Class GameLoop

src/GameLoop.js:6–98

import DefaultTouchProcessor from "./DefaultTouchProcessor";

export default class GameLoop extends Component {
  constructor(props) {
    super(props);
    this.timer = props.timer || new DefaultTimer();
    this.timer.subscribe(this.updateHandler);
    this.touches = [];
    this.screen = Dimensions.get("window");
    this.previousTime = null;
    this.previousDelta = null;
    this.touchProcessor = props.touchProcessor(this.touches);
    this.layout = null;
  }

  componentDidMount() {
    if (this.props.running) this.start();
  }

  componentWillUnmount() {
    this.stop();
    this.timer.unsubscribe(this.updateHandler);
    if (this.touchProcessor.end) this.touchProcessor.end();
  }

  UNSAFE_componentWillReceiveProps(nextProps) {
    if (nextProps.running !== this.props.running) {
      if (nextProps.running) this.start();
      else this.stop();
    }
  }

  start = () => {
    this.touches.length = 0;
    this.previousTime = null;
    this.previousDelta = null;
    this.timer.start();
  };

  stop = () => {
    this.timer.stop();
  };

  updateHandler = currentTime => {
    let args = {
      touches: this.touches,
      screen: this.screen,
      layout: this.layout,
      time: {
        current: currentTime,
        previous: this.previousTime,
        delta: currentTime - (this.previousTime || currentTime),
        previousDelta: this.previousDelta
      }
    };

    if (this.props.onUpdate) this.props.onUpdate(args);

    this.touches.length = 0;
    this.previousTime = currentTime;