[LibGDX] Player Movement lagging

Newbie & Debugging Questions
#1

So I’m trying to make the player move using Box2D. The player moves left and right using ‘A’ and ‘B’ keys.
When I press ‘A’ and ‘D’ very fast the movement lags or should i say twitches. Here is the code.

The Player class extends InputAdapter and I Override 2 methods, KeyDown and KeyUp.
The movement is Vector2 variable.

@Override
	public boolean keyUp(int keycode) {
		if(Keys.A == keycode || Keys.D == keycode && movement.x > 0) {
			body.setAngularVelocity(0);
			movement.x = 0f;
			body.setLinearVelocity(movement);
		}else
			return false;
		
		return true;
	}
	
	@Override
	public boolean keyDown(int keycode) {
		switch(keycode) {
		case Keys.A:
			movement.x = -velocity;
			break;
		case Keys.D:
			movement.x = velocity;
			break;
		default:
			return false;
		}
		return true;
	}

The Player class has also update method where I apply the movement

public void update() {
			body.applyLinearImpulse(movement, new Vector2(), true);
	}

And then I’ve just used the players update method in the render method like so player.update();
of course the i’ve added listenenrs and so on. Is there something that I’ve forgotten?

Here is the .jar file.
http://www.mediafire.com/download/x5aogpoqahcb87h/test.jar
Is it normal that the file is 18Mb?? :smiley:

Thank you very much.