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G'day everyone, welcome back.

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Okay let's have a look at how we can add some
dialogues to our app.

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There's a Google guide to dialogues at https://developer.android.com/guide/topics/ui/dialogs.html

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that's worth a read after you've watched these videos.

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This document mentions three dialogue subclasses;
AlertDialog, DatePickerDialog and TimePickerDialog.

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Unless you want the user to select a date or a time, which we will be doing later,

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you'd normally use an AlertDialog.

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We'll be  following the advice in this document, but I'm not going to read through it all here in the video.

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There are a couple of things worth noting, though.
Firstly, there's a link to a dialogs design guide,

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in the design call-out at the top of the document.

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That link describes the purpose and use of dialogs
in a material design context.

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It's well worth reading when you come to create your own.

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There are some great examples of different dialog types,
and advice on do's and don'ts when creating dialogs.

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Okay, back to the dialogs guide.

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There's a Contents box on the right hand side,

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and I wanted to mention the Passing Events Back to the Dialog's Host link.

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I won't go through this here, because we'll be covering it all in the videos,

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but it's another example of how important
callbacks and interfaces are in Android development.

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Our dialog will let the user decide whether  to perform an action or not.

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To start with, we'll be asking our user to confirm the deletion of a task.

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So we'll need some way for the calling activity to know which button was tapped, and for that we'll use callback.

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The final thing I want to look at here is right at the end, dismissing a dialog.

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I'll be coming back to this once our first dialog's written,
so we can see the exact behaviour.

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That will also explain how we know to code things the way we're going to.

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In the next video, we'll create  a general-purpose dialogue class for our app.

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It'll let us use the same class, whenever we want the user to confirm an action.

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See you in the next one.