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QtQuick Controls have been updated to a version 2 in Qt 5.7. For now, in the code, we use QtQuick Controls 1. The aim of this task is to see what needs to be changed, and how we can change them (for example Styles have been removed but we still have to have our own styles for buttons and other items). Phabricator task: https://phabricator.kde.org/T10168 Qt Quick page: https://doc.qt.io/qt-5.11/qtquickcontrols2-differences.html