Use QtQuick Controls 2 desktop style on the desktop

Also move some ifdef to a more modern style.

CMakeLists.txt

@@ -11,7 +11,7 @@ project(kalgebra VERSION ${RELEASE_SERVICE_VERSION})
 find_package(ECM 1.7.0 REQUIRED NO_MODULE)
 set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake" ${ECM_MODULE_PATH})
 
-find_package(Qt5 5.2 REQUIRED NO_MODULE COMPONENTS Qml Quick Xml Svg PrintSupport Test)
+find_package(Qt5 5.14 REQUIRED NO_MODULE COMPONENTS Qml Quick Xml Svg PrintSupport Test)
 include(KDEInstallDirs)
 include(KDECompilerSettings NO_POLICY_SCOPE)
 include(KDECMakeSettings)

mobile/CMakeLists.txt

@@ -12,13 +12,17 @@ target_link_libraries(kalgebramobile Qt5::Qml Qt5::Quick Qt5::Gui
 
 set(DESKTOPFILE_INSTALL ${KDE_INSTALL_APPDIR})
 
-if(CMAKE_SYSTEM_NAME STREQUAL "Android")
+if(ANDROID)
 #   Material requires QtSvg for icons
 #   if we don't link it here explicitly, androiddeployqt doesn't bring it
     find_package(Qt5Svg REQUIRED)
+    find_package(Qt5QuickControls2 REQUIRED)
     find_package(KF5Kirigami2 REQUIRED)
     kirigami_package_breeze_icons(ICONS list-add)
-    target_link_libraries(kalgebramobile Qt5::Svg KF5::Kirigami2)
+    target_link_libraries(kalgebramobile Qt5::Svg KF5::Kirigami2 Qt5::QuickControls2)
+else()
+    find_package(Qt5Widgets REQUIRED)
+    target_link_libraries(kalgebramobile Qt5::Widgets)
 endif()
 
 install(TARGETS kalgebramobile ${KDE_INSTALL_TARGETS_DEFAULT_ARGS})

mobile/main.cpp

@@ -17,6 +17,10 @@
  *************************************************************************************/
 
 #include <QGuiApplication>
+#ifndef Q_OS_ANDROID
+#include <QApplication>
+#include <QQuickStyle>
+#endif
 
 #include <KLocalizedContext>
 #include <KLocalizedString>
@@ -38,11 +42,15 @@
 
 Q_DECL_EXPORT int main(int argc, char *argv[])
 {
-#ifdef __ANDROID__
-    qputenv("QT_QUICK_CONTROLS_STYLE", "Material");
+#ifdef Q_OS_ANDROID
+    QQuickStyle::setStyle("Material");
 #endif
     QGuiApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
+#ifdef Q_OS_ANDROID
     QGuiApplication app(argc, argv);
+#else
+    QApplication app(argc, argv);
+#endif
     KLocalizedString::setApplicationDomain("kalgebramobile");
     KAboutData about(QStringLiteral("kalgebramobile"), QStringLiteral("KAlgebra"), QStringLiteral(KALGEBRA_VERSION_STRING), i18n("A portable calculator"),
              KAboutLicense::GPL, i18n("(C) 2006-2020 Aleix Pol i Gonzalez"));