Hi, I'm new to the flutter and looking for a way to expand a widget so that when I click on it, I get a text field that allows me to input data from the user.

So far, I've tried dynamic test fields or gesture detectors, but I couldn't find the answer I wanted, so I'm asking questions. Is there any class that I can refer to?

CodePudding user response：

You need to do few things...

create a variable

 bool textFieldDisplayed = false;

Wrap your widget with GestureDetector and use onTap of GestureDetector.

onTap: () {
        textFieldDisplayed = true;
        setState(() {});
      },

check the condition before your textField

if(textFieldDisplayed)
   TextFormField()

The whole code is below and you can make some changes as per yours....

class _MyHomePageState extends State<MyHomePage> {
  TextEditingController controller = TextEditingController();
  bool textFieldDisplayed = false;
  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: () {
        textFieldDisplayed = false;
        setState(() {});
      },
      child: Scaffold(
        body: GestureDetector(
          onTap: () {
            textFieldDisplayed = true;
            setState(() {});
          },
          child: Center(
            child: Container(
              color: Colors.blue,
              child: Column(
                mainAxisSize: MainAxisSize.min,
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  if(textFieldDisplayed)
                    Padding(
                      padding: const EdgeInsets.all(10.0),
                      child: SizedBox(
                        width: 100,
                        child: TextFormField(
                          decoration: InputDecoration(
                            enabledBorder: OutlineInputBorder(
                              borderSide: const BorderSide(width: 1, color: Colors.white),
                              borderRadius: BorderRadius.circular(5.0),
                            ),
                            border: OutlineInputBorder(
                              borderSide: const BorderSide(width: 1, color: Colors.white),
                              borderRadius: BorderRadius.circular(5.0),
                            ),
                            focusedBorder: OutlineInputBorder(
                                borderSide: const BorderSide(width: 1,color: Colors.white),
                                borderRadius: BorderRadius.circular(5.0),
                            ),
                          ),
                          controller: controller,

                        ),
                      ),
                    ),
                  Container(height: 20,width: 100,)
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}

CodePudding user response：

You can achieve this using the Visibility widget. Rohan's answer is correct but I wouldn't recommend using if statements in building widgets in a list since it makes the code look messy. I'll put and example bellow:

import 'package:flutter/material.dart';

const Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MyApp());
}

class MyApp extends StatefulWidget {

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  bool showWidget = false;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark().copyWith(
        scaffoldBackgroundColor: darkBlue,
      ),
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: Column(
            children: [
              Visibility(
                visible: showWidget,
                child: MyWidget()
              ),
              MyButton(
                onTap: (){
                  setState((){
                    showWidget = !showWidget;
                  });
                }
              )
            ],
          ),
        ),
      ),
    );
  }
}

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Text(
      'Hello, World!',
      style: Theme.of(context).textTheme.headline4,
    );
  }
}

class MyButton extends StatelessWidget {

  final Function() onTap;
  const MyButton({required this.onTap});

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: onTap,
      child: const Text('Press me!')
    );
  }
}

When visibility's value is true, it will display the content of its child property. Otherwise it will return a const SizedBox.shrink() by default. Or, you can change whatever widget you want to return adding the 'replacement' property.

Copy the code above and try on a new DartPad. Good Luck!