Reverse Wireless Charging UI

Author: empratyush

res/values/strings.xml

@@ -14592,4 +14592,7 @@
 
     <string name="app_info_install_time">Installed: %1$s</string>
     <string name="app_info_update_time">Updated: %1$s</string>
+
+    <string name="battery_share_description">Charge other devices by placing them on the back of your phone</string>
+    <string name="battery_share">Battery share</string>
 </resources>

res/xml/power_usage_summary.xml

@@ -64,6 +64,12 @@
         android:summary="@string/battery_percentage_description"
         settings:controller="com.android.settings.display.BatteryPercentagePreferenceController" />
 
+    <SwitchPreference
+        android:key="battery_share"
+        android:title="@string/battery_share"
+        android:summary="@string/battery_share_description"
+        settings:controller="com.android.settings.display.BatterySharePreferenceController" />
+
     <com.android.settingslib.widget.FooterPreference
         android:key="power_usage_footer"
         android:title="@string/battery_footer_summary"

src/com/android/settings/display/BatterySharePreferenceController.java

@@ -0,0 +1,98 @@
+package com.android.settings.display;
+
+import android.app.Activity;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.os.BatteryManager;
+
+import androidx.preference.Preference;
+import androidx.preference.PreferenceScreen;
+import androidx.preference.SwitchPreference;
+
+import com.android.internal.R;
+import com.android.internal.batteryShare.ReverseWirelessCharger;
+import com.android.settings.core.BasePreferenceController;
+import com.android.settings.core.PreferenceControllerMixin;
+import com.android.settingslib.core.lifecycle.LifecycleObserver;
+import com.android.settingslib.core.lifecycle.events.OnStart;
+import com.android.settingslib.core.lifecycle.events.OnStop;
+
+public class BatterySharePreferenceController extends BasePreferenceController implements
+        PreferenceControllerMixin, Preference.OnPreferenceChangeListener, LifecycleObserver,
+        OnStart, OnStop {
+
+    private static final String KEY_BATTERY_SHARE = "battery_share";
+    private final ReverseWirelessCharger wirelessCharger;
+    private final Context mContext;
+    private Preference mPreference;
+
+    private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            ((Activity) mContext).runOnUiThread(() -> update());
+        }
+    };
+
+
+    public BatterySharePreferenceController(Context context, String preferenceKey) {
+        super(context, preferenceKey);
+        mContext = context;
+        wirelessCharger = ReverseWirelessCharger.getInstance();
+    }
+
+    public boolean isPlugged(Context context) {
+        Intent intent = context.registerReceiver(null,
+                new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
+        int plugged = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);
+        return plugged == BatteryManager.BATTERY_PLUGGED_WIRELESS;
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mPreference = screen.findPreference(getPreferenceKey());
+        update();
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return KEY_BATTERY_SHARE;
+    }
+
+    private void update() {
+        if (mPreference == null) return;
+        boolean enabled = !isPlugged(mContext) && wirelessCharger.isRtxSupported();
+        mPreference.setEnabled(enabled);
+        ((SwitchPreference) mPreference).setChecked(wirelessCharger.isRtxModeOn());
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return wirelessCharger.isRtxSupported() ? AVAILABLE : UNSUPPORTED_ON_DEVICE;
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        update();
+    }
+
+    @Override
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
+        wirelessCharger.setRtxMode((Boolean) newValue);
+        return true;
+    }
+
+    @Override
+    public void onStart() {
+        IntentFilter filter = new IntentFilter();
+        filter.addAction(Intent.ACTION_BATTERY_CHANGED);
+        mContext.registerReceiver(mBroadcastReceiver, filter);
+    }
+
+    @Override
+    public void onStop() {
+        mContext.unregisterReceiver(mBroadcastReceiver);
+    }
+}