- Simple Refactoring: Creating a New Class 5:54
- Creating a New Class 2 objectives
- Simple Refactoring: Using a New Class 6:28
- Simple Refactoring 5 questions
- Dynamically Changing the Background Color 3:51
- Dynamically Changing the Background Color 1 objective
- Adding More Colors 3:43
- Using the New Colors 3:42
- Adding Colors 1 objective
- Adding an App Icon 4:50
- Adding an App Icon 3 questions
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Adding More Colors
3:43Let's continue with adding additional colors as the background for each new fun fact. We'll add a new Java object to hold the colors and serve one up on each tap of the button!
It's finally time to add
all the colors to our app.
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Let's create a new class called
ColorWheel that stores our colors and
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picks new ones for us.
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It'll be very similar
to our factBook class.
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In the Project pane, let's click on our
package name, and select New, Java Class.
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Let's name it ColorWheel and hit Enter.
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Now, we're going to copy and
paste our code from our factBook class and
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make a few key changes, but first,
let me close the Project pane.
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Let's switch over to our factBook
class and, before we copy anything,
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let's delete this extra space at
the top of the getFact method.
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Then let's select everything
after the word factBook and
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use Cmd or Ctrl+C to copy it.
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Then let's go back to
the ColorWheel class,
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select everything after the word ColorWhee
and use Cmd or Ctrl+V to paste it in.
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Android Studio then notices
that we're missing an import.
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We didn't copy the import
statement from our factBook class,
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which means it didn't get pasted here.
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Hit OK to generate the import and
now we're good to go.
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Instead of facts,
we'd like these to be colors.
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Let's start by refactoring
facts to be named colors.
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Right click on facts and
select Refactor, Rename, and
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note the keyboard shortcut is Shift + F6,
and type colors.
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Now I'm going to copy and paste in some
colors in the form of hexadecimal strings.
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You can find these colors
below in the teacher's notes.
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Okay, let's copy the array from
bracket to semicolon and then,
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back in Android Studio, let's paste
it over the existing facts array.
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And now that we've got all our colors,
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let's make a few changes
to the getFact method.
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First off, we probably shouldn't
call it getFact anymore.
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Let's change it to getColor.
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Since this method is never used,
that's what the gray text is telling us,
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we don't need to bother
with the refactoring.
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We can just rename it the old fashion way,
getColor.
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Great, now the cool thing is we
don't need to change anything
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about our random number generator,
we still use the Random class and
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we still pick a random number based
on the length of our array up here.
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Now let's go back to FunFactsActivity.
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And the first thing we need to do is
create a new ColorWheel object as a field,
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just like we did with factBook.
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Let's add a new line at the top, below our
factBook, and type private ColorWheel,
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name it colorWheel, and
set it equal to an new ColorWheel.
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Now, down in our OnClick method, we can
pick a new color just like we did for
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the fact.
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Let's add a couple lines after we
set our fact and type String color
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= colorWheel.getColor, then let's
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use our new color variable as a parameter
to the setBackgroundColor method.
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Which gives us an error.
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If we hover over it, we see that we're
getting an incompatible types error again.
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The method expects an int but
we're giving it a string.
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So how are we gonna make this work?
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Well, don't worry, as usual,
there is a simple solution.
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We need to convert data like
this a lot in programming.
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Remember, programming is primarily about
working with and manipulating data.
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Let's take a short break and
then the next video, we'll fix this error.
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