plasma-framework/tests/components/ComponentBase.qml

import QtQuick 2.0
import QtQuick.Layouts 1.2
import org.kde.plasma.core 2.0 as PlasmaCore
import org.kde.plasma.components 3.0 as PlasmaComponents
import org.kde.plasma.extras 2.0 as PlasmaExtras

PlasmaComponents.Page {
    id: mainPage
    title: "Test"
    width: Math.max(mainPage.contentWidth, mainPage.implicitHeaderWidth, mainPage.implicitFooterWidth)
        + leftPadding + rightPadding
    height: mainPage.contentHeight + mainPage.implicitHeaderHeight + mainPage.implicitFooterHeight
        + topPadding + bottomPadding

    padding: PlasmaCore.Units.gridUnit

    header: PlasmaComponents.ToolBar {
        leftPadding: mainPage.padding
        rightPadding: mainPage.padding
        contentItem: PlasmaExtras.Heading {
            text: mainPage.title
            /* FIXME: this line is needed to prevent vertical pixel
             * misalignment of controls, such as checkboxes.
             * The cause of the problem is unknown.
             */
            level: 2
        }
    }

    background: Rectangle {
        color:  PlasmaCore.ColorScope.backgroundColor
    }
}