title: Flutter cannot select, copy or paste in EditableText
body: <p>im trying to use an Editable text widget in Flutter and i cant select, copy, cut and paste don't work with it, i don't know why this is happening I've enabled everything that is related to selecting and copy pasting, but it still doesn't work</p>
  <pre><code>    class EditProfile extends StatefulWidget {
    @override
    _EditProfileState createState() =&gt; _EditProfileState();
  }
  
  class _EditProfileState extends State&lt;EditProfile&gt; {
    var _controller = TextEditingController();
    TextSelectionControls _mainContentSelectionController;
    @override
  
  
    Widget _backButton() {
      return InkWell(
        onTap: () {
          Navigator.pop(context);
        },
        child: Container(
          padding: EdgeInsets.symmetric(horizontal: 10),
          child: Row(
            children: &lt;Widget&gt;[
              Icon(
                Icons.clear,
                size: 30.0,
                color: Color(0xff8729e6),
              )
            ],
          ),
        ),
      );
    }
  
    @override
    Widget build(BuildContext context) {
      return Scaffold(
        body: SafeArea(
          child: SingleChildScrollView(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Container(
                  color: Colors.white,
                  child: EditableText(
                    controller: _controller,
                    toolbarOptions: ToolbarOptions(
                      paste: true,
                      copy: true,
                      selectAll: true,
                    ),
                    readOnly : false,
                    focusNode:  FocusNode(),
                    cursorColor: Colors.blue,
                    style: TextStyle(
                        color: Colors.black
                    ),
                    keyboardType: TextInputType.text,
                    autocorrect: false,
                    autofocus: false,
                    backgroundCursorColor: Colors.red,
                    maxLines: 10,
                    minLines: 1,
                    enableInteractiveSelection: true,
                    selectionColor: Colors.red,
                    selectionControls: _mainContentSelectionController,
  
                  ),
                )
              ],
            )
          ),
        ),
      );
    }
  }
  </code></pre>
  <p>i hope this code is enough, please let me know if you want me to provide more code or if you have any questions, Thank you!</p>