Adding Text to a Notification

[MUSIC] 0:00 [SOUND] Let's change gears a little bit and 0:04 talk about a different kind of communication. 0:06 Notifications, you probably know a little bit about using Notifications from earlier 0:08 work here at Treehouse. 0:13 As usual check the teacher's notes for links but 0:14 will cover it pretty well in this last section. 0:17 Let's take another look at the table we've been using in this course. 0:20 This last row shows an example of when we might want a notification. 0:23 When a service needs to send an update to the user. 0:27 In this example we'll extend an existing notification that shows in the drawer 0:30 when the user is playing a song. 0:35 Note in this list that we don't talk about using notifications 0:38 from an activity to the system. 0:41 We don't need a notification in that scenario because the activity's 0:42 already visible to the user and we can use a stacked bar or 0:45 some other in app mechanism for alerting the user to something. 0:49 Let's start here by taking a look at the documentation about notifications. 0:53 First part of a notification is the icon that appears 0:57 in the notification bar at the top. 1:00 Then when the user pulls the drawer down, the notification has its own 1:02 row in the drawer and we can even add actions to them like this. 1:06 This app is currently using a notification in the player service. 1:10 So let's check it out. 1:14 So here in the onStartCommand method we are using the builder pattern from 1:16 the notification class to build a simple notification. 1:21 All it does is display our app's icon when a song is playing and 1:24 then it goes away when the service stops playing music. 1:27 I think it would be nice to show the title of the song playing. 1:29 So let's see how to do that. 1:32 First the notification builder has a fluent interface. 1:34 So let's delete this semi-colon and chain some of these things together. 1:38 I'm gonna get rid of notification builder, tab over and 1:43 now at the end of this I can append another line .setContentTitle. 1:47 Okay how do we get the song title in here. 1:54 We need to pass in a song when this service is started. 1:57 Let's go back to Main Activity. 2:01 We're starting this service when the play button is tapped. 2:03 So let's look at the On Click listener we're going to scroll all the way up 2:06 to on create, and here we have mplay button and 2:10 in this listener is where we are starting the service. 2:14 All we need to do is add the song as an extra to this intent. 2:17 So we say, intent.putExtra. 2:22 We can use the EXTRA key word SONG, and 2:24 now for the song itself, we can just pass in the first song in our playlist. 2:29 Our playlist itself isn't fully functional. 2:34 Though that would be an interesting exercise if you'd like to extend this and 2:36 make it play everything in a given list. 2:39 Anyhow, let's type Playlist.songs, and 2:41 get the first one at index zero. 2:45 Now a challenge for you. 2:49 Pause me and see if you can set the song and artist back in the service. 2:51 Use autocomplete to help you figure out the additional text field 2:54 you might use for the artist name. 2:57 Okay did you get it? 3:01 I'm going to go back and 3:01 let's start with some place holders here before we build our notification. 3:03 We have a string called title and we'll initialize it to a blank string. 3:08 And then a string called artist also initialized to a blank value. 3:13 I'm setting these to blank strings because I'm going to do a null check and 3:18 I'll only update them if a song is passed in. 3:22 I don't want the app to crash if song data is missing. 3:24 So for the null check, if (intent.getParcelableExtra) and 3:27 then we can use MainActivity.EXTRA_SONG. 3:32 If that's not equal to null, then we can get a song and set title and artist. 3:37 So first, we have Song song = intent.getParcelableExtra 3:43 MainActivity EXTRA_SONG. 3:50 Now we can set title equal to song.getTitle and 3:53 artist equal to song.getArtist. 3:57 Now we can use these in our notification builder. 4:01 So for ContentTitle let's pass in title. 4:04 And then I'm going to chain the artist with .setContentText, and pass in artist. 4:07 And one more thing, 4:16 our regular app icon doesn't look very good as a notification icon. 4:17 So I downloaded another one. 4:20 Let's call R.Drawable.ic_queue_music_white. 4:23 Okay, let's try it out. 4:27 Okay, so we want to play some music. 4:32 There we go. 4:36 And look, there's our notification showing up, and if we pull it down. 4:37 Hey it's showing the icon, the title, and the artist. 4:40 Cool. 4:44 It would be really nice to open our app directly from this notification. 4:45 Let's try to do that in the next video. 4:49