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Welcome back.

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We've got the layouts for our reports.

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Next we need to create an adapter to provide the data for the RecyclerView.

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Most of this will be very similar to our existing

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cursor RecyclerView adapter

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that we created back in section 10.

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This one won't be responding to taps, so it's a bit simpler.

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It does have to perform some date formatting, but other than that,

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it's a basic adapter.

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If you're not sure how an adapter works with a RecyclerView,

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it's worth watching those earlier videos again.

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Okay. Right click the package name and create

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new Kotlin File/Class

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and call it DurationsRVAdapter.

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The name of the other adapter is a bit long

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because it wanted to warn you about the problems you could get with logging tags.

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I'll keep this one short by using RV rather than RecyclerView.

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It's useful to have that in the name

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because there are different types of adapters.

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Change the kind to class to save a bit of typing.

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Then click okay.

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Our class will extend RecyclerView.adapter,

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and we'll need to provide a view holder.

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We've already used the layout container interface

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to avoid having to call find view by ID.

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Our adapter will need to be a sub class

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of RecyclerView.adapter class,

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and we'll need to provide it with the context and the cursor.

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This is the same as we did for the cursor RecyclerView adapter class.

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I'll generate the functions we need to override

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just after the class declaration.

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The code for the GetItemCount function is straightforward.

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We're not doing anything fancy here. There are no records to display.

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The RecyclerView will just be blank.

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We also need the SwapCursor function,

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and I can copy that from our cursory RecyclerView.adapter class.

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It appears near the end of that class.

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I'll paste it just after the functions that we've generated.

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The code for this function is identical to the other adapter.

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In fact, you'll probably use the same code or something very similar

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in all your RecyclerView.adapters that use a cursor.

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The oncreateviewholder function is also very simple.

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It just inflates a view from our layout

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and uses it to create a ViewHolder then returns the ViewHolder.

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We're going to do some basic date formatting,

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so the app can display dates in a format that our users will expect.

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Dates in the United States appear with the month first,

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while in Europe and Australia amongst other places,

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the day appears before the month.

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There are also differences in the date separator that's used.

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Some countries use a slash, others use a dot.

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We can use a date format object for that

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to handle the formatting of the dates for us.

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When you're prompted for the import,

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make sure you choose the one from android text format.

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I'm going to add another function to this adapter.

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We're going to be using durations, which we want to format in hours,

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minutes and seconds.

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Using a colon to separate the three parts should be universally understood

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but we can't use a standard date formatter to do that.

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The reason is that the current duration for a task

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could be more than 24 hours.

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We're displaying the total duration for a week.

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And in a week, our users could easily spend

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more than 24 hours on a task. The

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normal date, time formatting functions

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will either attempt to convert that to days, hours, minutes and seconds

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or give an incorrect result when attempting to represent it as a time of day.

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If we try to use normal date formatting,

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it's going to go horribly wrong.

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Date classes can't handle a time with more than 24 hours.

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I'll add the function after onbindviewholder

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and call it formatDuration.

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There's not a lot to say about that.

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It takes number of seconds, calculates the hours,

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minutes and seconds remaining and returns them as a formatted string.

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We use a default locale,

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the one that the user has specified in the device settings.

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Some languages, such as Thai for example,

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use different characters for the digits,

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and the user may have specified that these are the ones that they want.

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All right. The last function we need to write is onbindviewholder.

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Once again, it's fairly standard code except for a bit of date formatting.

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I'll paste the code rather than typing it.

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You can pause the video here with the code on the screen,

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so that you can catch up with the code.

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There's nothing clever in there.

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We use a local variable for the cursor

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to allow Kotlin to perform smart casts after a null check.

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Most of the code just retrieves the data from the cursor.

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Note that we can refer to the ViewHolder fields directly

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because it implements the layout container interface,

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allowing the widgets to be accessed via the synthetic import

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instead of find view by ID.

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I'll discuss that date format briefly.

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If you're dealing with dates and times,

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you want to format them in a way that the user expects.

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Up on line 25, we created an instance of the date format class.

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The getDateFormat function is past a context,

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and it can use that to work out which locale it should use

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when formatting dates.

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We'll test that later

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and make sure that the dates do appear as they should

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in different parts of the world.

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Use ctrl Q or ctrl J on a mac

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to call up the documentation for that getDateFormat function.

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If you press control Q or control J a second time,

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your documentation will be locked to the right hand edge of the window,

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which can be more convenient.

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GetDateFormat returns an object

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that can format a date according to the current locale

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that means we'll get a different format on an American phone

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then I'll get on my Australian one.

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All the emulators are set to the United States locale by default.

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But we'll change that later to make sure everything's working.

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The other thing to check is that we don't try to access the description

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if the device is in portrait.

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We didn't include a texture for the description in the portrait layout.

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Rather than test for null,

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I've used the Kotlin safe call operator,

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that's tidier than the equivalent java.

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But I like to include a comment, a question mark is quite easy to miss

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when you're reading the code. That's our adapter finished.

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We've had to do a bit of processing on the data but all the hard work,

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totaling the daily durations for each task

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was performed when we created the view that we're using.

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In the next video, we'll create an activity to display the data

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so we can view our reports.

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The code will be temporary

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because we'll be using a view model to provide the data to the adapter.

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That will prevent things like having to re-query the database

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if the device is rotated.

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If we wait until I've written the view model before testing our adapter code,

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it can be harder to work out where any problems are.

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Also note that I haven't included any logging

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in this durations RV adapter code.

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You know how to do that now. And if you get any problems,

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adding logging will be your first step to diagnosing them.

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All right. I'll see you in the next video.