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In the last video, we got our YouTube app to play a video.

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There are a couple of improvements we can make to the app though, three in fact, but we're going to focus on the two

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obvious ones to start with.

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Now at the moment we have to press the play icon to start the video playing, and it would be neater 

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if the video started playing automatically when the app starts.

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And we're also going to fix the problem that happens when you rotate the device while a video is playing.

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So let's start by reviewing the problems. We're going to run the app

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Alright so as you can see, the video doesn't autoplay, and basically won't start until I come over here and click

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on the play icon.

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So there's that, but also when I rotate the device which I'll do now, you can see that the video stops,

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and it's actually cued at the right position, you can see here that it has progressed, and when I play it does start

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at the same place, it doesn't start at the start of the video,

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however it doesn't play automatically and it would be good if we could actually get that to happen,

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to get it to automatically play.

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So let's have a look at fixing those problems, so

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back to the code. In the onInitializationSuccess function,

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we're calling this cueVideo function of our YouTubePlayer.

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So let's actually see exactly what that does and also what else is available.

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So I've still got the documentation open so I'll just go back to a browser,

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so go back to there and then click on YouTubePlayer in the left hand menu, 

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over here. And that gives us a list of the various functions that are available. OK, and

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if I scroll down here down to public methods,

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and that's the list of the various functions that are actually available to us, and having a look at cueVideo,

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this one here, loads the specified video's thumbnail and prepares the player to play the video, but does not download

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any of the video stream until the play function is called. So to do that we need to call play,

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but I'm not going to do that because it won't work, and this can actually be a source of frustration.

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The documentation says you have to do something, called play in this case,

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however that doesn't work. It seems to be a timing issue.

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So we cue the video in the onInitializationSuccess function,

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but if we play too quickly, the video hasn't finished loading.

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So there's actually two things I suggest you do if you hit problems like this. First,

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add a lot of logging to all the functions, and that includes the callback functions that we haven't used. The logcat

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will then show the order that everything's happening which can provide useful information.

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Now what you'll find is that we'll be trying to call play, before the onLoaded callback's been received,

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the one in the playerStateChangeListener. So obviously the video can't play if it hasn't finished loading.

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So that's the first thing.

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But secondly, importantly, make sure you read all the documentation. Now if you scroll down all of these methods

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down here, you'll eventually get to one,

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loadVideo, loads and plays the specified video, which is really what we want to do here. So to fix the

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first problem, and to make our video play when the app loads, we really just need to replace the call to cue

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Video with the call to loadVideo. So let's actually go back and see if that works.

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Go back to android studio, change this cueVideo call to dot loadVideo.

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Remember it gets, loads and plays a video for us, and we also need to add an else here as well. Alright

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so that should work,

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but before we test it we have to think about the second problem.

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Now when we rotate the device the player's restored on the screen.

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The play position is where we left it as well, but unfortunately it doesn't start playing.

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But hang on, if the play is restored on the screen, then wasRestored

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probably going to be true, and

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we're only doing something when it's false. So perhaps we should call play when the play is restored.

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So let's go ahead and do that,

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so we'll put an else clause in here and some, and a code block, and we'll try YouTubePlayer questionmark dot play, and

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call the play method like that, and that actually should fix both problems,

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but let's actually try that and see if it does do that.

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And we're going to see if the video starts automatically, number one, and then we'll try rotate again and

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see what happens. Alright, so you can see this time perfect, we've got the video playing,

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whereas before we had to click on play, and now I'm going to rotate it into landscape and see what happens.

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And that's also good because it's actually played from the position, and just to be completely clear about that,

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let's advance the play head to about the one minute 17 mark, give it a second to buffer.

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Alright so that's working good as well. I didn't actually have to play,

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I didn't have to click play, it automatically played,

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but if I go back now to portrait mode again, we can see that's also still working, so no matter of when I

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rotate the device, in what mode,

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the video's playing without me having to actually click on the play button.

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So that's awesome, that's what we were trying to achieve here, so I'll just stop that now.

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And incidentally don't use Toast messages for diagnosing problems.

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Now even with the short duration, the Toast messages hang around for a while, so they actually get

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out of sync with what's happening.

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Toast messages are really just for you users, and we should be using logging in all those functions ourselves

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for debugging purposes. And just to confirm that problem with the Toast messages again, if I start

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actually doing that and start running it, and starting and pausing videos and having a play,

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you'll see that the messages will get out of sync. So let's just try that,

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and I've stopped now, as you can see those messages, the Toast messages are still trying to catch up.

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And you can see there it was quite some time after pressing pause, and we're still getting caught up on Toast messages.

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So obviously not a good way to do any form of debugging, you really want to use logcat for that. Alright,

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so I'm going to stop the video here. In the next one we're going to add to the app, to let it handle playlists as well,

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and we're also going to see how we can start new activities to perform different functions, using 

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a very important Android concept, intents. So see you in the next video.