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LaTeX Unicode Shortcuts

Highlight text then press [ALT+X] to convert LaTeX commands to their unicode equivalent (ex. \pi → π)

当前为 2020-07-21 提交的版本，查看 最新版本。

  1. // ==UserScript==
  2. // @name         LaTeX Unicode Shortcuts
  3. // @namespace    http://tampermonkey.net/
  4. // @version      0.1
  5. // @description  Highlight text then press [ALT+X] to convert LaTeX commands to their unicode equivalent (ex. \pi → π)
  6. // @author       eyl327
  7. // @match        *://*/*
  8. // @grant        none
  9. // ==/UserScript==
  10.  
  11. (function () {
  12.     'use strict';
  13.  
  14.     var convert;
  15.  
  16.     var dictLoaded = false;
  17.  
  18.     /* source url for shortcut file */
  19.     var dictionarySource = "https://raw.githubusercontent.com/eyl327/LaTeX-Gboard-Dictionary/master/dictionary.txt";
  20.  
  21.     /* fetch text file when requested */
  22.     function loadAsset(url, callback) {
  23.         var xhr = new XMLHttpRequest();
  24.         xhr.open("GET", url, false);
  25.         xhr.onreadystatechange = function () {
  26.             if (xhr.readyState === 4) {
  27.                 if (xhr.status === 200 || xhr.status === 0) {
  28.                     callback(xhr.responseText);
  29.                 }
  30.             }
  31.         }
  32.         xhr.send();
  33.     }
  34.  
  35.     /* on dictionary loaded callback */
  36.     function loaded(response) {
  37.         console.log("LaTeX Unicode Shortcuts has been loaded.");
  38.         /* generate dictionary from text file */
  39.         var dictArr = response.split("\n").slice(1);
  40.         var dictionary = {};
  41.         for (var i = 0, len = dictArr.length; i < len; ++i) {
  42.             var kvp = dictArr[i].split("\t");
  43.             dictionary[kvp[0]] = kvp[1];
  44.         }
  45.         /* conversion function */
  46.         convert = function (text) {
  47.             var result = text.replace(/{([A-Za-z0-9])}/g, '$1'); // {R} => R
  48.             for (var key in dictionary) {
  49.                 var pattern = new RegExp(key.replace(/([[^$.|\\?*+(){}])/g, '\\$1') + "\\b", 'g'); // clean and escape key
  50.                 var replaced = result.replace(pattern, dictionary[key]);
  51.                 if (replaced.length < result.length) {
  52.                     result = replaced;
  53.                 }
  54.             }
  55.             return result;
  56.         };
  57.         dictLoaded = true;
  58.     }
  59.  
  60.     /* get caret position within input box */
  61.     function getCaretPosition(el) {
  62.         if ("selectionStart" in el && document.activeElement == el) {
  63.             return {
  64.                 start: el.selectionStart,
  65.                 end: el.selectionEnd
  66.             };
  67.         }
  68.         else if (el.createTextRange) {
  69.             var sel = document.selection.createRange();
  70.             if (sel.parentElement() === el) {
  71.                 var range = el.createTextRange();
  72.                 range.moveToBookmark(sel.getBookmark());
  73.                 for (var len = 0;
  74.                     range.compareEndPoints("EndToStart", range) > 0;
  75.                     range.moveEnd("character", -1)) {
  76.                     len++;
  77.                 }
  78.                 range.setEndPoint("StartToStart", el.createTextRange());
  79.                 for (var pos = { start: 0, end: len };
  80.                     range.compareEndPoints("EndToStart", range) > 0;
  81.                     range.moveEnd("character", -1)) {
  82.                     pos.start++;
  83.                     pos.end++;
  84.                 }
  85.                 return pos;
  86.             }
  87.         }
  88.         return -1;
  89.     }
  90.  
  91.     /* set caret position within input box */
  92.     function setCaretPosition(el, pos) {
  93.         if (el.setSelectionRange) {
  94.             el.focus();
  95.             el.setSelectionRange(pos, pos);
  96.         }
  97.         else if (el.createTextRange) {
  98.             var range = el.createTextRange();
  99.             range.collapse(true);
  100.             range.moveEnd('character', pos);
  101.             range.moveStart('character', pos);
  102.             range.select();
  103.         }
  104.     }
  105.  
  106.     function replaceConversionInElement(activeEl, start, end) {
  107.         var fullText = activeEl.value;
  108.         var textToConvert = fullText.substring(start, end);
  109.         var before = fullText.substring(0, start);
  110.         var after = fullText.substring(end, fullText.length);
  111.         // convert selection
  112.         var convertedText = convert(textToConvert);
  113.         // overwrite text
  114.         activeEl.value = before + convertedText + after
  115.         // set cursor to be at end of selection
  116.         setCaretPosition(activeEl, before.length + convertedText.length);
  117.     }
  118.  
  119.     /* convert hilighted text in active element */
  120.     function convertSelection(activeEl) {
  121.         var caretRange = getCaretPosition(activeEl);
  122.         var selStart = caretRange.start;
  123.         var selEnd = caretRange.end;
  124.         /* if selection is empty, find word at caret */
  125.         if (selStart == selEnd) {
  126.             var fullText = activeEl.value;
  127.             // Find beginning and end of word
  128.             var left = fullText.slice(0, selStart + 1).search(/\S+$/);
  129.             var right = fullText.slice(selStart).search(/(\s|$)/);
  130.             /* convert the word at the caret selection */
  131.             replaceConversionInElement(activeEl, left, right + selStart)
  132.         }
  133.         /* else convert the selection */
  134.         else {
  135.             replaceConversionInElement(activeEl, selStart, selEnd);
  136.         }
  137.     }
  138.  
  139.     /* detect ALT+X keyboard shortcut */
  140.     async function enableLaTeXShortcuts(event) {
  141.         if (event.altKey && event.keyCode == 88) { // ALT+X
  142.             // load dictionary when first pressed
  143.             if (!dictLoaded) {
  144.                 await loadAsset(dictionarySource, loaded);
  145.             }
  146.             // convert selection
  147.             var activeEl = document.activeElement;
  148.             var activeElTag = activeEl.tagName.toLowerCase();
  149.             if (activeElTag == "textarea" || activeElTag == "input") {
  150.                 convertSelection(activeEl);
  151.             }
  152.         }
  153.     }
  154.  
  155.     document.addEventListener('keydown', enableLaTeXShortcuts, false);
  156.  
  157. })();