one/dist/cjs/link/prefetchViewport.cjs

One is a new React Framework that makes Vite serve both native and web.

var __defProp = Object.defineProperty;
var __getOwnPropDesc = Object.getOwnPropertyDescriptor;
var __getOwnPropNames = Object.getOwnPropertyNames;
var __hasOwnProp = Object.prototype.hasOwnProperty;
var __export = (target, all) => {
  for (var name in all) __defProp(target, name, {
    get: all[name],
    enumerable: true
  });
};
var __copyProps = (to, from, except, desc) => {
  if (from && typeof from === "object" || typeof from === "function") {
    for (let key of __getOwnPropNames(from)) if (!__hasOwnProp.call(to, key) && key !== except) __defProp(to, key, {
      get: () => from[key],
      enumerable: !(desc = __getOwnPropDesc(from, key)) || desc.enumerable
    });
  }
  return to;
};
var __toCommonJS = mod => __copyProps(__defProp({}, "__esModule", {
  value: true
}), mod);
var prefetchViewport_exports = {};
__export(prefetchViewport_exports, {
  createPrefetchViewport: () => createPrefetchViewport,
  observePrefetchViewport: () => observePrefetchViewport,
  startPrefetchViewport: () => startPrefetchViewport
});
module.exports = __toCommonJS(prefetchViewport_exports);
function createPrefetchViewport() {
  const done = /* @__PURE__ */new Set();
  const nodes = /* @__PURE__ */new Map();
  let io = null;
  let onPrefetch = null;
  function getObserver() {
    if (io) return io;
    io = new IntersectionObserver(entries => {
      for (const entry of entries) {
        if (!entry.isIntersecting) continue;
        const href = nodes.get(entry.target);
        if (href && !done.has(href)) {
          done.add(href);
          onPrefetch?.(href);
        }
      }
    }, {
      threshold: 0.5
    }
    // fires when mostly visible
    );
    return io;
  }
  function start(prefetch) {
    onPrefetch = prefetch;
  }
  function observe(el, href) {
    nodes.set(el, href);
    getObserver().observe(el);
    return () => {
      nodes.delete(el);
      io?.unobserve(el);
      done.delete(href);
    };
  }
  return {
    start,
    observe,
    done,
    nodes
  };
}
let instance = null;
function startPrefetchViewport(prefetch) {
  if (!instance) instance = createPrefetchViewport();
  instance.start(prefetch);
}
function observePrefetchViewport(el, href) {
  if (!instance) instance = createPrefetchViewport();
  return instance.observe(el, href);
}