function onKeyEventTargetKeyDown(e) {
      var macroModeState = vimGlobalState.macroModeState;
      var lastChange = macroModeState.lastInsertModeChanges;
      var keyName = CodeMirror.keyName(e);
      if (!keyName) { return; }
      function onKeyFound() {
        if (lastChange.maybeReset) {
          lastChange.changes = [];
          lastChange.maybeReset = false;
        }
        lastChange.changes.push(new InsertModeKey(keyName));
        return true;
      }
      if (keyName.indexOf('Delete') != -1 || keyName.indexOf('Backspace') != -1) {
        CodeMirror.lookupKey(keyName, 'vim-insert', onKeyFound);
      }
    }
Handles raw key down events from the text area.
- Should only be active in insert mode.
- For recording deletes in insert mode.