title: Format text in bluetooth printer
body: <p>actually, I have to implement a module the which connect to a BT termical printer and print in it. I have a simple but functionally example, it works with the printer. The problem is that these text are printed in plain text, and i have to give it format, bold, change the font size and others... How can i do it??. I don't know how... I use this Class: </p>
  
  <pre><code>/*
   * Copyright (C) 2009 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.edec.aptr;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.UUID;
  
  import android.bluetooth.BluetoothAdapter;
  import android.bluetooth.BluetoothDevice;
  import android.bluetooth.BluetoothServerSocket;
  import android.bluetooth.BluetoothSocket;
  import android.content.Context;
  import android.os.Bundle;
  import android.os.Handler;
  import android.os.Message;
  import android.util.Log;
  
  /**
   * This class does all the work for setting up and managing Bluetooth
   * connections with other devices. It has a thread that listens for incoming
   * connections, a thread for connecting with a device, and a thread for
   * performing data transmissions when connected.
   */
  public class BluetoothService {
      // Debugging
      private static final String TAG = "BluetoothService";
      private static final boolean D = true;
  
      // Name for the SDP record when creating server socket
      private static final String NAME = "BTPrinter";
  
      // Unique UUID for this application
      private static final UUID MY_UUID = UUID
              .fromString("00001101-0000-1000-8000-00805F9B34FB"); // change by
                                                                      // chongqing
                                                                      // jinou
  
      // Member fields
      private final BluetoothAdapter mAdapter;
      private final Handler mHandler;
      private AcceptThread mAcceptThread;
      private ConnectThread mConnectThread;
      private ConnectedThread mConnectedThread;
      private int mState;
  
      // Constants that indicate the current connection state
      public static final int STATE_NONE = 0; // we're doing nothing
      public static final int STATE_LISTEN = 1; // now listening for incoming
                                                  // connections
      public static final int STATE_CONNECTING = 2; // now initiating an outgoing
                                                      // connection
      public static final int STATE_CONNECTED = 3; // now connected to a remote
                                                      // device
  
      /**
       * Constructor. Prepares a new BTPrinter session.
       * 
       * @param context
       *            The UI Activity Context
       * @param handler
       *            A Handler to send messages back to the UI Activity
       */
      public BluetoothService(Context context, Handler handler) {
          mAdapter = BluetoothAdapter.getDefaultAdapter();
          mState = STATE_NONE;
          mHandler = handler;
      }
  
      /**
       * Set the current state of the connection
       * 
       * @param state
       *            An integer defining the current connection state
       */
      private synchronized void setState(int state) {
          if (D)
              Log.d(TAG, "setState() " + mState + " -&gt; " + state);
          mState = state;
  
          // Give the new state to the Handler so the UI Activity can update
          mHandler.obtainMessage(amarre.MESSAGE_STATE_CHANGE, state, -1)
                  .sendToTarget();
      }
  
      /**
       * Return the current connection state.
       */
      public synchronized int getState() {
          return mState;
      }
  
      /**
       * Start the service. Specifically start AcceptThread to begin a session in
       * listening (server) mode. Called by the Activity onResume()
       */
      public synchronized void start() {
          if (D)
              Log.d(TAG, "start");
  
          // Cancel any thread attempting to make a connection
          if (mConnectThread != null) {
              mConnectThread.cancel();
              mConnectThread = null;
          }
  
          // Cancel any thread currently running a connection
          if (mConnectedThread != null) {
              mConnectedThread.cancel();
              mConnectedThread = null;
          }
  
          // Start the thread to listen on a BluetoothServerSocket
          if (mAcceptThread == null) {
              mAcceptThread = new AcceptThread();
              mAcceptThread.start();
          }
          setState(STATE_LISTEN);
      }
  
      /**
       * Start the ConnectThread to initiate a connection to a remote device.
       * 
       * @param device
       *            The BluetoothDevice to connect
       */
      public synchronized void connect(BluetoothDevice device) {
          if (D)
              Log.d(TAG, "connect to: " + device);
  
          // Cancel any thread attempting to make a connection
          if (mState == STATE_CONNECTING) {
              if (mConnectThread != null) {
                  mConnectThread.cancel();
                  mConnectThread = null;
              }
          }
  
          // Cancel any thread currently running a connection
          if (mConnectedThread != null) {
              mConnectedThread.cancel();
              mConnectedThread = null;
          }
  
          // Start the thread to connect with the given device
          mConnectThread = new ConnectThread(device);
          mConnectThread.start();
          setState(STATE_CONNECTING);
      }
  
      /**
       * Start the ConnectedThread to begin managing a Bluetooth connection
       * 
       * @param socket
       *            The BluetoothSocket on which the connection was made
       * @param device
       *            The BluetoothDevice that has been connected
       */
      public synchronized void connected(BluetoothSocket socket,
              BluetoothDevice device) {
          if (D)
              Log.d(TAG, "connected");
  
          // Cancel the thread that completed the connection
          if (mConnectThread != null) {
              mConnectThread.cancel();
              mConnectThread = null;
          }
  
          // Cancel any thread currently running a connection
          if (mConnectedThread != null) {
              mConnectedThread.cancel();
              mConnectedThread = null;
          }
  
          // Cancel the accept thread because we only want to connect to one
          // device
          if (mAcceptThread != null) {
              mAcceptThread.cancel();
              mAcceptThread = null;
          }
  
          // Start the thread to manage the connection and perform transmissions
          mConnectedThread = new ConnectedThread(socket);
          mConnectedThread.start();
  
          // Send the name of the connected device back to the UI Activity
          Message msg = mHandler.obtainMessage(amarre.MESSAGE_DEVICE_NAME);
          Bundle bundle = new Bundle();
          bundle.putString(amarre.DEVICE_NAME, device.getName());
          msg.setData(bundle);
          mHandler.sendMessage(msg);
  
          setState(STATE_CONNECTED);
      }
  
      /**
       * Stop all threads
       */
      public synchronized void stop() {
          if (D)
              Log.d(TAG, "stop");
          setState(STATE_NONE);
          if (mConnectThread != null) {
              mConnectThread.cancel();
              mConnectThread = null;
          }
          if (mConnectedThread != null) {
              mConnectedThread.cancel();
              mConnectedThread = null;
          }
          if (mAcceptThread != null) {
              mAcceptThread.cancel();
              mAcceptThread = null;
          }
      }
  
      /**
       * Write to the ConnectedThread in an unsynchronized manner
       * 
       * @param out
       *            The bytes to write
       * @see ConnectedThread#write(byte[])
       */
      public void write(byte[] out) {
          // Create temporary object
          ConnectedThread r;
          // Synchronize a copy of the ConnectedThread
          synchronized (this) {
              if (mState != STATE_CONNECTED)
                  return;
              r = mConnectedThread;
          }
          // Perform the write unsynchronized
          r.write(out);
      }
  
      /**
       * Indicate that the connection attempt failed and notify the UI Activity.
       */
      private void connectionFailed() {
          setState(STATE_LISTEN);
  
          // Send a failure message back to the Activity
          Message msg = mHandler.obtainMessage(amarre.MESSAGE_TOAST);
          Bundle bundle = new Bundle();
          bundle.putString(
                  amarre.TOAST,
                  "No se puede conectar al dispostivo, verifique que éste se encuentra encendido y cercano a la tablet");
          msg.setData(bundle);
          mHandler.sendMessage(msg);
      }
  
      /**
       * Indicate that the connection was lost and notify the UI Activity.
       */
      private void connectionLost() {
          // setState(STATE_LISTEN);
  
          // Send a failure message back to the Activity
          Message msg = mHandler.obtainMessage(amarre.MESSAGE_TOAST);
          Bundle bundle = new Bundle();
          bundle.putString(amarre.TOAST,
                  "La conexión con el dispositivo se ha perdido");
          msg.setData(bundle);
          mHandler.sendMessage(msg);
      }
  
      /**
       * This thread runs while listening for incoming connections. It behaves
       * like a server-side client. It runs until a connection is accepted (or
       * until cancelled).
       */
      private class AcceptThread extends Thread {
          // The local server socket
          private final BluetoothServerSocket mmServerSocket;
  
          public AcceptThread() {
              BluetoothServerSocket tmp = null;
  
              // Create a new listening server socket
              try {
                  tmp = mAdapter
                          .listenUsingRfcommWithServiceRecord(NAME, MY_UUID);
              } catch (IOException e) {
                  Log.e(TAG, "listen() failed", e);
              }
              mmServerSocket = tmp;
          }
  
          public void run() {
              if (D)
                  Log.d(TAG, "BEGIN mAcceptThread" + this);
              setName("AcceptThread");
              BluetoothSocket socket = null;
  
              // Listen to the server socket if we're not connected
              while (mState != STATE_CONNECTED) {
                  try {
                      // This is a blocking call and will only return on a
                      // successful connection or an exception
                      socket = mmServerSocket.accept();
                  } catch (IOException e) {
                      Log.e(TAG, "accept() failed", e);
                      break;
                  }
  
                  // If a connection was accepted
                  if (socket != null) {
                      synchronized (BluetoothService.this) {
                          switch (mState) {
                          case STATE_LISTEN:
                          case STATE_CONNECTING:
                              // Situation normal. Start the connected thread.
                              connected(socket, socket.getRemoteDevice());
                              break;
                          case STATE_NONE:
                          case STATE_CONNECTED:
                              // Either not ready or already connected. Terminate
                              // new socket.
                              try {
                                  socket.close();
                              } catch (IOException e) {
                                  Log.e(TAG, "Could not close unwanted socket", e);
                              }
                              break;
                          }
                      }
                  }
              }
              if (D)
                  Log.i(TAG, "END mAcceptThread");
          }
  
          public void cancel() {
              if (D)
                  Log.d(TAG, "cancel " + this);
              try {
                  mmServerSocket.close();
              } catch (IOException e) {
                  Log.e(TAG, "close() of server failed", e);
              }
          }
      }
  
      /**
       * This thread runs while attempting to make an outgoing connection with a
       * device. It runs straight through; the connection either succeeds or
       * fails.
       */
      private class ConnectThread extends Thread {
          private final BluetoothSocket mmSocket;
          private final BluetoothDevice mmDevice;
  
          public ConnectThread(BluetoothDevice device) {
              mmDevice = device;
              BluetoothSocket tmp = null;
  
              // Get a BluetoothSocket for a connection with the
              // given BluetoothDevice
              try {
                  tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
              } catch (IOException e) {
                  Log.e(TAG, "create() failed", e);
              }
              mmSocket = tmp;
          }
  
          public void run() {
              Log.i(TAG, "BEGIN mConnectThread");
              setName("ConnectThread");
  
              // Always cancel discovery because it will slow down a connection
              mAdapter.cancelDiscovery();
  
              // Make a connection to the BluetoothSocket
              try {
                  // This is a blocking call and will only return on a
                  // successful connection or an exception
                  mmSocket.connect();
              } catch (IOException e) {
                  connectionFailed();
                  // Close the socket
                  try {
                      mmSocket.close();
                  } catch (IOException e2) {
                      Log.e(TAG,
                              "unable to close() socket during connection failure",
                              e2);
                  }
                  // Start the service over to restart listening mode
                  BluetoothService.this.start();
                  return;
              }
  
              // Reset the ConnectThread because we're done
              synchronized (BluetoothService.this) {
                  mConnectThread = null;
              }
  
              // Start the connected thread
              connected(mmSocket, mmDevice);
          }
  
          public void cancel() {
              try {
                  mmSocket.close();
              } catch (IOException e) {
                  Log.e(TAG, "close() of connect socket failed", e);
              }
          }
      }
  
      /**
       * This thread runs during a connection with a remote device. It handles all
       * incoming and outgoing transmissions.
       */
      private class ConnectedThread extends Thread {
          private final BluetoothSocket mmSocket;
          private final InputStream mmInStream;
          private final OutputStream mmOutStream;
  
          public ConnectedThread(BluetoothSocket socket) {
              Log.d(TAG, "create ConnectedThread");
              mmSocket = socket;
              InputStream tmpIn = null;
              OutputStream tmpOut = null;
  
              // Get the BluetoothSocket input and output streams
              try {
                  tmpIn = socket.getInputStream();
                  tmpOut = socket.getOutputStream();
              } catch (IOException e) {
                  Log.e(TAG, "temp sockets not created", e);
              }
  
              mmInStream = tmpIn;
              mmOutStream = tmpOut;
          }
  
          public void run() {
              Log.i(TAG, "BEGIN mConnectedThread");
              int bytes;
  
              // Keep listening to the InputStream while connected
              while (true) {
                  try {
                      byte[] buffer = new byte[256];
                      // Read from the InputStream
                      bytes = mmInStream.read(buffer);
                      if (bytes &gt; 0) {
                          // Send the obtained bytes to the UI Activity
                          mHandler.obtainMessage(amarre.MESSAGE_READ, bytes, -1,
                                  buffer).sendToTarget();
                      } else {
                          Log.e(TAG, "disconnected");
                          connectionLost();
  
                          // add by chongqing jinou
                          if (mState != STATE_NONE) {
                              Log.e(TAG, "disconnected");
                              // Start the service over to restart listening mode
                              BluetoothService.this.start();
                          }
                          break;
                      }
                  } catch (IOException e) {
                      Log.e(TAG, "disconnected", e);
                      connectionLost();
  
                      // add by chongqing jinou
                      if (mState != STATE_NONE) {
                          // Start the service over to restart listening mode
                          BluetoothService.this.start();
                      }
                      break;
                  }
              }
          }
  
          /**
           * Write to the connected OutStream.
           * 
           * @param buffer
           *            The bytes to write
           */
          public void write(byte[] buffer) {
              try {
                  mmOutStream.write(buffer);
                  // Share the sent message back to the UI Activity
                  mHandler.obtainMessage(amarre.MESSAGE_WRITE, -1, -1, buffer)
                          .sendToTarget();
              } catch (IOException e) {
                  Log.e(TAG, "Exception during write", e);
              }
          }
  
          public void cancel() {
              try {
                  mmSocket.close();
              } catch (IOException e) {
                  Log.e(TAG, "close() of connect socket failed", e);
              }
          }
      }
  }
  </code></pre>
  
  <p>I send the data from another class, so:</p>
  
  <pre><code>        byte[] send;
          try {
              send = message.getBytes("GB2312");
          } catch (UnsupportedEncodingException e) {
              send = message.getBytes();
  
          }
  
          mService.write(send);
  </code></pre>
  
  <p>message is a String var.. Then, how can I format the text??, or at least, change font size...</p>