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++ // Copyright (C) 2022 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
++
++
++
++ #include "dbusconnection_p.h"
++
++ #include <QtDBus/QDBusMessage>
++ #include <QtDBus/QDBusServiceWatcher>
++ #include <qdebug.h>
++
++ #include <QDBusConnectionInterface>
++
++ #include <QtGui/qguiapplication.h>
++ #include <qpa/qplatformnativeinterface.h>
++
++ QT_BEGIN_NAMESPACE
++
++ using namespace Qt::StringLiterals;
++ using namespace QtGuiPrivate; // for D-Bus accessibility wrappers
++
++ /* note: do not change these to QStringLiteral;
++ we are unloaded before QtDBus is done using the strings.
++ */
++ #define A11Y_SERVICE "org.a11y.Bus"_L1
++ #define A11Y_PATH "/org/a11y/bus"_L1
++
++ /*!
++ \class QAtSpiDBusConnection
++ \internal
++ \brief Connects to the accessibility dbus.
++
++ This is usually a different bus from the session bus.
++ */
++ QAtSpiDBusConnection::QAtSpiDBusConnection(QObject *parent)
++ : QObject(parent), m_a11yConnection(QString()), m_enabled(false)
++ {
++ // If the bus is explicitly set via env var it overrides everything else.
++ QByteArray addressEnv = qgetenv("AT_SPI_BUS_ADDRESS");
++ if (!addressEnv.isEmpty()) {
++ m_enabled = true;
++ connectA11yBus(QString::fromLocal8Bit(addressEnv));
++ return;
++ }
++
++ // Start monitoring if "org.a11y.Bus" is registered as DBus service.
++ QDBusConnection c = QDBusConnection::sessionBus();
++ if (!c.isConnected()) {
++ return;
++ }
++
++ m_a11yStatus = new OrgA11yStatusInterface(A11Y_SERVICE, A11Y_PATH, c, this);
++ m_dbusProperties = new OrgFreedesktopDBusPropertiesInterface(A11Y_SERVICE, A11Y_PATH, c, this);
++
++ dbusWatcher = new QDBusServiceWatcher(A11Y_SERVICE, c, QDBusServiceWatcher::WatchForRegistration, this);
++ connect(dbusWatcher, &QDBusServiceWatcher::serviceRegistered,
++ this, &QAtSpiDBusConnection::checkEnabledState);
++
++ // If it is registered already, setup a11y right away
++ if (c.interface()->isServiceRegistered(A11Y_SERVICE))
++ checkEnabledState();
++
++ // Subscribe to updates about a11y enabled state.
++ connect(m_dbusProperties, &OrgFreedesktopDBusPropertiesInterface::PropertiesChanged,
++ this, [this](const QString &interface_name) {
++ if (interface_name == QLatin1StringView(OrgA11yStatusInterface::staticInterfaceName()))
++ checkEnabledState();
++ });
++
++ if (QGuiApplication::platformName().startsWith("xcb"_L1)) {
++ // In addition try if there is an xatom exposing the bus address, this allows applications run as root to work
++ QString address = getAddressFromXCB();
++ if (!address.isEmpty()) {
++ m_enabled = true;
++ connectA11yBus(address);
++ }
++ }
++ }
++
++ QString QAtSpiDBusConnection::getAddressFromXCB()
++ {
++ QGuiApplication *app = qobject_cast<QGuiApplication *>(QCoreApplication::instance());
++ if (!app)
++ return QString();
++ QPlatformNativeInterface *platformNativeInterface = app->platformNativeInterface();
++ QByteArray *addressByteArray = reinterpret_cast<QByteArray*>(
++ platformNativeInterface->nativeResourceForIntegration(QByteArrayLiteral("AtspiBus")));
++ if (addressByteArray) {
++ QString address = QString::fromLatin1(*addressByteArray);
++ delete addressByteArray;
++ return address;
++ }
++ return QString();
++ }
++
++ void QAtSpiDBusConnection::checkEnabledState()
++ {
++ //The variable was introduced because on some embedded platforms there are custom accessibility
++ //clients which don't set Status.ScreenReaderEnabled to true. The variable is also useful for
++ //debugging.
++ static const bool a11yAlwaysOn = qEnvironmentVariableIsSet("QT_LINUX_ACCESSIBILITY_ALWAYS_ON");
++
++ bool enabled = a11yAlwaysOn || m_a11yStatus->screenReaderEnabled() || m_a11yStatus->isEnabled();
++
++ if (enabled != m_enabled) {
++ m_enabled = enabled;
++ if (m_a11yConnection.isConnected()) {
++ emit enabledChanged(m_enabled);
++ } else {
++ QDBusConnection c = QDBusConnection::sessionBus();
++ QDBusMessage m = QDBusMessage::createMethodCall(A11Y_SERVICE, A11Y_PATH, A11Y_SERVICE,
++ "GetAddress"_L1);
++ c.callWithCallback(m, this, SLOT(connectA11yBus(QString)), SLOT(dbusError(QDBusError)));
++ }
++ }
++ }
++
++ void QAtSpiDBusConnection::serviceUnregistered()
++ {
++ emit enabledChanged(false);
++ }
++
++ void QAtSpiDBusConnection::connectA11yBus(const QString &address)
++ {
++ if (address.isEmpty()) {
++ qWarning("Could not find Accessibility DBus address.");
++ return;
++ }
++ m_a11yConnection = QDBusConnection(QDBusConnection::connectToBus(address, "a11y"_L1));
++
++ if (m_enabled)
++ emit enabledChanged(true);
++ }
++
++ void QAtSpiDBusConnection::dbusError(const QDBusError &error)
++ {
++ qWarning() << "Accessibility encountered a DBus error:" << error;
++ }
++
++ /*!
++ Returns the DBus connection that got established.
++ Or an invalid connection if not yet connected.
++ */
++ QDBusConnection QAtSpiDBusConnection::connection() const
++ {
++ return m_a11yConnection;
++ }
++
++ QT_END_NAMESPACE
++
++ #include "moc_dbusconnection_p.cpp"