Function isReadOnly

static/editor.md/lib/codemirror/lib/codemirror.js:1070–1072

(cm)

  }

  function isReadOnly(cm) {
    return cm.options.readOnly || cm.doc.cantEdit;
  }

  // This will be set to an array of strings when copying, so that,
  // when pasting, we know what kind of selections the copied text