https:/.../2020-02-04_ap_witchel_x.x_fc2_listview_recyclerview_demo.mp4

♪ (Jazz music) ♪

I want to show you a demo
for the second flipped classroom

where we're going to be doing
ListViews and RecyclerViews.

Very exciting stuff because
these are -- RecyclerView really is

one of the basic android data structures
that we're going to be working with,

and you'll be working with your projects.
Super important.

So for this example, I sort of
went to the internet

and I found some colors.

This is a very extensive list of colors.
(laughs)

And it starts out with
always in the same order

with a lot of these dark blues
and greens, and color names

like Endeavor, which I don't know
if anyone really uses that

as a color name.
Tropical Rain Forest, Blue Ribbon.

Science Blue? I don't know.

So you'll notice -- Let's see. So --
Endeavour is above Camerone,

and now Endeavour is down here.
So you'll notice that if I click

on any of these --
And this is a ListView --

If I click on any of these,
they seemingly sort of disappear.

There's a lot of really dark,
a lot of dark colors in the beginning.

Anyway, if we go up to the top, we can
see what happens to all these. Oh. Hello?

Oh my god, do I need to restart
this thing?

Oh, there we go.

Oh, look. Well, we can actually recognize
some of these.

If you notice, when you click,
it goes to the top.

It sets the functionality
you have to implement.

If you click -- Oh, this is --
This blue is just called Blue.

So Blue is now on top,
Dark Blue on top,

Navy Blue on top.
This is so dark,

I don't know maybe it's Black,
maybe it's something

that's close to Black,
but we can't even read it

because in all of these cases,
the text is Black.

Okay, so that's the ListView
in a ListView functionality.

This flipped classroom
has some ListView stuff.

It also has some RecyclerView
stuff, and they're both

independent activities,
so this is one of the last cases

that we're going to have before
we hit fragments,

which are a little bit more
convenient way of managing

different screens, but for now,
we've got this --

I think it's called the Swap Icon,
so I don't exactly know

who it's really intended for,

but I use it to swap between these
two views.

And this view is much less
monotone.

This is a RecyclerView,
and part of what's going on here

is it's got this fancy grid layout,
so that's sort of nice,

and then all of the color names
are in these boxes,

which is this CardView.

So CardView is a built-in display class,
which has some nice borders

and rounded edges, and can give you
a little bit of a drop shadow if you want.

So, CardViews are pretty common
in RecylerViews.

And here, instead of when you click the --
So, something else happens

when you click the color name.
Let's click Blue Violet here

and that became Pickled Bean.

And Havelock Blue. And then it
became Portica, which is only

one line and you see everything
sort of shifted around.

What's nice about that is
you don't have to do any of that work.

That's all the RecyclerView layout.

The layout of the -- It's not the adapter,
it's the layout manager.

So anyway, along with all of these names,
we have these numbers,

which is the luminance, I believe.
Luminance being a sort of

measure of how bright or dark a color is.

And one thing that we do is when
the luminance is below 0.3,

we write a color name in white,
and when it's above,

we write it in black because
that is a high enough contrast

that we can now read all of
the color names. So that's sort of useful.

So, I just think this is pretty.

(laughs)

And -- Oh, yeah. What's happening
when I click is it's a random --

I believe it's a random swap --
and I believe every time this boots up,

there's a random order.

Not 100% sure though.

But anyway, this is your
flip classroom.

You'll be swapping colors
and learning the joys

of the difference between Cannon Pink
and Vin Rouge in no time.

Thanks.