Java tutorial
/* * Copyright (C) 2014 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.grandpaj.library2.bluetooth; import android.app.ActionBar; import android.app.Activity; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.content.Intent; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentActivity; import android.view.MenuItem; import android.widget.Toast; import com.grandpaj.library2.bluetooth.logger.Log; import com.grandpaj.library2.R; /** * This fragment controls Bluetooth to communicate with other devices. */ public class BluetoothCommunication extends Fragment { private static final String TAG = "BluetoothCommunication"; // Intent request codes private static final int REQUEST_CONNECT_DEVICE_SECURE = 1; private static final int REQUEST_CONNECT_DEVICE_INSECURE = 2; private static final int REQUEST_ENABLE_BT = 3; /** * Name of the connected device */ private String mConnectedDeviceName = null; /** * String buffer for outgoing messages */ private StringBuffer mOutStringBuffer; /** * Local Bluetooth adapter */ private BluetoothAdapter mBluetoothAdapter = null; /** * Member object for the chat services */ private BluetoothSerialService mChatService = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Get local Bluetooth adapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); // If the adapter is null, then Bluetooth is not supported if (mBluetoothAdapter == null) { FragmentActivity activity = getActivity(); Toast.makeText(activity, "Bluetooth is not available", Toast.LENGTH_LONG).show(); activity.finish(); } } @Override public void onStart() { super.onStart(); //startCommunication(); } @Override public void onDestroy() { super.onDestroy(); if (mChatService != null) { mChatService.stop(); } } @Override public void onResume() { super.onResume(); // Performing this check in onResume() covers the case in which BT was // not enabled during onStart(), so we were paused to enable it... // onResume() will be called when ACTION_REQUEST_ENABLE activity returns. if (mChatService != null) { // Only if the state is STATE_NONE, do we know that we haven't started already if (mChatService.getState() == BluetoothSerialService.STATE_NONE) { // Start the Bluetooth chat services mChatService.start(); } } } public void startCommunication() { // If BT is not on, request that it be enabled. // setupChat() will then be called during onActivityResult if (!mBluetoothAdapter.isEnabled()) { Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); startActivityForResult(enableIntent, REQUEST_ENABLE_BT); // Otherwise, setup the chat session } else if (mChatService == null) { setupChat(); } } /** * Set up the UI and background operations for chat. */ private void setupChat() { Log.d(TAG, "setupChat()"); // Initialize the BluetoothChatService to perform bluetooth connections mChatService = new BluetoothSerialService(getActivity(), mHandler); // Initialize the buffer for outgoing messages mOutStringBuffer = new StringBuffer(""); } /** * Makes this device discoverable. */ private void ensureDiscoverable() { if (mBluetoothAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) { Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE); discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300); startActivity(discoverableIntent); } } /** * Sends a message. * * @param message A string of text to send. */ private void sendMessage(String message) { // Check that we're actually connected before trying anything if (mChatService.getState() != BluetoothSerialService.STATE_CONNECTED) { Toast.makeText(getActivity(), R.string.not_connected, Toast.LENGTH_SHORT).show(); return; } // Check that there's actually something to send if (message.length() > 0) { // Get the message bytes and tell the BluetoothChatService to write byte[] send = message.getBytes(); mChatService.write(send); // Reset out string buffer to zero and clear the edit text field mOutStringBuffer.setLength(0); } } /** * Updates the status on the action bar. * * @param resId a string resource ID */ private void setStatus(int resId) { /* FragmentActivity activity = getActivity(); if (null == activity) { return; } final ActionBar actionBar = activity.getActionBar(); if (null == actionBar) { return; } actionBar.setSubtitle(resId); */ } /** * Updates the status on the action bar. * * @param subTitle status */ private void setStatus(CharSequence subTitle) { /* FragmentActivity activity = getActivity(); if (null == activity) { return; } final ActionBar actionBar = activity.getActionBar(); if (null == actionBar) { return; } actionBar.setSubtitle(subTitle); */ } /** * The Handler that gets information back from the BluetoothChatService */ private final Handler mHandler = new Handler() { @Override public void handleMessage(Message msg) { FragmentActivity activity = getActivity(); Log.d("mHandler", "got " + msg.what); switch (msg.what) { case Constants.MESSAGE_STATE_CHANGE: switch (msg.arg1) { case BluetoothSerialService.STATE_CONNECTED: setStatus(getString(R.string.title_connected_to, mConnectedDeviceName)); break; case BluetoothSerialService.STATE_CONNECTING: setStatus(R.string.title_connecting); break; case BluetoothSerialService.STATE_LISTEN: case BluetoothSerialService.STATE_NONE: setStatus(R.string.title_not_connected); break; } break; case Constants.MESSAGE_WRITE: byte[] writeBuf = (byte[]) msg.obj; // construct a string from the buffer String writeMessage = new String(writeBuf); Log.d("mHandler", "msg write " + writeMessage); break; case Constants.MESSAGE_READ: Log.d("mHandler", "msg read begin"); byte[] readBuf = (byte[]) msg.obj; // construct a string from the valid bytes in the buffer String readMessage = new String(readBuf, 0, msg.arg1); Log.d("mHandler", "msg read " + readMessage); break; case Constants.MESSAGE_DEVICE_NAME: // save the connected device's name mConnectedDeviceName = msg.getData().getString(Constants.DEVICE_NAME); if (null != activity) { Toast.makeText(activity, "Connected to " + mConnectedDeviceName, Toast.LENGTH_SHORT).show(); } break; case Constants.MESSAGE_TOAST: if (null != activity) { Toast.makeText(activity, msg.getData().getString(Constants.TOAST), Toast.LENGTH_SHORT).show(); } break; } } }; public void onActivityResult(int requestCode, int resultCode, Intent data) { switch (requestCode) { case REQUEST_CONNECT_DEVICE_SECURE: // When DeviceListActivity returns with a device to connect if (resultCode == Activity.RESULT_OK) { connectDevice(data, true); } break; case REQUEST_CONNECT_DEVICE_INSECURE: // When DeviceListActivity returns with a device to connect if (resultCode == Activity.RESULT_OK) { connectDevice(data, false); } 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 setupChat(); } else { // User did not enable Bluetooth or an error occurred Log.d(TAG, "BT not enabled"); Toast.makeText(getActivity(), R.string.bt_not_enabled_leaving, Toast.LENGTH_SHORT).show(); getActivity().finish(); } } } /** * Establish connection with other divice * * @param data An {@link Intent} with {@link DeviceListActivity#EXTRA_DEVICE_ADDRESS} extra. * @param secure Socket Security type - Secure (true) , Insecure (false) */ private void connectDevice(Intent data, boolean secure) { // Get the device MAC address String address = data.getExtras().getString(DeviceListActivity.EXTRA_DEVICE_ADDRESS); // Get the BluetoothDevice object BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address); // Attempt to connect to the device //mChatService.connect(device, secure); mChatService.connect(device); } @Override public boolean onOptionsItemSelected(MenuItem item) { int itemid = item.getItemId(); if (itemid == R.id.secure_connect_scan) { secure_connect_scan(); } else if (itemid == R.id.insecure_connect_scan) { insecure_connect_scan(); } else if (itemid == R.id.discoverable) { // Ensure this device is discoverable by others ensureDiscoverable(); return true; } return false; } public boolean secure_connect_scan() { // Launch the DeviceListActivity to see devices and do scan Intent serverIntent = new Intent(getActivity(), DeviceListActivity.class); startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE_SECURE); return true; } public boolean insecure_connect_scan() { // Launch the DeviceListActivity to see devices and do scan Intent serverIntent = new Intent(getActivity(), DeviceListActivity.class); startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE_INSECURE); return true; } }