Controlling Your Action Figure: Implementing Java Event Handlers and Using Lambda Expressions - Beginning Java 8 Games Development - page 301

result in more optimal Thread usage! The resulting Java 8 lambda expression code
structure should look like the following, as shown in Figure 9-11 :
scene .setOnKeyPressed (KeyEvent event ) -> {
switch ( event .getCode()) {
case UP: up = true; break; // UP, DOWN,
LEFT, RIGHT constants from KeyCode class
case DOWN: down = true; break;
case LEFT: left = true; break;
case RIGHT: right = true; break;
}
});
Figure 9-11 . Convert the KeyEvent method to a lambda expression; notice that the event variable is used in the switch
Next, let's use a block copy and paste operation, and copy the .OnKeyPressed()
KeyEvent handing structure underneath itself, changing it to be an .OnKeyReleased
KeyEvent handling structure, with false values instead of true.