Sound, mapping many keys to many actions, and building an instrument you can play.
Before you start: finish lesson 5.3. That is the last thing this project needs. Starting earlier is allowed and you will hit a method nobody has shown you yet.
Tutorial. Put this window on one side of your screen and Greenfoot on the other, then build along with it.
Every one of these appears in the build. The lesson number is where the
course teaches it, so if a row looks unfamiliar you have not missed anything,
you just have not got there yet.
Method
Taught in
What it does here
private String[] whiteKeys = { "A", "S", ... }
5.1
four arrays drive the whole instrument
whiteKeys.length
5.2
how many keys to build
for (int i = 0; i < whiteKeys.length; i++)
5.3
build them all in one loop
whiteKeys[i]
5.2
the index is which key, the value is which letter
new Key(letter, sound, up, down)
3.9
an actor constructor with four arguments
addObject(key, 54 + (i * 63), 140)
3.7
the counter spaces them out
super(800, 340, 1)
3.5
a wide, short world
Not covered by the course
This project uses these, and the lessons never get to them. That is not a
gap in your knowledge. Copy them from the video, or ask.
Method
Why it is here
blackKeys[i].equals("")
comparing two Strings. == does not work on them, and the course never covers this.
getBackground().drawString(...)
drawing text onto the world image rather than showText.
setColor(Color.WHITE)
needs import java.awt.Color at the top of the file.
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