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♪ (robotic music) ♪
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Hi, now that you know
exactly what Android is,
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let's just create
our first application in Android.
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To create that, you will be opening up
your Android Studio
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and you will be presented
with this window.
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And once you have downloaded all the SDKs,
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then you can go ahead
and design your first application.
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Click on the start a new
Android Studio Project.
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Here you need to give
the application a name.
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Let me just call it MyHelloFirstApp.
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And this is your company domain name,
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it can be anything you'd like it to be.
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In my case, it's com.example.demouser.
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Combining this Company name
and Application name,
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your package name will be formed.
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Make sure this package name is unique
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because when you're going
to upload your APK at the end,
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that APK package will be checked out
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by your Google Play Store.
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If it is not unique,
at that point in time,
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you might want to change
that package name.
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If you try to put this
com.example.demouser,
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is has already been taken
by Google, for example,
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you can't upload an application like this.
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Let's say you put
com.planet.MyHelloFirstApp
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and that domain is also taken
by somebody else,
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then you cannot upload it.
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It has to be unique.
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Next, this is your project location,
for our example purpose
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we are going to use
this package name only.
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This is the project location,
where our project is going to be saved.
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You can change it if you like.
Click on Next.
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Then you have to select minimum
and maximum SDK here.
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Maximum by default will be that latest one
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that is 25 API
or if you're using 24, 24 API.
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And then there will be a minimum
you will have to select.
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I could have gone all the way down to nine
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and you can see I will be targeting
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approximately 100% of the devices,
right now, in the market.
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The problem here is the more I go down
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the more I'm sacrificing the features.
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Because the Gingerbread will not contain
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all the features which
my Android API 25 contains.
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Of course, even if I am selecting 15,
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15 will not contain all the features
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which my API 25 contains, right?
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But till 15, I can get
the Android Support Library,
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that is the external leverage
provided by the Android Framework
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and you can get those libraries
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to support those features
up until a version.
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I cannot get support libraries below--
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all the way down to the 2.3.
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So that's why you need
to make a balance also,
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and you can see
while I'm selecting API 15,
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I can still target 97.4% of the devices.
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That's a good thing.
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Go to Next, then you will see
all of these templates,
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you can select any
of these templates to start
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your Android application development
as we are starting our very first app
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and we are going to start from scratch.
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I will click on Empty Activity
and press Next.
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Give the name of that activity,
I'm going to call it MainActivity only.
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That's it.
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You can give any name, whatever you like,
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this will ensure that
you're creating an activity name
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that is the Java file, plus the layout
that is the XML file.
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It will create a layout file,
if you don't want that, uncheck this.
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But you definitely want
the UI bar of your activity also,
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how, exactly activity
will look like on the screen.
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You want that,.
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And then there is
a backward compatibility checked.
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Turning this on that means your activity
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will be extending AppCompat activity.
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If you uncheck this then your activity
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will be extending extended activity class.
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So backward compatibility is to make sure
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that even the previous versions
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are able to access the new features
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which are there in new versions
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with the help of support libraries.
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Press on Finish.
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Let the Gradle build.
Gradle is a building tool here
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which is used by your Android system
to build your application.
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Please, wait for Gradle
to build your project first.
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If you try to keep on
clicking here and there,
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your Gradle might crash.
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You need a pretty fast machine
for Gradle not to crash.
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So let the Gradle build,
once the Gradle--
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you'll see down below "indexing is done"
and Gradle is built,
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after that, you can see
this is the Java file
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that is MainActivity,
the Activity in Java file,
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and this is the Activity's layout file.
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That is the XML file.
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This is how your first application
will look like.
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Now before doing anything else,
let me just run this application.
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To run this application, first of all,
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you need to create a virtual device.
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How can you create a virtual device?
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There's this icon, AVD manager,
known as "Android Virtual Device".
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Click on that.
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Either there will be
a by default virtual device
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created for you by Android
or you will be seeing this screen.
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You can even delete that Virtual Device
and come to this screen.
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Click on this button,
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and select one of the resolution device
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which you want to work on.
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That's a Nexus 5,
screen resolution 1080x1920.
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If you want to work
with this kind of resolution, go ahead.
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Or if you want to work
with any other resolution
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you can select that too.
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Press Next.
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Then it asks you what should be
your system image,
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which system image you want to run
on your virtual device.
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Now, here it will only show you
the system images
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that you downloaded,
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at the time of downloading
from your SDK manager.
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In mine, you can see there is
a 23 and a 25, so I will go with 25.
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I'm using x86_64
that too with Google API.
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If you don't want to use this Google API,
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then you can go with normal x86
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but then you must have downloaded
that system image here.
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Other images.
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Any ARM or image if you want
to work with that too.
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but I wouldn't recommend the ARM
as they are very slow.
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I'd recommend--
I'm using the latest one,
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To Google API, press Next.
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You can give the name
of your device or virtual device
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anything you want,
let's say Black_Knight_01
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and press Finish.
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Here you see my device is ready,
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all I have to do is press the Play button.
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Launch button
and it will launch the emulator.
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Wait some seconds and you can see
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the emulator will be
up and running in a bit.
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x86 emulators are way faster
as compared to your ARM.
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If this would have been an ARM machine,
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it would've taken a long time to run.
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This won't take hardly a minute to turn on
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and I would recommend
once your emulator is on,
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whenever you're developing,
do not close your emulator.
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Unless you are done for the day
or done with the development
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for the day, why ?
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Because every time you close
your emulator and run it again
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it will take the same time
to launch the emulator again and again.
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So what you can do here
is just run it once
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and then after that,
keep on running your application
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from your Android Studio
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and they will directly go
on your emulator.
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So your emulator doesn't have to restart
or get the resources again.
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How will you do that?
As you can see, my emulator is running,
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What I would do to run my application
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is here, you can see a Play button
launch button, or run button.
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Just click on that.
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My Android Studio automatically detected
that there is a device
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connected to me,
that's called Black_Knight.
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Press on OK.
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And this application will run
on my Android device.
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Just wait for it,
Gradle will start building.
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If there is any error or something,
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that also will be detected
at this point in time.
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There we go.
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So this is my very first app,
which I have created
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from the Android App Studio.
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Even if you close your app now,
you go to your apps,
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you can see your app here.
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You click on this, so it's just behaving
like any other app.
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Now before moving any further in Android,
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let's just learn a little bit
about your Android Studio ID, etc.
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The left bar is known as project panel,
we will come to that.
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This middle area is known as code area,
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or you can create your layout also here
by dragging and dropping.
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The middle part is known as your console.
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This is where you will be seeing
what is going on with your Android.
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I just ran an application here,
in my Android Virtual Device.
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So it gave me what was going on,
this was the run mode,
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what was going on
with my application in run mode.
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But you can go to your Android monitor,
also you will see a logcat.
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Logcat will be your friend
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throughout your Android
application development
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because it tells you what is going on
in your Android Virtual Device.
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Okay, so now you can see here,
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this part here is known as project panel,
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in this, what you are seeing
is the Android Project Data Key.
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We'll talk about other project data key
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but when we talk about
Android Project Data Key,
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you will see your project
is divided in two parts,
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one is your app folder,
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and the other one
is your Gradle script folder.
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Let's just talk about
Gradle's script folder first.
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When we open up our Gradle script,
you will see that in Gradle
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there are mainly three types
of Gradle file,
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one is called ProjectMyHello.Gradle
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which will contain nothing
but the information
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about my Gradle version itself
as you can see
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which Gradle I'm using
right now is Gradle 2.2.2
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and include all the repositories
in this project.
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Second Gradle file which we will be seeing
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is module level Gradle file.
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As I only have the mobile module here
so there is only one.
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If there would have been
an Android wear
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then there would be a wear also.
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If there would be TV, then
there would be a TV module file also.
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So there is only one,
what exactly it contains
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it contains the information
of all the module itself.
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What is the minimum version
of SDK I'm going to use,
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what is the target version for this SDK,
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what is the application ID,
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the compilation SDK version,
so all that information
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will be included
in this module-level Gradle,
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Even the dependencies you want to add
that is libraries and all--
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that will also be added in this.
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As you can see there are this many
libraries as of right now.
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I'm using the Espresso libraries com,
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and the com support,
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there is app compact support
libraries also,
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I'm using JUnit library also.
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If you want to add any external leverage
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that also will be adding
inside dependencies on it .
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So that's what the use
of the module build Gradle file
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it [inaudible]
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and gives you the information
about that particular modules.
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Next settings.gradle file,
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it's again one file per application.
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It tells the compiler which module
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has to part into the compilation
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at any particular time.
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For example, if you have
a better application
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designed also
for your mobile, TV, and wear,
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and your TV, and wear
are still not complete
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for the production level.
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Then, when your mobile app
for wear is complete
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then you can include the module
of mobile here only.
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Like this, mobile.
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Then the name of the Gradle file,
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like, right now, it's app here,
it will be mobile.
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And if there is a wear also,
then we will be putting wear too.
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Like this: wear.
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If there would be a wear
that's the condition,
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that there is a wear module too.
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Okay, so as of right now,
there is no wear,
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so it's only just one,
that's why this setting-gradle file
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contains only app
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because that's the only Gradle file
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you're going to compile
whenever you're going to run it.
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00:13:29,008 --> 00:13:31,368
Okay great, so that was Gradle scripts.
246
00:13:32,630 --> 00:13:34,630
Now let's talk about app bar,
247
00:13:34,630 --> 00:13:40,580
in the app bar you will see
mainly three folders.
248
00:13:40,580 --> 00:13:43,440
First is your manifest project.
249
00:13:43,440 --> 00:13:46,390
Inside this you will find
a file android manifest.xml,
250
00:13:46,390 --> 00:13:48,910
this is the file
which comes in contact
251
00:13:48,910 --> 00:13:51,320
with your Android device
for the very first time
252
00:13:51,320 --> 00:13:52,877
when you install your application.
253
00:13:52,877 --> 00:13:55,167
So when this application
is getting installed
254
00:13:55,167 --> 00:13:57,357
in any emulator or device,
255
00:13:57,357 --> 00:13:59,732
this is the file that will come in contact
256
00:13:59,732 --> 00:14:01,852
with your Android device
for the very first time.
257
00:14:01,852 --> 00:14:03,942
What exactly it contains,
it contains the information
258
00:14:03,942 --> 00:14:07,322
about the application itself,
like the package name,
259
00:14:07,322 --> 00:14:09,942
what's is going to be my package name,
260
00:14:09,942 --> 00:14:14,372
the application's information
like how many screens
261
00:14:14,372 --> 00:14:16,512
or how many activities it'll contain.
262
00:14:16,512 --> 00:14:19,712
If there are more screens,
then you have to register them here,
263
00:14:19,712 --> 00:14:22,113
only, again if there is another activity,
264
00:14:22,113 --> 00:14:23,873
there will be another activity tag.
265
00:14:23,873 --> 00:14:26,943
Or if there is more services
then there will be more services tags.
266
00:14:27,836 --> 00:14:31,756
And it will also include the permission,
let's say your application
267
00:14:31,756 --> 00:14:35,046
is going to contain any permission
like internet permission,
268
00:14:35,046 --> 00:14:38,566
or access netbook permission
or GPS permission.
269
00:14:38,566 --> 00:14:42,056
You need to declare those permissions
here inside this manifest file only.
270
00:14:42,056 --> 00:14:44,451
Let's say, I want to include
the internet permission
271
00:14:44,451 --> 00:14:47,571
I will use this permission, internet,
and there you go.
272
00:14:47,571 --> 00:14:50,200
So this is how your permission
gets added also.
273
00:14:52,851 --> 00:14:54,911
So that was Android manifest.
274
00:14:54,911 --> 00:14:59,371
In the manifest file you can see
there are many attributes,
275
00:15:00,091 --> 00:15:02,853
like AllowBackup will make sure
276
00:15:02,853 --> 00:15:08,383
that your application
is compatible for backing up.
277
00:15:08,724 --> 00:15:12,612
And icon attribute here
is getting the icon
278
00:15:12,612 --> 00:15:15,612
from @mipmap/ic_launcher.
279
00:15:15,612 --> 00:15:18,902
I will talk about this @mipmap in a bit,
280
00:15:18,902 --> 00:15:23,212
but know that this here
is getting the icon...
281
00:15:23,212 --> 00:15:27,842
Or this label attribute also
is getting the text
282
00:15:27,842 --> 00:15:29,692
from your resource folder.
283
00:15:29,692 --> 00:15:31,912
We'll talk about how it's getting there.
284
00:15:31,912 --> 00:15:34,636
SupportRTL is again right to left,
285
00:15:34,636 --> 00:15:38,236
there are language which go
from right to left
286
00:15:38,236 --> 00:15:41,786
so this application
will support RTL language too.
287
00:15:41,786 --> 00:15:44,826
And theme, I'm getting this style
from resource folder
288
00:15:44,826 --> 00:15:49,496
we'll talk about that also, but know
these attributes are setting...
289
00:15:49,496 --> 00:15:51,726
This one is setting the icon
to my application
290
00:15:51,726 --> 00:15:53,984
this one is setting the name
or label to my application
291
00:15:53,984 --> 00:15:57,034
and this one is setting the style
to my application.
292
00:15:57,874 --> 00:16:00,574
Now let's just go to our Java folder.
293
00:16:00,574 --> 00:16:03,694
When you open up your Java folder
you will find three package,
294
00:16:03,694 --> 00:16:06,284
First package is know
as development package.
295
00:16:06,284 --> 00:16:08,864
Second package is known
as Android test package
296
00:16:08,864 --> 00:16:10,239
or instrumented test package.
297
00:16:10,239 --> 00:16:12,475
Third package is known
as unit testing package.
298
00:16:12,475 --> 00:16:16,206
The first development package
299
00:16:16,206 --> 00:16:19,206
you will put all the code
for your application development.
300
00:16:19,206 --> 00:16:21,512
This is the package which
you'll be dealing a lot
301
00:16:21,512 --> 00:16:24,282
when you're doing
the Android application development.
302
00:16:24,282 --> 00:16:26,376
All your activities, services, broadcasts,
303
00:16:26,376 --> 00:16:28,666
content providers, database classes,
304
00:16:28,666 --> 00:16:32,586
all those classes will be kept inside
this development package only.
305
00:16:32,586 --> 00:16:35,276
As you can see there is
only one activity right now,
306
00:16:35,276 --> 00:16:37,184
that's MainActivity, if you open up,
307
00:16:37,184 --> 00:16:39,474
this is how your MainActivity looks like.
308
00:16:41,347 --> 00:16:43,911
Inside your MainActivity,
you can see that--
309
00:16:43,911 --> 00:16:47,841
activity is nothing but a class
which is extending AppCompatActivity
310
00:16:47,841 --> 00:16:51,681
and this AppCompatActivity
is being inherited from
311
00:16:51,681 --> 00:16:54,841
or is taken from
your Android support library.
312
00:16:55,436 --> 00:16:58,380
As you can see,
AppCompatLibrary is important
313
00:16:58,380 --> 00:17:00,710
for your android.support.v7. app.
314
00:17:00,710 --> 00:17:04,760
Now if I would have done activity also,
315
00:17:05,662 --> 00:17:08,922
then, also syntactically,
there would be no problem
316
00:17:08,922 --> 00:17:12,414
because ultimately,
this is activity only, right ?
317
00:17:16,581 --> 00:17:18,423
I'm designing for the latest version
318
00:17:18,423 --> 00:17:21,423
then the features like material design
319
00:17:21,423 --> 00:17:23,682
all the new features,
will not be supported
320
00:17:23,682 --> 00:17:26,522
by the previous version
if they are not included there.
321
00:17:26,522 --> 00:17:32,302
So that's the reason I want to do
the AppCompatActivity.
322
00:17:33,574 --> 00:17:37,154
Inside your activity, you can see
there's a method I'm using,
323
00:17:37,154 --> 00:17:39,004
an overrided method called OnCreate,
324
00:17:39,004 --> 00:17:40,774
so that OnCreate method is already defined
325
00:17:40,774 --> 00:17:43,354
inside AppCompatActivity
and I'm just overriding it.
326
00:17:43,354 --> 00:17:46,618
And inside this, there's
the very first statement I'm doing
327
00:17:46,618 --> 00:17:48,728
which is super.OnCreate.
328
00:17:48,728 --> 00:17:53,218
Super.OnCreate will make sure
that before I do anything,
329
00:17:53,218 --> 00:17:56,019
before I do any customization
in this particular method
330
00:17:56,019 --> 00:17:58,189
I want to use all the functionalities
331
00:17:58,189 --> 00:17:59,798
which was there in my parent activity.
332
00:17:59,798 --> 00:18:04,560
I don't want to temper
with the functionality
333
00:18:04,560 --> 00:18:08,227
which was provided to me
334
00:18:08,227 --> 00:18:11,927
by my Activity class,
the OnCreate functionality
335
00:18:11,927 --> 00:18:14,497
which was provided to me
by Activity class.
336
00:18:15,084 --> 00:18:16,234
I want that.
337
00:18:16,234 --> 00:18:20,415
Plus if I want any
of my own functionality
338
00:18:20,415 --> 00:18:23,705
that I would be including
after including this statement.
339
00:18:24,834 --> 00:18:27,624
Once I include this,
then I'm including my own statement
340
00:18:27,624 --> 00:18:29,134
that is SetContentView.
341
00:18:29,134 --> 00:18:34,314
I'm providing
a particular view to my activity
342
00:18:34,314 --> 00:18:37,714
and that I'm also doing
with R.layout.activity_main.
343
00:18:37,714 --> 00:18:41,047
Just for now, understand that
I'm attaching my layout file here.
344
00:18:41,047 --> 00:18:44,007
I'm attaching this layout file
as you can see, Activity_Main,
345
00:18:44,007 --> 00:18:45,097
Activity_Main.
346
00:18:45,097 --> 00:18:49,222
I will discuss into more detail in a bit
347
00:18:49,222 --> 00:18:51,332
on how exactly it's getting attached
348
00:18:51,332 --> 00:18:53,643
but you can see activity_main is the file
349
00:18:53,643 --> 00:18:57,833
which is getting attached
to this particular Main Activity here now.
350
00:18:57,833 --> 00:19:00,766
So that was the development package
351
00:19:00,766 --> 00:19:03,614
and that was the MainActivity file.
352
00:19:03,614 --> 00:19:06,884
In other packages like Android test,
353
00:19:06,884 --> 00:19:11,674
you will see the files
which are used for UI testing
354
00:19:11,674 --> 00:19:15,972
here all the UI testing class
will be put inside this--
355
00:19:15,972 --> 00:19:18,602
All the JUnit classes testing,
356
00:19:18,602 --> 00:19:20,612
all the classes for JUnit will be put.
357
00:19:20,981 --> 00:19:22,852
So that was the Java folder.
358
00:19:22,852 --> 00:19:26,332
So the Java folder will
specifically contain all your coding bar.
359
00:19:26,332 --> 00:19:27,942
Now let's just come to res folder.
360
00:19:27,942 --> 00:19:30,248
Now, res folder is a very important folder
361
00:19:30,248 --> 00:19:32,768
in your Android application development
362
00:19:32,768 --> 00:19:35,858
because Android application development
is not just about Java,
363
00:19:35,858 --> 00:19:40,188
it includes your resources
and they can be images.
364
00:19:40,188 --> 00:19:45,457
Resources can be layout files,
XML files, any values resources
365
00:19:45,457 --> 00:19:48,688
that you are providing [hard-coded].
366
00:19:48,688 --> 00:19:51,784
So let's talk about them in more detail.
367
00:19:51,784 --> 00:19:55,834
There will be a res folder
and inside that res folder
368
00:19:55,834 --> 00:19:58,344
there will be some
dedicated folders like drawable.
369
00:19:58,344 --> 00:20:03,024
Drawable is a folder which will be used
to include the images.
370
00:20:04,797 --> 00:20:06,317
Generally the drawable--
371
00:20:06,317 --> 00:20:09,905
Each and every folder you're gonna design
inside your res folder
372
00:20:09,905 --> 00:20:11,605
will have a specific purpose.
373
00:20:11,605 --> 00:20:14,254
So the drawable here
is used for your images
374
00:20:14,254 --> 00:20:17,254
or if you have any animations, selectors.
375
00:20:17,254 --> 00:20:19,841
For those kind of things
you will be using the drawable.
376
00:20:19,841 --> 00:20:22,797
You will be seeing more of it
in your folder's sessions
377
00:20:22,797 --> 00:20:27,277
what exactly this drawable folder
can be used more for.
378
00:20:27,277 --> 00:20:30,150
For now, understand that all the images
379
00:20:30,150 --> 00:20:32,540
and animation parts you'll put here.
380
00:20:32,540 --> 00:20:35,452
Next is your layout folder.
381
00:20:35,452 --> 00:20:38,246
Layout folder is a folder
where you will provide all the layout
382
00:20:38,246 --> 00:20:39,886
for your activity.
383
00:20:39,886 --> 00:20:44,329
All the UI part, any layout you want
to show to your screen
384
00:20:44,329 --> 00:20:46,829
this is the folder
where you want to design.
385
00:20:46,829 --> 00:20:50,829
So that file which you just saw,
this is where it resides.
386
00:20:51,715 --> 00:20:55,055
Activity_Main.xml,
387
00:20:55,055 --> 00:20:57,691
any XML file you're seeing,
any layout file you're seeing,
388
00:20:57,691 --> 00:20:59,981
they are in your layout folder.
389
00:20:59,981 --> 00:21:05,679
You can see that this layout here
is the drag and drop screen.
390
00:21:05,679 --> 00:21:10,149
That is called layout,
there you can drag any button right now,
391
00:21:10,149 --> 00:21:12,609
and place it where you want.
392
00:21:13,358 --> 00:21:17,332
This is the Drag & Drop bar,
when you click on the text tab here
393
00:21:17,332 --> 00:21:20,522
you will be able to see
the coding part, and the XML part also.
394
00:21:20,522 --> 00:21:22,474
We will discuss about the coding part
395
00:21:22,474 --> 00:21:26,074
and how exactly you can deal
with these XML parts
396
00:21:26,074 --> 00:21:27,732
for the session.
397
00:21:27,732 --> 00:21:30,192
But for now know that :
398
00:21:30,192 --> 00:21:33,202
in layout folder,
all the layout file exists
399
00:21:33,202 --> 00:21:37,642
and you can edit the layout
of these XML file
400
00:21:37,642 --> 00:21:39,782
with the app Layout Editor.
401
00:21:40,249 --> 00:21:41,789
Next is your mipmap.
402
00:21:41,789 --> 00:21:44,789
Mipmap is a folder which is, again,
used for your images only
403
00:21:44,789 --> 00:21:46,649
but here you can put
404
00:21:46,656 --> 00:21:51,136
the different screen resolution
images together.
405
00:21:53,723 --> 00:21:57,703
As you can see, the image here
is known as ic_launcher.png.
406
00:21:57,723 --> 00:22:01,458
Each and every image
is named the same here,
407
00:22:01,458 --> 00:22:03,838
like ic_launcher.png...
408
00:22:03,838 --> 00:22:06,958
but you can see the difference
is the resolution.
409
00:22:06,958 --> 00:22:08,741
There will be images which will be--
410
00:22:08,741 --> 00:22:11,274
This image here is high pixel image,
411
00:22:11,274 --> 00:22:13,424
then there is extra high pixel image,
412
00:22:13,424 --> 00:22:17,095
then there is extra, extra high pixel image,
so the resolution changes.
413
00:22:17,095 --> 00:22:19,537
If you have an image
of a different resolution,
414
00:22:19,537 --> 00:22:22,537
you will put it in the mipmap
415
00:22:22,537 --> 00:22:24,597
by putting the same name.
416
00:22:25,255 --> 00:22:27,205
If my image name is logo
417
00:22:27,205 --> 00:22:29,095
and I have five different
resolutions of logo
418
00:22:29,095 --> 00:22:33,085
I will put logo only
but the resolution will be different.
419
00:22:33,085 --> 00:22:36,815
Like one maybe 42x42, other maybe 72x72
420
00:22:36,815 --> 00:22:40,945
and other one, maybe,
extra high 128x128.
421
00:22:41,492 --> 00:22:44,752
So automatically, it will create a folder
422
00:22:44,752 --> 00:22:49,832
which will define my high density
pixel image differently,
423
00:22:49,837 --> 00:22:52,287
and medium density pixel differently,
424
00:22:52,287 --> 00:22:54,727
and extra high density
pixel image differently.
425
00:22:54,727 --> 00:22:56,567
So what are the use of it?
426
00:22:56,567 --> 00:22:59,320
If you run your application on any device
427
00:22:59,320 --> 00:23:01,750
which uses extra high density pixel,
428
00:23:01,750 --> 00:23:04,744
you don't have to specify
or put in the code
429
00:23:04,744 --> 00:23:06,884
that use this image.
430
00:23:06,884 --> 00:23:08,804
It will automatically adjust that,
431
00:23:08,804 --> 00:23:11,984
"okay this is my extra high
density pixel device".
432
00:23:11,984 --> 00:23:14,194
It will automatically
pick this image only.
433
00:23:14,526 --> 00:23:16,036
That was mipmap.
434
00:23:17,087 --> 00:23:20,303
Now let's talk about values,
now values is a folder
435
00:23:20,303 --> 00:23:23,133
where you generally put all
your other resource
436
00:23:23,133 --> 00:23:25,763
which you want to put
437
00:23:25,763 --> 00:23:28,473
or show to the users, like colors.
438
00:23:30,971 --> 00:23:33,311
Values is the folder where you want
439
00:23:33,311 --> 00:23:35,981
to define your different resources,
440
00:23:35,981 --> 00:23:37,741
to make the localization.
441
00:23:37,741 --> 00:23:41,151
So you don't have to define
those resources again, and again.
442
00:23:41,547 --> 00:23:45,463
It may be any string value,
or any title, or any color also.
443
00:23:45,463 --> 00:23:49,843
As you can see, I defined
a color file.xml separately
444
00:23:49,843 --> 00:23:52,843
and then defined the color tag.
445
00:23:53,445 --> 00:23:57,665
Remember that any resource
you want to define,
446
00:23:57,665 --> 00:24:00,244
you have to use the resource tag first.
447
00:24:00,244 --> 00:24:03,294
So now this will be a resource,
this color will be a resource
448
00:24:03,294 --> 00:24:06,725
and the name of the color by which
I'm going to access it anywhere,
449
00:24:06,725 --> 00:24:09,105
is now ColorPrimary.
450
00:24:10,295 --> 00:24:15,215
The use of this will define the resources,
451
00:24:15,215 --> 00:24:17,725
let's say, this is the color right now.
452
00:24:17,725 --> 00:24:22,644
As you can see, the color is 3F51B5.
453
00:24:22,644 --> 00:24:25,427
I don't have to remember
this color code
454
00:24:25,427 --> 00:24:27,167
or hashcode again and again.
455
00:24:27,167 --> 00:24:31,521
And I can directly use this ColorPrimary
wherever I want to use it.
456
00:24:31,521 --> 00:24:34,121
In a bit we are going to see
how exactly we can use it.
457
00:24:35,252 --> 00:24:38,423
In the second uses,
let's say tomorrow your boss says
458
00:24:38,423 --> 00:24:40,903
"I want to change this color".
459
00:24:40,903 --> 00:24:44,747
Instead of ColorPrimary,
460
00:24:44,750 --> 00:24:47,100
you define one more color here,
461
00:24:47,997 --> 00:24:51,977
and that color is Title_Color,
let's call it color.
462
00:24:54,766 --> 00:24:58,136
You define a color called 99ccc--
463
00:24:58,797 --> 00:25:00,837
So, 99cc00.
464
00:25:00,837 --> 00:25:02,509
Okay so this is my title color.
465
00:25:02,509 --> 00:25:06,039
Let's say tomorrow your boss say,
"we're going to change our title color".
466
00:25:06,039 --> 00:25:09,374
So you don't have to go
to each and every place
467
00:25:09,374 --> 00:25:11,644
where you had used this hashcode.
468
00:25:11,644 --> 00:25:13,575
If you would have done hard-coded here,
469
00:25:13,575 --> 00:25:16,015
you'd have to change the hashcode
in each and every place.
470
00:25:16,015 --> 00:25:20,055
Here you are just going
to change the color here
471
00:25:20,055 --> 00:25:22,913
and wherever you've used this name there,
472
00:25:22,913 --> 00:25:25,743
all those places
will be receiving the changes.
473
00:25:25,743 --> 00:25:28,843
So that's the beauty of defining
the resources here.
474
00:25:29,431 --> 00:25:32,561
So in this way I have
to find resource colors
475
00:25:32,561 --> 00:25:35,991
only here you can see ColorPrimary
476
00:25:35,991 --> 00:25:38,541
ColorDark, ColorAccent
and ColorTitle, right ?
477
00:25:39,683 --> 00:25:43,453
One more thing I want to point out here,
anything you put in your resource
478
00:25:43,453 --> 00:25:46,376
even a image, even a layout file,
even all these color
479
00:25:46,376 --> 00:25:49,807
which I'm putting here right now,
anything you put in your res folder,
480
00:25:49,807 --> 00:25:54,587
they get a registry inside a file
named as Android Java file.
481
00:25:54,587 --> 00:25:57,167
Android Java file is
a system generated file
482
00:25:57,167 --> 00:26:02,107
which is being provided to you
by your Android system itself,
483
00:26:02,107 --> 00:26:05,957
or the Android application itself,
so you don't have to create it
484
00:26:05,957 --> 00:26:08,547
but whatever you do inside the res folder
485
00:26:08,556 --> 00:26:11,796
that will get entry inside
the hard-coded Java file.
486
00:26:11,796 --> 00:26:14,626
As of right now, the color
which I have just defined,
487
00:26:14,626 --> 00:26:19,513
the whole entry plus the ActivityMain.xml
should also have entry
488
00:26:19,513 --> 00:26:22,103
and all these mipmap
should also have a entry.
489
00:26:22,954 --> 00:26:24,934
Let's just check that out.
490
00:26:24,948 --> 00:26:28,468
You won't be seeing R.java file
inside your Android data key.
491
00:26:28,468 --> 00:26:31,718
To see that, you'll need to change
the data key to package.
492
00:26:32,361 --> 00:26:36,361
and inside the package,
this is your development package.
493
00:26:37,008 --> 00:26:40,418
You can see R, just click
on this R.java file
494
00:26:40,418 --> 00:26:43,418
and you can go back to Android now.
495
00:26:44,079 --> 00:26:46,429
So this is your Android R.java
you can see that file
496
00:26:46,429 --> 00:26:49,049
under the build folder are generated
and should not be edited.
497
00:26:49,049 --> 00:26:51,349
So you are not to tamper with this file.
498
00:26:51,349 --> 00:26:55,239
I'm just showing you this
to prove my point
499
00:26:55,239 --> 00:26:58,776
that everything you put inside
your res folder is registered here.
500
00:26:58,776 --> 00:27:03,539
So I'm gonna find my ActivityMain first.
501
00:27:03,704 --> 00:27:06,468
Anything you put inside your res folder
502
00:27:06,468 --> 00:27:08,918
will get registered inside
your R.java file
503
00:27:08,918 --> 00:27:11,968
but in the same way
that you're defining it.
504
00:27:11,968 --> 00:27:14,968
Like your layout file
that is Activity_Main.xml,
505
00:27:15,366 --> 00:27:17,106
you have to find inside
a layout folder,
506
00:27:17,106 --> 00:27:20,046
so it will be inside your R.java folder
507
00:27:20,046 --> 00:27:21,576
but inside a class layout.
508
00:27:21,576 --> 00:27:24,167
So... Class Layout.
509
00:27:24,167 --> 00:27:26,997
You can see class layout
and then inside that,
510
00:27:26,997 --> 00:27:28,340
the name ActivityMain.
511
00:27:28,340 --> 00:27:30,150
[inaudible]
512
00:27:30,150 --> 00:27:33,242
Yeah, there we go.
So you can see the entry here now.
513
00:27:33,242 --> 00:27:35,642
In the same way, let's talk about mipmap.
514
00:27:35,642 --> 00:27:38,473
So mipmap will be registered
inside the R.java file
515
00:27:38,473 --> 00:27:40,643
but with class mipmap.
516
00:27:40,643 --> 00:27:43,153
You can see here under ic_launcher.
517
00:27:43,153 --> 00:27:45,643
Mainly this is just one image, right?
518
00:27:45,643 --> 00:27:48,983
So with just one name, so that's why
there is only one entry.
519
00:27:49,997 --> 00:27:54,977
I just saved a bunch of colors there
so to check out colors
520
00:27:55,508 --> 00:27:58,838
which class will it be saved in?
Color.
521
00:27:59,719 --> 00:28:01,109
Resources color.
522
00:28:01,762 --> 00:28:03,962
As you can see, the tag is color here.
523
00:28:03,962 --> 00:28:05,183
So, color.
524
00:28:05,183 --> 00:28:07,483
And inside color you can now find out
525
00:28:07,483 --> 00:28:09,193
what is the name by which you saved.
526
00:28:09,193 --> 00:28:11,592
ColorPrimary, ColorDark,
ColorAccent and Title_Color.
527
00:28:11,592 --> 00:28:14,852
So you just have to find out
the ColorPrimary, ColorDark...
528
00:28:17,451 --> 00:28:21,456
Yeah, see, ColorPrimary, ColorDark,
ColorPrimary Dark
529
00:28:21,456 --> 00:28:23,276
and the Title.
530
00:28:24,206 --> 00:28:26,436
I included my own, TitleColor.
531
00:28:28,761 --> 00:28:31,211
So it will be somewhere around here
532
00:28:37,553 --> 00:28:41,293
If anything is not there,
you can even rebuild your project
533
00:28:49,999 --> 00:28:52,009
and sync it now.
534
00:29:00,033 --> 00:29:04,423
Okay, now find color, class, color.
535
00:29:05,085 --> 00:29:09,085
So we have already seen
that ColorPrimary, ColorDark.
536
00:29:11,761 --> 00:29:12,981
Sorry, color.
537
00:29:14,981 --> 00:29:19,541
ColorPrimary, ColorDark,
ColorAccent,ColorPrimary Dark
538
00:29:19,541 --> 00:29:22,341
And there's TitleColor.
Yeah, there we go.
539
00:29:22,341 --> 00:29:24,786
TitleColor, which we saved here, right?
540
00:29:24,786 --> 00:29:27,496
So any resource you create,
there will be an entry.
541
00:29:27,496 --> 00:29:28,732
Now you can see...
542
00:29:29,768 --> 00:29:34,218
In the same way there is
a dimension folder or dimens folder.
543
00:29:34,218 --> 00:29:36,423
Inside which we are defining some spaces.
544
00:29:36,423 --> 00:29:41,354
Dimens are used to define blank spaces
545
00:29:41,354 --> 00:29:44,434
and putting some horizontal margin.
546
00:29:44,434 --> 00:29:47,977
That is 16dp for the default screen size.
547
00:29:48,518 --> 00:29:51,378
But if the same screen size is a tablet,
548
00:29:51,378 --> 00:29:55,948
or a screen size with a 7 inch screen,
or 10 inch screen
549
00:29:55,948 --> 00:29:59,088
the same horizontal margin will become 64.
550
00:29:59,438 --> 00:30:03,558
Can you see that?
The name of Activity_Horizontal_Margin
551
00:30:03,558 --> 00:30:06,358
is the same as Activity_Horizontal_Margin.
552
00:30:06,358 --> 00:30:09,534
So Android will automatically detect
which device it's running
553
00:30:09,534 --> 00:30:11,489
whether it's a tablet or a device.
554
00:30:11,489 --> 00:30:15,284
Accordingly, it will pick one
of these resources
555
00:30:15,284 --> 00:30:17,024
whenever they are being used.
556
00:30:17,024 --> 00:30:20,174
I still need to tell you
how to use these resources but...
557
00:30:20,174 --> 00:30:23,470
Know that this will get an entry
inside of your R.java file
558
00:30:25,420 --> 00:30:27,730
Dimens... Yeah, you can see that.
559
00:30:29,604 --> 00:30:33,054
There will be an activity_...
560
00:30:33,054 --> 00:30:35,543
Yeah. Activity_Horizontal_Margin
561
00:30:35,543 --> 00:30:38,053
and _Vertical.
562
00:30:38,053 --> 00:30:39,553
Next...String.
563
00:30:39,553 --> 00:30:42,480
So you can see here
there is a string also.
564
00:30:43,147 --> 00:30:46,491
I have created under resources string
with the app name
565
00:30:46,491 --> 00:30:48,021
My-Hello-First-App.
566
00:30:48,021 --> 00:30:51,222
The reason here is... See here.
567
00:30:51,222 --> 00:30:53,562
Every time you open up your app,
568
00:30:53,562 --> 00:30:56,983
you'll see this My Hello first App
569
00:30:56,983 --> 00:30:59,803
that is because you have to find it here.
570
00:30:59,803 --> 00:31:02,409
Now, let us see how exactly I use this,
571
00:31:02,409 --> 00:31:04,289
how exactly I use my resources.
572
00:31:04,289 --> 00:31:06,169
You must have seen in your manifest file,
573
00:31:06,169 --> 00:31:09,428
when you go to your manifest file
I told you that icon--
574
00:31:09,428 --> 00:31:11,458
this icon is used to set my icon.
575
00:31:11,458 --> 00:31:13,114
But, how exactly, it's setting my icon
576
00:31:13,114 --> 00:31:18,424
because there is @mipmap/ic_launcher
577
00:31:18,424 --> 00:31:23,174
so @mipmap means I'm going
or I'm referring to my mipmap class.
578
00:31:23,468 --> 00:31:27,038
@ first of all, let's
just talk about what is @.
579
00:31:27,689 --> 00:31:30,479
If you are defining or if you are
accessing your resources
580
00:31:30,479 --> 00:31:33,699
If you want to access a resource,
mipmap is what? A resource.
581
00:31:34,615 --> 00:31:37,828
If you want to access a resource
inside a XML file
582
00:31:37,828 --> 00:31:42,068
you'll be using @ to denote
your R.java file.
583
00:31:42,506 --> 00:31:46,506
This @ right now is denoting
or is referring to my R.java.
584
00:31:46,957 --> 00:31:48,767
So first statement will do what?
585
00:31:48,767 --> 00:31:51,257
@ that means it goes to R.java file
586
00:31:51,257 --> 00:31:55,957
and inside R.java file which class
I want to go ahead with?
587
00:31:55,957 --> 00:31:57,397
That is mipmap.
588
00:31:57,397 --> 00:32:01,307
So it will start searching
for class mipmap.
589
00:32:02,578 --> 00:32:06,998
So inside mipmap also
which file it want? Ic_launcher
590
00:32:06,998 --> 00:32:08,821
So is there an ic_launcher? Yes.
591
00:32:08,821 --> 00:32:12,282
So that's the reason you were able
to see the icon here.
592
00:32:12,282 --> 00:32:15,862
You were able to see this icon.
593
00:32:15,862 --> 00:32:19,892
If you want to change the icon
just give some other icon.
594
00:32:19,892 --> 00:32:21,699
If you have any other image here
595
00:32:21,699 --> 00:32:24,559
you can give any other image
and the icon will change.
596
00:32:24,559 --> 00:32:27,389
Let me just check
if I have any other image--
597
00:32:42,577 --> 00:32:46,271
Let me just copy this
and paste it here
598
00:32:46,271 --> 00:32:48,081
inside the drawable.
599
00:32:48,081 --> 00:32:50,856
I'm putting it in drawable
but you can put it in mipmap also,
600
00:32:50,856 --> 00:32:54,996
if you have more then one icon
601
00:32:54,996 --> 00:32:59,917
or different resolution size
of the same image.
602
00:32:59,917 --> 00:33:03,977
So, if I'm a referring it
from drawable, this time ,
603
00:33:03,977 --> 00:33:06,237
how, exactly, will I be referring it?
604
00:33:06,237 --> 00:33:08,888
Again, go to the R.java file
by using @,
605
00:33:08,888 --> 00:33:11,908
but this time I won't be using
mipmap, I'll be using drawable.
606
00:33:12,543 --> 00:33:15,293
You can see in the drawable
there is an dog icon.
607
00:33:15,293 --> 00:33:17,103
So if I run this...
608
00:33:17,103 --> 00:33:20,233
Just make sure if you are using icons,
609
00:33:20,233 --> 00:33:24,273
those icons should be
actually compatible to the icon size.
610
00:33:24,273 --> 00:33:27,934
You can't expect a big icon size
611
00:33:27,934 --> 00:33:30,344
or big image to become an icon.
612
00:33:30,344 --> 00:33:34,304
So I don't know if my image
is actually an icon... yeah.
613
00:33:34,304 --> 00:33:35,920
It was compatible to that.
614
00:33:35,920 --> 00:33:38,340
So you can see here,
My Hello App--
615
00:33:39,584 --> 00:33:41,044
now the icon has changed.
616
00:33:41,044 --> 00:33:43,504
So in this way you can use the resources.
617
00:33:43,783 --> 00:33:46,873
Every time you want to use
resource inside a res folder
618
00:33:46,873 --> 00:33:49,643
you'll be using @
and the class name.
619
00:33:49,643 --> 00:33:51,853
So in the same way you can see label.
620
00:33:51,853 --> 00:33:55,883
Label is one of the titles you see here.
621
00:33:55,883 --> 00:33:58,430
As you can see, I have MyHelloFirstApp
622
00:33:58,430 --> 00:34:02,520
how exactly it's picking up
@string in the resource folder,
623
00:34:02,520 --> 00:34:05,260
there is a string.
an @ string.
624
00:34:07,970 --> 00:34:11,410
And inside the string
there is a name App_Name.
625
00:34:12,790 --> 00:34:14,600
Did I define this resource? Yeah.
626
00:34:14,600 --> 00:34:17,309
You can see in this string,
I defined string
627
00:34:17,309 --> 00:34:19,239
and the string is app_name.
628
00:34:19,239 --> 00:34:21,779
If I change this here...
629
00:34:23,458 --> 00:34:26,458
First App.
630
00:34:27,617 --> 00:34:30,767
So now I don't have
to worry about changing it there.
631
00:34:32,206 --> 00:34:33,745
It'll automatically get changed
632
00:34:33,745 --> 00:34:36,605
and every time
you open your application now,
633
00:34:36,605 --> 00:34:41,075
there will be the title First App,
instead of MyHelloFirstApp.
634
00:34:41,571 --> 00:34:44,281
So you see First App.
There you go.
635
00:34:45,310 --> 00:34:48,683
So I hope this makes things clear
636
00:34:48,683 --> 00:34:51,633
in the same way you can
check all these styles.
637
00:34:52,170 --> 00:34:53,590
Style gives you--
638
00:34:54,730 --> 00:34:57,051
Style is, again, one of the resource
639
00:34:57,051 --> 00:35:00,051
which tells how exactly
your application will look like,
640
00:35:00,051 --> 00:35:03,890
so, in this particular style
you can see that I am using a theme.
641
00:35:03,890 --> 00:35:08,000
That theme is also
Theme.AppCompat.Light.DarkActionBar.
642
00:35:08,000 --> 00:35:10,240
Now this appcompat is very crucial
643
00:35:10,240 --> 00:35:13,930
because in your Java or in your Activity
644
00:35:13,930 --> 00:35:16,526
you are using AppCompat Activity.
645
00:35:16,526 --> 00:35:20,232
If you would be using
a normal Activity file here,
646
00:35:20,232 --> 00:35:22,802
now, at that point of time,
the syntax is right,
647
00:35:22,802 --> 00:35:24,802
but when you run this application,
648
00:35:24,802 --> 00:35:28,042
the theme will not be compatible
with the [source].
649
00:35:28,922 --> 00:35:31,982
The UI you want is not the--
650
00:35:31,982 --> 00:35:34,756
You may not get the same UI that you want.
651
00:35:34,756 --> 00:35:37,485
If you are using Activity
then according to that Activity,
652
00:35:37,485 --> 00:35:39,635
there will be a different theme.
653
00:35:39,635 --> 00:35:41,395
So I'm using AppCompat,
654
00:35:41,395 --> 00:35:44,083
so for AppCompat,
I'm using the AppCompat theme.
655
00:35:44,083 --> 00:35:45,983
Light and Dark action bar.
656
00:35:45,983 --> 00:35:50,103
And you can see I'm customizing it
by using one of the items.
657
00:35:50,103 --> 00:35:53,158
I'm going to customize one of the items
known as ColorPrimary.
658
00:35:53,158 --> 00:35:56,008
And here you can see Asset
is a XML file, right?
659
00:35:56,008 --> 00:35:57,763
So I won't be using colors,
660
00:35:57,763 --> 00:36:01,993
it will be @color/colorprimary.
661
00:36:01,993 --> 00:36:03,616
I have already defined a @color.
662
00:36:03,616 --> 00:36:07,194
Isn't it in the color file?
@color, color file--
663
00:36:07,194 --> 00:36:08,504
Great!
664
00:36:08,504 --> 00:36:10,764
In the same way
I'm customizing other also...
665
00:36:10,764 --> 00:36:13,944
Let's say I don't want
to put color primary,
666
00:36:13,944 --> 00:36:16,264
I want to use my color
which I have just defined.
667
00:36:16,264 --> 00:36:17,624
So it is title_color.
668
00:36:18,834 --> 00:36:22,024
So now, if you run this
you will be able
669
00:36:22,024 --> 00:36:25,534
to see the color has changed.
670
00:36:25,534 --> 00:36:29,038
So this is how your resource
of file works
671
00:36:29,038 --> 00:36:30,948
around in your Android.
672
00:36:30,948 --> 00:36:36,205
So this how you access your
resource file inside the XML.
673
00:36:36,205 --> 00:36:37,705
That is by using @.
674
00:36:37,705 --> 00:36:40,268
If you want to access
your resource file in your Java--
675
00:36:40,268 --> 00:36:43,168
As you can see
I have attached this layout,
676
00:36:43,168 --> 00:36:45,428
attached this file which
is defined in Layout
677
00:36:45,428 --> 00:36:50,078
inside my Java file,
inside my Activity
678
00:36:50,460 --> 00:36:52,869
with the help of resource file only.
679
00:36:52,869 --> 00:36:55,609
So if you are accessing a R.java file
680
00:36:55,609 --> 00:36:58,261
inside your Java folder,
681
00:36:58,261 --> 00:36:59,771
then you will be using .operator
682
00:36:59,771 --> 00:37:03,061
You can see, again, I'm using
R, this time no @
683
00:37:03,061 --> 00:37:06,061
R, then dot and then,
the class name that is layout.
684
00:37:06,061 --> 00:37:09,848
And then, the file name
which you want to process.
685
00:37:09,848 --> 00:37:12,258
That's how you'll be accessing it.
686
00:37:12,902 --> 00:37:16,512
Ok so, that was an overview
687
00:37:16,512 --> 00:37:19,491
on Android Studio
and the Project Data Key.
688
00:37:19,491 --> 00:37:23,001
And what are the different components
you see in your Android studio.
689
00:37:23,001 --> 00:37:25,504
I hope this will help you
in understanding
690
00:37:25,504 --> 00:37:27,084
your Android Studio better.
691
00:37:27,084 --> 00:37:31,084
In further session we will learn more
about designing UIs
692
00:37:31,613 --> 00:37:34,893
and how exactly we can work
around with our screens and all.
693
00:37:35,623 --> 00:37:38,511
So that's it from my side
an introduction
694
00:37:38,511 --> 00:37:40,211
to Android Studio and Android.
695
00:37:40,211 --> 00:37:41,461
Thank you
696
00:37:41,461 --> 00:37:45,091
♪ (robotic music) ♪