Hire everyone in this theater you are really going to go ahead and create another Android application.
So just click on this starts a new Android studio your project here and for the application name just
type in here app 28.
And then we can Next choose a 16 Android 4.1 Jelly Bean for a minimum STK next and here choose Blancher
activity next.
And then we can finish.
OK.
Now let's actually select this hello world takes you here.
And then press on delete key on your keyboard and then double click on the rest folder here.
Lay out activity underline minute example and here choose this fluting action but in here.
And then press on delete key on your keyboard.
OK so now let's actually go back and say this content underlined minute example.
And here we want to actually design the user interface of our application.
So first of all this actually track linearly and vertical at the center of this relatively out here.
OK.
And now actually drag up a vertical scroll view into this linearly athletico.
So just put it at the center of this linearly or vertical.
And now let's actually write another linearly or 12 circle into this scroll view here.
And now let's actually drag our own components into this linearly held vertical here.
So now let's actually track our large takes you into These are linearly out to a circle here.
OK.
And double click on it.
And here is just typing in desktop computer.
OK and person Enter key on your keyboard.
So now let's actually drag and other large takes you into this linearly outerwear cycle here.
Double click on it and then delete the text of the stakes view and for the ID just type in here to the
desktop computer and then a person Enter key on your keyboard.
And now let's actually write another large takes you into this linearly out vertical here.
Double click on it delete the text of this text view and for the ID just step in here to the desktop
computer performance.
OK.
And then our press on Enter key on your keyboard.
OK so now let's actually drag and other large takes you into These are linearly elsewhere equal here.
Double click on it.
And for the text just typing here a laptop computer and then press Enter key on your keyboard then drag
and other large takes you into this linearly out vertical here.
OK.
Double click on it delete the text of this text will and for the ID just type in here TXI the laptop
computer.
OK.
Now let's get you to the right and other large stakes into this linearly ultra vertical here.
Double click on it.
It's the text of the state's view.
And for the OED to step in here takes the laptop computer performance and then press enter key on your
keyboard.
So now let's actually track another large text view into this linearly outworks equal here.
Double click on it.
And for the text just typing here smartphone computer and then person enter key on your keyboard and
nounless actually do like and other large takes you into these linearly and vertical here double click
on it delete the text of this text.
And for the idea that they can hear the smartphone computer and then let's actually write another large
stakes into this linearly vertical here.
Double click on it delete the text of this text view and for the ID just type in here thinks the smartphone
computer
performance OK and then person enter key on your keyboard.
OK.
And now let's actually do like another large takes into this linearly out vertical here.
Double click on it and for the text just type in here tablet computer and then press and in key on your
keyboard.
And now let's actually do like another large takes you into this linearly or two vertical here.
Double click on it and delete the takes of this takes few and for the idea just they've been here takes
the tablet computer and then person enter key on your keyboard.
So now let's actually try again other large stakes into this linearly vertical here and double click
on it delete the text of this text view and for the ID just type in here TXI the tablet computer performance
and then press sun Enter key on your keyboard.
OK.
So now the design of our user interface is actually finished.
So now let's actually go back inside this main activity that Jobo file here and then actually did it.
These lines of code that are actually related to the Options menu.
And now let's actually deal is this a floating action button here as you can see these lines of code
that directly related to the floating action button.
And now this actually create some double classes here and there first class that I want to actually
create is actually a computer class.
So just click on File New and then click on Java class.
OK.
And for the class name just type in your computer and then click on OK.
And the second class that I want to actually create is actually a desktop computer class.
So a new Java class and for the class then just typing here our desktop
computer is but you don't.
There must be no space between your class names.
OK.
Desktop computer.
And then click on OK.
And here let's actually create another java class here five new and for the Java class here as you can
see click on Java class and for the name of the class just type in his laptop computer and then click
on OK let's actually create another java class 5 new Java class.
And here is actually create a smartphone or computer class smart phone computer.
OK.
And now find new Java class tablets computer tablet computer.
And then click on OK here OK.
So now let's go back and say it is a computer.
The java file here as you can see if you have a computer class here but are actually computer is actually
an abstract concept.
OK if you want to I asks you that please give me a computer.
You may ask.
You may actually ask me that or what computer.
What kind of computer do you want.
Do you want a desktop computer or a laptop computer or a smartphone computer or a tablet computer.
So a computer is actually an abstract class.
OK.
So public.
OK.
Abstract class computer.
OK.
Because a computer by itself is actually an abstract concept.
We need to actually declare this cause this class as an abstract class.
Ok so are abstract classes are actually a little bit different from the other classes that are actually
called concrete classes.
And you cannot actually create an object from an abstract class.
OK so now let's actually put in some lines of code here and then I'll explain to you what's going on
here.
OK so first of all I want to actually create some instance variables.
OK.
So here as you can see I actually declared some instance variables and as you can see in line 10.
I actually declare this instance variable the access modifier of this instance variable is private and
this instance variable is actually final.
And this means that this instance variable is constant.
And once we assign a value to this instance variable we cannot change that value leader.
OK.
And the type of this instance value about is strange and the name of this instance variable is name.
OK so every computer has a name.
OK.
And here in line 11 as you can see we have another instance variable private its final string screen.
OK.
Every computer has a screen and inline 12 as you can see private fine on screen keyboard and every computer
has a keyboard.
OK.
So now let's actually create a constructor inside of this class here.
So as you can see here this is our constructor that actually pasted here.
OK.
And the access modifier of this constructor is public.
The name of the constructor must be the same as the name of the class.
OK Computer and here this constructor actually to accept some arguments.
OK.
The first argument that this constructor accepts is actually of types 3 and name.
OK the second argument is again of types think screen and the first argument is again of type String
keyboard.
OK.
And here inside of these a constructor as you can see instantiating my instance variables that I actually
created inside of this computer class.
OK.