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TextEditingController strange behavior on the listener #64143
Description
Hi,
since the last stable 1.20.2 release, the listener of the TextEditingController has a strange behavior.
- on the first input, the listener is called twice
- when the controller is cleared, the listener is called 3 times.
- one with the empty text
- one with the previous text
- the last with the empty text again.
Steps to Reproduce
Code :
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key}) : super(key: key);
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
TextEditingController controller = TextEditingController();
@override
void initState() {
super.initState();
controller.addListener(() {
print(controller);
if (controller.selection.baseOffset > 0) {}
if (controller.text.length == 3) {
controller.clear();
}
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
TextFormField(
controller: controller,
decoration: InputDecoration(hintText: 'input'),
),
],
),
),
);
}
}Expected results on 1.17.5
I/flutter ( 3162): TextEditingController#9066a(TextEditingValue(text: ┤├, selection: TextSelection(baseOffset: 0, extentOffset: 0, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end: -1)))
I/flutter ( 3162): TextEditingController#9066a(TextEditingValue(text: ┤0├, selection: TextSelection(baseOffset: 1, extentOffset: 1, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end: -1)))
I/flutter ( 3162): TextEditingController#9066a(TextEditingValue(text: ┤00├, selection: TextSelection(baseOffset: 2, extentOffset: 2, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end: -1)))
I/flutter ( 3162): TextEditingController#9066a(TextEditingValue(text: ┤000├, selection: TextSelection(baseOffset: 3, extentOffset: 3, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end: -1)))
I/flutter ( 3162): TextEditingController#9066a(TextEditingValue(text: ┤├, selection: TextSelection(baseOffset: -1, extentOffset: -1, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end: -1)))
D/dalvikvm( 3162): GC_CONCURRENT freed 352K, 14% free 3264K/3780K, paused 2ms+0ms, total 4ms
Actual results on 1.20.2
I/flutter (25307): TextEditingController#83c21(TextEditingValue(text: ┤├, selection: TextSelection(baseOffset: 0, extentOffset: 0, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end: -1)))
I/flutter (25307): TextEditingController#83c21(TextEditingValue(text: ┤0├, selection: TextSelection(baseOffset: 1, extentOffset: 1, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: 0, end: 1)))
I/flutter (25307): TextEditingController#83c21(TextEditingValue(text: ┤0├, selection: TextSelection(baseOffset: 1, extentOffset: 1, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end: -1)))
I/flutter (25307): TextEditingController#83c21(TextEditingValue(text: ┤00├, selection: TextSelection(baseOffset: 2, extentOffset: 2, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end: -1)))
I/flutter (25307): TextEditingController#83c21(TextEditingValue(text: ┤000├, selection: TextSelection(baseOffset: 3, extentOffset: 3, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end: -1)))
I/flutter (25307): TextEditingController#83c21(TextEditingValue(text: ┤├, selection: TextSelection(baseOffset: -1, extentOffset: -1, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end: -1)))
I/flutter (25307): TextEditingController#83c21(TextEditingValue(text: ┤000├, selection: TextSelection(baseOffset: -1, extentOffset: -1, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end: -1)))
I/flutter (25307): TextEditingController#83c21(TextEditingValue(text: ┤├, selection: TextSelection(baseOffset: -1, extentOffset: -1, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end: -1)))
Activity
pedromassangocode commentedon Aug 19, 2020
I was able to reproduce part of this issue on latest master channel.
I can't reproduce this on
masterchannel. What is happening is that the first print happens when the TextFormField gains focus.This may be eventually caused because you're clearing the field inside the listener. I added a delay in the clear operation with a duration of one second and here is my output (the first line is when the field gains focus):
Note that after cleaning the field I got two prints, this may be the issue: the listener is being called multiple times when we call
controller.clear().complete sample code (with a delay before cleaning the text field)
flutter docctor -v
maheshj01 commentedon Jan 3, 2023
Reproducible on stable 3.3 and master 3.7,
Listener called on
console
flutter doctor -v (mac)
kamami commentedon May 24, 2023
Still happening in 3.10...
LuodiJackShen commentedon Dec 1, 2025
Still happening in 3.27.4