Completly rewritten and simplified source

README.md

@@ -2,6 +2,3 @@ SingleApplication
 =================
 
 This is a replacement of QSingleApplication for Qt5.
-
-P.S. I will document it dome day, when I have time.
-Otherwise it is pretty straighforward. I added a signal to notify the root proccess that another instance had been started. You can use it to raise the Main window of the root app, for example.

localserver.cpp

@@ -1,129 +0,0 @@
-#include "localserver.h"
-
-#include <QFile>
-#include <QStringList>
-
-/**
- * @brief LocalServer::LocalServer
- *  Constructor
- */
-LocalServer::LocalServer()
-{
-
-}
-
-/**
- * @brief LocalServer::~LocalServer
- *  Destructor
- */
-LocalServer::~LocalServer()
-{
-  server->close();
-  for(int i = 0; i < clients.size(); ++i)
-  {
-    clients[i]->close();
-  }
-}
-
-/**
- * -----------------------
- * QThread requred methods
- * -----------------------
- */
-
-/**
- * @brief run
- *  Initiate the thread.
- */
-void LocalServer::run()
-{
-  server = new QLocalServer();
-
-  QObject::connect(server, SIGNAL(newConnection()), this, SLOT(slotNewConnection()));
-  QObject::connect(this, SIGNAL(privateDataReceived(QString)), this, SLOT(slotOnData(QString)));
-
-#ifdef Q_OS_UNIX
-  // Make sure the temp address file is deleted
-  QFile address(QString("/tmp/" LOCAL_SERVER_NAME));
-  if(address.exists()){
-    address.remove();
-  }
-#endif
-
-  QString serverName = QString(LOCAL_SERVER_NAME);
-  server->listen(serverName);
-  while(server->isListening() == false){
-    server->listen(serverName);
-    msleep(100);
-  }
-  exec();
-}
-
-/**
- * @brief LocalServer::exec
- *  Keeps the thread alive. Waits for incomming connections
- */
-void LocalServer::exec()
-{
-  while(server->isListening())
-  {
-    msleep(100);
-    server->waitForNewConnection(100);
-    for(int i = 0; i < clients.size(); ++i)
-    {
-      if(clients[i]->waitForReadyRead(100)){
-        QByteArray data = clients[i]->readAll();
-        emit privateDataReceived(data);
-      }
-    }
-  }
-}
-
-/**
- * -------
- * SLOTS
- * -------
- */
-
-/**
- * @brief LocalServer::slotNewConnection
- *  Executed when a new connection is available
- */
-void LocalServer::slotNewConnection()
-{
-  clients.push_front(server->nextPendingConnection());
-}
-
-/**
- * @brief LocalServer::slotOnData
- *  Executed when data is received
- * @param data
- */
-void LocalServer::slotOnData(QString data)
-{
-  if(data.contains("CMD:", Qt::CaseInsensitive)){
-    onSGC(data);
-  } else {
-    emit dataReceived(data);
-  }
-}
-
-/**
- * -------
- * Helper methods
- * -------
- */
-
-void LocalServer::onCMD(QString data)
-{
-  //  Trim the leading part from the command
-  data.replace(0, 4, "");
-
-  QStringList commands;
-  commands << "showUp";
-
-  switch(commands.indexOf(data)){
-    case 0:
-      emit showUp();
-  }
-}

localserver.h

@@ -1,37 +0,0 @@
-#ifndef LOCALSERVER_H
-#define LOCALSERVER_H
-
-#include <QThread>
-#include <QVector>
-#include <QLocalServer>
-#include <QLocalSocket>
-
-class LocalServer : public QThread
-{
-  Q_OBJECT
-public:
-  LocalServer();
-  ~LocalServer();
-  void shut();
-
-protected:
-  void run();
-  void exec();
-
-signals:
-  void dataReceived(QString data);
-  void privateDataReceived(QString data);
-  void showUp();
-
-private slots:
-  void slotNewConnection();
-  void slotOnData(QString data);
-
-private:
-  QLocalServer* server;
-  QVector<QLocalSocket*> clients;
-  void onCMD(QString data);
-
-};
-
-#endif // LOCALSERVER_H

main.cpp

@@ -1,11 +0,0 @@
-#include "singleapplication.h"
-
-int main(int argc, char *argv[])
-{
-  SingleApplication app(argc, argv);
-
-  // Is another instance of the program is already running
-  if(!app.shouldContinue())return 0;
-
-  return app.exec();
-}

singleapplication.cpp

@@ -1,61 +1,52 @@
 #include "singleapplication.h"
+#include <cstdlib>
 
 /**
- * @brief SingleApplication::SingleApplication
- *  Constructor. Checks and fires up LocalServer or closes the program
+ * @brief Constructor. Checks and fires up LocalServer or closes the 
+program
  * if another instance already exists
  * @param argc
  * @param argv
  */
-SingleApplication::SingleApplication(int argc, char *argv[]) :
-  QGuiApplication(argc, argv)
+SingleApplication::SingleApplication(int argc, char *argv[])
+    : QApplication(argc, argv)
 {
-  _shouldContinue = false; // By default this is not the main process
-
-  socket = new QLocalSocket();
+    QString serverName = QApplication::organizationName() + 
+QApplication::applicationName();
+    serverName.replace(QRegExp("\\s"), "");
 
     // Attempt to connect to the LocalServer
-  socket->connectToServer(LOCAL_SERVER_NAME);
-  if(socket->waitForConnected(100)){
-    socket->write("CMD:showUp");
-    socket->flush();
-    QThread::msleep(100);
+    socket = new QLocalSocket();
+    socket->connectToServer(serverName);
+    if(socket->waitForConnected(1000)){
         socket->close();
+        ::exit(EXIT_SUCCESS); // Terminate the program using STDLib's 
+exit function
     } else {
-    // The attempt was insuccessful, so we continue the program
-    _shouldContinue = true;
-    server = new LocalServer();
-    server->start();
-    QObject::connect(server, SIGNAL(showUp()), this, SLOT(slotShowUp()));
+        // If the connection is insuccessful, this is the main process
+        // So we create a Local Server
+        server = new QLocalServer();
+        server->removeServer(serverName);
+        server->listen(serverName);
+        QObject::connect(server, SIGNAL(newConnection()), this, 
+SLOT(slotConnectionEstablished()));
     }
 }
 
 /**
- * @brief SingleApplication::~SingleApplication
- *  Destructor
+ * @brief Destructor
  */
-Application::~SingleApplication()
+SingleApplication::~SingleApplication()
 {
-  if(_shouldContinue){
-    server->terminate();
-  }
+    server->close();
 }
 
 /**
- * @brief SingleApplication::shouldContinue
- *  Weather the program should be terminated
- * @return bool
+ * @brief Executed when the showUp command is sent to LocalServer
  */
-bool SingleApplication::shouldContinue()
-{
-  return _shouldContinue;
-}
-
-/**
- * @brief SingleApplication::slotShowUp
- *  Executed when the showUp command is sent to LocalServer
- */
-void SingleApplication::slotShowUp()
+void SingleApplication::slotConnectionEstablished()
 {
+    server->nextPendingConnection();
     emit showUp();
 }
+

singleapplication.h

@@ -1,33 +1,33 @@
-#ifndef APPLICATION_H
-#define APPLICATION_H
+#ifndef SINGLE_APPLICATION_H
+#define SINGLE_APPLICATION_H
 
-#include "localserver.h"
-
-#include <QGuiApplication>
+#include <QApplication>
 #include <QLocalSocket>
+#include <QLocalServer>
 
 /**
- * @brief The Application class handles trivial application initialization procedures
+ * @brief The SingleApplication class handles multipe instances of the 
+same Application
+ * @see QApplication
  */
-class SingleApplication : public QGuiApplication
+class SingleApplication : public QApplication
 {
   Q_OBJECT
 public:
   explicit SingleApplication(int, char *[]);
   ~SingleApplication();
-  bool shouldContinue();
 
 signals:
   void showUp();
 
 private slots:
-  void slotShowUp();
+  void slotConnectionEstablished();
 
 private:
   QLocalSocket *socket;
-  LocalServer* server;
-  bool _shouldContinue;
+  QLocalServer *server;
 
 };
 
-#endif // APPLICATION_H
+#endif // SINGLE_APPLICATION_H
+