Revert "Merge branch 'mh/editor-indents' into 'master'"revert-editor-indents

This reverts commit 28f2225bdfee4d353f07a766c6c8b29ba6181397, reversing
changes made to 96ae5bd83da31350e9856a290127d7aa1469710a.

7 files changed, 19 insertions, 472 deletions

diff --git a/app/assets/javascripts/commons/polyfills.js b/app/assets/javascripts/commons/polyfills.js
index daa941a63cd..7a6ad3dc771 100644
--- a/app/assets/javascripts/commons/polyfills.js
+++ b/app/assets/javascripts/commons/polyfills.js
@@ -12,7 +12,6 @@ import 'core-js/es/promise/finally';
 import 'core-js/es/string/code-point-at';
 import 'core-js/es/string/from-code-point';
 import 'core-js/es/string/includes';
-import 'core-js/es/string/repeat';
 import 'core-js/es/string/starts-with';
 import 'core-js/es/string/ends-with';
 import 'core-js/es/symbol';
diff --git a/app/assets/javascripts/gl_form.js b/app/assets/javascripts/gl_form.js
index b98fe9f6ce2..a66555838ba 100644
--- a/app/assets/javascripts/gl_form.js
+++ b/app/assets/javascripts/gl_form.js
@@ -3,16 +3,9 @@ import autosize from 'autosize';
 import GfmAutoComplete, { defaultAutocompleteConfig } from 'ee_else_ce/gfm_auto_complete';
 import dropzoneInput from './dropzone_input';
 import { addMarkdownListeners, removeMarkdownListeners } from './lib/utils/text_markdown';
-import IndentHelper from './helpers/indent_helper';
-import { keystroke } from './lib/utils/common_utils';
-import * as keys from './lib/utils/keycodes';
-import UndoStack from './lib/utils/undo_stack';
 
 export default class GLForm {
   constructor(form, enableGFM = {}) {
-    this.handleKeyShortcuts = this.handleKeyShortcuts.bind(this);
-    this.setState = this.setState.bind(this);
-
     this.form = form;
     this.textarea = this.form.find('textarea.js-gfm-input');
     this.enableGFM = Object.assign({}, defaultAutocompleteConfig, enableGFM);
@@ -23,10 +16,6 @@ export default class GLForm {
         this.enableGFM[item] = Boolean(dataSources[item]);
       }
     });
-
-    this.undoStack = new UndoStack();
-    this.indentHelper = new IndentHelper(this.textarea[0]);
-
     // Before we start, we should clean up any previous data for this form
     this.destroy();
     // Set up the form
@@ -96,84 +85,9 @@ export default class GLForm {
   clearEventListeners() {
     this.textarea.off('focus');
     this.textarea.off('blur');
-    this.textarea.off('keydown');
     removeMarkdownListeners(this.form);
   }
 
-  setState(state) {
-    const selection = [this.textarea[0].selectionStart, this.textarea[0].selectionEnd];
-    this.textarea.val(state);
-    this.textarea[0].setSelectionRange(selection[0], selection[1]);
-  }
-
-  /*
-   Handle keypresses for a custom undo/redo stack.
-   We need this because the toolbar buttons and indentation helpers mess with the browser's
-   native undo/redo capability.
-   */
-  handleUndo(event) {
-    const content = this.textarea.val();
-    const { selectionStart, selectionEnd } = this.textarea[0];
-    const stack = this.undoStack;
-
-    if (stack.isEmpty()) {
-      // ==== Save initial state in undo history ====
-      stack.save(content);
-    }
-
-    if (keystroke(event, keys.Z_KEY_CODE, 'l')) {
-      // ==== Undo ====
-      event.preventDefault();
-      stack.save(content);
-      if (stack.canUndo()) {
-        this.setState(stack.undo());
-      }
-    } else if (keystroke(event, keys.Z_KEY_CODE, 'ls') || keystroke(event, keys.Y_KEY_CODE, 'l')) {
-      // ==== Redo ====
-      event.preventDefault();
-      if (stack.canRedo()) {
-        this.setState(stack.redo());
-      }
-    } else if (
-      keystroke(event, keys.SPACE_KEY_CODE) ||
-      keystroke(event, keys.ENTER_KEY_CODE) ||
-      selectionStart !== selectionEnd
-    ) {
-      // ==== Save after finishing a word or before deleting a large selection ====
-      stack.save(content);
-    } else if (content === '') {
-      // ==== Save after deleting everything ====
-      stack.save('');
-    } else {
-      // ==== Save after 1 second of inactivity ====
-      stack.scheduleSave(content);
-    }
-  }
-
-  handleIndent(event) {
-    if (keystroke(event, keys.LEFT_BRACKET_KEY_CODE, 'l')) {
-      // ==== Unindent selected lines ====
-      event.preventDefault();
-      this.indentHelper.unindent();
-    } else if (keystroke(event, keys.RIGHT_BRACKET_KEY_CODE, 'l')) {
-      // ==== Indent selected lines ====
-      event.preventDefault();
-      this.indentHelper.indent();
-    } else if (keystroke(event, keys.ENTER_KEY_CODE)) {
-      // ==== Auto-indent new lines ====
-      event.preventDefault();
-      this.indentHelper.newline();
-    } else if (keystroke(event, keys.BACKSPACE_KEY_CODE)) {
-      // ==== Auto-delete indents at the beginning of the line ====
-      this.indentHelper.backspace(event);
-    }
-  }
-
-  handleKeyShortcuts(event) {
-    this.handleIndent(event);
-    this.handleUndo(event);
-  }
-
   addEventListeners() {
     this.textarea.on('focus', function focusTextArea() {
       $(this)
@@ -185,6 +99,5 @@ export default class GLForm {
         .closest('.md-area')
         .removeClass('is-focused');
     });
-    this.textarea.on('keydown', e => this.handleKeyShortcuts(e.originalEvent));
   }
 }
diff --git a/app/assets/javascripts/helpers/indent_helper.js b/app/assets/javascripts/helpers/indent_helper.js
deleted file mode 100644
index a8815fac04e..00000000000
--- a/app/assets/javascripts/helpers/indent_helper.js
+++ /dev/null
@@ -1,182 +0,0 @@
-const INDENT_SEQUENCE = '    ';
-
-function countLeftSpaces(text) {
-  const i = text.split('').findIndex(c => c !== ' ');
-  return i === -1 ? text.length : i;
-}
-
-/**
- * IndentHelper provides methods that allow manual and smart indentation in
- * textareas. It supports line indent/unindent, selection indent/unindent,
- * auto indentation on newlines, and smart deletion of indents with backspace.
- */
-export default class IndentHelper {
-  /**
-   * Creates a new IndentHelper and binds it to the given `textarea`. You can provide a custom indent sequence in the second parameter, but the `newline` and `backspace` operations may work funny if the indent sequence isn't spaces only.
-   */
-  constructor(textarea, indentSequence = INDENT_SEQUENCE) {
-    this.element = textarea;
-    this.seq = indentSequence;
-  }
-
-  getSelection() {
-    return { start: this.element.selectionStart, end: this.element.selectionEnd };
-  }
-
-  isRangeSelection() {
-    return this.element.selectionStart !== this.element.selectionEnd;
-  }
-
-  /**
-   * Re-implementation of textarea's setRangeText method, because IE/Edge don't support it.
-   *
-   * @see https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#dom-textarea%2Finput-setrangetext
-   */
-  setRangeText(replacement, start, end, selectMode) {
-    // Disable eslint to remain as faithful as possible to the above linked spec
-    /* eslint-disable no-param-reassign, no-case-declarations */
-    const text = this.element.value;
-
-    if (start > end) {
-      throw new RangeError('setRangeText: start index must be less than or equal to end index');
-    }
-
-    // Clamp to [0, len]
-    start = Math.max(0, Math.min(start, text.length));
-    end = Math.max(0, Math.min(end, text.length));
-
-    let selection = { start: this.element.selectionStart, end: this.element.selectionEnd };
-
-    this.element.value = text.slice(0, start) + replacement + text.slice(end);
-
-    const newLength = replacement.length;
-    const newEnd = start + newLength;
-
-    switch (selectMode) {
-      case 'select':
-        selection = { start, newEnd };
-        break;
-      case 'start':
-        selection = { start, end: start };
-        break;
-      case 'end':
-        selection = { start: newEnd, end: newEnd };
-        break;
-      case 'preserve':
-      default:
-        const oldLength = end - start;
-        const delta = newLength - oldLength;
-        if (selection.start > end) {
-          selection.start += delta;
-        } else if (selection.start > start) {
-          selection.start = start;
-        }
-        if (selection.end > end) {
-          selection.end += delta;
-        } else if (selection.end > start) {
-          selection.end = newEnd;
-        }
-    }
-
-    this.element.setSelectionRange(selection.start, selection.end);
-
-    /* eslint-enable no-param-reassign, no-case-declarations */
-  }
-
-  /**
-   * Returns an array of lines in the textarea, with information about their
-   * start/end offsets and whether they are included in the current selection.
-   */
-  splitLines() {
-    const { start, end } = this.getSelection();
-
-    const lines = this.element.value.split('\n');
-    let textStart = 0;
-    const lineObjects = [];
-    lines.forEach(line => {
-      const lineObj = {
-        text: line,
-        start: textStart,
-        end: textStart + line.length,
-      };
-      lineObj.inSelection = lineObj.start <= end && lineObj.end >= start;
-      lineObjects.push(lineObj);
-      textStart += line.length + 1;
-    });
-    return lineObjects;
-  }
-
-  /**
-   * Indents selected lines by one level.
-   */
-  indent() {
-    const { start } = this.getSelection();
-
-    const selectedLines = this.splitLines().filter(line => line.inSelection);
-    if (!this.isRangeSelection() && start === selectedLines[0].start) {
-      // Special case: if cursor is at the beginning of the line, move it one
-      // indent right.
-      const line = selectedLines[0];
-      this.setRangeText(this.seq, line.start, line.start, 'end');
-    } else {
-      selectedLines.reverse();
-      selectedLines.forEach(line => {
-        this.setRangeText(INDENT_SEQUENCE, line.start, line.start, 'preserve');
-      });
-    }
-  }
-
-  /**
-   * Unindents selected lines by one level.
-   */
-  unindent() {
-    const lines = this.splitLines().filter(line => line.inSelection);
-    lines.reverse();
-    lines
-      .filter(line => line.text.startsWith(this.seq))
-      .forEach(line => {
-        this.setRangeText('', line.start, line.start + this.seq.length, 'preserve');
-      });
-  }
-
-  /**
-   * Emulates a newline keypress, automatically indenting the new line.
-   */
-  newline() {
-    const { start, end } = this.getSelection();
-
-    if (this.isRangeSelection()) {
-      // Manually kill the selection before calculating the indent
-      this.setRangeText('', start, end, 'start');
-    }
-
-    // Auto-indent the next line
-    const currentLine = this.splitLines().find(line => line.end >= start);
-    const spaces = countLeftSpaces(currentLine.text);
-    this.setRangeText(`\n${' '.repeat(spaces)}`, start, start, 'end');
-  }
-
-  /**
-   * If the cursor is positioned at the end of a line's leading indents,
-   * emulates a backspace keypress by deleting a single level of indents.
-   * @param event The DOM KeyboardEvent that triggers this action, or null.
-   */
-  backspace(event) {
-    const { start } = this.getSelection();
-
-    // If the cursor is at the end of leading indents, delete an indent.
-    if (!this.isRangeSelection()) {
-      const currentLine = this.splitLines().find(line => line.end >= start);
-      const cursorPosition = start - currentLine.start;
-      if (countLeftSpaces(currentLine.text) === cursorPosition && cursorPosition > 0) {
-        if (event) event.preventDefault();
-
-        let spacesToDelete = cursorPosition % this.seq.length;
-        if (spacesToDelete === 0) {
-          spacesToDelete = this.seq.length;
-        }
-        this.setRangeText('', start - spacesToDelete, start, 'start');
-      }
-    }
-  }
-}
diff --git a/app/assets/javascripts/lib/utils/common_utils.js b/app/assets/javascripts/lib/utils/common_utils.js
index 1a94aee2398..5e90893b684 100644
--- a/app/assets/javascripts/lib/utils/common_utils.js
+++ b/app/assets/javascripts/lib/utils/common_utils.js
@@ -203,71 +203,6 @@ export const isMetaKey = e => e.metaKey || e.ctrlKey || e.altKey || e.shiftKey;
 // 3) Middle-click or Mouse Wheel Click (e.which is 2)
 export const isMetaClick = e => e.metaKey || e.ctrlKey || e.which === 2;
 
-export const getPlatformLeaderKey = () => {
-  // eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings
-  if (navigator && navigator.platform && navigator.platform.startsWith('Mac')) {
-    return 'meta';
-  }
-  return 'ctrl';
-};
-
-export const getPlatformLeaderKeyHTML = () => {
-  if (getPlatformLeaderKey() === 'meta') {
-    return '&#8984;';
-  }
-  // eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings
-  return 'Ctrl';
-};
-
-export const isPlatformLeaderKey = e => {
-  if (getPlatformLeaderKey() === 'meta') {
-    return Boolean(e.metaKey);
-  }
-  return Boolean(e.ctrlKey);
-};
-
-/**
- * Tests if a KeyboardEvent corresponds exactly to a keystroke.
- *
- * This function avoids hacking around an old version of Mousetrap, which we ship at the moment. It should be removed after we upgrade to the newest Mousetrap. See:
- * - https://gitlab.com/gitlab-org/gitlab-ce/issues/63182
- * - https://gitlab.com/gitlab-org/gitlab-ce/issues/64246
- *
- * @example
- *     // Matches the enter key with exactly zero modifiers
- *     keystroke(event, 13)
- *
- * @example
- *     // Matches Control-Shift-Z
- *     keystroke(event, 90, 'cs')
- *
- * @param e The KeyboardEvent to test.
- * @param keyCode The key code of the key to test. Why keycodes? IE/Edge don't support the more convenient `key` and `code` properties.
- * @param modifiers A string of modifiers keys. Each modifier key is represented by one character. The set of pressed modifier keys must match the given string exactly. Available options are 'a' for Alt/Option, 'c' for Control, 'm' for Meta/Command, 's' for Shift, and 'l' for the leader key (Meta on MacOS and Control otherwise).
- * @returns {boolean} True if the KeyboardEvent corresponds to the given keystroke.
- */
-export const keystroke = (e, keyCode, modifiers = '') => {
-  if (!e || !keyCode) {
-    return false;
-  }
-
-  const leader = getPlatformLeaderKey();
-  const mods = modifiers.toLowerCase().replace('l', leader.charAt(0));
-
-  // Match depressed modifier keys
-  if (
-    e.altKey !== mods.includes('a') ||
-    e.ctrlKey !== mods.includes('c') ||
-    e.metaKey !== mods.includes('m') ||
-    e.shiftKey !== mods.includes('s')
-  ) {
-    return false;
-  }
-
-  // Match the depressed key
-  return keyCode === (e.keyCode || e.which);
-};
-
 export const contentTop = () => {
   const perfBar = $('#js-peek').outerHeight() || 0;
   const mrTabsHeight = $('.merge-request-tabs').outerHeight() || 0;
diff --git a/app/assets/javascripts/lib/utils/keycodes.js b/app/assets/javascripts/lib/utils/keycodes.js
index e24fcf47d71..5e0f9b612a2 100644
--- a/app/assets/javascripts/lib/utils/keycodes.js
+++ b/app/assets/javascripts/lib/utils/keycodes.js
@@ -1,10 +1,4 @@
-export const BACKSPACE_KEY_CODE = 8;
-export const ENTER_KEY_CODE = 13;
-export const ESC_KEY_CODE = 27;
-export const SPACE_KEY_CODE = 32;
 export const UP_KEY_CODE = 38;
 export const DOWN_KEY_CODE = 40;
-export const Y_KEY_CODE = 89;
-export const Z_KEY_CODE = 90;
-export const LEFT_BRACKET_KEY_CODE = 219;
-export const RIGHT_BRACKET_KEY_CODE = 221;
+export const ENTER_KEY_CODE = 13;
+export const ESC_KEY_CODE = 27;
diff --git a/app/assets/javascripts/lib/utils/undo_stack.js b/app/assets/javascripts/lib/utils/undo_stack.js
deleted file mode 100644
index 6cfdc2a0a0f..00000000000
--- a/app/assets/javascripts/lib/utils/undo_stack.js
+++ /dev/null
@@ -1,105 +0,0 @@
-/**
- * UndoStack provides a custom implementation of an undo/redo engine. It was originally written for GitLab's Markdown editor (`gl_form.js`), whose rich text editing capabilities broke native browser undo/redo behaviour.
- *
- * UndoStack supports predictable undos/redos, debounced saves, maximum history length, and duplicate detection.
- *
- * Usage:
- *   - `stack = new UndoStack();`
- *   - Saves a state to the stack with `stack.save(state)`.
- *   - Get the current state with `stack.current()`.
- *   - Revert to the previous state with `stack.undo()`.
- *   - Redo a previous undo with `stack.redo()`;
- *   - Queue a future save with `stack.scheduleSave(state, delay)`. Useful for text editors.
- *   - See the full undo history in `stack.history`.
- */
-export default class UndoStack {
-  constructor(maxLength = 1000) {
-    this.clear();
-    this.maxLength = maxLength;
-
-    // If you're storing reference-types in the undo stack, you might want to
-    // reassign this property to some deep-equals function.
-    this.comparator = (a, b) => a === b;
-  }
-
-  current() {
-    if (this.cursor === -1) {
-      return undefined;
-    }
-    return this.history[this.cursor];
-  }
-
-  isEmpty() {
-    return this.history.length === 0;
-  }
-
-  clear() {
-    this.clearPending();
-    this.history = [];
-    this.cursor = -1;
-  }
-
-  save(state) {
-    this.clearPending();
-    if (this.comparator(state, this.current())) {
-      // Don't save state if it's the same as the current state
-      return;
-    }
-
-    this.history.length = this.cursor + 1;
-    this.history.push(state);
-    this.cursor += 1;
-
-    if (this.history.length > this.maxLength) {
-      this.history.shift();
-      this.cursor -= 1;
-    }
-  }
-
-  scheduleSave(state, delay = 1000) {
-    this.clearPending();
-    this.pendingState = state;
-    this.timeout = setTimeout(this.saveNow.bind(this), delay);
-  }
-
-  saveNow() {
-    // Persists scheduled saves immediately
-    this.save(this.pendingState);
-    this.clearPending();
-  }
-
-  clearPending() {
-    // Cancels any scheduled saves
-    if (this.timeout) {
-      clearTimeout(this.timeout);
-      delete this.timeout;
-      delete this.pendingState;
-    }
-  }
-
-  canUndo() {
-    return this.cursor > 0;
-  }
-
-  undo() {
-    this.clearPending();
-    if (!this.canUndo()) {
-      return undefined;
-    }
-    this.cursor -= 1;
-    return this.history[this.cursor];
-  }
-
-  canRedo() {
-    return this.cursor >= 0 && this.cursor < this.history.length - 1;
-  }
-
-  redo() {
-    this.clearPending();
-    if (!this.canRedo()) {
-      return undefined;
-    }
-    this.cursor += 1;
-    return this.history[this.cursor];
-  }
-}
diff --git a/app/assets/javascripts/vue_shared/components/markdown/toolbar.vue b/app/assets/javascripts/vue_shared/components/markdown/toolbar.vue
index 21c44b59520..8ce5b615795 100644
--- a/app/assets/javascripts/vue_shared/components/markdown/toolbar.vue
+++ b/app/assets/javascripts/vue_shared/components/markdown/toolbar.vue
@@ -1,6 +1,5 @@
 <script>
 import { GlLink } from '@gitlab/ui';
-import { s__, sprintf } from '~/locale';
 
 export default {
   components: {
@@ -23,28 +22,8 @@ export default {
     },
   },
   computed: {
-    toolbarHelpHtml() {
-      const mdLinkStart = `<a href="${this.markdownDocsPath}" target="_blank" rel="noopener noreferrer" tabindex="-1">`;
-      const actionsLinkStart = `<a href="${this.quickActionsDocsPath}" target="_blank" rel="noopener noreferrer" tabindex="-1">`;
-      const linkEnd = '</a>';
-
-      if (this.markdownDocsPath && !this.quickActionsDocsPath) {
-        return sprintf(
-          s__('Editor|%{mdLinkStart}Markdown is supported%{mdLinkEnd}'),
-          { mdLinkStart, mdLinkEnd: linkEnd },
-          false,
-        );
-      } else if (this.markdownDocsPath && this.quickActionsDocsPath) {
-        return sprintf(
-          s__(
-            'Editor|%{mdLinkStart}Markdown%{mdLinkEnd} and %{actionsLinkStart}quick actions%{actionsLinkEnd} are supported',
-          ),
-          { mdLinkStart, mdLinkEnd: linkEnd, actionsLinkStart, actionsLinkEnd: linkEnd },
-          false,
-        );
-      }
-
-      return null;
+    hasQuickActionsDocsPath() {
+      return this.quickActionsDocsPath !== '';
     },
   },
 };
@@ -53,7 +32,21 @@ export default {
 <template>
   <div class="comment-toolbar clearfix">
     <div class="toolbar-text">
-      <span v-html="toolbarHelpHtml"></span>
+      <template v-if="!hasQuickActionsDocsPath && markdownDocsPath">
+        <gl-link :href="markdownDocsPath" target="_blank" tabindex="-1">{{
+          __('Markdown is supported')
+        }}</gl-link>
+      </template>
+      <template v-if="hasQuickActionsDocsPath && markdownDocsPath">
+        <gl-link :href="markdownDocsPath" target="_blank" tabindex="-1">{{
+          __('Markdown')
+        }}</gl-link>
+        and
+        <gl-link :href="quickActionsDocsPath" target="_blank" tabindex="-1">{{
+          __('quick actions')
+        }}</gl-link>
+        are supported
+      </template>
     </div>
     <span v-if="canAttachFile" class="uploading-container">
       <span class="uploading-progress-container hide">