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Now that you've seen what
the final project looks like,

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we're going to get the project
files set up on your computer.

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If you've watched online
coding tutorials before,

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I'm sure you've probably done
this kind of setup before.

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I strongly encourage
you to stick around for

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this video just to make sure
everything is in the right place.

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Having a different setup than the one
we follow in the video can cause some

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unnecessary frustration, so
we definitely don't want that to happen.

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I promise I'll keep this short,
sweet, and to the point.

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Go ahead and

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click the link in the teacher's notes to
download the zipped up starter files.

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In them, you'll find six folders in total.

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Each video where we write code will
have a before and after state,

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in case you want to try and challenge
yourself to perhaps watch a video, and

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then go and
implement the changes I make from memory.

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You definitely don't have to do this,
and it's simply an option,

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but this kind of set up helps me learn,
so I figured I'd share it with you.

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In each video,
I will start from the before state and

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end in the after state of the code for
that particular video.

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I've also included to do comments
in the code where I make changes so

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that can be easily found using
Android Studios built in to do window.

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Once you've downloaded the zip of
the project files, make sure that the zip

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files in the location on your computer
where you'd like them to live.

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Once they're there go ahead and
unzip them.

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Within the unzip folders, you will
see sub folders corresponding to each

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video where we write code or
where want to include it's due comment.

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To start, we'll open Android Studio and
then open the folder called 01-exercise.

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Let's have a look around this code.

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In the project, there are two packages.

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One for the login related code and
the other for the messages related code.

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Let's take a peak at
the login package first.

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Once you open the package,
you'll see there are two classes.

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One for the login screen itself,
and a utility class for

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determining if a user is logged in.

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In the LoginActivity, if there's a user
already logged in, I start the messaging

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activity, close the log in activity, and
return so no further code is called.

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Then, I set a listener on the edit
text to log in the user when the Enter

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button is pressed.

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I also set a listener on the log
in button to do the same thing.

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Next, we'll explore the messages package.

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This is where all the fun
FireBase stuff will happen.

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First, I want to show you the Messages
class that will represent a message in our

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Firebase.

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There are a couple of key things here
I want to call your attention to.

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First, notice that there is
a no arguments constructor.

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Firebase requires this in
order to deserialize objects.

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You'll also notice
the @IgnoreExtraProperties

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annotation on this class.

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There will be an error with
that annotation at first, but

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we'll fix this shortly.

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That annotation does
exactly what it looks like.

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It ignores properties that
don't map the class fields.

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In other words, if there is a method for
getting a value that doesn't directly

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correspond to a class field, it's ignored
when setting your data to Firebase.

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Next, we'll look at the MessagingActivity.

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We also have simple classes for
MessageAdapter and MessageViewHolder.

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But those are simply boiler plate
required to populate a recycler view.

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And I will leave it up to you
to explore those classes.

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Within the MessagingActivity, I've set
the adapter on the recycler view and

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wired up the button to send a message and

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the edit text to send a message when
a user clicks the Enter button.

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Currently, the activity will show a toast
when we attempt to send a message, but

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we will update that behavior soon.

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There are also methods below for
clearing a text of the edit text,

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hiding the keyboard, and
scrolling to the most recent message.

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Those methods are all simply for

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a better user experience and
certainly aren't required by Firebase.

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Let's run the starter project and
see what it looks like.

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I'm going to comment out the Firebase
annotation on our Message class since

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I haven't yet included the Firebase
library in this project.

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But, again, we'll fix that very soon.

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When you run this project, you'll
first see the username entry screen.

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After you provide a username,

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you'll see a screen where a list of
messages will eventually be displayed.

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For now, if we type a message and
hit send.

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We'll see that the message goes away,
but isn't actually sent anywhere.

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In the next video, we'll learn how to
create a Firebase project in the Firebase

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console, taking the first step to sending
your message to everyone in real time.