Updater stuff.

CMakeLists.txt

@@ -261,12 +261,13 @@ elseif(WIN32 AND MSVC)
   set(APP_SOURCES ${APP_SOURCES} ${CMAKE_CURRENT_BINARY_DIR}/resources/executable_properties/rssguard_win.rc)
 endif(MINGW AND WIN32)
 
-# Add source files.
+# APP source files.
 set(APP_SOURCES
   ${APP_SOURCES}
 
   # QTSINGLEAPPLICATION sources.
   src/qtsingleapplication/qtlocalpeer.cpp
+  src/qtsingleapplication/qtsinglecoreapplication.cpp
   src/qtsingleapplication/qtsingleapplication.cpp
 
   # GUI sources.
@@ -340,12 +341,13 @@ set(APP_SOURCES
   src/main.cpp
 )
 
-# Add headers.
+# APP headers.
 set(APP_HEADERS
   ${APP_HEADERS}
 
   # QTSINGLEAPPLICATION headers.
   src/qtsingleapplication/qtlocalpeer.h
+  src/qtsingleapplication/qtsinglecoreapplication.h
   src/qtsingleapplication/qtsingleapplication.h
 
   # GUI headers.
@@ -410,7 +412,7 @@ set(APP_HEADERS
   src/application.h
 )
 
-# Add form files.
+# APP form files.
 set(APP_FORMS
   src/gui/formupdate.ui
   src/gui/formmain.ui
@@ -421,7 +423,7 @@ set(APP_FORMS
   src/gui/toolbareditor.ui
 )
 
-# Add translations.
+# APP translations.
 set(APP_TRANSLATIONS
   localization/rssguard-cs_CZ.ts
   localization/rssguard-de_DE.ts
@@ -480,10 +482,57 @@ include_directories (
   ${CMAKE_CURRENT_SOURCE_DIR}/src/gui
   ${CMAKE_CURRENT_SOURCE_DIR}/src/network-web
   ${CMAKE_CURRENT_SOURCE_DIR}/src/dynamic-shortcuts
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/updater
   ${CMAKE_CURRENT_BINARY_DIR}
   ${CMAKE_CURRENT_BINARY_DIR}/src
 )
 
+if(WIN32 OR OS2)
+  project(updater)
+
+  set(UPDATER_SOURCES
+    # QTSINGLEAPPLICATION sources.
+    src/qtsingleapplication/qtlocalpeer.cpp
+    src/qtsingleapplication/qtsinglecoreapplication.cpp
+
+    src/updater/detector.cpp
+    src/updater/main.cpp
+  )
+
+  set(UPDATER_HEADERS
+    # QTSINGLEAPPLICATION headers.
+    src/qtsingleapplication/qtlocalpeer.h
+    src/qtsingleapplication/qtsinglecoreapplication.h
+
+    src/updater/detector.h
+  )
+
+  if(${USE_QT_5})
+    add_executable("updater"
+      ${UPDATER_SOURCES}
+    )
+
+    # Use modules from Qt.
+    qt5_use_modules(updater
+      Core
+      Network
+    )
+  else(${USE_QT_5})
+    qt4_wrap_cpp(UPDATER_MOC ${UPDATER_HEADERS})
+
+    add_executable("updater"
+      ${UPDATER_SOURCES}
+      ${UPDATER_MOC}
+    )
+
+    # Link modules from Qt.
+    target_link_libraries("updater"
+      ${QT_QTCORE_LIBRARY}
+      ${QT_QTNETWORK_LIBRARY}
+    )
+  endif(${USE_QT_5})
+endif(WIN32 OR OS2)
+
 # Setup compilation for Qt 5.
 if(${USE_QT_5})
   add_executable(${EXE_NAME} WIN32 MACOSX_BUNDLE

src/core/feedsmodelfeed.cpp

@@ -145,7 +145,7 @@ QPair<FeedsModelFeed*, QNetworkReply::NetworkError> FeedsModelFeed::guessFeed(co
   }
 
   QByteArray feed_contents;
-  if ((result.second = NetworkFactory::downloadFeedFile(url,
+  if ((result.second = NetworkFactory::downloadFile(url,
                                                         Settings::instance()->value(APP_CFG_FEEDS, "feed_update_timeout", DOWNLOAD_TIMEOUT).toInt(),
                                                         feed_contents,
                                                         !username.isEmpty(),
@@ -349,7 +349,7 @@ QVariant FeedsModelFeed::data(int column, int role) const {
 void FeedsModelFeed::update() {
   QByteArray feed_contents;
   int download_timeout = Settings::instance()->value(APP_CFG_FEEDS, "feed_update_timeout", DOWNLOAD_TIMEOUT).toInt();
-  QNetworkReply::NetworkError download_result = NetworkFactory::downloadFeedFile(url(),
+  QNetworkReply::NetworkError download_result = NetworkFactory::downloadFile(url(),
                                                                                  download_timeout,
                                                                                  feed_contents,
                                                                                  passwordProtected(),

src/definitions/definitions.h.in

@@ -103,6 +103,7 @@
 
 #define APP_REVISION        "@APP_REVISION@"
 
+#define APP_QUIT_INSTANCE   "app_quit"
 #define APP_IS_RUNNING      "app_is_running"
 #define APP_SKIN_DEFAULT    "base/vergilius.xml"
 #define APP_THEME_DEFAULT   "mini-kfaenza"

src/gui/formmain.cpp

@@ -172,6 +172,9 @@ void FormMain::processExecutionMessage(const QString &message) {
 
     display();
   }
+  else if (message == APP_QUIT_INSTANCE) {
+    qApp->quit();
+  }
 }
 
 void FormMain::quit() {

src/gui/formupdate.cpp

@@ -27,6 +27,7 @@
 
 #include <QNetworkReply>
 #include <QDesktopServices>
+#include <QProcess>
 
 
 FormUpdate::FormUpdate(QWidget *parent)
@@ -78,7 +79,7 @@ void FormUpdate::checkForUpdates() {
     m_ui->m_lblAvailableRelease->setText(update.first.m_availableVersion);
     m_ui->m_txtChanges->setText(update.first.m_changes);
 
-    if (update.first.m_availableVersion > APP_VERSION) {
+    if (update.first.m_availableVersion >= APP_VERSION) {
       m_ui->m_lblStatus->setStatus(WidgetWithStatus::Ok,
                                    tr("New release available."),
                                    tr("This is new version which can be\ndownloaded and installed."));
@@ -108,6 +109,44 @@ void FormUpdate::startUpdate() {
     url_file = APP_URL;
   }
 
+#if defined(Q_OS_WIN) || defined(Q_OS_OS2)
+  // On Windows/OS2 we can update the application right away.
+  // Download the files.
+  QByteArray output;
+  //NetworkFactory::downloadFile(url_file, DOWNLOAD_TIMEOUT, output);
+
+#if QT_VERSION >= 0x050000
+  QString temp_directory = QStandardPaths::writableLocation(QStandardPaths::TempLocation);
+#else
+  QString temp_directory = QDesktopServices::storageLocation(QDesktopServices::TempLocation);
+#endif
+
+  if (!temp_directory.isEmpty()) {
+    QString output_file_name = url_file.mid(url_file.lastIndexOf('/') + 1);
+    QFile output_file(temp_directory + QDir::separator() + output_file_name);
+
+    if (output_file.exists()) {
+      output_file.remove();
+    }
+
+    if (output_file.open(QIODevice::WriteOnly)) {
+      output_file.write(output);
+      output_file.flush();
+      output_file.close();
+
+      // TODO: spustit updater
+      // pouzit qprocess, nebo neco multiplatformniho
+    }
+    else {
+      // TODO: chyba - nelze zapisovat do souboru
+    }
+
+  }
+  else {
+    // TODO: chyba - nelze ulozit soubor.
+  }
+
+#else
   if (!WebFactory::instance()->openUrlInExternalBrowser(url_file)) {
     if (SystemTrayIcon::isSystemTrayActivated()) {
       SystemTrayIcon::instance()->showMessage(tr("Cannot update application"),
@@ -123,4 +162,5 @@ void FormUpdate::startUpdate() {
                           "manually on project website."));
     }
   }
+#endif
 }

src/main.cpp

@@ -66,7 +66,7 @@ int main(int argc, char *argv[]) {
 #endif
 
   // Instantiate base application object.
-  QtSingleApplication application(argc, argv);
+  QtSingleApplication application(APP_LOW_NAME, argc, argv);
   qDebug("Instantiated QtSingleApplication class.");
 
   // Check if another instance is running.

src/miscellaneous/systemfactory.cpp

@@ -170,7 +170,7 @@ QPair<UpdateInfo, QNetworkReply::NetworkError> SystemFactory::checkForUpdates()
   QPair<UpdateInfo, QNetworkReply::NetworkError> result;
   QByteArray releases_xml;
 
-  result.second = NetworkFactory::downloadFeedFile(RELEASES_LIST,
+  result.second = NetworkFactory::downloadFile(RELEASES_LIST,
                                                    5000,
                                                    releases_xml);
 

src/network-web/networkfactory.cpp

@@ -105,9 +105,9 @@ QNetworkReply::NetworkError NetworkFactory::downloadIcon(const QString &url,
 #endif
   QByteArray icon_data;
 
-  QNetworkReply::NetworkError network_result =  downloadFeedFile(google_s2_with_url,
+  QNetworkReply::NetworkError network_result =  downloadFile(google_s2_with_url,
-                                                                 timeout,
+                                                             timeout,
-                                                                 icon_data);
+                                                             icon_data);
 
   if (network_result == QNetworkReply::NoError) {
     QPixmap icon_pixmap;
@@ -118,12 +118,12 @@ QNetworkReply::NetworkError NetworkFactory::downloadIcon(const QString &url,
   return network_result;
 }
 
-QNetworkReply::NetworkError NetworkFactory::downloadFeedFile(const QString &url,
+QNetworkReply::NetworkError NetworkFactory::downloadFile(const QString &url,
-                                                             int timeout,
+                                                         int timeout,
-                                                             QByteArray &output,
+                                                         QByteArray &output,
-                                                             bool protected_contents,
+                                                         bool protected_contents,
-                                                             const QString &username,
+                                                         const QString &username,
-                                                             const QString &password) {
+                                                         const QString &password) {
   // Original asynchronous behavior of QNetworkAccessManager
   // is replaced by synchronous behavior in order to make
   // process of downloading of a file easier to understand.

src/network-web/networkfactory.h

@@ -41,7 +41,7 @@ class NetworkFactory {
 
     // Performs SYNCHRONOUS download of file with given URL
     // and given timeout.
-    static QNetworkReply::NetworkError downloadFeedFile(const QString &url,
+    static QNetworkReply::NetworkError downloadFile(const QString &url,
                                                         int timeout,
                                                         QByteArray &output,
                                                         bool protected_contents = false,

src/qtsingleapplication/qtlocalpeer.cpp

@@ -49,7 +49,7 @@
 typedef BOOL(WINAPI*PProcessIdToSessionId)(DWORD,DWORD*);
 static PProcessIdToSessionId pProcessIdToSessionId = 0;
 #endif
-#if defined(Q_OS_UNIX) || defined(Q_OS_OS2)
+#if defined(Q_OS_UNIX)
 #include <sys/types.h>
 #include <time.h>
 #include <unistd.h>
@@ -67,129 +67,137 @@ namespace QtLP_Private {
 const char* QtLocalPeer::ack = "ack";
 
 QtLocalPeer::QtLocalPeer(QObject* parent, const QString &appId)
-  : QObject(parent), id(appId) {
+    : QObject(parent), id(appId)
-  QString prefix = id;
+{
-  if (id.isEmpty()) {
+    QString prefix = id;
-    id = QCoreApplication::applicationFilePath();
+    if (id.isEmpty()) {
+        id = QCoreApplication::applicationFilePath();
 #if defined(Q_OS_WIN)
-    id = id.toLower();
+        id = id.toLower();
 #endif
-    prefix = id.section(QLatin1Char('/'), -1);
+        prefix = id.section(QLatin1Char('/'), -1);
-  }
+    }
-  prefix.remove(QRegExp("[^a-zA-Z]"));
+    prefix.remove(QRegExp("[^a-zA-Z]"));
-  prefix.truncate(6);
+    prefix.truncate(6);
 
-  QByteArray idc = id.toUtf8();
+    QByteArray idc = id.toUtf8();
-  quint16 idNum = qChecksum(idc.constData(), idc.size());
+    quint16 idNum = qChecksum(idc.constData(), idc.size());
-  socketName = QLatin1String("qtsingleapp-") + prefix
+    socketName = QLatin1String("qtsingleapp-") + prefix
-               + QLatin1Char('-') + QString::number(idNum, 16);
+                 + QLatin1Char('-') + QString::number(idNum, 16);
 
 #if defined(Q_OS_WIN)
-  if (!pProcessIdToSessionId) {
+    if (!pProcessIdToSessionId) {
-    QLibrary lib("kernel32");
+        QLibrary lib("kernel32");
-    pProcessIdToSessionId = (PProcessIdToSessionId)lib.resolve("ProcessIdToSessionId");
+        pProcessIdToSessionId = (PProcessIdToSessionId)lib.resolve("ProcessIdToSessionId");
-  }
+    }
-  if (pProcessIdToSessionId) {
+    if (pProcessIdToSessionId) {
-    DWORD sessionId = 0;
+        DWORD sessionId = 0;
-    pProcessIdToSessionId(GetCurrentProcessId(), &sessionId);
+        pProcessIdToSessionId(GetCurrentProcessId(), &sessionId);
-    socketName += QLatin1Char('-') + QString::number(sessionId, 16);
+        socketName += QLatin1Char('-') + QString::number(sessionId, 16);
-  }
+    }
 #else
-  socketName += QLatin1Char('-') + QString::number(::getuid(), 16);
+    socketName += QLatin1Char('-') + QString::number(::getuid(), 16);
 #endif
 
-  server = new QLocalServer(this);
+    server = new QLocalServer(this);
-  QString lockName = QDir(QDir::tempPath()).absolutePath()
+    QString lockName = QDir(QDir::tempPath()).absolutePath()
-                     + QLatin1Char('/') + socketName
+                       + QLatin1Char('/') + socketName
-                     + QLatin1String("-lockfile");
+                       + QLatin1String("-lockfile");
-  lockFile.setFileName(lockName);
+    lockFile.setFileName(lockName);
-  lockFile.open(QIODevice::ReadWrite);
+    lockFile.open(QIODevice::ReadWrite);
 }
 
-bool QtLocalPeer::isClient() {
-  if (lockFile.isLocked())
-    return false;
 
-  if (!lockFile.lock(QtLP_Private::QtLockedFile::WriteLock, false))
-    return true;
 
-  bool res = server->listen(socketName);
+bool QtLocalPeer::isClient()
+{
+    if (lockFile.isLocked())
+        return false;
+
+    if (!lockFile.lock(QtLP_Private::QtLockedFile::WriteLock, false))
+        return true;
+
+    bool res = server->listen(socketName);
 #if defined(Q_OS_UNIX) && (QT_VERSION >= QT_VERSION_CHECK(4,5,0))
-  // ### Workaround
+    // ### Workaround
-  if (!res && server->serverError() == QAbstractSocket::AddressInUseError) {
+    if (!res && server->serverError() == QAbstractSocket::AddressInUseError) {
-    QFile::remove(QDir::cleanPath(QDir::tempPath())+QLatin1Char('/')+socketName);
+        QFile::remove(QDir::cleanPath(QDir::tempPath())+QLatin1Char('/')+socketName);
-    res = server->listen(socketName);
+        res = server->listen(socketName);
-  }
+    }
 #endif
-  if (!res)
+    if (!res)
-    qWarning("QtSingleCoreApplication: listen on local socket failed, %s", qPrintable(server->errorString()));
+        qWarning("QtSingleCoreApplication: listen on local socket failed, %s", qPrintable(server->errorString()));
-  QObject::connect(server, SIGNAL(newConnection()), SLOT(receiveConnection()));
+    QObject::connect(server, SIGNAL(newConnection()), SLOT(receiveConnection()));
-  return false;
+    return false;
 }
 
-bool QtLocalPeer::sendMessage(const QString &message, int timeout) {
-  if (!isClient())
-    return false;
 
-  QLocalSocket socket;
+bool QtLocalPeer::sendMessage(const QString &message, int timeout)
-  bool connOk = false;
+{
-  for(int i = 0; i < 2; i++) {
+    if (!isClient())
-    // Try twice, in case the other instance is just starting up
+        return false;
-    socket.connectToServer(socketName);
+
-    connOk = socket.waitForConnected(timeout/2);
+    QLocalSocket socket;
-    if (connOk || i)
+    bool connOk = false;
-      break;
+    for(int i = 0; i < 2; i++) {
-    int ms = 250;
+        // Try twice, in case the other instance is just starting up
+        socket.connectToServer(socketName);
+        connOk = socket.waitForConnected(timeout/2);
+        if (connOk || i)
+            break;
+        int ms = 250;
 #if defined(Q_OS_WIN)
-    Sleep(DWORD(ms));
+        Sleep(DWORD(ms));
 #else
-    struct timespec ts = { ms / 1000, (ms % 1000) * 1000 * 1000 };
+        struct timespec ts = { ms / 1000, (ms % 1000) * 1000 * 1000 };
-    nanosleep(&ts, NULL);
+        nanosleep(&ts, NULL);
 #endif
-  }
+    }
-  if (!connOk)
+    if (!connOk)
-    return false;
+        return false;
 
-  QByteArray uMsg(message.toUtf8());
+    QByteArray uMsg(message.toUtf8());
-  QDataStream ds(&socket);
+    QDataStream ds(&socket);
-  ds.writeBytes(uMsg.constData(), uMsg.size());
+    ds.writeBytes(uMsg.constData(), uMsg.size());
-  bool res = socket.waitForBytesWritten(timeout);
+    bool res = socket.waitForBytesWritten(timeout);
-  if (res) {
+    if (res) {
-    res &= socket.waitForReadyRead(timeout);   // wait for ack
+        res &= socket.waitForReadyRead(timeout);   // wait for ack
-    if (res)
+        if (res)
-      res &= (socket.read(qstrlen(ack)) == ack);
+            res &= (socket.read(qstrlen(ack)) == ack);
-  }
+    }
-  return res;
+    return res;
 }
 
-void QtLocalPeer::receiveConnection() {
-  QLocalSocket* socket = server->nextPendingConnection();
-  if (!socket)
-    return;
 
-  while (socket->bytesAvailable() < (int)sizeof(quint32))
+void QtLocalPeer::receiveConnection()
-    socket->waitForReadyRead();
+{
-  QDataStream ds(socket);
+    QLocalSocket* socket = server->nextPendingConnection();
-  QByteArray uMsg;
+    if (!socket)
-  quint32 remaining;
+        return;
-  ds >> remaining;
+
-  uMsg.resize(remaining);
+    while (socket->bytesAvailable() < (int)sizeof(quint32))
-  int got = 0;
+        socket->waitForReadyRead();
-  char* uMsgBuf = uMsg.data();
+    QDataStream ds(socket);
-  do {
+    QByteArray uMsg;
-    got = ds.readRawData(uMsgBuf, remaining);
+    quint32 remaining;
-    remaining -= got;
+    ds >> remaining;
-    uMsgBuf += got;
+    uMsg.resize(remaining);
-  } while (remaining && got >= 0 && socket->waitForReadyRead(2000));
+    int got = 0;
-  if (got < 0) {
+    char* uMsgBuf = uMsg.data();
-    qWarning("QtLocalPeer: Message reception failed %s", socket->errorString().toLatin1().constData());
+    do {
+        got = ds.readRawData(uMsgBuf, remaining);
+        remaining -= got;
+        uMsgBuf += got;
+    } while (remaining && got >= 0 && socket->waitForReadyRead(2000));
+    if (got < 0) {
+        qWarning("QtLocalPeer: Message reception failed %s", socket->errorString().toLatin1().constData());
+        delete socket;
+        return;
+    }
+    QString message(QString::fromUtf8(uMsg));
+    socket->write(ack, qstrlen(ack));
+    socket->waitForBytesWritten(1000);
+    socket->waitForDisconnected(1000); // make sure client reads ack
     delete socket;
-    return;
+    emit messageReceived(message); //### (might take a long time to return)
-  }
-  QString message(QString::fromUtf8(uMsg));
-  socket->write(ack, qstrlen(ack));
-  socket->waitForBytesWritten(1000);
-  socket->waitForDisconnected(1000); // make sure client reads ack
-  delete socket;
-  emit messageReceived(message); //### (might take a long time to return)
 }

src/qtsingleapplication/qtlocalpeer.h

@@ -47,23 +47,21 @@
 
 #include "qtlockedfile.h"
 
-class QtLocalPeer : public QObject {
+class QtLocalPeer : public QObject
+{
     Q_OBJECT
 
 public:
-    explicit QtLocalPeer(QObject *parent = 0, const QString &appId = QString());
+    QtLocalPeer(QObject *parent = 0, const QString &appId = QString());
-
     bool isClient();
     bool sendMessage(const QString &message, int timeout);
+    QString applicationId() const
+        { return id; }
 
-    QString applicationId() const {
+Q_SIGNALS:
-      return id;
-    }
-
-  Q_SIGNALS:
     void messageReceived(const QString &message);
 
-  protected Q_SLOTS:
+protected Q_SLOTS:
     void receiveConnection();
 
 protected:

src/qtsingleapplication/qtlockedfile.cpp

@@ -158,8 +158,8 @@ QtLockedFile::LockMode QtLockedFile::lockMode() const
     can be locked.
 
     If \a block is true, this function will block until the lock is
-    acquired. If \a block is false, this function returns \e false
+    aquired. If \a block is false, this function returns \e false
-    immediately if the lock cannot be acquired.
+    immediately if the lock cannot be aquired.
 
     If this object already has a lock of type \a mode, this function
     returns \e true immediately. If this object has a lock of a

src/qtsingleapplication/qtlockedfile.h

@@ -69,8 +69,8 @@ class QT_QTLOCKEDFILE_EXPORT QtLockedFile : public QFile
 public:
     enum LockMode { NoLock = 0, ReadLock, WriteLock };
 
-    explicit QtLockedFile();
+    QtLockedFile();
-    explicit QtLockedFile(const QString &name);
+    QtLockedFile(const QString &name);
     ~QtLockedFile();
 
     bool open(OpenMode mode);

src/qtsingleapplication/qtsingleapplication.cpp

@@ -38,79 +38,310 @@
 **
 ****************************************************************************/
 
+
 #include "qtsingleapplication.h"
 #include "qtlocalpeer.h"
 #include <QWidget>
 
 
-void QtSingleApplication::sysInit(const QString &appId) {
+/*!
-  actWin = 0;
+    \class QtSingleApplication qtsingleapplication.h
-  peer = new QtLocalPeer(this, appId);
+    \brief The QtSingleApplication class provides an API to detect and
-  connect(peer, SIGNAL(messageReceived(const QString&)), SIGNAL(messageReceived(const QString&)));
+    communicate with running instances of an application.
+
+    This class allows you to create applications where only one
+    instance should be running at a time. I.e., if the user tries to
+    launch another instance, the already running instance will be
+    activated instead. Another usecase is a client-server system,
+    where the first started instance will assume the role of server,
+    and the later instances will act as clients of that server.
+
+    By default, the full path of the executable file is used to
+    determine whether two processes are instances of the same
+    application. You can also provide an explicit identifier string
+    that will be compared instead.
+
+    The application should create the QtSingleApplication object early
+    in the startup phase, and call isRunning() to find out if another
+    instance of this application is already running. If isRunning()
+    returns false, it means that no other instance is running, and
+    this instance has assumed the role as the running instance. In
+    this case, the application should continue with the initialization
+    of the application user interface before entering the event loop
+    with exec(), as normal.
+
+    The messageReceived() signal will be emitted when the running
+    application receives messages from another instance of the same
+    application. When a message is received it might be helpful to the
+    user to raise the application so that it becomes visible. To
+    facilitate this, QtSingleApplication provides the
+    setActivationWindow() function and the activateWindow() slot.
+
+    If isRunning() returns true, another instance is already
+    running. It may be alerted to the fact that another instance has
+    started by using the sendMessage() function. Also data such as
+    startup parameters (e.g. the name of the file the user wanted this
+    new instance to open) can be passed to the running instance with
+    this function. Then, the application should terminate (or enter
+    client mode).
+
+    If isRunning() returns true, but sendMessage() fails, that is an
+    indication that the running instance is frozen.
+
+    Here's an example that shows how to convert an existing
+    application to use QtSingleApplication. It is very simple and does
+    not make use of all QtSingleApplication's functionality (see the
+    examples for that).
+
+    \code
+    // Original
+    int main(int argc, char **argv)
+    {
+        QApplication app(argc, argv);
+
+        MyMainWidget mmw;
+        mmw.show();
+        return app.exec();
+    }
+
+    // Single instance
+    int main(int argc, char **argv)
+    {
+        QtSingleApplication app(argc, argv);
+
+        if (app.isRunning())
+            return !app.sendMessage(someDataString);
+
+        MyMainWidget mmw;
+        app.setActivationWindow(&mmw);
+        mmw.show();
+        return app.exec();
+    }
+    \endcode
+
+    Once this QtSingleApplication instance is destroyed (normally when
+    the process exits or crashes), when the user next attempts to run the
+    application this instance will not, of course, be encountered. The
+    next instance to call isRunning() or sendMessage() will assume the
+    role as the new running instance.
+
+    For console (non-GUI) applications, QtSingleCoreApplication may be
+    used instead of this class, to avoid the dependency on the QtGui
+    library.
+
+    \sa QtSingleCoreApplication
+*/
+
+
+void QtSingleApplication::sysInit(const QString &appId)
+{
+    actWin = 0;
+    peer = new QtLocalPeer(this, appId);
+    connect(peer, SIGNAL(messageReceived(const QString&)), SIGNAL(messageReceived(const QString&)));
 }
 
+
+/*!
+    Creates a QtSingleApplication object. The application identifier
+    will be QCoreApplication::applicationFilePath(). \a argc, \a
+    argv, and \a GUIenabled are passed on to the QAppliation constructor.
+
+    If you are creating a console application (i.e. setting \a
+    GUIenabled to false), you may consider using
+    QtSingleCoreApplication instead.
+*/
+
 QtSingleApplication::QtSingleApplication(int &argc, char **argv, bool GUIenabled)
-  : QApplication(argc, argv, GUIenabled) {
+    : QApplication(argc, argv, GUIenabled)
-  sysInit();
+{
+    sysInit();
 }
 
+
+/*!
+    Creates a QtSingleApplication object with the application
+    identifier \a appId. \a argc and \a argv are passed on to the
+    QAppliation constructor.
+*/
+
 QtSingleApplication::QtSingleApplication(const QString &appId, int &argc, char **argv)
-  : QApplication(argc, argv) {
+    : QApplication(argc, argv)
-  sysInit(appId);
+{
+    sysInit(appId);
 }
 
 #if QT_VERSION < 0x050000
+
+/*!
+    Creates a QtSingleApplication object. The application identifier
+    will be QCoreApplication::applicationFilePath(). \a argc, \a
+    argv, and \a type are passed on to the QAppliation constructor.
+*/
 QtSingleApplication::QtSingleApplication(int &argc, char **argv, Type type)
-  : QApplication(argc, argv, type) {
+    : QApplication(argc, argv, type)
-  sysInit();
+{
+    sysInit();
 }
 
-#if defined(Q_WS_X11)
+
+#  if defined(Q_WS_X11)
+/*!
+  Special constructor for X11, ref. the documentation of
+  QApplication's corresponding constructor. The application identifier
+  will be QCoreApplication::applicationFilePath(). \a dpy, \a visual,
+  and \a cmap are passed on to the QApplication constructor.
+*/
 QtSingleApplication::QtSingleApplication(Display* dpy, Qt::HANDLE visual, Qt::HANDLE cmap)
-  : QApplication(dpy, visual, cmap) {
+    : QApplication(dpy, visual, cmap)
-  sysInit();
+{
+    sysInit();
 }
 
+/*!
+  Special constructor for X11, ref. the documentation of
+  QApplication's corresponding constructor. The application identifier
+  will be QCoreApplication::applicationFilePath(). \a dpy, \a argc, \a
+  argv, \a visual, and \a cmap are passed on to the QApplication
+  constructor.
+*/
 QtSingleApplication::QtSingleApplication(Display *dpy, int &argc, char **argv, Qt::HANDLE visual, Qt::HANDLE cmap)
-  : QApplication(dpy, argc, argv, visual, cmap) {
+    : QApplication(dpy, argc, argv, visual, cmap)
-  sysInit();
+{
+    sysInit();
 }
 
+/*!
+  Special constructor for X11, ref. the documentation of
+  QApplication's corresponding constructor. The application identifier
+  will be \a appId. \a dpy, \a argc, \a
+  argv, \a visual, and \a cmap are passed on to the QApplication
+  constructor.
+*/
 QtSingleApplication::QtSingleApplication(Display* dpy, const QString &appId, int argc, char **argv, Qt::HANDLE visual, Qt::HANDLE cmap)
-  : QApplication(dpy, argc, argv, visual, cmap) {
+    : QApplication(dpy, argc, argv, visual, cmap)
-  sysInit(appId);
+{
+    sysInit(appId);
 }
 #  endif // Q_WS_X11
 #endif // QT_VERSION < 0x050000
 
-bool QtSingleApplication::isRunning() {
+
-  return peer->isClient();
+/*!
+    Returns true if another instance of this application is running;
+    otherwise false.
+
+    This function does not find instances of this application that are
+    being run by a different user (on Windows: that are running in
+    another session).
+
+    \sa sendMessage()
+*/
+
+bool QtSingleApplication::isRunning()
+{
+    return peer->isClient();
 }
 
-bool QtSingleApplication::sendMessage(const QString &message, int timeout) {
+
-  return peer->sendMessage(message, timeout);
+/*!
+    Tries to send the text \a message to the currently running
+    instance. The QtSingleApplication object in the running instance
+    will emit the messageReceived() signal when it receives the
+    message.
+
+    This function returns true if the message has been sent to, and
+    processed by, the current instance. If there is no instance
+    currently running, or if the running instance fails to process the
+    message within \a timeout milliseconds, this function return false.
+
+    \sa isRunning(), messageReceived()
+*/
+bool QtSingleApplication::sendMessage(const QString &message, int timeout)
+{
+    return peer->sendMessage(message, timeout);
 }
 
-QString QtSingleApplication::id() const {
+
-  return peer->applicationId();
+/*!
+    Returns the application identifier. Two processes with the same
+    identifier will be regarded as instances of the same application.
+*/
+QString QtSingleApplication::id() const
+{
+    return peer->applicationId();
 }
 
-void QtSingleApplication::setActivationWindow(QWidget* aw, bool activateOnMessage) {
+
-  actWin = aw;
+/*!
-  if (activateOnMessage)
+  Sets the activation window of this application to \a aw. The
-    connect(peer, SIGNAL(messageReceived(const QString&)), this, SLOT(activateWindow()));
+  activation window is the widget that will be activated by
-  else
+  activateWindow(). This is typically the application's main window.
-    disconnect(peer, SIGNAL(messageReceived(const QString&)), this, SLOT(activateWindow()));
+
+  If \a activateOnMessage is true (the default), the window will be
+  activated automatically every time a message is received, just prior
+  to the messageReceived() signal being emitted.
+
+  \sa activateWindow(), messageReceived()
+*/
+
+void QtSingleApplication::setActivationWindow(QWidget* aw, bool activateOnMessage)
+{
+    actWin = aw;
+    if (activateOnMessage)
+        connect(peer, SIGNAL(messageReceived(const QString&)), this, SLOT(activateWindow()));
+    else
+        disconnect(peer, SIGNAL(messageReceived(const QString&)), this, SLOT(activateWindow()));
 }
 
-QWidget* QtSingleApplication::activationWindow() const {
+
-  return actWin;
+/*!
+    Returns the applications activation window if one has been set by
+    calling setActivationWindow(), otherwise returns 0.
+
+    \sa setActivationWindow()
+*/
+QWidget* QtSingleApplication::activationWindow() const
+{
+    return actWin;
 }
 
-void QtSingleApplication::activateWindow() {
+
-  if (actWin) {
+/*!
-    actWin->setWindowState(actWin->windowState() & ~Qt::WindowMinimized);
+  De-minimizes, raises, and activates this application's activation window.
-    actWin->raise();
+  This function does nothing if no activation window has been set.
-    actWin->activateWindow();
+
-  }
+  This is a convenience function to show the user that this
+  application instance has been activated when he has tried to start
+  another instance.
+
+  This function should typically be called in response to the
+  messageReceived() signal. By default, that will happen
+  automatically, if an activation window has been set.
+
+  \sa setActivationWindow(), messageReceived(), initialize()
+*/
+void QtSingleApplication::activateWindow()
+{
+    if (actWin) {
+        actWin->setWindowState(actWin->windowState() & ~Qt::WindowMinimized);
+        actWin->raise();
+        actWin->activateWindow();
+    }
 }
+
+
+/*!
+    \fn void QtSingleApplication::messageReceived(const QString& message)
+
+    This signal is emitted when the current instance receives a \a
+    message from another instance of this application.
+
+    \sa sendMessage(), setActivationWindow(), activateWindow()
+*/
+
+
+/*!
+    \fn void QtSingleApplication::initialize(bool dummy = true)
+
+    \obsolete
+*/

src/qtsingleapplication/qtsingleapplication.h

@@ -61,18 +61,19 @@ class QtLocalPeer;
 #  define QT_QTSINGLEAPPLICATION_EXPORT
 #endif
 
-class QT_QTSINGLEAPPLICATION_EXPORT QtSingleApplication : public QApplication {
+class QT_QTSINGLEAPPLICATION_EXPORT QtSingleApplication : public QApplication
+{
     Q_OBJECT
 
-  public:
+public:
-    explicit QtSingleApplication(int &argc, char **argv, bool GUIenabled = true);
+    QtSingleApplication(int &argc, char **argv, bool GUIenabled = true);
-    explicit QtSingleApplication(const QString &id, int &argc, char **argv);
+    QtSingleApplication(const QString &id, int &argc, char **argv);
 #if QT_VERSION < 0x050000
-    explicit QtSingleApplication(int &argc, char **argv, Type type);
+    QtSingleApplication(int &argc, char **argv, Type type);
 #  if defined(Q_WS_X11)
-    explicit QtSingleApplication(Display* dpy, Qt::HANDLE visual = 0, Qt::HANDLE colormap = 0);
+    QtSingleApplication(Display* dpy, Qt::HANDLE visual = 0, Qt::HANDLE colormap = 0);
-    explicit QtSingleApplication(Display *dpy, int &argc, char **argv, Qt::HANDLE visual = 0, Qt::HANDLE cmap= 0);
+    QtSingleApplication(Display *dpy, int &argc, char **argv, Qt::HANDLE visual = 0, Qt::HANDLE cmap= 0);
-    explicit QtSingleApplication(Display* dpy, const QString &appId, int argc, char **argv, Qt::HANDLE visual = 0, Qt::HANDLE colormap = 0);
+    QtSingleApplication(Display* dpy, const QString &appId, int argc, char **argv, Qt::HANDLE visual = 0, Qt::HANDLE colormap = 0);
 #  endif // Q_WS_X11
 #endif // QT_VERSION < 0x050000
 
@@ -83,23 +84,19 @@ class QT_QTSINGLEAPPLICATION_EXPORT QtSingleApplication : public QApplication {
     QWidget* activationWindow() const;
 
     // Obsolete:
-    void initialize(bool dummy = true) {
+    void initialize(bool dummy = true)
-      isRunning();
+        { isRunning(); Q_UNUSED(dummy) }
-      Q_UNUSED(dummy)
-    }
 
-    static QtSingleApplication *instance() {
+public Q_SLOTS:
-      return static_cast<QtSingleApplication*>(qApp);
-    }
-
-  public Q_SLOTS:
     bool sendMessage(const QString &message, int timeout = 5000);
     void activateWindow();
 
-  Q_SIGNALS:
+
+Q_SIGNALS:
     void messageReceived(const QString &message);
 
-  private:
+
+private:
     void sysInit(const QString &appId = QString());
     QtLocalPeer *peer;
     QWidget *actWin;

src/qtsingleapplication/qtsinglecoreapplication.cpp

@@ -0,0 +1,149 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Solutions component.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
+**     of its contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+#include "qtsinglecoreapplication.h"
+#include "qtlocalpeer.h"
+
+/*!
+    \class QtSingleCoreApplication qtsinglecoreapplication.h
+    \brief A variant of the QtSingleApplication class for non-GUI applications.
+
+    This class is a variant of QtSingleApplication suited for use in
+    console (non-GUI) applications. It is an extension of
+    QCoreApplication (instead of QApplication). It does not require
+    the QtGui library.
+
+    The API and usage is identical to QtSingleApplication, except that
+    functions relating to the "activation window" are not present, for
+    obvious reasons. Please refer to the QtSingleApplication
+    documentation for explanation of the usage.
+
+    A QtSingleCoreApplication instance can communicate to a
+    QtSingleApplication instance if they share the same application
+    id. Hence, this class can be used to create a light-weight
+    command-line tool that sends commands to a GUI application.
+
+    \sa QtSingleApplication
+*/
+
+/*!
+    Creates a QtSingleCoreApplication object. The application identifier
+    will be QCoreApplication::applicationFilePath(). \a argc and \a
+    argv are passed on to the QCoreAppliation constructor.
+*/
+
+QtSingleCoreApplication::QtSingleCoreApplication(int &argc, char **argv)
+    : QCoreApplication(argc, argv)
+{
+    peer = new QtLocalPeer(this);
+    connect(peer, SIGNAL(messageReceived(const QString&)), SIGNAL(messageReceived(const QString&)));
+}
+
+
+/*!
+    Creates a QtSingleCoreApplication object with the application
+    identifier \a appId. \a argc and \a argv are passed on to the
+    QCoreAppliation constructor.
+*/
+QtSingleCoreApplication::QtSingleCoreApplication(const QString &appId, int &argc, char **argv)
+    : QCoreApplication(argc, argv)
+{
+    peer = new QtLocalPeer(this, appId);
+    connect(peer, SIGNAL(messageReceived(const QString&)), SIGNAL(messageReceived(const QString&)));
+}
+
+
+/*!
+    Returns true if another instance of this application is running;
+    otherwise false.
+
+    This function does not find instances of this application that are
+    being run by a different user (on Windows: that are running in
+    another session).
+
+    \sa sendMessage()
+*/
+
+bool QtSingleCoreApplication::isRunning()
+{
+    return peer->isClient();
+}
+
+
+/*!
+    Tries to send the text \a message to the currently running
+    instance. The QtSingleCoreApplication object in the running instance
+    will emit the messageReceived() signal when it receives the
+    message.
+
+    This function returns true if the message has been sent to, and
+    processed by, the current instance. If there is no instance
+    currently running, or if the running instance fails to process the
+    message within \a timeout milliseconds, this function return false.
+
+    \sa isRunning(), messageReceived()
+*/
+
+bool QtSingleCoreApplication::sendMessage(const QString &message, int timeout)
+{
+    return peer->sendMessage(message, timeout);
+}
+
+
+/*!
+    Returns the application identifier. Two processes with the same
+    identifier will be regarded as instances of the same application.
+*/
+
+QString QtSingleCoreApplication::id() const
+{
+    return peer->applicationId();
+}
+
+
+/*!
+    \fn void QtSingleCoreApplication::messageReceived(const QString& message)
+
+    This signal is emitted when the current instance receives a \a
+    message from another instance of this application.
+
+    \sa sendMessage()
+*/

src/qtsingleapplication/qtsinglecoreapplication.h

@@ -0,0 +1,71 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Solutions component.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
+**     of its contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QTSINGLECOREAPPLICATION_H
+#define QTSINGLECOREAPPLICATION_H
+
+#include <QCoreApplication>
+
+class QtLocalPeer;
+
+class QtSingleCoreApplication : public QCoreApplication
+{
+    Q_OBJECT
+
+public:
+    QtSingleCoreApplication(int &argc, char **argv);
+    QtSingleCoreApplication(const QString &id, int &argc, char **argv);
+
+    bool isRunning();
+    QString id() const;
+
+public Q_SLOTS:
+    bool sendMessage(const QString &message, int timeout = 5000);
+
+
+Q_SIGNALS:
+    void messageReceived(const QString &message);
+
+
+private:
+    QtLocalPeer* peer;
+};
+
+#endif // QTSINGLECOREAPPLICATION_H

src/updater/detector.cpp

@@ -0,0 +1,11 @@
+#include "updater/detector.h"
+
+
+Detector::Detector(QObject *parent) : QObject(parent) {
+}
+
+void Detector::handleMessage(const QString &message) {
+  if (message == "app_is_running") {
+    qDebug("Detected another instance of RSS Guard/Updater was starting...");
+  }
+}

src/updater/detector.h

@@ -0,0 +1,17 @@
+#ifndef DETECTOR_H
+#define DETECTOR_H
+
+#include <QObject>
+
+
+class Detector : public QObject {
+    Q_OBJECT
+
+  public:
+    explicit Detector(QObject *parent = 0);
+
+  public slots:
+    void handleMessage(const QString& message);
+};
+
+#endif // DETECTOR_H

src/updater/main.cpp

@@ -0,0 +1,48 @@
+// This file is part of RSS Guard.
+//
+// Copyright (C) 2011-2014 by Martin Rotter <rotter.martinos@gmail.com>
+//
+// RSS Guard is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// RSS Guard 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with RSS Guard. If not, see <http://www.gnu.org/licenses/>.
+
+#include "qtsingleapplication/qtsinglecoreapplication.h"
+#include "updater/detector.h"
+
+#include <QTranslator>
+#include <QDebug>
+#include <QThread>
+
+
+int main(int argc, char *argv[]) {
+  // Instantiate base application object.
+  QtSingleCoreApplication application("rssguard", argc, argv);
+  qDebug("Instantiated QtSingleApplication class.");
+
+  // Check if main RSS Guard instance is running.
+  if (application.sendMessage("app_quit")) {
+    qDebug("RSS Guard application is running. Quitting it...");
+  }
+
+  Detector detector;
+
+  qDebug().nospace() << "Running updater in thread: \'" <<
+                        QThread::currentThreadId() << "\'.";
+
+  // Setup single-instance behavior.
+  QObject::connect(&application, SIGNAL(messageReceived(QString)),
+                   &detector, SLOT(handleMessage(QString)));
+
+  // Enter global event loop.
+  return QtSingleCoreApplication::exec();
+}
+