[nemo-qml-plugin-dbus] Add an auto quit feature for DBus adaptors. Contributes to JB#54789

src/plugin/declarativedbusabstractobject.cpp

@@ -0,0 +1,245 @@
+/****************************************************************************************
+**
+** Copyright (c) 2013 - 2021 Jolla Ltd.
+** All rights reserved.
+**
+** You may use this file under the terms of the GNU Lesser General
+** Public License version 2.1 as published by the Free Software Foundation
+** and appearing in the file license.lgpl included in the packaging
+** of this file.
+**
+** This library is free software; you can redistribute it and/or
+** modify it under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation
+** and appearing in the file license.lgpl included in the packaging
+** of this file.
+**
+** This library is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+** Lesser General Public License for more details.
+**
+****************************************************************************************/
+
+#include "declarativedbusabstractobject.h"
+
+#include "dbus.h"
+
+#include <QDBusArgument>
+#include <QDBusMessage>
+#include <QDBusConnection>
+
+#include <QTimerEvent>
+
+#include <qqmlinfo.h>
+
+DeclarativeDBusAbstractObject::DeclarativeDBusAbstractObject(QObject *parent)
+    : QDBusVirtualObject(parent)
+    , m_bus(DeclarativeDBus::SessionBus)
+    , m_quitTimerId(-1)
+    , m_quitTimeout(30)
+    , m_quitOnTimeout(false)
+    , m_complete(true)
+{
+}
+
+DeclarativeDBusAbstractObject::~DeclarativeDBusAbstractObject()
+{
+    QDBusConnection conn = DeclarativeDBus::connection(m_bus);
+    conn.unregisterObject(m_path);
+
+    // In theory an application could have multiple AbstractObject items for different paths or
+    // interfaces and destroying one would unregister the whole service.
+    // If problems arise we could introduce refcounting for services so that
+    // the last service would be responsible for unregisting the service upon
+    // destruction. Unregisration should also take into account unregistration happening
+    // from C++ side.
+    if (!m_service.isEmpty()) {
+        if (!conn.unregisterService(m_service)) {
+            qmlInfo(this) << "Failed to unregister service " << m_service;
+            qmlInfo(this) << conn.lastError().message();
+        }
+    }
+}
+
+QString DeclarativeDBusAbstractObject::service() const
+{
+    return m_service;
+}
+
+void DeclarativeDBusAbstractObject::setService(const QString &service)
+{
+    if (m_service != service) {
+        m_service = service;
+        emit serviceChanged();
+    }
+}
+
+QString DeclarativeDBusAbstractObject::path() const
+{
+    return m_path;
+}
+
+void DeclarativeDBusAbstractObject::setPath(const QString &path)
+{
+    if (m_path != path) {
+        m_path = path;
+        emit pathChanged();
+    }
+}
+
+/*
+    The XML service description. This could be derived from the meta-object but since it's unlikely
+    to be needed most of the time this and type conversion is non-trivial it's not, and there is
+    this property instead if it is needed.
+*/
+
+QString DeclarativeDBusAbstractObject::xml() const
+{
+    return m_xml;
+}
+
+void DeclarativeDBusAbstractObject::setXml(const QString &xml)
+{
+    if (m_xml != xml) {
+        m_xml = xml;
+        emit xmlChanged();
+    }
+}
+
+DeclarativeDBus::BusType DeclarativeDBusAbstractObject::bus() const
+{
+    return m_bus;
+}
+
+void DeclarativeDBusAbstractObject::setBus(DeclarativeDBus::BusType bus)
+{
+    if (m_bus != bus) {
+        m_bus = bus;
+        emit busChanged();
+    }
+}
+
+int DeclarativeDBusAbstractObject::quitTimeout() const
+{
+    return m_quitTimeout;
+}
+
+void DeclarativeDBusAbstractObject::setQuitTimeout(int timeout)
+{
+    if (m_quitTimeout != timeout) {
+        m_quitTimeout = timeout;
+
+        emit quitTimeoutChanged();
+    }
+}
+
+
+bool DeclarativeDBusAbstractObject::quitOnTimeout() const
+{
+    return m_quitOnTimeout;
+}
+
+void DeclarativeDBusAbstractObject::setQuitOnTimeout(bool quit)
+{
+    if (m_quitOnTimeout != quit && (!m_complete || !quit)) {
+        m_quitOnTimeout = quit;
+
+        if (m_quitTimerId != -1) {
+            killTimer(m_quitTimerId);
+            m_quitTimerId = -1;
+        }
+
+        emit quitOnTimeoutChanged();
+
+        m_quitLocker.reset();
+    }
+}
+
+void DeclarativeDBusAbstractObject::classBegin()
+{
+    m_complete = false;
+}
+
+void DeclarativeDBusAbstractObject::componentComplete()
+{
+    m_complete = true;
+
+    QDBusConnection conn = DeclarativeDBus::connection(m_bus);
+
+    // It is still valid to publish an object on the bus without first registering a service name,
+    // a remote process would have to connect directly to the DBus address.
+    if (!m_path.isEmpty() && !conn.registerVirtualObject(m_path, this)) {
+        qmlInfo(this) << "Failed to register object " << m_path;
+        qmlInfo(this) << conn.lastError().message();
+    }
+
+    // Register service name only if it has been set.
+    if (!m_service.isEmpty()) {
+        if (!conn.registerService(m_service)) {
+            qmlInfo(this) << "Failed to register service " << m_service;
+            qmlInfo(this) << conn.lastError().message();
+        }
+    }
+
+    if (m_quitOnTimeout && m_quitTimeout > 0) {
+        m_quitLocker.reset(new QEventLoopLocker);
+
+        m_quitTimerId = startTimer(m_quitTimeout * 1000);
+    }
+}
+
+QString DeclarativeDBusAbstractObject::introspect(const QString &) const
+{
+    return m_xml;
+}
+
+bool DeclarativeDBusAbstractObject::handleMessage(
+        const QDBusMessage &message, const QDBusConnection &connection)
+{
+    const QVariantList dbusArguments = message.arguments();
+
+    QString member = message.member();
+    QString interface = message.interface();
+
+    // Don't try to handle introspect call. It will be handled
+    // internally for QDBusVirtualObject derived classes.
+    if (interface == QLatin1String("org.freedesktop.DBus.Introspectable")) {
+        return false;
+    } else if (interface == QLatin1String("org.freedesktop.DBus.Properties")) {
+        if (member == QLatin1String("Get")) {
+            return getProperty(
+                        message,
+                        connection,
+                        dbusArguments.value(0).toString(),
+                        dbusArguments.value(1).toString());
+        } else if (member == QLatin1String("GetAll")) {
+            return getProperties(
+                        message,
+                        connection,
+                        dbusArguments.value(0).toString());
+        } else if (member == QLatin1String("Set")) {
+            return setProperty(
+                        dbusArguments.value(0).toString(),
+                        dbusArguments.value(1).toString(),
+                        NemoDBus::demarshallDBusArgument(dbusArguments.value(2)));
+        }
+    } else {
+        return invoke(message, connection, interface, member, dbusArguments);
+    }
+
+    return false;
+}
+
+void DeclarativeDBusAbstractObject::timerEvent(QTimerEvent *event)
+{
+    if (event->timerId() == m_quitTimerId) {
+        killTimer(m_quitTimerId);
+
+        m_quitTimerId = -1;
+
+        m_quitLocker.reset();
+    } else {
+        QDBusVirtualObject::timerEvent(event);
+    }
+}

src/plugin/declarativedbusabstractobject.h

@@ -0,0 +1,120 @@
+/****************************************************************************************
+**
+** Copyright (c) 2013 - 2021 Jolla Ltd.
+** All rights reserved.
+**
+** You may use this file under the terms of the GNU Lesser General
+** Public License version 2.1 as published by the Free Software Foundation
+** and appearing in the file license.lgpl included in the packaging
+** of this file.
+**
+** This library is free software; you can redistribute it and/or
+** modify it under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation
+** and appearing in the file license.lgpl included in the packaging
+** of this file.
+**
+** This library is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+** Lesser General Public License for more details.
+**
+****************************************************************************************/
+
+#ifndef DECLARATIVEDBUSABSTRACTOBJECT_H
+#define DECLARATIVEDBUSABSTRACTOBJECT_H
+
+#include <QQmlListProperty>
+#include <QQmlParserStatus>
+#include <QUrl>
+#include <QJSValue>
+
+#include <QDBusVirtualObject>
+
+#include <QEventLoopLocker>
+
+#include "declarativedbus.h"
+
+class DeclarativeDBusAbstractObject : public QDBusVirtualObject, public QQmlParserStatus
+{
+    Q_OBJECT
+    Q_PROPERTY(QString service READ service WRITE setService NOTIFY serviceChanged)
+    Q_PROPERTY(QString path READ path WRITE setPath NOTIFY pathChanged)
+    Q_PROPERTY(QString xml READ xml WRITE setXml NOTIFY xmlChanged)
+    Q_PROPERTY(DeclarativeDBus::BusType bus READ bus WRITE setBus NOTIFY busChanged)
+    Q_PROPERTY(bool quitOnTimeout READ quitOnTimeout WRITE setQuitOnTimeout NOTIFY quitOnTimeoutChanged)
+    Q_PROPERTY(int quitTimeout READ quitTimeout WRITE setQuitTimeout NOTIFY quitTimeoutChanged)
+
+    Q_INTERFACES(QQmlParserStatus)
+
+public:
+    explicit DeclarativeDBusAbstractObject(QObject *parent = nullptr);
+    ~DeclarativeDBusAbstractObject() override;
+
+    QString service() const;
+    void setService(const QString &service);
+
+    QString path() const;
+    void setPath(const QString &path);
+
+    QString xml() const;
+    void setXml(const QString &xml);
+
+    DeclarativeDBus::BusType bus() const;
+    void setBus(DeclarativeDBus::BusType bus);
+
+    bool quitOnTimeout() const;
+    void setQuitOnTimeout(bool quit);
+
+    int quitTimeout() const;
+    void setQuitTimeout(int timeout);
+
+    void classBegin() override;
+    void componentComplete() override;
+
+    QString introspect(const QString &path) const override;
+    bool handleMessage(const QDBusMessage &message, const QDBusConnection &connection) override;
+
+signals:
+    void serviceChanged();
+    void pathChanged();
+    void xmlChanged();
+    void busChanged();
+    void quitOnTimeoutChanged();
+    void quitTimeoutChanged();
+
+protected:
+    void timerEvent(QTimerEvent *event) override;
+
+    virtual bool getProperty(
+            const QDBusMessage &message,
+            const QDBusConnection &connection,
+            const QString &interface,
+            const QString &member) = 0;
+    virtual bool getProperties(
+            const QDBusMessage &message,
+            const QDBusConnection &connection,
+            const QString &interface) = 0;
+    virtual bool setProperty(
+            const QString &interface, const QString &member, const QVariant &value) = 0;
+    virtual bool invoke(
+            const QDBusMessage &message,
+            const QDBusConnection &connection,
+            const QString &interface,
+            const QString &name,
+            const QVariantList &dbusArguments) = 0;
+
+private:
+
+    QScopedPointer<QEventLoopLocker> m_quitLocker;
+    QString m_service;
+    QString m_path;
+    QString m_xml;
+    DeclarativeDBus::BusType m_bus;
+    int m_quitTimerId;
+    int m_quitTimeout;
+    bool m_quitOnTimeout;
+    bool m_complete;
+};
+
+#endif