BluetoothController.Main.java

package com.BluetoothController;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class Main extends Activity {
    //string that defines the title of the message in logcat
    private final String TAG = "Main";

    //objects for the graphical elements
    private Button mButton = null; //button to toggle led
    private TextView textField = null; //text field to show status

    //bluetooth related objects
    private BluetoothAdapter mBluetoothAdapter = null;
    private BluetoothSocket mBTSock = null;

    //constants for DeviceListActivity usage
    private static final int REQUEST_CONNECT_DEVICE = 1;
    private static final int REQUEST_ENABLE_BT = 2;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        //bind the objects to their view elements
        mButton = (Button) findViewById(R.id.mButton);
        textField = (TextView) findViewById(R.id.textField);

        textField.setText("init");

        //define that if the button is clicked the led should be toggled
        mButton.setOnClickListener(new OnClickListener(){
            @Override
            public void onClick(View arg0) {
                toggleLed();
            }
        });

        //Get the default bluetooth adapter
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

        //If the adapter is null, then Bluetooth is not supported
        if (mBluetoothAdapter == null) {
            Toast.makeText(this, "Bluetooth is not available", Toast.LENGTH_LONG).show();
            finish();
            return;
        }
        Log.d(TAG, "got bluetooth adapter");

        //Check if the adapter is enabled
        if (!mBluetoothAdapter.isEnabled()) {
            Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
        }else{
            setupBT();
        }
        Log.d(TAG,"onCreate:done");
    }

    @Override
    public void onDestroy(){
        //if the app is closed, should try to close the socket
        try {
            mBTSock.close();
            Log.d(TAG,"socket closed");
        } catch (IOException e) {
            Log.e(TAG,"error closing socket");
        }
        super.onDestroy();
    }

    //here the status returned from the DeviceListActivity or Intent to activate bluetooth is treated
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        Log.d(TAG, "onActivityResult():" + resultCode);
        switch (requestCode) {
            case REQUEST_CONNECT_DEVICE:
                // When DeviceListActivity returns with a device to connect
                if (resultCode == Activity.RESULT_OK) {
                    // Get the device MAC address
                    String address = data.getExtras().getString(DeviceListActivity.EXTRA_DEVICE_ADDRESS);

                    // Get the BLuetoothDevice object
                    BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);

                    //this UUID is the default id for devices/modules
                    UUID mUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
                    try {
                        //create socket
                        mBTSock = device.createRfcommSocketToServiceRecord(mUUID);

                        textField.setText("connecting...");

                        //connect to device
                        mBTSock.connect();

                        Log.d(TAG,"socket connected");
                        textField.setText("connected.");

                    } catch (IOException e) {
                        Log.d(TAG,"ioexception creating socket");
                        textField.setText("IOException!");
                    }
                }
                break;
            case REQUEST_ENABLE_BT:
                // When the request to enable Bluetooth returns
                if (resultCode == Activity.RESULT_OK) {
                    // Bluetooth is now enabled, so set up a chat session
                    setupBT();

                } else {
                    // User did not enable Bluetooth or an error occured
                    Log.d(TAG, "BT is not enabled");
                    Toast.makeText(this, "Bluetooth is not enabled!", Toast.LENGTH_SHORT).show();
                    finish();
                }
                break;
        }
    }

    void setupBT(){
        Log.d(TAG,"setupBT");
        Intent deviceList = new Intent(this, DeviceListActivity.class);
        startActivityForResult(deviceList, REQUEST_CONNECT_DEVICE);
    }

    void toggleLed(){
        try {
            //create streams for sending and receiving data
                OutputStream outStream = mBTSock.getOutputStream();
                InputStream inStream = mBTSock.getInputStream();
                Log.d(TAG,"streams created");

            //send message via bluetooth
                textField.setText("sending message...");
                String msg = "led";
                outStream.write(msg.getBytes());
                Log.d(TAG,"message sent");

            //wait for answer
            //TODO:timeout?
                textField.setText("waiting for some data...");
                while(inStream.available() == 0);

                Log.d(TAG,"data available");

                byte[] bytez = new byte[50];
                if(inStream.read(bytez) != 0){
                    textField.setText("recv:"+new String(bytez));
                }else{
                    textField.setText("no data...");
                }

        } catch (IOException e) {
            textField.setText("IOException while connecting to client");
            Log.d(TAG,"IOException...");
        }
    }
}