CLI Keyboard tool for KDE Plasma

README

Just a little keyboard layout tool for KDE Plasma.

I wrote this so I could swap between Dvorak and US when gaming. It isn't strictly necessary since
all my games run on Proton which renders via Xwayland (which you change the layout using setxkbmap),
but I like consistency, so I swap the layout for both Wayland and Xwayland at the same time.

Steam -> Launch Options:
  setxkbmap us; kdekbtool -i 1; %command%; setxkbmap dvorak; kdekbtool -i 0

Requires Qt, written/tested with Qt 6.5.2 and Plasma 5.27.5 (Qt 5.15.9) on Fedora 38

Just put both files into a directory then run "qmake . && make".

[doneill@galena build]$ ./kdekbtool -h
Usage: ./kdekbtool [options]
KDE Plasma Keyboard Tool

Options:
  -h, --help                   Displays help on commandline options.
  --help-all                   Displays help including Qt specific options.
  -v, --version                Displays version information.
  -q                           Get current keyboard layout
  -l                           Get list of keyboard layouts
  -i, --layout_id <layout_id>  Set current keyboard layout to <layout_id>.


The layout listing format is:
 index : layout : variant : name (user specified)

[doneill@galena build]$ kdekbtool -l
0 : us : dv : English (Dvorak)
1 : us :  : English (US)

kdekbtool.cpp

#include <QDBusInterface>
#include <QDBusMessage>
#include <QDBusReply>
#include <QDBusVariant>
#include <QDebug>
#include <QCommandLineOption>
#include <QCommandLineParser>
#include <QCoreApplication>

int getCurrentLayoutID()
{
    QDBusInterface query( "org.kde.keyboard", "/Layouts" );
    QDBusReply<quint32> reply = query.call("getLayout");
    if ( reply.isValid() )
        return reply.value();

    qInfo() << reply.error();
    return -1;
}

void setLayoutID(quint32 id)
{
    QDBusInterface query( "org.kde.keyboard", "/Layouts" );
    QDBusReply<bool> reply = query.call("setLayout", id);
    if( !reply.isValid() )
        qInfo() << reply.error();
}

QList< QMap<QString, QString> > getLayoutsList()
{
    QList< QMap<QString, QString> > result;
    QDBusInterface query( "org.kde.keyboard", "/Layouts" );
    QDBusMessage msg = query.call(QDBus::AutoDetect, "getLayoutsList");
    if( msg.type() != QDBusMessage::ReplyMessage )
    {
        qWarning() << "Invalid Reply";
        return QList< QMap<QString, QString> >();
    }

    QList< QVariant > args = msg.arguments();
    for( QVariant varg : args )
    {
        int x = 0;
        const QDBusArgument dbusarg = varg.value<QDBusArgument>();
        dbusarg.beginArray();
        while( !dbusarg.atEnd() && x++ < 20 )
        {
            dbusarg.beginStructure();
            QMap<QString, QString> ent;
            QString blarg, blorg, blag;
            dbusarg >> blarg >> blorg >> blag;
            dbusarg.endStructure();

            ent["layout"] = blarg;
            ent["variant"] = blorg;
            ent["name"] = blag;
            result.append( ent );
        }
        dbusarg.endArray();
    }

    return result;
}

int main(int argc, char **argv)
{
    QCoreApplication app(argc, argv);
    QCoreApplication::setApplicationName("kdekbtool");
    QCoreApplication::setApplicationVersion("1.0");

    auto connection = QDBusConnection::sessionBus();
    if (!connection.isConnected()) {
        qWarning("Cannot connect to the D-Bus session bus.\n"
                 "To start it, run:\n"
                 "\teval `dbus-launch --auto-syntax`\n");
        return 1;
    }

    QCommandLineParser parser;
    parser.setApplicationDescription("KDE Plasma Keyboard Tool");
    parser.addHelpOption();
    parser.addVersionOption();

    QCommandLineOption queryCurrentOption("q", QCoreApplication::translate("main", "Get current keyboard layout"));
    parser.addOption(queryCurrentOption);

    QCommandLineOption queryLayouts("l", QCoreApplication::translate("main", "Get list of keyboard layouts"));
    parser.addOption(queryLayouts);

    QCommandLineOption setLayoutOption(QStringList() << "i" << "layout_id",
            QCoreApplication::translate("main", "Set current keyboard layout to <layout_id>."),
            QCoreApplication::translate("main", "layout_id"));
    parser.addOption(setLayoutOption);

    parser.process(app);

    if( parser.isSet(setLayoutOption) )
    {
        const QString idxOption = parser.value(setLayoutOption);
        quint32 idx = idxOption.toInt();
        setLayoutID(idx);
    }

    if( parser.isSet(queryCurrentOption) )
    {
        int curId = getCurrentLayoutID();

        QList< QMap< QString, QString > > layouts = getLayoutsList();

        int x=0;
        for( QMap< QString, QString > ent : layouts )
        {
            if( curId != x )
            {
                x++;
                continue;
            }

            printf("%d : %s : %s : %s\n",
                   x,
                   ent["layout"].toStdString().c_str(),
                   ent["variant"].toStdString().c_str(),
                   ent["name"].toStdString().c_str());

            x++;
        }
    }

    if( parser.isSet(queryLayouts) )
    {
        QList< QMap< QString, QString > > layouts = getLayoutsList();

        int x=0;
        for( QMap< QString, QString > ent : layouts )
        {
            printf("%d : %s : %s : %s\n",
                   x++,
                   ent["layout"].toStdString().c_str(),
                   ent["variant"].toStdString().c_str(),
                   ent["name"].toStdString().c_str());
        }
    }

    return 0;
}

kdekbtool.pro

TARGET = kdekbtool
QT += core dbus
QT -= gui
SOURCES += kdekbtool.cpp