUnregistered()
+{
+    emit enabledChanged(false);
+}
+
+void DBusConnection::enabledStateCallback(const QDBusVariant &enabled)
+{
+    m_enabled = enabled.variant().toBool();
+    if (m_a11yConnection.isConnected()) {
+        emit enabledChanged(m_enabled);
+    } else {
+        QDBusConnection c = QDBusConnection::sessionBus();
+        QDBusMessage m = QDBusMessage::createMethodCall(QLatin1String("org.a11y.Bus"),
+                                                        QLatin1String("/org/a11y/bus"),
+                                                        QLatin1String("org.a11y.Bus"), QLatin1String("GetAddress"));
+        c.callWithCallback(m, this, SLOT(connectA11yBus(QString)), SLOT(dbusError(QDBusError)));
     }
+}
 
-    QString busAddress = reply.arguments().at(0).toString();
+void DBusConnection::connectA11yBus(const QString &address)
-    return busAddress;
+{
+    if (address.isEmpty()) {
+        qWarning("Could not find Accessibility DBus address.");
+        return;
+    }
+    m_a11yConnection = QDBusConnection(QDBusConnection::connectToBus(address, QStringLiteral("a11y")));
+
+    if (m_enabled)
+        emit enabledChanged(true);
 }
 
 /*!
   Returns the DBus connection that got established.
+  Or an invalid connection if not yet connected.
 */
 QDBusConnection DBusConnection::connection() const
 {
-    return dbusConnection;
+    return m_a11yConnection;
 }
 
 QT_END_NAMESPACE

src/platformsupport/linuxaccessibility/dbusconnection_p.h

@@ -45,21 +45,41 @@
 
 #include <QtCore/QString>
 #include <QtDBus/QDBusConnection>
+#include <QtDBus/QDBusVariant>
 
 QT_BEGIN_HEADER
 QT_BEGIN_NAMESPACE
 
-class DBusConnection
+class QDBusServiceWatcher;
+
+class DBusConnection : public QObject
 {
+    Q_OBJECT
+
 public:
-    DBusConnection();
+    DBusConnection(QObject *parent = 0);
     QDBusConnection connection() const;
+    bool isEnabled() const { return m_enabled; }
+
+Q_SIGNALS:
+    // Emitted when the global accessibility status changes to enabled
+    void enabledChanged(bool enabled);
+
+private Q_SLOTS:
+    void serviceRegistered();
+    void serviceUnregistered();
+    void enabledStateCallback(const QDBusVariant &enabled);
+//    void enabledStateChanged(const QDBusVariant &);
+    void connectA11yBus(const QString &address);
+
+    void dbusError(const QDBusError &error);
 
 private:
     QString getAccessibilityBusAddress() const;
-    QDBusConnection connectDBus();
 
-    QDBusConnection dbusConnection;
+    QDBusServiceWatcher *dbusWatcher;
+    QDBusConnection m_a11yConnection;
+    bool m_enabled;
 };
 
 QT_END_NAMESPACE

tests/auto/other/qaccessibilitylinux/tst_qaccessibilitylinux.cpp

@@ -67,11 +67,8 @@ class AccessibleTestWindow : public QWidget
 public:
     AccessibleTestWindow()
     {
-        DBusConnection c;
-        m_address = c.connection().baseService().toLatin1().data();
         new QHBoxLayout(this);
     }
-    QString dbusAddress() const { return m_address; }
 
     void addWidget(QWidget* widget)
     {
@@ -85,10 +82,6 @@ public:
         qDeleteAll(children());
         new QHBoxLayout(this);
     }
-
-private:
-    QString m_address;
-    QString m_bus;
 };
 
 
@@ -116,7 +109,6 @@ private:
 
     AccessibleTestWindow *m_window;
 
-    QString bus;
     QString address;
     QDBusInterface *root; // the root object on dbus (for the app)
     QDBusInterface *rootApplication;
@@ -129,10 +121,12 @@ private:
 QStringList tst_QAccessibilityLinux::getChildren(QDBusInterface *interface)
 {
     QSpiObjectReferenceArray list;
-    interface->call(QDBus::Block, "GetChildren").arguments().first().value<QDBusArgument>() >> list;
+    const QList<QVariant> args = interface->call(QDBus::Block, "GetChildren").arguments();
+    Q_ASSERT(args.size() == 1);
+    Q_ASSERT(args.first().isValid());
+    args.first().value<QDBusArgument>() >> list;
 
     Q_ASSERT(interface->property("ChildCount").toInt() == list.count());
-
     QStringList children;
     Q_FOREACH (const QSpiObjectReference &ref, list)
         children << ref.path.path();
@@ -164,26 +158,18 @@ QDBusInterface *tst_QAccessibilityLinux::getInterface(const QString &path, const
 void tst_QAccessibilityLinux::initTestCase()
 {
     // Oxygen style creates many extra items, it's simply unusable here
-    qDebug() << "Using fusion style...";
     qApp->setStyle("fusion");
     qApp->setApplicationName("tst_QAccessibilityLinux app");
-    dbus = DBusConnection();
+
+    QTRY_VERIFY(dbus.isEnabled());
+    QTRY_VERIFY(dbus.connection().isConnected());
+    address = dbus.connection().baseService().toLatin1().data();
 
     m_window = new AccessibleTestWindow();
     m_window->show();
 
-    // this has the side-effect of immediately activating accessibility
-    qDebug() << "Explicitly activating accessibility...";
-    delete QAccessible::queryAccessibleInterface(m_window);
-
     QTest::qWaitForWindowExposed(m_window);
-
-    address = m_window->dbusAddress();
     registerDbus();
-
-    QStringList appChildren = getChildren(root);
-    QString window = appChildren.at(0);
-    mainWindow = getInterface(window, "org.a11y.atspi.Accessible");
 }
 
 void tst_QAccessibilityLinux::cleanupTestCase()