TextField Cursor Position Flutter WEB

Question

What this code does is print the position of the cursor in the text when you click on it.

  TextEditingController controller = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(
          widget.title,
        ),
      ),
      body: TextField(
        controller: controller,
        keyboardType: TextInputType.multiline,
        maxLines: null,
        onTap: () {
          int pos = controller.selection.start;
          print(
            "Position: $pos",
          );
        },
      ),
    );
  }

But the problem is that this is for web so I need it to say the position of the cursor whenever it moves not only when I tap on it. I mean if you move the cursor with the keyboard it should also print the position.

I already tried with GestureDetector and Focus and nothing. Any idea what I can use?

UPDATE: The solution I found was the following and it works perfectly, for what I need:

TextEditingController controller = TextEditingController();

int cursorPosition = 0;

@override
void initState() {
  controller.addListener(() {
    setState(() {
      cursorPosition = controller.selection.base.offset;
      print("cursorPosition: $cursorPosition");
    });
  });
  super.initState();
}

@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(
      title: Text(
        widget.title,
      ),
    ),
    body: TextField(
      controller: controller,
      keyboardType: TextInputType.multiline,
      maxLines: null,
    ),
  );
}

Full Code:

    import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  TextEditingController controller = TextEditingController();

  int cursorPosition = 0;

  @override
  void initState() {
    controller.addListener(() {
      setState(() {
        cursorPosition = controller.selection.base.offset;
        print("cursorPosition: $cursorPosition");
      });
    });
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(
          widget.title,
        ),
      ),
      body: TextField(
        controller: controller,
        keyboardType: TextInputType.multiline,
        maxLines: null,
      ),
    );
  }
}

score 0 · Answer 1 · answered Feb 19 '21 at 16:22

The solution I found was the following and it works perfectly, for what I need:

TextEditingController controller = TextEditingController();

int cursorPosition = 0;

@override
void initState() {
  controller.addListener(() {
    setState(() {
      cursorPosition = controller.selection.base.offset;
      print("cursorPosition: $cursorPosition");
    });
  });
  super.initState();
}

@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(
      title: Text(
        widget.title,
      ),
    ),
    body: TextField(
      controller: controller,
      keyboardType: TextInputType.multiline,
      maxLines: null,
    ),
  );
}

Full Code:

    import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  TextEditingController controller = TextEditingController();

  int cursorPosition = 0;

  @override
  void initState() {
    controller.addListener(() {
      setState(() {
        cursorPosition = controller.selection.base.offset;
        print("cursorPosition: $cursorPosition");
      });
    });
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(
          widget.title,
        ),
      ),
      body: TextField(
        controller: controller,
        keyboardType: TextInputType.multiline,
        maxLines: null,
      ),
    );
  }
}

score -1 · Answer 2 · answered Feb 19 '21 at 06:50

-1

onChanged: (value) {
      int pos = controller.selection.start;
      print(
        "Position: $pos",
      );
    },

answered Feb 19 '21 at 06:50

Hamza Siddiqui

675
5
12

It does not work, when you move the cursor with the keyboard it does not take it as a change so it does not print anything – PandicornGhost Feb 19 '21 at 06:59

TextField Cursor Position Flutter WEB

2 Answers2