TimerActivity.java

// // Copyright 2015 Google Inc. All Rights Reserved. // // 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.example.google.timerservice; import android.app.Notification; import android.app.PendingIntent; import android.app.Service; import android.content.ComponentName; import android.content.Intent; import android.content.ServiceConnection; import android.os.Binder; import android.os.Bundle; import android.os.Handler; import android.os.IBinder; import android.os.Message; import android.support.v4.app.NotificationCompat; import android.support.v7.app.AppCompatActivity; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.TextView; import java.lang.ref.WeakReference; /** * Example activity to manage a long-running timer, which survives the destruction of the activity * by using a foreground service and notification * * Add the following to the manifest: * <service android:name=".MainActivity$TimerService" android:exported="false" /> */ public class TimerActivity extends AppCompatActivity { private static final String TAG = TimerActivity.class.getSimpleName(); private TimerService timerService; private boolean serviceBound; private Button timerButton; private TextView timerTextView; // Handler to update the UI every second when the timer is running private final Handler mUpdateTimeHandler = new UIUpdateHandler(this); // Message type for the handler private final static int MSG_UPDATE_TIME = 0; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); timerButton = (Button)findViewById(R.id.timer_button); timerTextView = (TextView)findViewById(R.id.timer_text_view); } @Override protected void onStart() { super.onStart(); if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, "Starting and binding service"); } Intent i = new Intent(this, TimerService.class); startService(i); bindService(i, mConnection, 0); } @Override protected void onStop() { super.onStop(); updateUIStopRun(); if (serviceBound) { // If a timer is active, foreground the service, otherwise kill the service if (timerService.isTimerRunning()) { timerService.foreground(); } else { stopService(new Intent(this, TimerService.class)); } // Unbind the service unbindService(mConnection); serviceBound = false; } } public void runButtonClick(View v) { if (serviceBound && !timerService.isTimerRunning()) { if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, "Starting timer"); } timerService.startTimer(); updateUIStartRun(); } else if (serviceBound && timerService.isTimerRunning()) { if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, "Stopping timer"); } timerService.stopTimer(); updateUIStopRun(); } } /** * Updates the UI when a run starts */ private void updateUIStartRun() { mUpdateTimeHandler.sendEmptyMessage(MSG_UPDATE_TIME); timerButton.setText(R.string.timer_stop_button); } /** * Updates the UI when a run stops */ private void updateUIStopRun() { mUpdateTimeHandler.removeMessages(MSG_UPDATE_TIME); timerButton.setText(R.string.timer_start_button); } /** * Updates the timer readout in the UI; the service must be bound */ private void updateUITimer() { if (serviceBound) { timerTextView.setText(timerService.elapsedTime() + " seconds"); } } /** * Callback for service binding, passed to bindService() */ private ServiceConnection mConnection = new ServiceConnection() { @Override public void onServiceConnected(ComponentName className, IBinder service) { if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, "Service bound"); } TimerService.RunServiceBinder binder = (TimerService.RunServiceBinder) service; timerService = binder.getService(); serviceBound = true; // Ensure the service is not in the foreground when bound timerService.background(); // Update the UI if the service is already running the timer if (timerService.isTimerRunning()) { updateUIStartRun(); } } @Override public void onServiceDisconnected(ComponentName name) { if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, "Service disconnect"); } serviceBound = false; } }; /** * When the timer is running, use this handler to update * the UI every second to show timer progress */ static class UIUpdateHandler extends Handler { private final static int UPDATE_RATE_MS = 1000; private final WeakReference<TimerActivity> activity; UIUpdateHandler(TimerActivity activity) { this.activity = new WeakReference<>(activity); } @Override public void handleMessage(Message message) { if (MSG_UPDATE_TIME == message.what) { if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, "updating time"); } activity.get().updateUITimer(); sendEmptyMessageDelayed(MSG_UPDATE_TIME, UPDATE_RATE_MS); } } } /** * Timer service tracks the start and end time of timer; service can be placed into the * foreground to prevent it being killed when the activity goes away */ public static class TimerService extends Service { private static final String TAG = TimerService.class.getSimpleName(); // Start and end times in milliseconds private long startTime, endTime; // Is the service tracking time? private boolean isTimerRunning; // Foreground notification id private static final int NOTIFICATION_ID = 1; // Service binder private final IBinder serviceBinder = new RunServiceBinder(); public class RunServiceBinder extends Binder { TimerService getService() { return TimerService.this; } } @Override public void onCreate() { if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, "Creating service"); } startTime = 0; endTime = 0; isTimerRunning = false; } @Override public int onStartCommand(Intent intent, int flags, int startId) { if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, "Starting service"); } return Service.START_STICKY; } @Override public IBinder onBind(Intent intent) { if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, "Binding service"); } return serviceBinder; } @Override public void onDestroy() { super.onDestroy(); if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, "Destroying service"); } } /** * Starts the timer */ public void startTimer() { if (!isTimerRunning) { startTime = System.currentTimeMillis(); isTimerRunning = true; } else { Log.e(TAG, "startTimer request for an already running timer"); } } /** * Stops the timer */ public void stopTimer() { if (isTimerRunning) { endTime = System.currentTimeMillis(); isTimerRunning = false; } else { Log.e(TAG, "stopTimer request for a timer that isn't running"); } } /** * @return whether the timer is running */ public boolean isTimerRunning() { return isTimerRunning; } /** * Returns the elapsed time * * @return the elapsed time in seconds */ public long elapsedTime() { // If the timer is running, the end time will be zero return endTime > startTime ? (endTime - startTime) / 1000 : (System.currentTimeMillis() - startTime) / 1000; } /** * Place the service into the foreground */ public void foreground() { startForeground(NOTIFICATION_ID, createNotification()); } /** * Return the service to the background */ public void background() { stopForeground(true); } /** * Creates a notification for placing the service into the foreground * * @return a notification for interacting with the service when in the foreground */ private Notification createNotification() { NotificationCompat.Builder builder = new NotificationCompat.Builder(this) .setContentTitle("Timer Active") .setContentText("Tap to return to the timer") .setSmallIcon(R.mipmap.ic_launcher); Intent resultIntent = new Intent(this, TimerActivity.class); PendingIntent resultPendingIntent = PendingIntent.getActivity(this, 0, resultIntent, PendingIntent.FLAG_UPDATE_CURRENT); builder.setContentIntent(resultPendingIntent); return builder.build(); } } }