Keyboard

Use keyboard input to control your game. Obtain the Keyboard module using engine.keyboard().

Check for key status

The Keyboard provides multiple method for checking the status of a key. Instead of the event driven AWT / Swing approach ScrewBox encourages using a polling mechanism. This makes it easier to write thread safe code.

To check for key status use the desired method.

// will be true as long as the key is down
boolean isSpaceDown = keyboard.isDown(Key.SPACE);

// will be true only in the first frame when space is down
// must be released and pressed again to be true
boolean isSpacePressed = keyboard.isPressed(Key.SPACE);

// will only be true when both keys are down at the same time
final KeyCombination quit = KeyCombination.ofKeys(Key.SHIFT_LEFT, Key.Q);
boolean isQuit = keyboard.isDown(quit);

Using aliases

Aliases can be used to make the key bindings configurable. Also aliases may improve the readability of your source. Any enum value may be an alias.

1. define alias

enum MyKeybindings {
    JUMP,
    LEFT,
    RIGHT
}

2. set up alias binding

keyboard.bindAlias(MyKeybindings.JUMP, Key.SPACE);

3. using alias

boolean isJump = keyboard.isDown(MyKeybindings.JUMP);

The alias binding can also be added by annotating the enum values with @DefaultKey. The default value can be overwritten by using keyboard.bindAlias(...).

enum MyKeybindings {
    
    @DefaultKey(Key.SPACE)
    JUMP,
    
    @DefaultKey(Key.ARROW_LEFT)
    LEFT,

    @DefaultKey(Key.ARROW_RIGHT)
    RIGHT
}

Movement input

The keyboard also provides a very simple way to receive direction input for the arrow keys and the also very common wsad-combination:

// will be Vector.$(10,0) when pressing arrow right
Vector movement = keyboard.arrowKeysMovement(10);

// will be Vector.$(7.07, 7.07]) when pressing w and d at the same time
Vector movement = keyboard.wsadMovement(10);

Recording text

To receive an input string from the keyboard the record mode must be started.

keyboard.recordedText(); // = Optional.empty()
keyboard.isRecording(); // = false

keyboard.startRecording();
keyboard.isRecording(); // = true

keyboard.recordedText(); // = Optional.of("")
// press a, b, c, backspace, d
keyboard.recordedText(); // = Optional.of("abd")