lubuntu-update/main.cpp

#include "ipcfilewatcher.h"
#include "orchestrator.h"
#include "mainwindow.h"
#include "conffilehandlerdialog.h"

#include <QApplication>
#include <QDialog>
#include <QLocale>
#include <QProcess>
#include <QTranslator>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QTranslator translator;
    const QStringList uiLanguages = QLocale::system().uiLanguages();
    for (const QString &locale : uiLanguages) {
        const QString baseName = "lubuntu-update_" + QLocale(locale).name();
        if (translator.load(":/i18n/" + baseName)) {
            a.installTranslator(&translator);
            break;
        }
    }

    /*
     * If Lubuntu Update is already running, create
     * /dev/shm/lubuntu-update/lubuntu-update-show-win and exit. This will
     * trigger the existing process to pop up a window.
     */

    QProcess procDetector;
    procDetector.setProgram("/usr/bin/bash");
    procDetector.setArguments(QStringList() << "-c" << "ps axo comm | grep lubuntu-update");
    procDetector.start();
    procDetector.waitForFinished();
    QString procDetectResult = procDetector.readAllStandardOutput();
    procDetectResult = procDetectResult.trimmed();
    QStringList procDetectResultList = procDetectResult.split('\n');
    if (procDetectResultList.count() > 1) {
        QFile flagFile("/dev/shm/lubuntu-update/lubuntu-update-show-win");
        flagFile.open(QFile::WriteOnly);
        flagFile.close();
        return 0;
    }

    // Don't want the updater to stop just because the user closed it :P
    a.setQuitOnLastWindowClosed(false);

    /*
     * IPCFileWatcher just watches the /dev/shm/lubuntu-update folder for the
     * creation of a lubuntu-update-show-win file. If it detects it, it
     * immediately deletes it and emits a signal. This is then used later to
     * cause the updater window to pop up.
     */

    IPCFileWatcher *p = new IPCFileWatcher();

    if (p->didInitFail()) {
        return 1;
    }

    /*
     * As this is a background process, we don't pop up any window upon
     * startup. An Orchestrator object periodically checks to see if new
     * updates have been detected, and offers them to the user (by displaying
     * a tray icon) if so. The user can click on this tray icon to see the
     * updater window.
     *
     * Orchestrator's constructor automatically starts the update checker, so
     * there's no need to do anything with this except create it and then
     * start the event loop.
     */

    Orchestrator *o = new Orchestrator();

    QObject::connect(p, &IPCFileWatcher::showWindowFlagDetected, o, &Orchestrator::displayUpdater);

    /*
     * This is an artifact from testing the conffile handler window. You can
     * uncomment this and rebuild lubuntu-update in order to test the conffile
     * handler UI and develop it further.
     *
     * ConffileHandlerDialog cfhd(QStringList() << "/home/user/testfile");
     * cfhd.show();
     */

    return a.exec();
}