Java tutorial
/* * Copyright 2017 Oleksandr Finchuk * * This file is part of ClockPlus. * * ClockPlus is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * ClockPlus is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with ClockPlus. If not, see <http://www.gnu.org/licenses/>. */ package com.finchuk.clock2.timers; import android.app.PendingIntent; import android.content.Context; import android.content.Intent; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.support.v4.util.SimpleArrayMap; import android.util.Log; import com.finchuk.clock2.MainActivity; import com.finchuk.clock2.chronometer.ChronometerNotificationService; import com.finchuk.clock2.timers.data.AsyncTimersTableUpdateHandler; import com.finchuk.clock2.timers.data.TimerCursor; import com.finchuk.clock2.util.ContentIntentUtils; import com.finchuk.clock2.util.ParcelableUtil; /** * Handles the notification for an active Timer. * TOneverDO: extend IntentService, it is ill-suited for our requirement that * this remains alive until we explicitly stop it. Otherwise, it would finish * a single task and immediately destroy itself, which means we lose all of * our instance state. */ public class TimerNotificationService extends ChronometerNotificationService { private static final String TAG = "TimerNotifService"; private static final String ACTION_CANCEL_NOTIFICATION = "com.finchuk.clock2.timers.action.CANCEL_NOTIFICATION"; public static final String ACTION_ADD_ONE_MINUTE = "com.finchuk.clock2.timers.action.ADD_ONE_MINUTE"; public static final String EXTRA_TIMER = "com.finchuk.clock2.timers.extra.TIMER"; private static final String EXTRA_CANCEL_TIMER_ID = "com.finchuk.clock2.timers.extra.CANCEL_TIMER_ID"; private AsyncTimersTableUpdateHandler mUpdateHandler; private final SimpleArrayMap<Long, Timer> mTimers = new SimpleArrayMap<>(); private final SimpleArrayMap<Long, TimerController> mControllers = new SimpleArrayMap<>(); private long mMostRecentTimerId; /** * Helper method to start this Service for its default action: to show * the notification for the Timer with the given id. */ public static void showNotification(Context context, Timer timer) { Intent intent = new Intent(context, TimerNotificationService.class); intent.putExtra(EXTRA_TIMER, ParcelableUtil.marshall(timer)); context.startService(intent); } /** * Helper method to cancel the notification previously shown from calling * {@link #showNotification(Context, Timer)}. This does NOT start the Service * and call through to {@link #onStartCommand(Intent, int, int)}, because * the work does not require so. * @param timerId the id of the Timer associated with the notification * you want to cancel */ public static void cancelNotification(Context context, long timerId) { Intent intent = new Intent(context, TimerNotificationService.class).setAction(ACTION_CANCEL_NOTIFICATION) .putExtra(EXTRA_CANCEL_TIMER_ID, timerId); context.startService(intent); } @Override protected int getSmallIcon() { return com.finchuk.clock2.R.drawable.ic_timer_24dp; } @Nullable @Override protected PendingIntent getContentIntent() { // The base class won't call this for us because this is not a foreground service, // as we require multiple notifications created as needed. Instead, this is called after // we call registerNewNoteBuilder() in handleDefaultAction(). // Before we called registerNewNoteBuilder(), we saved a reference to the most recent timer id. return ContentIntentUtils.create(this, MainActivity.PAGE_TIMERS, mMostRecentTimerId); } @Override protected boolean isCountDown() { return true; } @Override protected int getNoteId() { // Since isForeground() returns false, this won't be called by the base class. return 0; } @Override protected String getNoteTag() { // This is so we can cancel notifications in our static helper method // cancelNotification(Context, long) with the static TAG constant return TAG; } @Override protected boolean isForeground() { // We're going to post a separate notification for each Timer. // Foreground services are limited to one notification. return false; } @Override public void onCreate() { super.onCreate(); mUpdateHandler = new AsyncTimersTableUpdateHandler(this, null); } @Override public void onDestroy() { super.onDestroy(); // After being cancelled due to time being up, sometimes the active timer notification posts again // with a static 00:00 text, along with the Time's up notification. My theory is // our thread has enough leeway to sneak in a final call to post the notification before it // is actually quit(). // As such, try cancelling the notification with this (tag, id) pair again. for (int i = 0; i < mTimers.size(); i++) { cancelNotification(mTimers.keyAt(i)); } } @Override public int onStartCommand(Intent intent, int flags, int startId) { if (intent == null) { Log.d(TAG, "Recreated service, starting chronometer again."); // Restore all running timers. This restores all of the base // class's member state as well, due to the various API // calls required. new Thread(new Runnable() { @Override public void run() { TimerCursor cursor = mUpdateHandler.getTableManager().queryStartedTimers(); while (cursor.moveToNext()) { // We actually don't need any args since this will be // passed directly to our handler method. If we were going // to startService() with this, then we would need to // specify them. Intent intent = new Intent( /*TimerNotificationService.this, TimerNotificationService.class*/); final Timer timer = cursor.getItem(); intent.putExtra(EXTRA_TIMER, ParcelableUtil.marshall(timer)); // TODO: Should we startService() instead? handleDefaultAction(intent, 0, 0); } } }).start(); } return super.onStartCommand(intent, flags, startId); } @Override protected void handleDefaultAction(Intent intent, int flags, int startId) { final byte[] bytes = intent.getByteArrayExtra(EXTRA_TIMER); if (bytes == null) { throw new IllegalStateException("Cannot start TimerNotificationService without a Timer"); } final Timer timer = ParcelableUtil.unmarshall(bytes, Timer.CREATOR); final long id = timer.getId(); boolean updateChronometer = false; Timer oldTimer = mTimers.put(id, timer); if (oldTimer != null) { updateChronometer = oldTimer.endTime() != timer.endTime(); } mControllers.put(id, new TimerController(timer, mUpdateHandler)); mMostRecentTimerId = id; // If isUpdate == true, this won't call through because the id already exists in the // internal mappings as well. registerNewNoteBuilder(id); // The note's title should change here every time, especially if the Timer's label was updated. String title = timer.label(); if (title.isEmpty()) { title = getString(com.finchuk.clock2.R.string.timer); } setContentTitle(id, title); if (updateChronometer) { // Immediately push any duration updates, or else there will be a noticeable delay. setBase(id, timer.endTime()); updateNotification(id, true); } // This handles any other notification updates like the title or actions, even if // the timer is not running because the current thread will update the notification // (besides the content text) before quitting. syncNotificationWithTimerState(id, timer.isRunning()); } @Override protected void handleStartPauseAction(Intent intent, int flags, int startId) { long id = getActionId(intent); mControllers.get(id).startPause(); syncNotificationWithTimerState(id, mTimers.get(id).isRunning()); } @Override protected void handleStopAction(Intent intent, int flags, int startId) { long id = getActionId(intent); mControllers.get(id).stop(); // We leave removing the notification up to AsyncTimersTableUpdateHandler // when it calls cancelAlarm() from onPostAsyncUpdate(). // This calls the static helper cancelNotification(), which // starts this service to handle ACTION_CANCEL_NOTIFICATION. } @Override protected void handleAction(@NonNull String action, Intent intent, int flags, int startId) { if (ACTION_ADD_ONE_MINUTE.equals(action)) { // While the notification's countdown would automatically be extended by one minute, // there is a noticeable delay before the minute gets added on. // Update the text immediately, because there's no harm in doing so. long id = getActionId(intent); final Timer orig = mTimers.get(id); // We have to add the minute to a copy Timer. If we had modified the original Timer, // then the controller would also add another minute to the same instance, and what // would happen after the DB update is the Timer instance with this ID ends up // being extended by 2 minutes. // // Why not just do something like: `t.endTime() + 60000`? Because extending timers that // are paused is a special case, and Timer.addOneMinute() already has the logic to handle // that. Timer copy = Timer.create(orig.hour(), orig.minute(), orig.second(), orig.group(), orig.label()); orig.copyMutableFieldsTo(copy); copy.addOneMinute(); setBase(id, copy.endTime()); updateNotification(id, true); mControllers.get(id).addOneMinute(); } else if (ACTION_CANCEL_NOTIFICATION.equals(action)) { long id = intent.getLongExtra(EXTRA_CANCEL_TIMER_ID, -1); cancelNotification(id); // TODO: SHould this be before cancelNotification()? I'm worried // that the thread's handler will have enough leeway to sneak // in a notification update before it is quit. If it did, // then at least cancelNotification should theoretically // remove it... releaseResources(id); } else { throw new IllegalArgumentException("TimerNotificationService cannot handle action " + action); } } @Override protected void releaseResources(long id) { super.releaseResources(id); mTimers.remove(id); mControllers.remove(id); // TODO: Should we make a private method? // This private method would first call releaseResources(), // and then this block. if (mTimers.isEmpty()) { // We could check any map, since they should all have the same sizes stopSelf(); } } private void syncNotificationWithTimerState(long id, boolean running) { // The actions from the last time we configured the Builder are still here. // We have to retain the relative ordering of the actions while updating // just the start/pause action, so clear them and set them again. clearActions(id); addAction(ACTION_ADD_ONE_MINUTE, com.finchuk.clock2.R.drawable.ic_add_24dp, getString(com.finchuk.clock2.R.string.minute), id); addStartPauseAction(running, id); addStopAction(id); quitCurrentThread(id); if (running) { startNewThread(id, mTimers.get(id).endTime()); } } private long getActionId(Intent intent) { return intent.getLongExtra(EXTRA_ACTION_ID, -1); } }