[ui] use configuration file

gui/components/Preferences.qml

@@ -9,8 +9,9 @@ ThemedPage {
 
     Column {
         id: prefCol
-        // FIXME the checkboxes seem to have a bigger lineHeight themselves, need to pack more.
-        spacing: 1
+        // FIXME checkboxes in Material style force lineHeights too big.
+        // need to override the style
+        // See: https://bugreports.qt.io/browse/QTBUG-95385
         topPadding: root.width * 0.05
         leftPadding: root.width * 0.1
         rightPadding: root.width * 0.15

gui/gui.qrc

@@ -2,6 +2,7 @@
     <qresource prefix="/">
 
         <file>main.qml</file>
+        <file>qtquickcontrols2.conf</file>
 
         <!-- gui components -->
         <file>themes/themes.js</file>

gui/main.cpp

@@ -173,6 +173,7 @@ int main(int argc, char **argv) {
 
     QJsonModel *model = new QJsonModel;
 
+    // FIXME use qgetenv
     QString desktop = QString::fromStdString(getEnv("XDG_CURRENT_DESKTOP"));
     QString debug = QString::fromStdString(getEnv("DEBUG"));
 
@@ -190,7 +191,10 @@ int main(int argc, char **argv) {
     ctx->setContextProperty("systrayAvailable", availableSystray);
     ctx->setContextProperty("qmlDebug", debug == "1");
 
-    QQuickStyle::setStyle("Material");
+    //XXX we're doing configuration via config file, but this is a mechanism
+    //to change to Dark Theme if desktop has it.
+    //qputenv("QT_QUICK_CONTROLS_MATERIAL_VARIANT", "Dense");
+    //QQuickStyle::setStyle("Material");
     engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
 
     /* connect the jsonChanged signal explicitely.

gui/qtquickcontrols2.conf

+[Controls]
+Style=Material
+
+[Material]
+Theme=Light
+Variant=Dense