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

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    ♪ (Jazz music) ♪
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    I want to show you a demo
    for the second flipped classroom
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    where we're going to be doing
    ListViews and RecyclerViews.
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    Very exciting stuff because
    these are -- RecyclerView really is
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    one of the basic android data structures
    that we're going to be working with,
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    and you'll be working with your projects.
    Super important.
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    So for this example, I sort of
    went to the internet
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    and I found some colors.
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    This is a very extensive list of colors.
    (laughs)
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    And it starts out with
    always in the same order
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    with a lot of these dark blues
    and greens, and color names
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    like Endeavor, which I don't know
    if anyone really uses that
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    as a color name.
    Tropical Rain Forest, Blue Ribbon.
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    Science Blue? I don't know.
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    So you'll notice -- Let's see. So --
    Endeavour is above Camerone,
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    and now Endeavour is down here.
    So you'll notice that if I click
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    on any of these --
    And this is a ListView --
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    If I click on any of these,
    they seemingly sort of disappear.
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    There's a lot of really dark,
    a lot of dark colors in the beginning.
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    Anyway, if we go up to the top, we can
    see what happens to all these. Oh. Hello?
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    Oh my god, do I need to restart
    this thing?
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    Oh, there we go.
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    Oh, look. Well, we can actually recognize
    some of these.
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    If you notice, when you click,
    it goes to the top.
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    It sets the functionality
    you have to implement.
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    If you click -- Oh, this is --
    This blue is just called Blue.
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    So Blue is now on top,
    Dark Blue on top,
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    Navy Blue on top.
    This is so dark,
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    I don't know maybe it's Black,
    maybe it's something
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    that's close to Black,
    but we can't even read it
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    because in all of these cases,
    the text is Black.
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    Okay, so that's the ListView
    in a ListView functionality.
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    This flipped classroom
    has some ListView stuff.
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    It also has some RecyclerView
    stuff, and they're both
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    independent activities,
    so this is one of the last cases
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    that we're going to have before
    we hit fragments,
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    which are a little bit more
    convenient way of managing
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    different screens, but for now,
    we've got this --
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    I think it's called the Swap Icon,
    so I don't exactly know
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    who it's really intended for,
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    but I use it to swap between these
    two views.
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    And this view is much less
    monotone.
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    This is a RecyclerView,
    and part of what's going on here
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    is it's got this fancy grid layout,
    so that's sort of nice,
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    and then all of the color names
    are in these boxes,
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    which is this CardView.
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    So CardView is a built-in display class,
    which has some nice borders
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    and rounded edges, and can give you
    a little bit of a drop shadow if you want.
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    So, CardViews are pretty common
    in RecylerViews.
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    And here, instead of when you click the --
    So, something else happens
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    when you click the color name.
    Let's click Blue Violet here
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    and that became Pickled Bean.
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    And Havelock Blue. And then it
    became Portica, which is only
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    one line and you see everything
    sort of shifted around.
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    What's nice about that is
    you don't have to do any of that work.
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    That's all the RecyclerView layout.
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    The layout of the -- It's not the adapter,
    it's the layout manager.
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    So anyway, along with all of these names,
    we have these numbers,
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    which is the luminance, I believe.
    Luminance being a sort of
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    measure of how bright or dark a color is.
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    And one thing that we do is when
    the luminance is below 0.3,
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    we write a color name in white,
    and when it's above,
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    we write it in black because
    that is a high enough contrast
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    that we can now read all of
    the color names. So that's sort of useful.
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    So, I just think this is pretty.
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    (laughs)
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    And -- Oh, yeah. What's happening
    when I click is it's a random --
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    I believe it's a random swap --
    and I believe every time this boots up,
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    there's a random order.
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    Not 100% sure though.
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    But anyway, this is your
    flip classroom.
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    You'll be swapping colors
    and learning the joys
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    of the difference between Cannon Pink
    and Vin Rouge in no time.
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    Thanks.
Pavadinimas:
https:/.../2020-02-04_ap_witchel_x.x_fc2_listview_recyclerview_demo.mp4
Video Language:
English
Duration:
05:28

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