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.anand.bluetoothsample; 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.annotation.Nullable; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentActivity; import android.util.Log; import android.view.KeyEvent; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.inputmethod.EditorInfo; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.EditText; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; /** * This fragment controls Bluetooth to communicate with other devices. */ public class BluetoothChatFragment extends Fragment { private static final String TAG = "BluetoothChatFragment"; // 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; // Layout Views private ListView mConversationView; private EditText mOutEditText; private Button mSendButton; /** * Name of the connected device */ private String mConnectedDeviceName = null; /** * Array adapter for the conversation thread */ private ArrayAdapter<String> mConversationArrayAdapter; /** * String buffer for outgoing messages */ private StringBuffer mOutStringBuffer; /** * Local Bluetooth adapter */ private BluetoothAdapter mBluetoothAdapter = null; /** * Member object for the chat services */ private BluetoothChatService mChatService = null; public static BluetoothDevice currentDevice; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); //setHasOptionsMenu(true); // 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(); // 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(); } } @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() == BluetoothChatService.STATE_NONE) { // Start the Bluetooth chat services mChatService.start(); } } } @Override public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { return inflater.inflate(R.layout.chat_list, container, false); } @Override public void onViewCreated(View view, @Nullable Bundle savedInstanceState) { mConversationView = (ListView) view.findViewById(R.id.in); mOutEditText = (EditText) view.findViewById(R.id.edit_text_out); mSendButton = (Button) view.findViewById(R.id.button_send); } /** * Set up the UI and background operations for chat. */ private void setupChat() { Log.d(TAG, "setupChat()"); // Initialize the array adapter for the conversation thread mConversationArrayAdapter = new ArrayAdapter<String>(getActivity(), R.layout.chat); mConversationView.setAdapter(mConversationArrayAdapter); // Initialize the compose field with a listener for the return key mOutEditText.setOnEditorActionListener(mWriteListener); // Initialize the send button with a listener that for click events mSendButton.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { // Send a message using content of the edit text widget View view = getView(); if (null != view) { TextView textView = (TextView) view.findViewById(R.id.edit_text_out); String myMessage = textView.getText().toString(); if (myMessage != null && currentDevice != null) { new ConnectToDeviceThread(currentDevice, myMessage).start(); } else { Toast.makeText(getActivity().getApplicationContext(), "Please Enter a Messsage to send", Toast.LENGTH_SHORT).show(); } } } }); // Initialize the BluetoothChatService to perform bluetooth connections mChatService = new BluetoothChatService(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() != BluetoothChatService.STATE_CONNECTED) { Toast.makeText(getActivity(), "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); mOutEditText.setText(mOutStringBuffer); } } /** * The action listener for the EditText widget, to listen for the return key */ private TextView.OnEditorActionListener mWriteListener = new TextView.OnEditorActionListener() { public boolean onEditorAction(TextView view, int actionId, KeyEvent event) { // If the action is a key-up event on the return key, send the message if (actionId == EditorInfo.IME_NULL && event.getAction() == KeyEvent.ACTION_UP) { String myMessage = view.getText().toString(); if (myMessage != null && currentDevice != null) { new ConnectToDeviceThread(currentDevice, myMessage).start(); } else { Toast.makeText(getActivity().getApplicationContext(), "Please Enter a Messsage to send", Toast.LENGTH_SHORT).show(); } } return true; } }; // /** // * 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(); switch (msg.what) { case 1: switch (msg.arg1) { case BluetoothChatService.STATE_CONNECTED: setStatus(getString(R.string.title_connected_to, mConnectedDeviceName)); mConversationArrayAdapter.clear(); break; case BluetoothChatService.STATE_CONNECTING: setStatus(R.string.title_connecting); break; case BluetoothChatService.STATE_LISTEN: case BluetoothChatService.STATE_NONE: setStatus(R.string.title_not_connected); break; } break; case 3: byte[] writeBuf = (byte[]) msg.obj; // construct a string from the buffer String writeMessage = new String(writeBuf); mConversationArrayAdapter.add("Me: " + writeMessage); break; case 2: byte[] readBuf = (byte[]) msg.obj; // construct a string from the valid bytes in the buffer String readMessage = new String(readBuf, 0, msg.arg1); mConversationArrayAdapter.add(mConnectedDeviceName + ": " + readMessage); break; case 4: // save the connected device's name mConnectedDeviceName = msg.getData().getString("device_name"); if (null != activity) { Toast.makeText(activity, "Connected to " + mConnectedDeviceName, Toast.LENGTH_SHORT).show(); } break; case 5: if (null != activity) { Toast.makeText(activity, msg.getData().getString("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(DevicesListViewAdapter.adrr); // Get the BluetoothDevice object BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address); // Attempt to connect to the device mChatService.connect(device, secure); } // @Override // public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { // inflater.inflate(R.menu.bluetooth_chat, menu); // } // // @Override // public boolean onOptionsItemSelected(MenuItem item) { // switch (item.getItemId()) { // case R.id.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; // } // case R.id.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; // } // case R.id.discoverable: { // // Ensure this device is discoverable by others // ensureDiscoverable(); // return true; // } // } // return false; // } }