@applicaster/zapp-react-native-ui-components/Components/Viewport/ViewportEvents/index.js

Applicaster Zapp React Native ui components for the Quick Brick App

import * as React from "react";

import { removeItemFromList } from "@applicaster/zapp-react-native-utils/arrayUtils";

export class ViewportEvents {
  constructor(firesLastEventOnAdd = false) {
    this.listeners = [];
    this.lastEvent = null;
    this.firesLastEventOnAdd = firesLastEventOnAdd;
  }

  addListener(listener) {
    if (!this.listeners.includes(listener)) {
      this.listeners.push(listener);

      if (this.firesLastEventOnAdd && this.lastEvent) {
        listener(this.lastEvent);
      }
    }
  }

  removeListener(listener) {
    this.listeners = removeItemFromList(listener, this.listeners);
  }

  notify = (event) => {
    this.lastEvent = event;
    this.listeners.forEach((listener) => listener(event));
  };
}

export const ViewportEventContext = React.createContext(null);

export function useViewportEventsContext() {
  return React.useContext(ViewportEventContext);
}