在带有Scene2D的LibGDX中，当按下按钮时，如何连续向右行走？

Question

I have the following piece of code in my InputAdapter :

...
@Override
public boolean keyDown (int keycode) {
    if (keycode == Keybindings.KEY_RIGHT) this.player.right();
    return super.keyDown(keycode);
}

@Override
public boolean keyUp (int keycode) {
    if (keycode == Keybindings.KEY_RIGHT) this.player.stopMovingRight();
    return super.keyUp(keycode);
}
...

And my PlayerActor class is responsible for right() and stopMovingRight() :

...
public void right () {
    this.right = true;
    this.setX(this.getX() + 1f);
}

public void stopMovingRight () {
    this.right = false;
}
...

Now, when I run the application, my PlayerActor moves just 1 unit when I press the KEY_RIGHT key (the 'D' key on the keyboard). The problem is that I instead want to continuously move the PlayerActor while I am pressing down the key.

Situation now:

• Hold down key -> move (just) 1 unit to the right
• Let go of key -> nothing happens

Desired situation:

• Hold down key -> move 1 unit to the right continuously
• Let go of key -> stop moving to the right

I would love to hear your thoughts on this matter, cheers!

Answer 1

The problem you encourted here is, that keyDown() is called only once, therefore your player id moved only by 1 unit. What you need to do is, create some variable, for example isMovingRight and check it every time the game is updated.

Game class:

public final void render(float delta) {
...
   player.update();
...
}

Player class:

public void update() {
   if(isMovingRight) {
      this.setX(this.getX() + 1f);
   }
}