Minimal Permission Example

MainActivity.java

package ly.soundl.test.batterytester;

import android.Manifest;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.Unbinder;

public class MainActivity extends AppCompatActivity {

    public static final String TAG = MainActivity.class.getSimpleName();
    private static final int REQUEST_CODE_RECORD_AUDIO = 0x10;
    private final Messenger mMessenger = new Messenger(new IncomingHandler());

    /* Auto-Generated Method Stub */
    @BindView(R.id.label) protected TextView mTextViewLabel;
    @BindView(R.id.btn_start_service) protected Button mBtnStartService;
    @BindView(R.id.btn_stop_service) protected Button mBtnStopService;
    @BindView(R.id.toolbar) protected Toolbar toolbar;
    private Unbinder mUnbinder;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.setContentView(R.layout.activity_main);
        mUnbinder = ButterKnife.bind(this);
        this.setSupportActionBar(toolbar);

        /* Declare Target Service */
        ComponentName componentName = new ComponentName(MainService.class.getPackage().getName(), MainService.class.getCanonicalName());
        Intent intent = new Intent();
        intent.setComponent(componentName);

        /* Request Mic Permission only */
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.RECORD_AUDIO) == PackageManager.PERMISSION_GRANTED) {
            mTextViewLabel.setText(R.string.permission_granted);
        } else {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.RECORD_AUDIO}, REQUEST_CODE_RECORD_AUDIO);
        }

        /* Start & Bind Service */
        mBtnStartService.setOnClickListener(view -> {
            this.startService(intent);
            this.bindService(intent, mServiceConnection, Context.BIND_AUTO_CREATE);
            Toast.makeText(this, "Service successfully binded", Toast.LENGTH_SHORT).show();
        });

        /* Unbind & Stop Service */
        mBtnStopService.setOnClickListener(view -> {
            try {
                this.unbindService(mServiceConnection);
                Toast.makeText(this, "Service successfully unbinded", Toast.LENGTH_SHORT).show();
            } catch (IllegalArgumentException e) {
                Toast.makeText(this, "Running Service Not Found", Toast.LENGTH_SHORT).show();
            }
            this.stopService(intent);
        });
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        mUnbinder.unbind();
    }

    ServiceConnection mServiceConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            Log.d(TAG, "onServiceConnected : " + name.toShortString() + " on " + service.toString());
            Messenger messenger = new Messenger(service);
            Message msg = Message.obtain(null, 1);
            msg.replyTo = mMessenger;
            try {
                messenger.send(msg);
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            Log.d(TAG, "onServiceDisconnected : " + name.toShortString());
        }
    };

    private static class IncomingHandler extends Handler {

        @Override
        public void handleMessage(Message msg) {
            // Actually, does nothing since super has empty body
            super.handleMessage(msg);
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case REQUEST_CODE_RECORD_AUDIO: {
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    // Permission Granted
                    mTextViewLabel.setText(R.string.permission_granted);
                } else {
                    // Permission Denied. Disabling the functionality depends on the permission
                    mTextViewLabel.setText(R.string.permission_denied);
                    mBtnStartService.setEnabled(false);
                    mBtnStopService.setEnabled(false);
                }
            }
        }
    }
}