About page

Informations about your application

Kirigami.AboutPage allows you to have a page that shows the copyright notice of the application together with the list of contributors and some information of which platform it's running on.

First, we are going to edit our main.cpp file from previous tutorials.

main.cpp

#include <QApplication>
#include <QQmlApplicationEngine>
#include <QtQml>
#include <QUrl>
#include <KAboutData>
#include <KLocalizedContext>
#include <KLocalizedString>

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

    QApplication app(argc, argv);

    KLocalizedString::setApplicationDomain("helloworld");
    QCoreApplication::setOrganizationName(QStringLiteral("KDE"));
    QCoreApplication::setOrganizationDomain(QStringLiteral("kde.org"));
    QCoreApplication::setApplicationName(QStringLiteral("Hello World"));

    if (qEnvironmentVariableIsEmpty("QT_QUICK_CONTROLS_STYLE")) {
        QQuickStyle::setStyle(QStringLiteral("org.kde.desktop"));
    }

    KAboutData aboutData(
        QStringLiteral("helloworld"),
        i18nc("@title", "Hello World"),
        QStringLiteral("1.0"),
        i18n("Hello world application"),
        KAboutLicense::GPL,
        i18n("(c) 2021"));

    aboutData.addAuthor(
        i18nc("@info:credit", "Your name"),
        i18nc("@info:credit", "Author Role"),
        QStringLiteral("[email protected]"),
        QStringLiteral("https://yourwebsite.com"));

    // Set aboutData as information about the app
    KAboutData::setApplicationData(aboutData);

    // Register a singleton that will be accessible from QML.
    qmlRegisterSingletonType(
        "org.kde.example", // How the import statement should look like
        1, 0, // Major and minor versions of the import
        "About", // The name of the QML object
        [](QQmlEngine* engine, QJSEngine *) -> QJSValue {
            // Here we retrieve our aboutData and give it to the QML engine
            // to turn it into a QML type
            return engine->toScriptValue(KAboutData::applicationData());
        }
    );

    // Load an application from a QML file
    QQmlApplicationEngine engine;

    engine.rootContext()->setContextObject(new KLocalizedContext(&engine));
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

    if (engine.rootObjects().isEmpty()) {
        return -1;
    }

    return app.exec();
}

In the main.cpp file we include KAboutData, a core KDE frameworks component that lets us store information about our application. This information can then be reused by many other KDE Frameworks components. We instantiate a new aboutData object with its fairly complete default constructor and add author information.

After all the required information has been set, we call KAboutData::setApplicationData to initialize the properties of the QApplication object.

We then create a qmlRegisterSingletonType(). This is used to allow us to import the C++ code as a module in our main.qml with import org.kde.example 1.0.

Its first argument is the URI that will be used for the import, the second and third arguments are major and minor versions respectively, the fourth is the type name, the name that we will call when accessing our About type, and the last is a reference to the C++ object that is exposed to QML. In the latter's case, we use a lambda to instantiate the aboutData of our application in place.

main.qml

import QtQuick
import QtQuick.Layouts
import QtQuick.Controls as Controls
import org.kde.kirigami as Kirigami

import org.kde.example 1.0

Kirigami.ApplicationWindow {
    id: root

    title: i18nc("@title:window", "Day Kountdown")

    globalDrawer: Kirigami.GlobalDrawer {
        isMenu: true
        actions: [
            Kirigami.Action {
                text: i18n("Quit")
                icon.name: "gtk-quit"
                shortcut: StandardKey.Quit
                onTriggered: Qt.quit()
            },

            Kirigami.Action { // <==== Action to open About page
                text: i18n("About")
                icon.name: "help-about"
                onTriggered: pageStack.layers.push(aboutPage)
            }
        ]
    }

    Component { // <==== Component that instantiates the Kirigami.AboutPage
        id: aboutPage

        Kirigami.AboutPage {
            aboutData: About
        }
    }

    ListModel {
        id: kountdownModel
    }

    AddEditSheet {
        id: addEditSheet
        onAdded: kountdownModel.append({
            "name": name,
            "description": description,
            "date": Date.parse(kdate)
        });
        onEdited: kountdownModel.set(index, {
            "name": name,
            "description": description,
            "date": Date.parse(kdate)
        });
        onRemoved: kountdownModel.remove(index, 1)
    }

    function openPopulatedSheet(mode, index = -1, listName = "", listDesc = "", listDate = "") {
        addEditSheet.mode = mode
        addEditSheet.index = index;
        addEditSheet.name = listName
        addEditSheet.description = listDesc
        addEditSheet.kdate = listDate

        addEditSheet.open()
    }


    pageStack.initialPage: Kirigami.ScrollablePage {
        title: i18nc("@title", "Kountdown")

        actions: [
            Kirigami.Action {
                id: addAction
                icon.name: "list-add"
                text: i18nc("@action:button", "Add kountdown")
                onTriggered: openPopulatedSheet("add")
            }
        ]

        Kirigami.CardsListView {
            id: layout
            model: kountdownModel
            delegate: KountdownDelegate {}
        }
    }
}

First, we use the import we defined in the main.cpp file, namely org.kde.example. We then add a Kirigami.Action to our global drawer that will send us to the About page, and create a component with a Kirigami.AboutPage in it, which expects a KAboutData::applicationData() object. We exposed precisely that in our main.cpp and called it About, so we can pass it here.

CMakeLists

cmake_minimum_required(VERSION 3.16)
project(helloworld)

find_package(ECM REQUIRED NO_MODULE)

set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH})

include(KDEInstallDirs)
include(KDECMakeSettings)
include(KDECompilerSettings NO_POLICY_SCOPE)

find_package(Qt6 REQUIRED NO_MODULE COMPONENTS
    Core
    Quick
    Test
    Gui
    QuickControls2
    Widgets
)

find_package(KF6 REQUIRED COMPONENTS
    Kirigami2
    I18n
    CoreAddons
)

add_subdirectory(src)

feature_summary(WHAT ALL INCLUDE_QUIET_PACKAGES FATAL_ON_MISSING_REQUIRED_PACKAGES)

In the CMakeLists.txt file in our top-level folder, be sure to have CoreAddons in your find_package() call. It is needed for KAboutData.

add_executable(helloworld)

target_sources(helloworld PRIVATE
    main.cpp
    resources.qrc
)

target_link_libraries(helloworld
    Qt6::Quick
    Qt6::Qml
    Qt6::Gui
    Qt6::QuickControls2
    Qt6::Widgets
    KF6::Kirigami2
    KF6::I18n
    KF6::CoreAddons
)

In the CMakeLists.txt file in the src/ directory, nothing is needed since we instantiated out aboutData in place.

Running the application

Now if you run your application and trigger the "About" action in the global drawer you should see our about page.

Screenshot of the Kirigami About Page