function editOnKeyDown()

in src/component/handlers/edit/editOnKeyDown.js [86:204]

• 84 lines of code
• 28 McCabe index (conditional complexity)

function editOnKeyDown(
  editor: DraftEditor,
  e: SyntheticKeyboardEvent<HTMLElement>,
): void {
  const keyCode = e.which;
  const editorState = editor._latestEditorState;
  function callDeprecatedHandler(
    handlerName:
      | 'onDownArrow'
      | 'onEscape'
      | 'onLeftArrow'
      | 'onRightArrow'
      | 'onTab'
      | 'onUpArrow',
  ): boolean {
    const deprecatedHandler = editor.props[handlerName];
    if (deprecatedHandler) {
      deprecatedHandler(e);
      return true;
    } else {
      return false;
    }
  }
  switch (keyCode) {
    case Keys.RETURN:
      e.preventDefault();
      // The top-level component may manually handle newline insertion. If
      // no special handling is performed, fall through to command handling.
      if (
        editor.props.handleReturn &&
        isEventHandled(editor.props.handleReturn(e, editorState))
      ) {
        return;
      }
      break;
    case Keys.ESC:
      e.preventDefault();
      if (callDeprecatedHandler('onEscape')) {
        return;
      }
      break;
    case Keys.TAB:
      if (callDeprecatedHandler('onTab')) {
        return;
      }
      break;
    case Keys.UP:
      if (callDeprecatedHandler('onUpArrow')) {
        return;
      }
      break;
    case Keys.RIGHT:
      if (callDeprecatedHandler('onRightArrow')) {
        return;
      }
      break;
    case Keys.DOWN:
      if (callDeprecatedHandler('onDownArrow')) {
        return;
      }
      break;
    case Keys.LEFT:
      if (callDeprecatedHandler('onLeftArrow')) {
        return;
      }
      break;
    case Keys.SPACE:
      // Prevent Chrome on OSX behavior where option + space scrolls.
      if (isChrome && isOptionKeyCommand(e)) {
        e.preventDefault();
      }
  }

  const command = editor.props.keyBindingFn(e);

  // If no command is specified, allow keydown event to continue.
  if (command == null || command === '') {
    if (keyCode === Keys.SPACE && isChrome && isOptionKeyCommand(e)) {
      // The default keydown event has already been prevented in order to stop
      // Chrome from scrolling. Insert a nbsp into the editor as OSX would for
      // other browsers.
      const contentState = DraftModifier.replaceText(
        editorState.getCurrentContent(),
        editorState.getSelection(),
        '\u00a0',
      );
      editor.update(
        EditorState.push(editorState, contentState, 'insert-characters'),
      );
    }
    return;
  }

  if (command === 'undo') {
    // Since undo requires some special updating behavior to keep the editor
    // in sync, handle it separately.
    keyCommandUndo(e, editorState, editor.update);
    return;
  }

  // At this point, we know that we're handling a command of some kind, so
  // we don't want to insert a character following the keydown.
  e.preventDefault();

  // Allow components higher up the tree to handle the command first.
  if (
    editor.props.handleKeyCommand &&
    isEventHandled(
      editor.props.handleKeyCommand(command, editorState, e.timeStamp),
    )
  ) {
    return;
  }

  const newState = onKeyCommand(command, editorState, e);
  if (newState !== editorState) {
    editor.update(newState);
  }
}