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Hire anyone in this theater you are really going to go ahead and create another Android application.



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So just click on this start in your Android studio project



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and for the name of the application just type in hit app app 49 and then click on next and here choose.



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AP is 16 Android 4.1 Jelly Bean for a minimum SDK.



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And then click on next and here choose empty activity next and then click on finish.



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So now as you can see our Android application is actually created.



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So now let's actually go inside this this folder and then go is go inside this folder and then go inside



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this activity Underland main that is and here.



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And as you can see here this is the user interface of our application.



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And as you can see I have this direct action bar theme here.



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So if I click on it now I can actually select a theme for my user interface.



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So I chose this material light and here I chose this one material that light the dark action one and



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then click on OK.



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So now I want to actually design the user interface of my application.



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So here first of all because I want to actually download an image from it from the internet I need an



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image view here so I'll just select this image inside this widgets folder and then put it here.



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As you can see this is actually relatively out and I can actually put it anywhere I want and here as



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you can see it's in these lines here.



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And as you can see I am actually positioning this image view relatively to other components here on



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the screen as you can see here.



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Right.



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So first of all let's actually drag linearly out of vertical vertical at the center of this relatively



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out here.



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So just put it at the center of this relatively out and then let's actually isolate this image view



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here inside these widgets folder and put it here at the center of this linearly out vertical.



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OK.



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And here in the properties section as you can see here selectees image view and here as you can see



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I have this layout with here.



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OK.



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So just selected and assigned the value 300 for the layout of this image view.



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And as you can see selecting a layout height and here assigned the value of three hundred for the layout



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height of this image view and then let's actually track our pattern here into this linearly out vertical.



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So inside this widgets folder as you can see I have this button here.



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Just select it and put it below this image view.



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OK.



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And double click on it.



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So for the text just typing here.



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Download an image from the Internet.



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



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So now the user interface as you can see here this is the user interface of my application.



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And I actually finished the design of this user interface.



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So now let's actually go back and say this main activity that I have a file here.



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So first of all let's actually declare an object of type image view.



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So Image view and the name of this image is going to be image view and then I put a semicolon at the



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end of your statement.



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So let's go back and say this activity on.



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And in that example and if I double click on this image here as you can see the idea is in his view



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right.



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So let's go inside this man activity a double file here and now it's actually declared a button.



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So button between download and then put a semi-colon at the end of your statement.



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So inside this uncreate Smurfette that's actually initialize these objects that we declared inside this



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main activity class.



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So here I can just type an image view.



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Assignment operator and then I can actually track this object to a image view object find view by ID



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are that Id dot image view and then put a semicolon at the end of your statement.



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And here let's actually initialize this PTEN download button.



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So between download assignment operator so here that actually cast this object to a button object find



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you by ID on that ID dot PTEN download and then put a semi-colon at the end of your statement.



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So here you want to actually make the spot in this and as you can see here a listener to the clicks



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of the user.



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So in say the main activity that have a file here I just need to type in bit here and download the data



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set on click listener and here inside the prentices I can just put this context in activity to this.



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OK so this is going to be the context.



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And now I need to actually implement the the view that Uncle listener interface.



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So here at the top after this extends our computer activity I just need to type in implements and here



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I need to refer to the name of my interface view that unclick listener.



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OK.



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So here we need to actually implement the abstract method that is inside this interface.



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Uncle listener so that if it is on click OK.



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So this is going to be that Meffert as you can see here.



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So here are let's actually change the name of these arguments to view.



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And if I click on this button here these are Meffert here as you can see it's going to be executed.



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So now it's actually inside the main activity class.



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Let's create an inner class.



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OK.



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So an inner class is actually like a usual class here as you can see here but and you know class is



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inside this you know this outer class here.



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For example this meant main activity class and an inner class actually actually I can access all the



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features and behaviors of the outer class.



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For example the instance variables are or the methods or other variables.



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OK so here inside is our main activity class you want to actually create another class.



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So make sure that you that you are actually inside this main activity class here.



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So this is the curly braces at this end in curly brace is going to be the ending calibers of this main



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activity class right.



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So inside is our main activity class here.



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I want to actually create an inner class.



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So first of all I need to specify the axis modifier of the Smith of this class.



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So here I can just type in private.



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OK class and the name of this class is going to be download image task.



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So the job of downloading the image from the Internet is going to be up for this class locate this class



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is going to download an image from the Internet.



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And then we can put that image on this image for you.



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OK.



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So I created a separate class for downloading an image from the Internet.



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And the name of this class is download image task.



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And this class extends OK from this scene.



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Task here has class.



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So what is this async task class.



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So let's actually open the Android documentation.



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So as you can see here if this is the android documentation you can actually put this all in your search



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for Endeavor on your web browser here developer that Android dot com and you will be guided to this



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page.



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So inside the search here inside the search bar I can search for a scene our class here a sink task



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class.



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OK.



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So this is going to be a syntax class.



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So just select this class here as you can see Android AP Olly's.



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So I have this azing test class.



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And as you can see this class is actually public abstract.



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OK so we cannot actually create an object directly from this class async task list.



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And he had as he can see this class extends from the object class and here as you can see we have some



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descriptions about this class here and it says a simple task enable is proper and easy use of the UI



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it.



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This class allows you to perform background operations and publish results on the UI for it without



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having to manipulate Fritz and or hand-wrote handlers.



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So what does this mean.



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This means that because we want to actually download an image from the Internet and that task and downloading



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an image from the end a task is actually a little bit heavy.



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OK.



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So if you want to actually put that task on the UI if read to you the user interface for it.



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Going to actually take some time and our application may freeze or actually crash.



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So because downloading an image from the internet is a truly is a heavy task.



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We need to put that operation put that task in the background.



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OK a background for it so that it's not going to actually block the user interface.



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Ok so that the user can actually interact with the user interface while the emet is actually downloading



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downloaded from the Internet.



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OK.



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And the user can actually interact with that application.



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So that's the job of this class.



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This class allows us to actually do something and put the operation of downloading the image from the



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internet in the background for it not the UI for it.



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OK.



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And after the image is downloaded from the Internet we have a method and that if it is post execute



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we have an.



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And we can actually put that image which is downloaded from the Internet and we can put that image on



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the UI thread on the user interface for it and we can show that image to the user.



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So hopefully that makes sense.