import playn.core.Keyboard; //导入依赖的package包/类
public Showcase (Platform plat, DeviceService deviceService) {
  super(plat, 25); // 25 simulation updates per second
  this.deviceService = deviceService;

  // wire up a layer pointer dispatcher
  new Pointer(plat, rootLayer, true);

  plat.input().keyboardEvents.connect(new Keyboard.KeySlot() {
    @Override public void onEmit (Keyboard.KeyEvent event) {
      if (event.down && backKeys.contains(event.key)) activateDemo(menuDemo);
    }
  });
  plat.input().touchEvents.connect(new Slot<Touch.Event[]>() {
    public void onEmit (Touch.Event[] touches) {
      if (touches.length > 1 && touches[0].kind.isStart) activateDemo(menuDemo);
    }
  });
  activateDemo(menuDemo);
}
 

import playn.core.Keyboard; //导入依赖的package包/类
@Override
public void onEmit(Keyboard.Event event) {
    if (event instanceof Keyboard.KeyEvent) {
        Keyboard.KeyEvent keyEvent = (Keyboard.KeyEvent) event;
        if (keyEvent.down && actionMap.containsKey(keyEvent.key)) {
            actionMap.get(keyEvent.key).run();
        }
    }
}
 

import playn.core.Keyboard; //导入依赖的package包/类
@Override public void create (final Showcase game, Closeable.Set onClose) {
  GroupLayer layer = new GroupLayer();
  game.rootLayer.add(layer);
  onClose.add(layer);

  // create our UI manager and configure it to process pointer events
  Interface iface = new Interface(game.plat, game.paint);
  onClose.add(iface);

  // create our demo interface
  final Root root = iface.createRoot(AxisLayout.vertical().gap(15),
                                     SimpleStyles.newSheet(game.plat.graphics()));
  root.setSize(game.plat.graphics().viewSize);
  root.addStyles(Style.BACKGROUND.is(Background.solid(0xFF99CCFF).inset(5)));
  layer.add(root.layer);

  Group buttons;
  root.add(new Label("PlayN Demos:"),
           buttons = new Group(AxisLayout.vertical().offStretch()),
           new Label("ESC/BACK key or two-finger tap returns to menu from demo").addStyles(
             Style.TEXT_WRAP.is(true)),
           new Label("(renderer: " + game.plat.graphics().getClass().getSimpleName() + " " +
                     game.plat.graphics().viewSize + ")"),
           new Label("(device: " + game.deviceService.info() + ")").addStyles(
             Style.TEXT_WRAP.is(true)));

  int key = 1;
  for (final Showcase.Demo demo : game.demos) {
    Button button = new Button(key++ + " - " + demo.name);
    buttons.add(button);
    button.clicked().connect(new UnitSlot() {
      @Override public void onEmit() { game.activateDemo(demo); }
    });
  }

  // wire up keyboard shortcuts
  onClose.add(game.plat.input().keyboardEvents.connect(new Keyboard.KeySlot() {
    public void onEmit (Keyboard.KeyEvent event) {
      // this is a bit hacky, but serves our purpose
      int demoIndex = event.key.ordinal() - Key.K1.ordinal();
      if (demoIndex >= 0 && demoIndex < game.demos.size()) {
        game.activateDemo(game.demos.get(demoIndex));
      }
    }
  }));

  // resize our root if the view rotates
  onClose.add(game.rotate.connect(new UnitSlot() {
    public void onEmit () { root.setSize(game.plat.graphics().viewSize); }
  }));
}