Flutter Dynamic Height of Widget in Row

Question

How I can expand a height of a Widget dynamically to a parent widget.

Specially in my example I want to expand the red bar to parent widgets. My text can be changed to x lines.

Current code:

import 'package:flutter/material.dart';

class ExampleView extends StatelessWidget {
  final String title;

  const ExampleView({Key key, this.onTap, this.title}) : super(key: key);

  final text = 'Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et';

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.only(left: 40),
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      color: Colors.grey[200],
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Container(
            margin: const EdgeInsets.only(right: 12, top: 4, bottom: 4),
            width: 6,
            height: 80, // FIXME: Dynamic
            color: Colors.red,
          ),
          Expanded(
            child: Text(text),
          )
        ],
      ),
    );
  }
}

Current solution:

Desired solution:

Thank you in advance for your help!

Answer 1

You can copy paste run full code below
You can use IntrinsicHeight
code snippet

IntrinsicHeight(
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            Container(
              margin: const EdgeInsets.only(right: 12, top: 4, bottom: 4),
              width: 6,
              color: Colors.red,
            ),

working demo

full code

import 'package:flutter/material.dart';

class ExampleView extends StatelessWidget {
  final String title;

  const ExampleView({Key key, this.title}) : super(key: key);

  final text = 'Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et';

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.only(left: 40),
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      color: Colors.grey[200],
      child: IntrinsicHeight(
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            Container(
              margin: const EdgeInsets.only(right: 12, top: 4, bottom: 4),
              width: 6,
              color: Colors.red,
            ),
            Expanded(
              child: Text(text),
            )
          ],
        ),
      ),
    );
  }
}

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

class MyApp extends StatelessWidget {  
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(       
        primarySwatch: Colors.blue,       
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      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> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {     
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {    
    return Scaffold(
      appBar: AppBar(       
        title: Text(widget.title),
      ),
      body: Center(        
        child: Column(          
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            ExampleView(),
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

Answer 2

Solution #1

In this particular case, you do not need to use Row widget. You can add your red column as a Border instead of a Container widget. The code would then look like this:

class ExampleView extends StatelessWidget {
  final String title;

  const ExampleView({Key key, this.title}) : super(key: key);

  final text =
      'Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et';

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.only(left: 40),
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      color: Colors.grey[200],
      child: Container(
        decoration: BoxDecoration(
            border: Border(left: BorderSide(width: 6, color: Colors.red))),
        margin: const EdgeInsets.only(right: 12, top: 4, bottom: 4),
        padding: const EdgeInsets.only(left: 8),
        child: Text(text),
      ),
    );
  }
}

Solution #2

Instead of a border, you can translate your child Container and wrap it with one more Container that has a gradient.

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.only(left: 40),
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      color: Colors.grey[200],
      child: Container(
        margin: const EdgeInsets.only(right: 12, top: 4, bottom: 4),
        decoration: BoxDecoration(
            gradient: LinearGradient(
          begin: Alignment.topCenter,
          end: Alignment.bottomCenter,
          colors: [
            Color.fromRGBO(255, 25, 25, 1),
            Color.fromRGBO(180, 21, 236, 1)
          ],
        )),
        child: Container(
          color: Colors.grey[200],
          transform: Matrix4.translationValues(6, 0, 0),
          padding: const EdgeInsets.only(left: 8),
          child: Text(text),
        ),
      ),
    );
  }