I am going to write program using Qt for some image processing and I want it to be able to run in non-gui mode (daemon mode?). I'm inspired by VLC player, which is "typically" GUI program, where you can configure it using GUI, but you can also run it in non-gui
option when it runs without GUI. Then it uses some configuration file created in GUI mode.
Question is how should be such a program design? Should be some program core, which is GUI independent and depending on options it is being connected with GUI interface?
Yes, you could use a "headless" or "gui" option for the binary using QCommandLineParser. Note that it is only available from 5.3, but the migration path is pretty smooth within the major series if you still do not use that.
#include <QApplication>
#include <QLabel>
#include <QDebug>
#include <QCommandLineParser>
#include <QCommandLineOption>
int main(int argc, char **argv)
{
QApplication application(argc, argv);
QCommandLineParser parser;
parser.setApplicationDescription("My program");
parser.addHelpOption();
parser.addVersionOption();
// A boolean option for running it via GUI (--gui)
QCommandLineOption guiOption(QStringList() << "gui", "Running it via GUI.");
parser.addOption(guiOption);
// Process the actual command line arguments given by the user
parser.process(application);
QLabel label("Runninig in GUI mode");
if (parser.isSet(guiOption))
label.show();
else
qDebug() << "Running in headless mode";
return application.exec();
}
TEMPLATE = app
TARGET = main
QT += widgets
SOURCES += main.cpp
qmake && make && ./main
qmake && make && ./main --gui
Usage: ./main [options]
My program
Options:
-h, --help Displays this help.
-v, --version Displays version information.
--gui Running it via GUI.