Apply font scaling and font weight settings under Android

tray/android/src/io/github/martchus/syncthingtray/Activity.java

@@ -2,6 +2,7 @@
 
 import android.content.ActivityNotFoundException;
 import android.content.Intent;
+import android.content.res.Configuration;
 import android.media.MediaScannerConnection;
 import android.os.Build;
 import android.os.Bundle;
@@ -23,6 +24,8 @@
 
 public class Activity extends QtActivity {
     private static final String TAG = "SyncthingActivity";
+    private float m_fontScale = 1.0f;
+    private int m_fontWeightAdjustment = 0;
 
     public boolean performHapticFeedback() {
         View rootView = getWindow().getDecorView().getRootView();
@@ -116,10 +119,27 @@ void handleSendText(Intent intent) {
         }
     }
 
+    public float fontScale() {
+        return m_fontScale;
+    }
+
+    public int fontWeightAdjustment() {
+        return m_fontWeightAdjustment;
+    }
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         Log.i(TAG, "Creating");
         super.onCreate(savedInstanceState);
+
+        // read font scale as Qt does not handle this automatically on Android
+        Configuration config = getResources().getConfiguration();
+        m_fontScale = config.fontScale;
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+            m_fontWeightAdjustment = config.fontWeightAdjustment;
+        }
+
+        // read text another app might have shared with us
         Intent intent = getIntent();
         String action = intent.getAction();
         String type = intent.getType();

tray/gui/qml/Main.qml

@@ -412,10 +412,15 @@ ApplicationWindow {
         onAccepted: pageStack.pop(true)
     }
 
-    // handle global keyboard and mouse events
     Component.onCompleted: {
+        // propagate palette of Qt Quick Controls 2 style to regular QPalette of QGuiApplication for icon rendering
         App.setPalette(Material.foreground, Material.background);
 
+        // apply font scaling (on platforms where additional scaling is necassary because Qt doesn't do it such as Android)
+        window.font.pixelSize *= App.fontScale;
+        window.font.weight += App.fontWeightAdjustment;
+
+        // handle global keyboard and mouse events
         window.contentItem.forceActiveFocus(Qt.ActiveWindowFocusReason);
         window.contentItem.Keys.released.connect((event) => {
             const key = event.key;

tray/gui/quick/app.cpp

@@ -559,6 +559,24 @@ DiffHighlighter *App::createDiffHighlighter(QTextDocument *parent)
     return new DiffHighlighter(parent);
 }
 
+float App::fontScale() const
+{
+#ifdef Q_OS_ANDROID
+    return QJniObject(QNativeInterface::QAndroidApplication::context()).callMethod<jfloat>("fontScale", "()F");
+#else
+    return 1.0f;
+#endif
+}
+
+int App::fontWeightAdjustment() const
+{
+#ifdef Q_OS_ANDROID
+    return QJniObject(QNativeInterface::QAndroidApplication::context()).callMethod<jint>("fontWeightAdjustment", "()I");
+#else
+    return 0;
+#endif
+}
+
 bool App::eventFilter(QObject *object, QEvent *event)
 {
     if (object != m_app) {

tray/gui/quick/app.h

@@ -73,6 +73,8 @@ class App : public QObject {
     Q_PROPERTY(QIcon statusIcon READ statusIcon NOTIFY statusInfoChanged)
     Q_PROPERTY(QString additionalStatusText READ additionalStatusText NOTIFY statusInfoChanged)
     Q_PROPERTY(bool scanSupported READ isScanSupported CONSTANT)
+    Q_PROPERTY(float fontScale READ fontScale CONSTANT)
+    Q_PROPERTY(int fontWeightAdjustment READ fontWeightAdjustment CONSTANT)
     QML_ELEMENT
     QML_SINGLETON
 
@@ -201,6 +203,8 @@ class App : public QObject {
         return false;
 #endif
     }
+    float fontScale() const;
+    int fontWeightAdjustment() const;
 
     // helper functions invoked from QML
     Q_INVOKABLE bool loadMain();