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node_modules/vant/es/lazyload/vue-lazyload/util.mjs

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+import { inBrowser } from "@vant/use";
+const hasIntersectionObserver = inBrowser && "IntersectionObserver" in window && "IntersectionObserverEntry" in window && "intersectionRatio" in window.IntersectionObserverEntry.prototype;
+const modeType = {
+  event: "event",
+  observer: "observer"
+};
+function remove(arr, item) {
+  if (!arr.length) return;
+  const index = arr.indexOf(item);
+  if (index > -1) return arr.splice(index, 1);
+}
+function getBestSelectionFromSrcset(el, scale) {
+  if (el.tagName !== "IMG" || !el.getAttribute("data-srcset")) return;
+  let options = el.getAttribute("data-srcset");
+  const container = el.parentNode;
+  const containerWidth = container.offsetWidth * scale;
+  let spaceIndex;
+  let tmpSrc;
+  let tmpWidth;
+  options = options.trim().split(",");
+  const result = options.map((item) => {
+    item = item.trim();
+    spaceIndex = item.lastIndexOf(" ");
+    if (spaceIndex === -1) {
+      tmpSrc = item;
+      tmpWidth = 999998;
+    } else {
+      tmpSrc = item.substr(0, spaceIndex);
+      tmpWidth = parseInt(
+        item.substr(spaceIndex + 1, item.length - spaceIndex - 2),
+        10
+      );
+    }
+    return [tmpWidth, tmpSrc];
+  });
+  result.sort((a, b) => {
+    if (a[0] < b[0]) {
+      return 1;
+    }
+    if (a[0] > b[0]) {
+      return -1;
+    }
+    if (a[0] === b[0]) {
+      if (b[1].indexOf(".webp", b[1].length - 5) !== -1) {
+        return 1;
+      }
+      if (a[1].indexOf(".webp", a[1].length - 5) !== -1) {
+        return -1;
+      }
+    }
+    return 0;
+  });
+  let bestSelectedSrc = "";
+  let tmpOption;
+  for (let i = 0; i < result.length; i++) {
+    tmpOption = result[i];
+    bestSelectedSrc = tmpOption[1];
+    const next = result[i + 1];
+    if (next && next[0] < containerWidth) {
+      bestSelectedSrc = tmpOption[1];
+      break;
+    } else if (!next) {
+      bestSelectedSrc = tmpOption[1];
+      break;
+    }
+  }
+  return bestSelectedSrc;
+}
+const getDPR = (scale = 1) => inBrowser ? window.devicePixelRatio || scale : scale;
+function supportWebp() {
+  if (!inBrowser) return false;
+  let support = true;
+  try {
+    const elem = document.createElement("canvas");
+    if (elem.getContext && elem.getContext("2d")) {
+      support = elem.toDataURL("image/webp").indexOf("data:image/webp") === 0;
+    }
+  } catch (err) {
+    support = false;
+  }
+  return support;
+}
+function throttle(action, delay) {
+  let timeout = null;
+  let lastRun = 0;
+  return function(...args) {
+    if (timeout) {
+      return;
+    }
+    const elapsed = Date.now() - lastRun;
+    const runCallback = () => {
+      lastRun = Date.now();
+      timeout = false;
+      action.apply(this, args);
+    };
+    if (elapsed >= delay) {
+      runCallback();
+    } else {
+      timeout = setTimeout(runCallback, delay);
+    }
+  };
+}
+function on(el, type, func) {
+  el.addEventListener(type, func, {
+    capture: false,
+    passive: true
+  });
+}
+function off(el, type, func) {
+  el.removeEventListener(type, func, false);
+}
+const loadImageAsync = (item, resolve, reject) => {
+  const image = new Image();
+  if (!item || !item.src) {
+    return reject(new Error("image src is required"));
+  }
+  image.src = item.src;
+  if (item.cors) {
+    image.crossOrigin = item.cors;
+  }
+  image.onload = () => resolve({
+    naturalHeight: image.naturalHeight,
+    naturalWidth: image.naturalWidth,
+    src: image.src
+  });
+  image.onerror = (e) => reject(e);
+};
+class ImageCache {
+  constructor({ max }) {
+    this.options = {
+      max: max || 100
+    };
+    this.caches = [];
+  }
+  has(key) {
+    return this.caches.indexOf(key) > -1;
+  }
+  add(key) {
+    if (this.has(key)) return;
+    this.caches.push(key);
+    if (this.caches.length > this.options.max) {
+      this.free();
+    }
+  }
+  free() {
+    this.caches.shift();
+  }
+}
+export {
+  ImageCache,
+  getBestSelectionFromSrcset,
+  getDPR,
+  hasIntersectionObserver,
+  loadImageAsync,
+  modeType,
+  off,
+  on,
+  remove,
+  supportWebp,
+  throttle
+};