Let's start by opening Android Studio and start a new project 1
select all the default settings in plain app with an activity let's give it some time to start so 2
once we generate a new project we will see some processes running in the background. 3
These are related to Gradle. Gradle is the build system on the Android Studio. You have all the build 4
properties in your gradle properties file, here you can include libraries from repositories and once 5
you update the code the project will start building these gradle scripts and download whatever is 6
included in them if it's the first time you're ever doing this it might take a while 7
so let's just have a quick look at what is included in the application. 8
So this is just an out of the box hello world application right we can see over here is the main activity 9
which is created by default let's have a look inside. 10
Next we have the layout of an application in our activity we point to a layout which is where we have 11
the user interface another important file is the android manifest. 12
Think of it as a file that explains the main features of an app to the Android operating system. 13
Here we will define all app components and permissions that an app uses. 14
Android wants to know in advance what the components in an application are so it goes to the Android 15
manifest file and all the components will be defined within the manifest. 16
There are different types of components. 17
The idea of this section is to develop an app that makes use of all of these components another important 18
thing defined in the manifest is the permissions. So for example say we want to make an application that 19
can send S M S's. OK. 20
You can write the code inside your activity. 21
So say you go to your activity and write telephony manager dot send sms or something along those 22
lines. 23
This will not work unless we define the permission over here in the manifest. 24
Saying this app can send sms. We'll show you how to do that later on in the course. 25
OK. 26
So we have the activity, the layout and the manifest. 27
We also have the resources directory. Any resources that are to be included in the app be it xml files, 28
strings or images, you should be placed in the resources directory. 29
So for example under resources and values we have a file called strings. 30
And this is where we would put all the strings that we refer to in the application. 31
So for example say there's an app title that we want to refer to in different places in the application 32
we'll define a string. 33
Call it my title and then we can just refer to it across the application by using string slash my title. 34
This is just used to keep everything consistent throughout the application similarly we have styles 35
over here. 36
So say for example in your app you don't want to show the taskbar or the action bar at the top then 37
you can remove it from the style and every layout referring to this style will make use of it. 38
So what else. OK. 39
So the layout of the user interface that's associated with an activity. 40
So here we see that by default it creates an activity called main activity. 41
And the main activity sets the content to the activity underscore main layout and if we go on activity 42
main layout we'll see that this is the user interface that's created by default. 43
We'll be looking at these user interfaces later on in the course. Drawables, here we can put any images. 44
So for example by default you get the android logo as an image, so if for example you have your own logo 45
you upload it over here and change the reference then all logos will be changed to yours. So that's our 46
default application out of the box.