Spellcheck - first try to fix #2176

browser/lib/contextMenuBuilder.js

@@ -0,0 +1,65 @@
+const {remote} = require('electron')
+const {Menu} = remote.require('electron')
+const spellcheck = require('./spellcheck')
+
+/**
+ * Creates the context menu that is shown when there is a right click in the editor of a (not-snippet) note.
+ * If the word is does not contains a spelling error (determined by the 'error style'), no suggestions for corrections are requested
+ * => they are not visible in the context menu
+ * @param editor CodeMirror editor
+ * @param {MouseEvent} event that has triggered the creation of the context menu
+ * @returns {Electron.Menu} The created electron context menu
+ */
+const buildEditorContextMenu = function (editor, event) {
+  if (editor == null || event == null || event.pageX == null || event.pageY == null) {
+    return null
+  }
+  const cursor = editor.coordsChar({left: event.pageX, top: event.pageY})
+  const wordRange = editor.findWordAt(cursor)
+  const word = editor.getRange(wordRange.anchor, wordRange.head)
+  const existingMarks = editor.findMarks(wordRange.anchor, wordRange.head) || []
+  let isMisspelled = false
+  for (const mark of existingMarks) {
+    if (mark.className === spellcheck.getCSSClassName()) {
+      isMisspelled = true
+      break
+    }
+  }
+  let suggestion = []
+  if (isMisspelled) {
+    suggestion = spellcheck.getSpellingSuggestion(word)
+  }
+
+  const selection = {
+    isMisspelled: isMisspelled,
+    spellingSuggestions: suggestion
+  }
+  const template = [{
+    role: 'cut'
+  }, {
+    role: 'copy'
+  }, {
+    role: 'paste'
+  }, {
+    role: 'selectall'
+  }]
+
+  if (selection.isMisspelled) {
+    const suggestions = selection.spellingSuggestions
+    template.unshift.apply(template, suggestions.map(function (suggestion) {
+      return {
+        label: suggestion,
+        click: function (suggestion) {
+          if (editor != null) {
+            editor.replaceRange(suggestion.label, wordRange.anchor, wordRange.head)
+          }
+        }
+      }
+    }).concat({
+      type: 'separator'
+    }))
+  }
+  return Menu.buildFromTemplate(template)
+}
+
+module.exports = buildEditorContextMenu

browser/lib/spellcheck.js

@@ -0,0 +1,229 @@
+import styles from '../components/CodeEditor.styl'
+import i18n from 'browser/lib/i18n'
+
+const Typo = require('typo-js')
+const _ = require('lodash')
+
+const CSS_ERROR_CLASS = 'codeEditor-typo'
+const SPELLCHECK_DISABLED = 'NONE'
+const DICTIONARY_PATH = '../dictionaries'
+const MILLISECONDS_TILL_LIVECHECK = 500
+
+let dictionary = null
+let self
+
+function getAvailableDictionaries () {
+  return [
+    {label: i18n.__('Disabled'), value: SPELLCHECK_DISABLED},
+    {label: i18n.__('English'), value: 'en_GB'},
+    {label: i18n.__('German'), value: 'de_DE'},
+    {label: i18n.__('French'), value: 'fr_FR'}
+  ]
+}
+
+/**
+ * Only to be used in the tests :)
+ */
+function setDictionaryForTestsOnly (newDictionary) {
+  dictionary = newDictionary
+}
+
+/**
+ * @description Initializes the spellcheck. It removes all existing marks of the current editor.
+ * If a language was given (i.e. lang !== this.SPELLCHECK_DISABLED) it will load the stated dictionary and use it to check the whole document.
+ * @param {Codemirror} editor CodeMirror-Editor
+ * @param {String} lang on of the values from getAvailableDictionaries()-Method
+ */
+function setLanguage (editor, lang) {
+  self = this
+  dictionary = null
+
+  if (editor == null) {
+    return
+  }
+
+  const existingMarks = editor.getAllMarks() || []
+  for (const mark of existingMarks) {
+    mark.clear()
+  }
+  if (lang !== SPELLCHECK_DISABLED) {
+    dictionary = new Typo(lang, false, false, {
+      dictionaryPath: DICTIONARY_PATH,
+      asyncLoad: true,
+      loadedCallback: () =>
+        checkWholeDocument(editor)
+    })
+  }
+}
+
+/**
+ * Checks the whole content of the editor for typos
+ * @param {Codemirror} editor CodeMirror-Editor
+ */
+function checkWholeDocument (editor) {
+  const lastLine = editor.lineCount() - 1
+  const textOfLastLine = editor.getLine(lastLine) || ''
+  const lastChar = textOfLastLine.length
+  const from = {line: 0, ch: 0}
+  const to = {line: lastLine, ch: lastChar}
+  checkMultiLineRange(editor, from, to)
+}
+
+/**
+ * Checks the given range for typos
+ * @param {Codemirror} editor CodeMirror-Editor
+ * @param {line, ch} from starting position of the spellcheck
+ * @param {line, ch} to end position of the spellcheck
+ */
+function checkMultiLineRange (editor, from, to) {
+  function sortRange (pos1, pos2) {
+    if (pos1.line > pos2.line || (pos1.line === pos2.line && pos1.ch > pos2.ch)) {
+      return {from: pos2, to: pos1}
+    }
+    return {from: pos1, to: pos2}
+  }
+
+  const {from: smallerPos, to: higherPos} = sortRange(from, to)
+  for (let l = smallerPos.line; l <= higherPos.line; l++) {
+    const line = editor.getLine(l) || ''
+    let w = 0
+    if (l === smallerPos.line) {
+      w = smallerPos.ch
+    }
+    let wEnd = line.length
+    if (l === higherPos.line) {
+      wEnd = higherPos.ch
+    }
+    while (w <= wEnd) {
+      const wordRange = editor.findWordAt({line: l, ch: w})
+      self.checkWord(editor, wordRange)
+      w += (wordRange.head.ch - wordRange.anchor.ch) + 1
+    }
+  }
+}
+
+/**
+ * @description Checks whether a certain range of characters in the editor (i.e. a word) contains a typo.
+ * If so the ranged will be marked with the class CSS_ERROR_CLASS.
+ * Note: Due to performance considerations, only words with more then 3 signs are checked.
+ * @param {Codemirror} editor CodeMirror-Editor
+ * @param wordRange Object specifying the range that should be checked.
+ * Having the following structure: <code>{anchor: {line: integer, ch: integer}, head: {line: integer, ch: integer}}</code>
+ */
+function checkWord (editor, wordRange) {
+  const word = editor.getRange(wordRange.anchor, wordRange.head)
+  if (word == null || word.length <= 3) {
+    return
+  }
+  if (!dictionary.check(word)) {
+    editor.markText(wordRange.anchor, wordRange.head, {className: styles[CSS_ERROR_CLASS]})
+  }
+}
+
+/**
+ * Checks the changes recently made (aka live check)
+ * @param {Codemirror} editor CodeMirror-Editor
+ * @param fromChangeObject codeMirror changeObject describing the start of the editing
+ * @param toChangeObject codeMirror changeObject describing the end of the editing
+ */
+function checkChangeRange (editor, fromChangeObject, toChangeObject) {
+  /**
+   * Calculate the smallest respectively largest position as a start, resp. end, position and return it
+   * @param start CodeMirror change object
+   * @param end CodeMirror change object
+   * @returns {{start: {line: *, ch: *}, end: {line: *, ch: *}}}
+   */
+  function getStartAndEnd (start, end) {
+    const possiblePositions = [start.from, start.to, end.from, end.to]
+    let smallest = start.from
+    let biggest = end.to
+    for (const currentPos of possiblePositions) {
+      if (currentPos.line < smallest.line || (currentPos.line === smallest.line && currentPos.ch < smallest.ch)) {
+        smallest = currentPos
+      }
+      if (currentPos.line > biggest.line || (currentPos.line === biggest.line && currentPos.ch > biggest.ch)) {
+        biggest = currentPos
+      }
+    }
+    return {start: smallest, end: biggest}
+  }
+
+  if (dictionary === null || editor == null) { return }
+
+  try {
+    const {start, end} = getStartAndEnd(fromChangeObject, toChangeObject)
+
+    // Expand the range to include words after/before whitespaces
+    start.ch = Math.max(start.ch - 1, 0)
+    end.ch = end.ch + 1
+
+    // clean existing marks
+    const existingMarks = editor.findMarks(start, end) || []
+    for (const mark of existingMarks) {
+      mark.clear()
+    }
+
+    self.checkMultiLineRange(editor, start, end)
+  } catch (e) {
+    console.info('Error during the spell check. It might be due to problems figuring out the range of the new text..', e)
+  }
+}
+
+function saveLiveSpellCheckFrom (changeObject) {
+  liveSpellCheckFrom = changeObject
+}
+let liveSpellCheckFrom
+const debouncedSpellCheckLeading = _.debounce(saveLiveSpellCheckFrom, MILLISECONDS_TILL_LIVECHECK, {
+  'leading': true,
+  'trailing': false
+})
+const debouncedSpellCheck = _.debounce(checkChangeRange, MILLISECONDS_TILL_LIVECHECK, {
+  'leading': false,
+  'trailing': true
+})
+
+/**
+ * Handles a keystroke. Buffers the input and performs a live spell check after a certain time. Uses _debounce from lodash to buffer the input
+ * @param {Codemirror} editor CodeMirror-Editor
+ * @param changeObject codeMirror changeObject
+ */
+function handleChange (editor, changeObject) {
+  debouncedSpellCheckLeading(changeObject)
+  debouncedSpellCheck(editor, liveSpellCheckFrom, changeObject)
+}
+
+/**
+ * Returns an array of spelling suggestions for the given (wrong written) word.
+ * Returns an empty array if the dictionary is null (=> spellcheck is disabled) or the given word was null
+ * @param word word to be checked
+ * @returns {String[]} Array of suggestions
+ */
+function getSpellingSuggestion (word) {
+  if (dictionary == null || word == null) {
+    return []
+  }
+  return dictionary.suggest(word)
+}
+
+/**
+ * Returns the name of the CSS class used for errors
+ */
+function getCSSClassName () {
+  return styles[CSS_ERROR_CLASS]
+}
+
+module.exports = {
+  DICTIONARY_PATH,
+  CSS_ERROR_CLASS,
+  SPELLCHECK_DISABLED,
+  getAvailableDictionaries,
+  setLanguage,
+  checkChangeRange,
+  handleChange,
+  getSpellingSuggestion,
+  checkWord,
+  checkMultiLineRange,
+  checkWholeDocument,
+  setDictionaryForTestsOnly,
+  getCSSClassName
+}