BatteryActivity.java

public class BatteryActivity extends Activity {

    //UI Elements                
    private TextView mTextViewLevel;
    private TextView mTextViewTemperature;
    private TextView mTextViewVoltage;
    private TextView mTextViewHealth;
    
    //Battery details
    private int level;
    private int voltage;
    private int temperature;
    private int healthState;
    private int chargePlug;
    private int status;

    boolean celsius = true;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_battery);
        final WatchViewStub stub = (WatchViewStub) findViewById(R.id.watch_view_stub);
        stub.setOnLayoutInflatedListener(new WatchViewStub.OnLayoutInflatedListener() {
            @Override
            public void onLayoutInflated(WatchViewStub stub) {
                //ui elements
                mTextViewLevel = (TextView) stub.findViewById(R.id.level);
                mTextViewTemperature = (TextView) stub.findViewById(R.id.temperature);
                mTextViewVoltage = (TextView) stub.findViewById(R.id.voltage);
                mTextViewHealth = (TextView) stub.findViewById(R.id.health);

                //update battery details
                updateBattery();
            }
        });


    }

    private void updateBattery() {

        IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        Intent batteryStatus = registerReceiver(null, ifilter);

        //Level
        level = batteryStatus.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);

        //Health
        healthState = batteryStatus.getIntExtra(BatteryManager.EXTRA_HEALTH, -1);
        int healthId = getResources().getIdentifier("battery_health_" + healthState,
                "string", this.getPackageName());
        String health = getString(healthId);

        //Battery status
        //status = batteryStatus.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
        //int resIdCharging = getResources().getIdentifier("charging_" + status,"string", this.getPackageName());
        //String charging = getString(resIdCharging);

        //Temperature
        temperature = batteryStatus.getIntExtra(
                BatteryManager.EXTRA_TEMPERATURE, 0);
        if (celsius){
            temperature= temperature/10;
        }else{
            temperature= temperature/10;
            //temperature= (int)( (float)((9.0f * temperature) / 5.0f) + 32.0f);
            temperature= (int)( 9.0 * temperature / 5.0 + 32.0);
        }

        //Voltage
        voltage = batteryStatus.getIntExtra(BatteryManager.EXTRA_VOLTAGE, 0);

        //Charge
        //chargePlug = batteryStatus.getIntExtra(
        //        BatteryManager.EXTRA_PLUGGED, -1);
        //int resId = getResources().getIdentifier("charge_" + chargePlug,
        //        "string", this.getPackageName());
        //String charge = getString(resId);

        if (mTextViewLevel!=null) mTextViewLevel.setText(""+level+"%");
        if (mTextViewTemperature!=null) mTextViewTemperature.setText(temperature+"°C");
        if (mTextViewVoltage!=null) mTextViewVoltage.setText(voltage+"mV");
        if (mTextViewHealth!=null) mTextViewHealth.setText(health);
    }
}