img_preview

微信公证号文章中,图片预览

目前為 2023-07-14 提交的版本,檢視 最新版本

// ==UserScript==
// @name         img_preview
// @namespace    http://tampermonkey.net/
// @version      0.0.10
// @description  微信公证号文章中,图片预览
// @author       Enjoy
// @icon         https://foruda.gitee.com/avatar/1671100286067517749/4867929_enjoy_li_1671100285.png!avatar60
// @match        *://mp.weixin.qq.com/s/*
// @grant        GM_addElement
// @grant        GM_addStyle
// @grant        GM_setClipboard
// @license      GPL License
// ==/UserScript==

// 函数文档 https://www.tampermonkey.net/documentation.php#api:GM_addElement

(function () {
  GM_addElement('script',{
    textContent: 'window.addEventListener(\'load\',()=>{\nconsole.log(\'执行 img-preview\')\n onImgPreview({\n    selector: \'img.wxw-img\'\n  })\n  function onImgPreview(options = {}) {\n    let defaultOptions = {}\n    let { onContentSelector,selector = \'img\' } = Object({},defaultOptions,options)\n    let scale = 1\n    let offset = {\n      left: 0,\n      top: 0\n    }\n    let origin = \'center\'\n    let initialData = {\n      offset: {},\n      origin: \'center\',\n      scale: 1\n    }\n    let startPoint = {\n      x: 0,\n      y: 0\n    }\n    // 记录初始触摸点位\n    let isTouching = false\n    // 标记是否正在移动\n    let isMove = false\n    // 正在移动中,与点击做区别\n    let touches = new Map()\n    // 触摸点数组\n    let lastDistance = 0\n    let lastScale = 1\n    // 记录下最后的缩放值\n    let scaleOrigin = {\n      x: 0,\n      y: 0,\n    }\n\n    const { innerWidth: winWidth,innerHeight: winHeight } = window\n    // let cloneEl = null\n    let cloneEl = document.createElement(\'img\')\n    let originalEl = null\n\n    let onContent = onContentSelector ? document.querySelector(onContentSelector) : window\n    onContent.addEventListener(\'click\',function (e) {\n      console.log(\'e.target\',e.target)\n      let imgDoms = [...document.querySelectorAll(selector)]\n      e.preventDefault()\n      if (imgDoms.find(item => item === e.target)) {\n        originalEl = e.target\n        // cloneEl = originalEl.cloneNode(true)\n        cloneEl.src = originalEl.src\n        // originalEl.style.opacity = 0\n        openPreview()\n      }\n    })\n\n    function createStyle() {\n\n      const style = document.createElement(\'style\')\n      style.innerHTML = `/* 图片预览 */\n.modal {\ntouch-action: none;\nposition: fixed;\nz-index: 99;\ntop: 0;\nleft: 0;\nwidth: 100vw;\nheight: 100vh;\nbackground-color: rgba(0, 0, 0, 0.75);\nuser-select: none;\n}\n\n.modal>img {\nposition: absolute;\npadding: 0;\nmargin: 0;\n/* transition: all var(--delay_time); */\ntransform: translateZ(0);\n}`\n      return style\n    }\n    function openPreview() {\n      scale = 1\n      const { offsetWidth,offsetHeight } = originalEl\n      const { top,left } = originalEl.getBoundingClientRect()\n      // 创建蒙层\n      const mask = document.createElement(\'div\')\n      mask.classList.add(\'modal\')\n      mask.appendChild(createStyle())\n      // 添加在body下\n      document.body.appendChild(mask)\n      // 注册(不可用)事件\n      mask.addEventListener("click",clickFunc)\n      mask.addEventListener(\'mousewheel\',zoom,{\n        passive: false\n      })\n      // 遮罩点击事件\n      function clickFunc() {\n        setTimeout(() => {\n          if (isMove) {\n            isMove = false\n          } else {\n            changeStyle(cloneEl,[\'transition: all .3s\',`left: ${left}px`,`top: ${top}px`,`transform: translate(0,0)`,`width: ${offsetWidth}px`])\n            setTimeout(() => {\n              document.body.removeChild(this)\n              originalEl.style.opacity = 1\n              mask.removeEventListener(\'click\',clickFunc)\n            }\n              ,300)\n          }\n        }\n          ,280)\n      }\n      // 添加图片\n      changeStyle(cloneEl,[`left: ${left}px`,`top: ${top}px`])\n      mask.appendChild(cloneEl)\n      // 移动图片到屏幕中心位置\n      const originalCenterPoint = {\n        x: offsetWidth / 2 + left,\n        y: offsetHeight / 2 + top\n      }\n      const winCenterPoint = {\n        x: winWidth / 2,\n        y: winHeight / 2\n      }\n      const offsetDistance = {\n        left: winCenterPoint.x - originalCenterPoint.x + left,\n        top: winCenterPoint.y - originalCenterPoint.y + top\n      }\n      const diffs = {\n        left: ((adaptScale() - 1) * offsetWidth) / 2,\n        top: ((adaptScale() - 1) * offsetHeight) / 2\n      }\n      changeStyle(cloneEl,[\'transition: all 0.3s\',`width: ${offsetWidth * adaptScale() + \'px\'}`,`transform: translate(${offsetDistance.left - left - diffs.left}px, ${offsetDistance.top - top - diffs.top}px)`])\n      // 消除偏差\n      setTimeout(() => {\n        changeStyle(cloneEl,[\'transition: all 0s\',`left: 0`,`top: 0`,`transform: translate(${offsetDistance.left - diffs.left}px, ${offsetDistance.top - diffs.top}px)`])\n        offset = {\n          left: offsetDistance.left - diffs.left,\n          top: offsetDistance.top - diffs.top\n        }\n        // 记录值\n        record()\n      }\n        ,300)\n    }\n\n    // 滚轮缩放\n    const zoom = (event) => {\n      if (!event.deltaY) {\n        return\n      }\n      event.preventDefault()\n      origin = `${event.offsetX}px ${event.offsetY}px`\n      // 缩放执行\n      if (event.deltaY < 0) {\n        scale += 0.1\n        // 放大\n      } else if (event.deltaY > 0) {\n        scale >= 0.2 && (scale -= 0.1)\n        // 缩小\n      }\n      if (scale < initialData.scale) {\n        reduction()\n      }\n      offset = getOffsetCorrection(event.offsetX,event.offsetY)\n      changeStyle(cloneEl,[\'transition: all .15s\',`transform-origin: ${origin}`,`transform: translate(${offset.left + \'px\'}, ${offset.top + \'px\'}) scale(${scale})`])\n    }\n\n    // 获取中心改变的偏差\n    function getOffsetCorrection(x = 0,y = 0) {\n      const touchArr = Array.from(touches)\n      if (touchArr.length === 2) {\n        const start = touchArr[0][1]\n        const end = touchArr[1][1]\n        x = (start.offsetX + end.offsetX) / 2\n        y = (start.offsetY + end.offsetY) / 2\n      }\n      origin = `${x}px ${y}px`\n      const offsetLeft = (scale - 1) * (x - scaleOrigin.x) + offset.left\n      const offsetTop = (scale - 1) * (y - scaleOrigin.y) + offset.top\n      scaleOrigin = {\n        x,\n        y\n      }\n      return {\n        left: offsetLeft,\n        top: offsetTop\n      }\n    }\n\n    // 操作事件\n    window.addEventListener(\'pointerdown\',function (e) {\n      e.preventDefault()\n      touches.set(e.pointerId,e)\n      // TODO: 点击存入触摸点\n      isTouching = true\n      startPoint = {\n        x: e.clientX,\n        y: e.clientY\n      }\n      if (touches.size === 2) {\n        // TODO: 判断双指触摸,并立即记录初始数据\n        lastDistance = getDistance()\n        lastScale = scale\n      }\n    })\n    window.addEventListener(\'pointerup\',function (e) {\n      touches.delete(e.pointerId)\n      // TODO: 抬起移除触摸点\n      if (touches.size <= 0) {\n        isTouching = false\n      } else {\n        const touchArr = Array.from(touches)\n        // 更新点位\n        startPoint = {\n          x: touchArr[0][1].clientX,\n          y: touchArr[0][1].clientY\n        }\n      }\n      setTimeout(() => {\n        isMove = false\n      }\n        ,300);\n    })\n    window.addEventListener(\'pointermove\',(e) => {\n      e.preventDefault()\n      if (isTouching) {\n        isMove = true\n        if (touches.size < 2) {\n          // 单指滑动\n          offset = {\n            left: offset.left + (e.clientX - startPoint.x),\n            top: offset.top + (e.clientY - startPoint.y),\n          }\n          changeStyle(cloneEl,[\'transition: all 0s\',`transform: translate(${offset.left + \'px\'}, ${offset.top + \'px\'}) scale(${scale})`,`transform-origin: ${origin}`])\n          // 更新点位\n          startPoint = {\n            x: e.clientX,\n            y: e.clientY\n          }\n        } else {\n          // 双指缩放\n          touches.set(e.pointerId,e)\n          const ratio = getDistance() / lastDistance\n          scale = ratio * lastScale\n          offset = getOffsetCorrection()\n          if (scale < initialData.scale) {\n            reduction()\n          }\n          changeStyle(cloneEl,[\'transition: all 0s\',`transform: translate(${offset.left + \'px\'}, ${offset.top + \'px\'}) scale(${scale})`,`transform-origin: ${origin}`])\n        }\n      }\n    }\n    )\n    window.addEventListener(\'pointercancel\',function (e) {\n      touches.clear()\n      // 可能存在特定事件导致中断,真机操作时 pointerup 在某些边界情况下不会生效,所以需要清空\n    })\n\n    // 修改样式,减少回流重绘\n    function changeStyle(el,arr) {\n      const original = el.style.cssText.split(\';\')\n      original.pop()\n      el.style.cssText = original.concat(arr).join(\';\') + \';\'\n    }\n\n    // 计算自适应屏幕的缩放值\n    function adaptScale() {\n      const { offsetWidth: w,offsetHeight: h } = originalEl\n      let scale = 0\n      scale = winWidth / w\n      if (h * scale > winHeight - 80) {\n        scale = (winHeight - 80) / h\n      }\n      return scale\n    }\n\n    // 获取距离\n    function getDistance() {\n      const touchArr = Array.from(touches)\n      if (touchArr.length < 2) {\n        return 0\n      }\n      const start = touchArr[0][1]\n      const end = touchArr[1][1]\n      return Math.hypot(end.x - start.x,end.y - start.y)\n    }\n\n    // 记录初始化数据\n    function record() {\n      initialData = Object.assign({},{\n        offset,\n        origin,\n        scale\n      })\n    }\n\n    // 还原记录,用于边界处理\n    let timer = null\n    function reduction() {\n      timer && clearTimeout(timer)\n      timer = setTimeout(() => {\n        // offset = initialData.offset\n        // origin = initialData.origin\n        // scale = initialData.scale\n        changeStyle(cloneEl,[`transform: translate(${offset.left + \'px\'}, ${offset.top + \'px\'}) scale(${scale})`,`transform-origin: ${origin}`])\n      }\n        ,300)\n    }\n  }\n})'
  })})();

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