Techmeme improve navigation on mobile

Adds a history entry when tapping Techmeme's "more" link on each story on its mobile site so Browser Back closes the overlay and Forward reopens it.

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey 篡改猴Greasemonkey 油猴子Violentmonkey 暴力猴,才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey 篡改猴,才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey 篡改猴Violentmonkey 暴力猴,才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey 篡改猴Userscripts ,才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey 篡改猴,才能安装此脚本。

您需要先安装一款用户脚本管理器扩展后才能安装此脚本。

(我已经安装了用户脚本管理器,让我安装!)

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

(我已经安装了用户样式管理器,让我安装!)

// ==UserScript==
// @name         Techmeme improve navigation on mobile
// @namespace    https://fanis.dev/userscripts
// @author       Fanis Hatzidakis
// @license      PolyForm-Internal-Use-1.0.0; https://polyformproject.org/licenses/internal-use/1.0.0/
// @version      1.0.0
// @description  Adds a history entry when tapping Techmeme's "more" link on each story on its mobile site so Browser Back closes the overlay and Forward reopens it.
// @match        https://www.techmeme.com/*
// @match        https://techmeme.com/*
// @run-at       document-start
// @grant        none
// ==/UserScript==

// SPDX-License-Identifier: PolyForm-Internal-Use-1.0.0
// Copyright (c) 2025 Fanis Hatzidakis
// License: PolyForm Internal Use License 1.0.0
// Summary: Free for personal and internal business use. No redistribution, resale,
// or offering as a service without a separate commercial license from the author.
// Full text: https://polyformproject.org/licenses/internal-use/1.0.0/

(() => {
  "use strict";

  const HASH_PREFIX = "#tm_more=";

  const parseItemIdFromOnclick = (onclick) => {
    if (!onclick) return null;
    const m = onclick.match(/openItemPage\('(\d+)'/);
    return m ? m[1] : null;
  };

  const pushMoreState = (itemId) => {
    if (!itemId) return;
    if (location.hash.startsWith(HASH_PREFIX)) return;

    const newUrl = `${location.pathname}${location.search}${HASH_PREFIX}${encodeURIComponent(
      itemId
    )}`;

    history.pushState({ tmMore: true, itemId }, "", newUrl);
  };

  const closeOverlay = () => {
    const back = document.getElementById("back_selector");
    if (back) {
      back.click();
      return true;
    }
    return false;
  };

  const reopenOverlay = (itemId) => {
    if (!itemId) return false;

    const cell = document.querySelector(
      `td.nav_to_more[onclick*="openItemPage('${CSS.escape(itemId)}'"]`
    );
    if (!cell) return false;

    const onclick = cell.getAttribute("onclick");
    const parsed = parseItemIdFromOnclick(onclick);
    if (!parsed) return false;

    const fn = window.openItemPage;
    if (typeof fn !== "function") return false;

    // Techmeme signature: openItemPage('0', this, ['...'])
    // Passing only (id, element) is typically fine; the function can read element state.
    fn(parsed, cell);
    return true;
  };

  // 1) When tapping the "more" cell, push a history entry before Techmeme opens the overlay.
  document.addEventListener(
    "click",
    (e) => {
      const cell = e.target?.closest?.("td.nav_to_more");
      if (!cell) return;

      const onclick = cell.getAttribute("onclick");
      const itemId = parseItemIdFromOnclick(onclick);
      if (!itemId) return;

      pushMoreState(itemId);
      // Do not stop propagation; Techmeme must still run its onclick to open the overlay.
    },
    true
  );

  // 2) On Back/Forward gesture, close or reopen based on the hash.
  window.addEventListener("popstate", () => {
    const hash = location.hash || "";

    // Back: returning to base URL (no tm_more hash) -> close overlay.
    if (!hash.startsWith(HASH_PREFIX)) {
      const closed = closeOverlay();
      if (!closed) {
        location.replace(`${location.pathname}${location.search}`);
      }
      return;
    }

    // Forward: tm_more hash present -> reopen overlay for that itemId.
    const itemId = decodeURIComponent(hash.slice(HASH_PREFIX.length));
    const reopened = reopenOverlay(itemId);

    // Fallback: if we couldn't reopen, clean up the URL.
    if (!reopened) {
      location.replace(`${location.pathname}${location.search}`);
    }
  });
})();