Open file in already open App



  • Hi,

    I am working on a tabbed code editor. I managed to associate a file type with my app but when I double click a second file the app started again. The idea was that the second file would be opened in the already open app as a second tab.

    This is my main.cpp. How can I modify it so that no duplicates of this app are started?

    #include "mainwindow.h"
    #include <QApplication>
    
    int main(int argc, char *argv[])
    {
        Q_INIT_RESOURCE(qrc);
    
        QApplication app(argc, argv);
        app.setStyleSheet("QSplitter::handle { background-color: #999999 }");
    
        QCoreApplication::setOrganizationName("innoBiz");
        QCoreApplication::setApplicationName("phpPad");
        QCoreApplication::setApplicationVersion(QT_VERSION_STR);
        QCommandLineParser parser;
        parser.setApplicationDescription(QCoreApplication::applicationName());
        parser.addHelpOption();
        parser.addVersionOption();
        parser.addPositionalArgument("file", "The file to open.");
        parser.process(app);
    
        MainWindow mainWin;
        if (!parser.positionalArguments().isEmpty()){
            QString path = parser.positionalArguments().first();
            path.replace(QString("\\"), QString("/"));
            mainWin.addEditor(path);
        }
        mainWin.show();
    
        return app.exec();
    }
    

    I copied this code from the Application Example. Actually I do not really understand how this parser thing works...

    Thanks for any help.


  • Moderators



  • Thanks for the link. I guess that is what I need.


  • Lifetime Qt Champion

    Hi,

    While the suggestion is correct, you should rather use http://code.qt.io/cgit/qt-solutions/qt-solutions.git/ which is the official repository. Github is just a mirror.



  • If been trying to get the qtsingleapplication class to work with no success. Is there another option out there, which is easier to implement?



  • I got the qtsingleapplicaiton "plugin" to work. My main.cpp looks like this now:

    #include "mainwindow.h"
    #include <QApplication>
    #include <qtsingleapplication.h>
    
    int main(int argc, char *argv[])
    {
        Q_INIT_RESOURCE(qrc);
    
        QtSingleApplication app(argc, argv);
    
        if (app.isRunning()){
            QString message;
            for (int a = 1; a < argc; ++a) {
                message += argv[a];
    
            if (a < argc-1)
                message += " ";
            }
    
            return !app.sendMessage(message);
        }
    
        app.setStyleSheet("QSplitter::handle { background-color: #999999 }");
    
        QCoreApplication::setOrganizationName("innoBiz");
        QCoreApplication::setApplicationName("phpPad");
        QCoreApplication::setApplicationVersion(QT_VERSION_STR);
        QCommandLineParser parser;
        parser.setApplicationDescription(QCoreApplication::applicationName());
        parser.addHelpOption();
        parser.addVersionOption();
        parser.addPositionalArgument("file", "The file to open.");
        parser.process(app);
    
        MainWindow mainWin;
        app.setActivationWindow(&mainWin);
        if (!parser.positionalArguments().isEmpty()){
            QStringList files = parser.positionalArguments();
            foreach(QString path, files){
                path.replace(QString("\\"), QString("/"));
                mainWin.addEditor(path);
            }
        }
        mainWin.show();
    
        QObject::connect(&app, SIGNAL(messageReceived(const QString&)), &mainWin,SLOT(handleAppOpenMessage(const QString&)));
    
        return app.exec();
    }
    

    In my MainWindow I added the slot handleAppOpenMessage(QString message) which does the same as the for each loop above

    message.replace(QString("\\"), QString("/"));
    addEditor(path);
    

    This is probably not a very nice bit of code but currently is is working on Windows. If someone likes to make a suggestion on how to do this better, I am open to feedback.

    I believe the for loop to build the message is not required. If I try to open e.g. three files on windows three messages are send and not one with three files.


  • Lifetime Qt Champion

    You can use QDir::fromNativeSeparators to convert your paths.


Log in to reply