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Loading Additional Pages
2:40Now we need to refactor our code to load different pages from our Story class. We also need to add OnClickListeners to our buttons to trigger the loadPage() method.
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We left off with a simple load page
method that gets called when our activity
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is first created.
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And as of right now,
simply loads the first page of the story,
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which is at page zero.
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Now we want to change this to load a new
page of the story based on whatever
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the user taps on as one of the choices.
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So, to do that, we need to add
OnClickListeners to our buttons and
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call this loadPage method
when a button is tapped.
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That will cause all these views to
be repopulated with fresh page data,
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we arent' ever leaving the activity.
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We're just updating all
the views inside it.
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So let's add the new OnClickListeners
down here where we're setting the text
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for the buttons.
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I'm going to keep the choice
one code together so,
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I'll add a few lines between here and
then type choice1Button.setOnClickListener
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new OnClickListener, hit Enter and
there we go, we have the onClick method.
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In here, the first thing we need is
the index of the new page we want to load.
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So int nextPage =, and
then from the page story we can getChoice1
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because we're in Choice1 button and
get the NextPage.
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Okay, I was actually expecting to see
an error here about page not being final.
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It looks like Android Studio might have
automatically added the final keyword to
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our page variable to make sure that we
can access it down here in this anonymous
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inner class.
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We have to remember that this anonymous
inner class this onClickListener is
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a self-contained unit and
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it can't reference anything from outside
of it unless we make that kind of change.
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All right, so now we can simply load
this nextPage by calling, loadPage and
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passing in nextPage.
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Now we wanna do the exact same thing for
choice two.
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Let's cheat and do a quick copy paste.
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As usual, I want to warn you to be very
careful when copying and pasting code.
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It's very easy to make a copy and
paste errors.
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Okay, so we want to change this
to Choice2Button as well and
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then we want to change down here
instead of getting from Choice1,
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let's get the next page from Choice2.
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Okay, we should be set.
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Let's run this to make sure that
it's working as we expect it to.
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All right, I'm going to go back to the
Pixel, Use that for future launches and
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click OK.
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Okay, so this time,
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I'm going to type in a different name,
let's use Pasan, START YOUR ADVENTURE.
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And once again,
we see the name being plugged in.
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And now, let's try the first choice,
STOP AND INVESTIGATE.
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Okay, cool, look at that,
we went to a new page.
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And, let's try the second choice too,
EXPLORE THE ROVER.
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All right, look at this.
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We're working through the story.
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Let's EXPLORE THE COORDINATES.
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Uh-oh, we've run into an error.
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All right, so what's going on here?
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Here's a challenge.
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See if you can figure out
what the error is, and
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then, I'll show you how we're
going to fix it in the next video.
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