App 2.19.2: Full screen for CarPlay (experiment)

Adds com.allgo.carplay.service to immersive.full in Android 9's
policy_control setting when switched on, removes only that entry when
off. Car build (system user) only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LhzAVaUyqcw5PkGjz4mWW6

app/build.gradle

@@ -34,8 +34,8 @@ android {
         applicationId "com.stinnesbeck.nilsmg4"
         minSdk 27
         targetSdk 36
-        versionCode 100
-        versionName "2.19.1"
+        versionCode 101
+        versionName "2.19.2"
 
         // Nothing about the server ships in the APK: its URL and ingest token are entered in
         // the app's Server tab (ServerConfig), and the database is only reachable by the server.

app/src/main/java/com/evsuite/abrp/MainActivity.java

@@ -1066,6 +1066,56 @@ public class MainActivity extends AppCompatActivity {
 
     // ---------- Upload page ----------
 
+    /** The car's CarPlay app, as the Logs tab's foreground list showed it on SWI68. */
+    private static final String CARPLAY_PACKAGE = "com.allgo.carplay.service";
+
+    /**
+     * Experiment: forces CarPlay into immersive mode through Android 9's policy_control setting.
+     * The switch shows what the setting holds, not a preference, and switching off removes only
+     * our entry. Writing it needs WRITE_SECURE_SETTINGS, which only the car build (system user)
+     * has; elsewhere the switch is disabled.
+     */
+    private void bindCarPlayFullScreen() {
+        com.google.android.material.switchmaterial.SwitchMaterial sw =
+                settingsPane.findViewById(R.id.carplay_full_screen_switch);
+        boolean mayWrite = checkSelfPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
+                == android.content.pm.PackageManager.PERMISSION_GRANTED;
+        String current = android.provider.Settings.Global.getString(getContentResolver(), PolicyControl.KEY);
+        sw.setOnCheckedChangeListener(null);
+        sw.setChecked(PolicyControl.hasFull(current, CARPLAY_PACKAGE));
+        sw.setEnabled(mayWrite);
+        if (!mayWrite) {
+            ((TextView) settingsPane.findViewById(R.id.carplay_full_screen_hint))
+                    .setText(R.string.hint_carplay_full_screen_unavailable);
+            return;
+        }
+        sw.setOnCheckedChangeListener((btn, checked) -> diagReader.execute(() -> {
+            boolean ok;
+            try {
+                android.content.ContentResolver cr = getContentResolver();
+                String before = android.provider.Settings.Global.getString(cr, PolicyControl.KEY);
+                String after = checked ? PolicyControl.withFull(before, CARPLAY_PACKAGE)
+                        : PolicyControl.withoutFull(before, CARPLAY_PACKAGE);
+                android.provider.Settings.Global.putString(cr, PolicyControl.KEY, after);
+                String now = android.provider.Settings.Global.getString(cr, PolicyControl.KEY);
+                ok = PolicyControl.hasFull(now, CARPLAY_PACKAGE) == checked;
+                android.util.Log.i("EVABRP.Settings", "policy_control " + (checked ? "on" : "off") + ": " + now);
+            } catch (RuntimeException e) {
+                android.util.Log.w("EVABRP.Settings", "policy_control not written", e);
+                ok = false;
+            }
+            final boolean written = ok;
+            runOnUiThread(() -> {
+                if (isDestroyed()) return;
+                if (!written) {
+                    Toast.makeText(this, R.string.carplay_full_screen_failed, Toast.LENGTH_LONG).show();
+                    bindCarPlayFullScreen();
+                }
+                refreshForeground();
+            });
+        }));
+    }
+
     private void bindServicePane() {
         voiceKeySwitch = settingsPane.findViewById(R.id.voice_key_switch);
         voiceKeySwitch.setChecked(UploadSettings.voiceKeyOpensApp(prefs));
@@ -1079,6 +1129,7 @@ public class MainActivity extends AppCompatActivity {
             prefs.edit().putBoolean(UploadSettings.KEY_FULL_SCREEN, checked).apply();
             applyFullScreen();
         });
+        bindCarPlayFullScreen();
         liveTelemetrySwitch = servicePane.findViewById(R.id.abrp_upload_switch);
         intervalChoices = servicePane.findViewById(R.id.interval_choices);
         boostSwitch = servicePane.findViewById(R.id.boost_switch);

app/src/main/java/com/evsuite/abrp/PolicyControl.java

@@ -0,0 +1,79 @@
+package com.evsuite.abrp;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * The value of Android 9's {@code policy_control} global setting, which forces other apps into
+ * immersive mode: {@code immersive.full=pkg1,pkg2:immersive.status=pkg3}. This adds or removes
+ * one package in {@code immersive.full} and leaves every other entry as it was, so switching
+ * our experiment off restores what was there before. Pure Java, so it is unit-tested.
+ */
+final class PolicyControl {
+
+    static final String KEY = "policy_control";
+    static final String FULL = "immersive.full";
+
+    private PolicyControl() {}
+
+    /** Whether {@code pkg} is named in {@code immersive.full}. */
+    static boolean hasFull(String value, String pkg) {
+        List<String> list = parse(value).get(FULL);
+        return list != null && list.contains(pkg);
+    }
+
+    /** {@code value} with {@code pkg} added to {@code immersive.full}. */
+    static String withFull(String value, String pkg) {
+        Map<String, List<String>> map = parse(value);
+        List<String> list = map.get(FULL);
+        if (list == null) {
+            list = new ArrayList<>();
+            map.put(FULL, list);
+        }
+        if (!list.contains(pkg)) list.add(pkg);
+        return format(map);
+    }
+
+    /** {@code value} without {@code pkg} in {@code immersive.full}; null when nothing is left. */
+    static String withoutFull(String value, String pkg) {
+        Map<String, List<String>> map = parse(value);
+        List<String> list = map.get(FULL);
+        if (list != null) {
+            list.remove(pkg);
+            if (list.isEmpty()) map.remove(FULL);
+        }
+        return format(map);
+    }
+
+    private static Map<String, List<String>> parse(String value) {
+        Map<String, List<String>> map = new LinkedHashMap<>();
+        if (value == null) return map;
+        for (String part : value.split(":")) {
+            int eq = part.indexOf('=');
+            if (eq <= 0) continue;
+            String name = part.substring(0, eq).trim();
+            List<String> list = map.get(name);
+            if (list == null) {
+                list = new ArrayList<>();
+                map.put(name, list);
+            }
+            for (String p : part.substring(eq + 1).split(",")) {
+                String t = p.trim();
+                if (!t.isEmpty() && !list.contains(t)) list.add(t);
+            }
+        }
+        return map;
+    }
+
+    private static String format(Map<String, List<String>> map) {
+        StringBuilder sb = new StringBuilder();
+        for (Map.Entry<String, List<String>> e : map.entrySet()) {
+            if (e.getValue().isEmpty()) continue;
+            if (sb.length() > 0) sb.append(':');
+            sb.append(e.getKey()).append('=').append(String.join(",", e.getValue()));
+        }
+        return sb.length() == 0 ? null : sb.toString();
+    }
+}

app/src/main/res/layout-w1000dp/pane_settings.xml

@@ -10,14 +10,22 @@
                 <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/hint_full_screen" android:textAppearance="@style/Text.EV.Secondary" />
                 <com.google.android.material.switchmaterial.SwitchMaterial android:id="@+id/voice_key_switch" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:text="@string/label_voice_key" android:textAppearance="@style/Text.EV.Body" android:paddingTop="8dp" android:paddingBottom="8dp" app:useMaterialThemeColors="true" app:thumbTint="@color/switch_thumb" app:trackTint="@color/switch_track" android:textColor="@color/ev_text_primary" />
                 <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/hint_voice_key" android:textAppearance="@style/Text.EV.Secondary" />
-                <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/label_tire_unit" android:textAppearance="@style/Text.EV.Body" android:layout_marginTop="8dp" />
-                <com.google.android.material.textfield.TextInputLayout style="@style/Widget.EV.Dropdown" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="4dp">
-                    <com.google.android.material.textfield.MaterialAutoCompleteTextView android:id="@+id/tire_unit_choices" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:inputType="none" android:textSize="20sp" app:simpleItemLayout="@layout/dropdown_item" />
-                </com.google.android.material.textfield.TextInputLayout>
-                <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/label_accent" android:textAppearance="@style/Text.EV.Body" android:layout_marginTop="8dp" />
-                <com.google.android.material.textfield.TextInputLayout style="@style/Widget.EV.Dropdown" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="4dp">
-                    <com.google.android.material.textfield.MaterialAutoCompleteTextView android:id="@+id/accent_choices" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:inputType="none" android:textSize="20sp" app:simpleItemLayout="@layout/dropdown_item" />
-                </com.google.android.material.textfield.TextInputLayout>
+                <com.google.android.material.switchmaterial.SwitchMaterial android:id="@+id/carplay_full_screen_switch" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:text="@string/label_carplay_full_screen" android:textAppearance="@style/Text.EV.Body" android:paddingTop="8dp" android:paddingBottom="8dp" app:useMaterialThemeColors="true" app:thumbTint="@color/switch_thumb" app:trackTint="@color/switch_track" android:textColor="@color/ev_text_primary" />
+                <TextView android:id="@+id/carplay_full_screen_hint" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/hint_carplay_full_screen" android:textAppearance="@style/Text.EV.Secondary" />
+                <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:baselineAligned="false">
+                    <LinearLayout android:layout_width="0dp" android:layout_weight="2" android:layout_height="wrap_content" android:layout_marginEnd="12dp" android:orientation="vertical">
+                        <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/label_tire_unit" android:textAppearance="@style/Text.EV.Body" android:layout_marginTop="8dp" />
+                        <com.google.android.material.textfield.TextInputLayout style="@style/Widget.EV.Dropdown" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="4dp">
+                            <com.google.android.material.textfield.MaterialAutoCompleteTextView android:id="@+id/tire_unit_choices" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:inputType="none" android:textSize="20sp" app:simpleItemLayout="@layout/dropdown_item" />
+                        </com.google.android.material.textfield.TextInputLayout>
+                    </LinearLayout>
+                    <LinearLayout android:layout_width="0dp" android:layout_weight="3" android:layout_height="wrap_content" android:orientation="vertical">
+                        <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/label_accent" android:textAppearance="@style/Text.EV.Body" android:layout_marginTop="8dp" />
+                        <com.google.android.material.textfield.TextInputLayout style="@style/Widget.EV.Dropdown" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="4dp">
+                            <com.google.android.material.textfield.MaterialAutoCompleteTextView android:id="@+id/accent_choices" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:inputType="none" android:textSize="20sp" app:simpleItemLayout="@layout/dropdown_item" />
+                        </com.google.android.material.textfield.TextInputLayout>
+                    </LinearLayout>
+                </LinearLayout>
             </LinearLayout>
         </LinearLayout>
         <LinearLayout android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:orientation="vertical" android:layout_marginEnd="16dp">

app/src/main/res/layout/pane_settings.xml

@@ -7,6 +7,8 @@
             <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/hint_full_screen" android:textAppearance="@style/Text.EV.Secondary" />
             <com.google.android.material.switchmaterial.SwitchMaterial android:id="@+id/voice_key_switch" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:text="@string/label_voice_key" android:textAppearance="@style/Text.EV.Body" android:paddingTop="8dp" android:paddingBottom="8dp" app:useMaterialThemeColors="true" app:thumbTint="@color/switch_thumb" app:trackTint="@color/switch_track" android:textColor="@color/ev_text_primary" />
             <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/hint_voice_key" android:textAppearance="@style/Text.EV.Secondary" />
+            <com.google.android.material.switchmaterial.SwitchMaterial android:id="@+id/carplay_full_screen_switch" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:text="@string/label_carplay_full_screen" android:textAppearance="@style/Text.EV.Body" android:paddingTop="8dp" android:paddingBottom="8dp" app:useMaterialThemeColors="true" app:thumbTint="@color/switch_thumb" app:trackTint="@color/switch_track" android:textColor="@color/ev_text_primary" />
+            <TextView android:id="@+id/carplay_full_screen_hint" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/hint_carplay_full_screen" android:textAppearance="@style/Text.EV.Secondary" />
             <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/label_tire_unit" android:textAppearance="@style/Text.EV.Body" android:layout_marginTop="20dp" />
             <com.google.android.material.textfield.TextInputLayout style="@style/Widget.EV.Dropdown" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="12dp">
                 <com.google.android.material.textfield.MaterialAutoCompleteTextView android:id="@+id/tire_unit_choices" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:inputType="none" android:textSize="20sp" app:simpleItemLayout="@layout/dropdown_item" />

app/src/main/res/values/strings.xml

@@ -28,7 +28,7 @@
     <string name="vehicle_row_power_average">Power, 5-min average</string>
     <string name="power_kw">%1$.1f kW</string>
     <string name="power_waiting">needs a minute of data</string>
-    <string name="label_tire_unit">Tyre pressure unit</string>
+    <string name="label_tire_unit">Tyre pressure</string>
     <string name="label_accent">Accent colour</string>
     <string name="energy_kwh">%1$.1f kWh</string>
     <string name="energy_trip_note">net, after recuperation</string>
@@ -114,6 +114,10 @@
 
     <string name="label_full_screen">Full screen</string>
     <string name="hint_full_screen">Hides the car\'s top and bottom bars while this app is open. Swipe in from the top or bottom edge to show them briefly, e.g. for the climate controls.</string>
+    <string name="label_carplay_full_screen">Full screen for CarPlay (experiment)</string>
+    <string name="hint_carplay_full_screen">Hides the car\'s bars over CarPlay too, from its next start. A black strip? Reconnect the phone. Off restores the setting.</string>
+    <string name="hint_carplay_full_screen_unavailable">Needs the car build: only a system app may change this.</string>
+    <string name="carplay_full_screen_failed">Could not change the CarPlay full-screen setting</string>
     <string name="label_voice_key">Double-press the voice key to open this app</string>
     <string name="hint_voice_key">Press the voice key on the steering wheel twice quickly. The voice assistant may still react to the presses.</string>
     <string name="label_abrp_upload_enabled">Send live data</string>

app/src/test/java/com/evsuite/abrp/PolicyControlTest.java

@@ -0,0 +1,50 @@
+package com.evsuite.abrp;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+/** The policy_control value the CarPlay full-screen switch writes — pure JVM. */
+public class PolicyControlTest {
+
+    private static final String CP = "com.allgo.carplay.service";
+
+    @Test
+    public void unsetGainsOnlyOurEntryAndLosesItAgain() {
+        String on = PolicyControl.withFull(null, CP);
+        assertEquals("immersive.full=" + CP, on);
+        assertTrue(PolicyControl.hasFull(on, CP));
+        assertNull(PolicyControl.withoutFull(on, CP));
+    }
+
+    @Test
+    public void otherEntriesSurviveOnAndOff() {
+        String before = "immersive.status=com.a:immersive.full=com.b";
+        String on = PolicyControl.withFull(before, CP);
+        assertEquals("immersive.status=com.a:immersive.full=com.b," + CP, on);
+        assertEquals(before, PolicyControl.withoutFull(on, CP));
+    }
+
+    @Test
+    public void addingTwiceAddsOnce() {
+        String once = PolicyControl.withFull(null, CP);
+        assertEquals(once, PolicyControl.withFull(once, CP));
+    }
+
+    @Test
+    public void onlyAnExactPackageCounts() {
+        assertFalse(PolicyControl.hasFull("immersive.full=" + CP + ".other", CP));
+        assertFalse(PolicyControl.hasFull("immersive.status=" + CP, CP));
+        assertFalse(PolicyControl.hasFull(null, CP));
+        assertFalse(PolicyControl.hasFull("", CP));
+    }
+
+    @Test
+    public void removingWhatIsNotThereKeepsTheRest() {
+        assertEquals("immersive.status=com.a", PolicyControl.withoutFull("immersive.status=com.a", CP));
+        assertNull(PolicyControl.withoutFull(null, CP));
+    }
+}