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.mohammedx.cart.android.client; 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.Menu; import android.view.MenuInflater; import android.view.MenuItem; 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 BluetoothFragment extends Fragment { private static final String TAG = "BluetoothFragment"; // 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; private MenuItem mConnButton; private MenuItem mDisButton; private boolean disnotfiy = false; /** * Name of the connected device */ private String mConnectedDeviceName = null; /** * Array adapter for the conversation thread */ private ArrayAdapter<String> mConversationArrayAdapter; /** * The Handler that gets information back from the BluetoothService */ private final Handler mHandler = new Handler() { @Override public void handleMessage(Message msg) { FragmentActivity activity = getActivity(); switch (msg.what) { case Constants.MESSAGE_STATE_CHANGE: switch (msg.arg1) { case BluetoothService.STATE_CONNECTED: setStatus(getString(R.string.title_connected_to)); mConversationArrayAdapter.clear(); MainActivity.isConncted = true; disnotfiy = true; break; case BluetoothService.STATE_CONNECTING: setStatus(R.string.title_connecting); break; case BluetoothService.STATE_LISTEN: case BluetoothService.STATE_NONE: setStatus(R.string.title_not_connected); MainActivity.isConncted = false; if (disnotfiy) { MainActivity.notifydis(getActivity(), "Connection", "Lost connection with the cart"); } break; } break; case Constants.MESSAGE_WRITE: byte[] writeBuf = (byte[]) msg.obj; // construct a string from the buffer String writeMessage = new String(writeBuf); mConversationArrayAdapter.add("Me: " + writeMessage); break; case Constants.MESSAGE_READ: 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 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 cart", 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; } } }; /** * String buffer for outgoing messages */ private StringBuffer mOutStringBuffer; /** * Local Bluetooth adapter */ private BluetoothAdapter mBluetoothAdapter = null; /** * Member object for the chat services */ private BluetoothService mChatService = null; /** * 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 message = view.getText().toString(); sendMessage(message); } return true; } }; @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(); Intent serverIntent = new Intent(getActivity(), ScanActivity.class); startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE_SECURE); } } @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() == BluetoothService.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.fragment_bluetooth_chat, 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<>(getActivity(), R.layout.message); 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 message = textView.getText().toString(); sendMessage(message); } } }); // Initialize the BluetoothService to perform bluetooth connections mChatService = new BluetoothService(getActivity(), mHandler); // Initialize the buffer for outgoing messages mOutStringBuffer = new StringBuffer(""); } /** * Sends a message. * * @param message A string of text to send. */ public void sendMessage(String message) { // Check that we're actually connected before trying anything if (mChatService.getState() != BluetoothService.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 BluetoothService 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); } } /** * 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); } public void onActivityResult(int requestCode, int resultCode, Intent data) { switch (requestCode) { case REQUEST_CONNECT_DEVICE_SECURE: if (resultCode == Activity.RESULT_OK) { connectDevice(data, false); } break; case REQUEST_CONNECT_DEVICE_INSECURE: 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(); Intent serverIntent = new Intent(getActivity(), ScanActivity.class); startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE_SECURE); } 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 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(ScanActivity.EXTRA_DEVICE_ADDRESS); // 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 void onPrepareOptionsMenu(Menu menu) { super.onPrepareOptionsMenu(menu); mConnButton = menu.findItem(R.id.secure_connect_scan); mDisButton = menu.findItem(R.id.secure_disconnect_scan); } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.secure_connect_scan: { Intent serverIntent = new Intent(getActivity(), ScanActivity.class); startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE_SECURE); return true; } case R.id.secure_disconnect_scan: { mChatService.stop(); setupChat(); } } return false; } }