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Hi everyone in this year Toli all we're going to go ahead and create another Android application.



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So just click on this start in your Android studio project and then for the name of the application



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just type in here app 58 and then click on next and here choose AP I-69 Android 4.1 Jelly Bean for minimum



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STK and then it could be next.



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And he had to choose empty activity next and then click on finish.



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So now as you can see here our project is created.



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So actually double click on the rest folder and then double click on the lay out folder here and then



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here double click on the activity underline made that example.



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So as you can see here now we can actually designed to use an interface of our application.



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So as you can see here we've got a rendering problems here.



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So are actually mixing styles.



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So when you actually choose the correct field for our application.



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So as you can see here I just need to click on this apophyses here and then he had actually Candie's



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material light and here choose this material that light that dark action.



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And in theory.



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OK.



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So as you can see here this is going to be the theme of my application.



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So now let's actually select this hello world text you here and then present delete key on your keyboard.



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So now it's actually the public Licinius activity underline minute example tap in order to make this



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a design area Vider.



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So first of all let's write a linearly out protocol into this relatively out here.



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So just select selectees linearly out here and just put it at the center of this relatively out here



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and now let's actually track some text fields into these linearly mathematical.



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So as you can see here inside these text fields Well there you've got these text fields.



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So just select is a plain text field here and put it at the center of this linearly as vertical and



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then it lets actually drag and order a plain text field here.



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Just select it and put it here.



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OK.



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And now I just select this first text with here and afford the ID just type in here.



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EDT our computer it is the computer name.



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And then press on entelechy on your keyboard and we have to select the second textfield here.



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Double click on it and for the ID just type in here it is the computer a type and then person enter



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key on your keyboard.



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So that is actually a sign a hint to the text with here.



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Just select this first place here and now let's actually find the hint attribute.



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So as you can see here this is the hint attribute.



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I just need to assign to just who they've here.



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Enter a computer name dot dot dot and in person in Tokyo on your keyboard and then select the second



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Topsfield here.



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And for the attributes assigned a value enter computer type and then person enter key on your keyboard.



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So now let's actually drag our linearly out horizontally into this linearly as vertical.



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So Enceladus layouts fall there just select it linearly or horizontal here and put it below these textfield



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here and now I want to actually drag two buttons into this linearly at horizontal.



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So here inside these widgets folder as you can see if you've got this button here just select it and



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put it inside these linearly or horizontal as you can see here in statis componentry section.



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Just put it inside these linearly as horizontal and now essentially the right and other a button into



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this linearly at what is on top.



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So just select the spot in here and put it inside linearly out horizontal here and now just select both



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of these buttons here.



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And for the layout out we assign the value zero.



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And for the lay out weight assigned the value 50.



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So now both of these buttons are going to actually take a half of its parents as you can see here that



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this linearly or horizontally is actually the parent of these two buttons.



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And now the width of these buttons are actually taking a half of the width of the parents which is this



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linearly or horizontal by assigning the value 0 for the lay out weight and assign the value number 50



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for the lay out wait for both of these buttons.



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As you can see here and that just select is a.



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First about in here.



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Double click on it.



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And for the text just type in here at and for the ID just type in here between ADD and then put a sun



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Enter key on your keyboard and then select is a second bottom here.



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Double click on it for the text just type in here.



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Delete.



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And for the ID just type in here between delete and then press on Enter key on your keyboard.



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So now I want to actually drag our list view into this linearly out vertical.



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So inside these containers fall there as you can see here we've got the list view here.



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Just select it and put it inside this linearly at vertical OK.



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Below it is linearly at horizontal and inside is linearly and vertical at the center of this linearly



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mathematical.



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So just put it here and double click on it.



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And as you can see here the idea is list view.



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So let's leave there leave the ID as default here.



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That's enough for us.



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We want to use that idea that default ID for our application.



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So just a.



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Let's go inside this main activity that I will find here and now I want to actually declare some objects.



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So I want to actually declare an edit text so Eddie takes it itty bitty computer name Karma.



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So here I can actually declare some objects that are actually of type.



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It takes in one line and the second object is going to be.



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Computer type Okay and then just put a semicolon at the end of your statement and then let's actually



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declare some objects of type button so Potin and the first object is going to be between and comma and



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now I want to actually declare another object which is of type button in one line.



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OK.



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Between delete and put a semicolon at the end of your statement and then let's actually declare another



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object which is of type list view.



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So here I can just type in list view list view and the name of the name of my object is going to be



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List View and then I need to put a semicolon at the end of my statement.



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So here inside is uncreate Smurfit.



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I want to actually instantiate these objects that they actually declare inside this main activity class.



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So here first what I want to actually to instantiate is EDT computer name.



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So here I can just say EDT computer name assignment operator and then here I just need to cast this



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object to a edit text object find view by ID are that Id Dud's EDT computer Terni and that I need to



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put a semi-colon at the end of my statement and then the second object is going to be EDT computer type.



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So EDT computer type assignment operator.



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And then I need to cast this object to a text object find the by ID are taught ID dot EDT computer type



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and then I need to put a semicolon at the end of my statement.



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And here I need to actually instantiate these button objects.



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So the first one is going to be between an assignment operator and then here I need to cast this object



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to a button object find view by ID or that ID that PETN add and that here I need to instantiate the



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speedy and delete object between the late assignment operator.



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Excuse me PTEN delete assignment operator and that he had any chance this object to a button object



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find view by ID or that Id dot PTEN delete.



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And then I need to put a semicolon at the end of my statement and here I want to instantiate this list



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view object.



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So here I just need to type in list view assignment operator and then here I just need to cast this



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object to a list view object find view by ID or that ID that list view and that I need to put a semicolon



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at the end of my statement.



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So as you can see here I just declare these objects and then inside is noncreative had I just instantiated



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these objects.



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So now let's actually create another Dava class named computer so that this class is going to actually



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hold the data that are related to the computer objects.



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So just selectees a package here that this I mean activity is inside it.



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Right.



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Just like this package.



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Right click on it and then you new and then Java class and then for the name of our class just type



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in here computer with Capitol C computer and then click on OK.



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So as you can see here our computer class is actually created.



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So let's actually declare some instance variables.



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So the first instance of it it's going to be int ID semicolon and the second instance variable is going



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to be of type string and the name of this string instance variable is going to be a computer name semicolon.



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And let's actually declare another instance variable which is of type strange and the name of this instance



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variable is going to be computer type.



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OK.



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So this class is responsible for holding Delk data that are related to the computer objects.



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So now as you can see here these are the instance variables of our computer class.



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Right.



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So I need to actually declare these instance variables as private instance variables.



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This is really important to remember that I told you in the top section of the course that you must



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always you should always declare your instance variables are private and then provide setters and get



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her.



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For this instance variables in order to allow other classes to access or for example to access or change



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the values of these instance variables.



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So first of all let me actually create some constructors for this computer class.



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So remember that I told you the access modifier of the constructor must be public.



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OK the name of the constructor must be the same as the name of this computer class.



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As you can see here and then I need to put a pair of Prentice's here and then I need to open and close



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these constructed by using these curly braces.



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So this is going to be the empty constructor OK.



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And this constructor actually implicitly calls the constructor of the superclass OK which is the object



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class right.



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So remember that I told you that all objects all classes are in Java actually inherits from the Object



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class.



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Ok it directly or indirectly this class actually directly inherit from the Object class.



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So the constructor of this computer class is actually implicitly calling the constructor of the superclass



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which is actually an empty constructor.



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OK.



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So this is going to be an empty constructor of our computer class.



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So I just create a comment here and then just type in here an empty an empty constructor.



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Of our computer class.