Flutter position stack widget in center

Question

I have widgets in a stack so I'd like to position my button bar in the bottom center of the stack but nothing works. The widget just sticks to the left side. here is my code.

new Positioned(
            bottom: 40.0,
            child: new Container(
              margin: const EdgeInsets.all(16.0),
              child: new Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[
                  new Align(
                    alignment: Alignment.bottomCenter,
                    child: new ButtonBar(
                      alignment: MainAxisAlignment.center,
                      children: <Widget>[
                        new OutlineButton(
                          onPressed: () {
                            Navigator.push(
                                context,
                                new MaterialPageRoute(
                                    builder: (context) => new LoginPage()));
                          },
                          child: new Text(
                            "Login",
                            style: new TextStyle(color: Colors.white),
                          ),
                        ),
                        new RaisedButton(
                          color: Colors.white,
                          onPressed: () {
                            Navigator.push(
                                context,
                                new MaterialPageRoute(
                                    builder: (context) =>
                                        new RegistrationPage()));
                          },
                          child: new Text(
                            "Register",
                            style: new TextStyle(color: Colors.black),
                          ),
                        )
                      ],
                    ),
                  )
                ],
              ),
            ),
          )

I have literally tried every center alignment, please help

did you try mainAxisSize: MainAxisSize.min on Column ? And by removing the Align widget — Rémi Rousselet
– Rémi Rousselet, Commented Jun 12, 2018 at 14:15
Yes i tried it @RémiRousselet , it still aligns to the left — spongyboss
– spongyboss, Commented Jun 12, 2018 at 14:42

Mehul Kabaria · Accepted Answer · 2020-04-16 07:37:23Z

462

You can use the Positioned.fill with Align inside a Stack:

Stack(
  children: <Widget>[      
    Positioned.fill(
      child: Align(
        alignment: Alignment.centerRight,
        child: ....                
      ),
    ),
  ],
),

edited Apr 16, 2020 at 7:37

Mehul Kabaria

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answered May 16, 2019 at 11:23

Yousif khalid

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2 Comments

Bernardo Ferrari Over a year ago

@JoãoAbrantes when calling Positioned.fill(), you are getting the full size (it will fill the view), then Align can do whatever it wants inside it. If you replaced the Align with a container with a red background, the stack would get all red.

Jakub S. Over a year ago

i only used aligned and it did a job

Sunit Gautam · Accepted Answer · 2020-12-08 20:27:39Z

414

Probably the most elegant way.

You can simply use the alignment option present in Stack

child: Stack(
  alignment: Alignment.center
)

edited Dec 8, 2020 at 20:27

answered Apr 2, 2020 at 11:20

Sunit Gautam

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2 Comments

kashlo Over a year ago

Works perfectly and doesn't stretch the content as Positioned.fill do

JAgüero Over a year ago

But how to do it when you have more than one child on the Stack and you only want one of them to be in the center?

NaKib · Accepted Answer · 2021-03-01 11:10:06Z

90

For anyone who is reaching here and is not able to solve their issue, I used to make my widget horizontally center by setting both right and left to 0 like below:

Stack(
  children: <Widget>[
    Positioned(
      top: 100,
      left: 0,
      right: 0,
      child: Text("Search",
        style: TextStyle(
          color: Color(0xff757575),
          fontWeight: FontWeight.w700,
          fontFamily: "Roboto",
          fontStyle: FontStyle.normal,
          fontSize: 56.0,
        ),
        textAlign: TextAlign.center,
      ),
    ),
  ]
)

edited Mar 1, 2021 at 11:10

NaKib

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answered Jul 27, 2019 at 14:48

Amir Ghezelbash

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6 Comments

Abdul Rahman Shamair Over a year ago

Can you explain why the left and right values were required?

esengineer Over a year ago

A practice commonly used in Web. 👍

Anoop Thiruonam Over a year ago

Now this is what I call a simple solution! Thanks mate

Eight Rice Over a year ago

Nope.. it just makes it take up the entire width

user206209 Over a year ago

This only works because of that textAlign: center. The widget is stretched edge to edge.

|

Apoleo · Accepted Answer · 2020-06-11 16:56:37Z

79

Remove everything, but this:

Align(
  alignment: Alignment.bottomCenter,
  child: new ButtonBar(
    alignment: MainAxisAlignment.center,
    children: <Widget>[
      new OutlineButton(
        onPressed: () {
          Navigator.push(
            context,
            new MaterialPageRoute(
              builder: (context) => new LoginPage()));
        },
        child: new Text(
          "Login",
          style: new TextStyle(color: Colors.white),
        ),
      ),
      new RaisedButton(
        color: Colors.white,
        onPressed: () {
          Navigator.push(
            context,
            new MaterialPageRoute(
              builder: (context) =>
                new RegistrationPage()));
        },
        child: new Text(
          "Register",
          style: new TextStyle(color: Colors.black),
        ),
      )
    ],
  ),
)

In my theory, the additional Container is destroying it. I would advise you to just surround this by adding Padding:

Padding(
  padding: EdgeInsets.only(bottom: 20.0),
  child: Align...
),

This seems a lot more reasonable to me than the Positioned and also I do not quite understand your Column with a single child only.

edited Jun 11, 2020 at 16:56

Apoleo

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answered Jun 12, 2018 at 15:17

creativecreatorormaybenot

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1 Comment

spongyboss Over a year ago

Woah, thanks man, I never knew Align can position widgets in a Stack to be honest

Taba · Accepted Answer · 2020-05-12 04:52:39Z

Thanks to all of the above answers I'd like to share something that may come in handy in some certain cases. So lets see what happens when you use Positioned:( right: 0.0, left:0.0, bottom:0.0) :

      Padding(
        padding: const EdgeInsets.all(4.0),
        child: Stack(
          children: <Widget>[
            Positioned(
                bottom: 0.0,
                right: 0.0,
                left: 0.0,
                child: Padding(
                  padding: const EdgeInsets.symmetric(horizontal: 8.0),
                  child: Container(
                      color: Colors.blue,
                      child: Center(
                        child: Text('Hello',
                          style: TextStyle(color: Color(0xffF6C37F),
                          fontSize: 46, fontWeight: FontWeight.bold),),
                      )
                  ),
                )
            ),
          ],
        ),
      ),

This would be the output of the above code:

As you can see it would fill the whole width with the container even though you don't want it and you just want the container to wrap its children. so for this you can try trick below:

      Padding(
        padding: const EdgeInsets.all(4.0),
        child: Stack(
          children: <Widget>[
            Positioned(
                bottom: 0.0,
                right: 0.0,
                left: 0.0,
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: <Widget>[
                    Container(),
                    Padding(
                      padding: const EdgeInsets.symmetric(horizontal: 8.0),
                      child: Container(
                          color: Colors.blue,
                          child: Text('Hello',
                            style: TextStyle(color: Color(0xffF6C37F), 
                            fontSize: 46, fontWeight: FontWeight.bold),)
                      ),
                    ),
                    Container(),
                  ],
                )
            ),
          ],
        ),
      ),

Marco · Accepted Answer · 2019-04-19 07:36:07Z

14

You can change the Positioned with Align inside a Stack:

Align(
  alignment: Alignment.bottomCenter,
  child: ... ,
),

For more info about Stack: Exploring Stack

answered Apr 19, 2019 at 7:36

Marco

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1 Comment

Osman Over a year ago

the best solution so far, especially for positioning Texts. Positioned with left:0 and right:0 expands the actual widget horizontally.

chemamolins · Accepted Answer · 2018-06-12 19:56:06Z

11

The Problem is the Container that gets the smallest possible size.

Just give a width: to the Container (in red) and you are done.

width: MediaQuery.of(context).size.width

  new Positioned(
  bottom: 0.0,
  child: new Container(
    width: MediaQuery.of(context).size.width,
    color: Colors.red,
    margin: const EdgeInsets.all(0.0),
    child: new Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[
        new Align(
          alignment: Alignment.bottomCenter,
          child: new ButtonBar(
            alignment: MainAxisAlignment.center,
            children: <Widget>[
              new OutlineButton(
                onPressed: null,
                child: new Text(
                  "Login",
                  style: new TextStyle(color: Colors.white),
                ),
              ),
              new RaisedButton(
                color: Colors.white,
                onPressed: null,
                child: new Text(
                  "Register",
                  style: new TextStyle(color: Colors.black),
                ),
              )
            ],
          ),
        )
      ],
    ),
  ),
),

answered Jun 12, 2018 at 19:56

chemamolins

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2 Comments

user1717140 Over a year ago

Why don't you just use Columns / Rows here?

chemamolins Over a year ago

There are different solutions to achieve the expected result. My answer was trying to explain why the solution the OP provided did not work.

Ariwizzy · Accepted Answer · 2023-09-11 18:13:42Z

3

this code does the trick

    Positioned(
                    bottom: 10,
                    width: MediaQuery.of(context).size.width,
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        Container(
                       
                        ),
                      ],
                    ),
                  ),

answered Sep 11, 2023 at 18:13

Ariwizzy

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1 Comment

Jeremy Caney Over a year ago

Thank you for your interest in contributing to the Stack Overflow community. This question already has quite a few answers—including one that has been extensively validated by the community. Are you certain your approach hasn’t been given previously? If so, it would be useful to explain how your approach is different, under what circumstances your approach might be preferred, and/or why you think the previous answers aren’t sufficient. Can you kindly edit your answer to offer an explanation?

RIX · Accepted Answer · 2020-08-11 01:00:57Z

1

Have a look at this solution I came up with

Positioned( child: SizedBox( child: CircularProgressIndicator(), width: 50, height: 50,), left: MediaQuery.of(context).size.width / 2 - 25);

answered Aug 11, 2020 at 1:00

RIX

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1 Comment

Levi Roelofsma Over a year ago

This actually works in the case of using a relatively small widget, where you could set a fixed width.

theCaptainXgod · Accepted Answer · 2020-10-13 07:15:07Z

1

The Best way worked for me, was using Align. I needed to make the profile picture of a user in the bottom center of the Cover picture.

return Container(
  height: 220,
  color: Colors.red,
  child: Stack(
    children: [
      Container(
        height: 160,
        color: Colors.yellow,
      ),
      Align(
        alignment: Alignment.bottomCenter,
        child: UserProfileImage(),
      ),
    ],
  ),
);

This worked like a charm.

answered Oct 13, 2020 at 7:15

theCaptainXgod

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Comments

mohammad mowludi · Accepted Answer · 2023-09-23 12:25:59Z

0

short solushion put widget in Center() widget

answered Sep 23, 2023 at 12:25

mohammad mowludi

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Comments

ethicnology · Accepted Answer · 2024-06-04 19:44:30Z

0

Like @Ariwizzy answer but without the extra Row

Positioned(
  bottom: 10,
  width: MediaQuery.of(context).size.width / 2,
  left: MediaQuery.of(context).size.width / 4,
  child: Container(),
)

answered Jun 4, 2024 at 19:44

ethicnology

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Comments

A.Ktns · Accepted Answer · 2025-10-20 12:56:49Z

0

Do not wrap the Widget that you want to be centered with the Positioned Widget. Instead, use the parameter alignment: AlignmentDirectional.center of the Stack Widget.

answered Oct 20 at 12:56

A.Ktns

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Comments

Hellomik U · Accepted Answer · 2021-09-29 11:47:52Z

It can work like Positioned.center You determine the center of the widget and set the same center of widget and point.

import 'dart:developer';

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'dart:math' as math;

class AlignPositioned extends SingleChildRenderObjectWidget {
  const AlignPositioned({
    Key? key,
    this.alignment = Alignment.center,
    required this.centerPoint,
    this.widthFactor,
    this.heightFactor,
    Widget? child,
  })  : assert(widthFactor == null || widthFactor >= 0.0),
        assert(heightFactor == null || heightFactor >= 0.0),
        super(key: key, child: child);

  final AlignmentGeometry alignment;
  final Offset centerPoint;

  final double? widthFactor;

  final double? heightFactor;

  @override
  _RenderPositionedBox createRenderObject(BuildContext context) {
    return _RenderPositionedBox(
      alignment: alignment,
      widthFactor: widthFactor,
      heightFactor: heightFactor,
      textDirection: Directionality.maybeOf(context),
      centerPoint: this.centerPoint,
    );
  }

  @override
  void updateRenderObject(
      BuildContext context, _RenderPositionedBox renderObject) {
    renderObject
      ..alignment = alignment
      ..widthFactor = widthFactor
      ..heightFactor = heightFactor
      ..textDirection = Directionality.maybeOf(context)
      ..centerPoint = centerPoint;
  }

  @override
  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
    super.debugFillProperties(properties);
    properties
        .add(DiagnosticsProperty<AlignmentGeometry>('alignment', alignment));
    properties
        .add(DoubleProperty('widthFactor', widthFactor, defaultValue: null));
    properties
        .add(DoubleProperty('heightFactor', heightFactor, defaultValue: null));
  }
}

class _RenderPositionedBox extends RenderAligningShiftedBox {
  Offset centerPoint;

  _RenderPositionedBox({
    RenderBox? child,
    double? widthFactor,
    double? heightFactor,
    AlignmentGeometry alignment = Alignment.center,
    TextDirection? textDirection,
    required this.centerPoint,
  })  : assert(widthFactor == null || widthFactor >= 0.0),
        assert(heightFactor == null || heightFactor >= 0.0),
        _widthFactor = widthFactor,
        _heightFactor = heightFactor,
        super(child: child, alignment: alignment, textDirection: textDirection);

  double? get widthFactor => _widthFactor;
  double? _widthFactor;

  set widthFactor(double? value) {
    assert(value == null || value >= 0.0);
    if (_widthFactor == value) return;
    _widthFactor = value;
    markNeedsLayout();
  }

  set alignment(AlignmentGeometry value) {
    super.alignment = value;
    _resolvedAlignment = alignment.resolve(textDirection);
  }

  double? get heightFactor => _heightFactor;
  double? _heightFactor;
  late Alignment _resolvedAlignment = alignment.resolve(textDirection);

  set heightFactor(double? value) {
    assert(value == null || value >= 0.0);
    if (_heightFactor == value) return;
    _heightFactor = value;
    markNeedsLayout();
  }

  @override
  Size computeDryLayout(BoxConstraints constraints) {
    final bool shrinkWrapWidth =
        _widthFactor != null || constraints.maxWidth == double.infinity;
    final bool shrinkWrapHeight =
        _heightFactor != null || constraints.maxHeight == double.infinity;
    if (child != null) {
      final Size childSize = child!.getDryLayout(constraints.loosen());
      return constraints.constrain(Size(
        shrinkWrapWidth
            ? childSize.width * (_widthFactor ?? 1.0)
            : double.infinity,
        shrinkWrapHeight
            ? childSize.height * (_heightFactor ?? 1.0)
            : double.infinity,
      ));
    }
    return constraints.constrain(Size(
      shrinkWrapWidth ? 0.0 : double.infinity,
      shrinkWrapHeight ? 0.0 : double.infinity,
    ));
  }

  @override
  void performLayout() {
    final BoxConstraints constraints = this.constraints;
    final bool shrinkWrapWidth =
        _widthFactor != null || constraints.maxWidth == double.infinity;
    final bool shrinkWrapHeight =
        _heightFactor != null || constraints.maxHeight == double.infinity;

    if (child != null) {
      child!.layout(constraints.loosen(), parentUsesSize: true);
      size = constraints.constrain(Size(
        shrinkWrapWidth
            ? child!.size.width * (_widthFactor ?? 1.0)
            : double.infinity,
        shrinkWrapHeight
            ? child!.size.height * (_heightFactor ?? 1.0)
            : double.infinity,
      ));

      final BoxParentData childParentData = child!.parentData! as BoxParentData;
      final moveX = _resolvedAlignment.x - 1;
      final moveY = _resolvedAlignment.y - 1;
      log(_resolvedAlignment.y.toString());
      childParentData.offset = this.centerPoint +
          Offset(
            child!.size.width / 2 * moveX,
            child!.size.height / 2 * moveY,
          );
      // log(_resolvedAlignment.x.toString());
      // log(_resolvedAlignment.y.toString());

      // _resolvedAlignment.alongOffset(size - child!.size as Offset);
    } else {
      size = constraints.constrain(Size(
        shrinkWrapWidth ? 0.0 : double.infinity,
        shrinkWrapHeight ? 0.0 : double.infinity,
      ));
    }
  }

  @override
  void debugPaintSize(PaintingContext context, Offset offset) {
    super.debugPaintSize(context, offset);
    assert(() {
      final Paint paint;
      if (child != null && !child!.size.isEmpty) {
        final Path path;
        paint = Paint()
          ..style = PaintingStyle.stroke
          ..strokeWidth = 1.0
          ..color = const Color(0xFFFFFF00);
        path = Path();
        final BoxParentData childParentData =
            child!.parentData! as BoxParentData;
        if (childParentData.offset.dy > 0.0) {
          // vertical alignment arrows
          final double headSize =
              math.min(childParentData.offset.dy * 0.2, 10.0);
          path
            ..moveTo(offset.dx + size.width / 2.0, offset.dy)
            ..relativeLineTo(0.0, childParentData.offset.dy - headSize)
            ..relativeLineTo(headSize, 0.0)
            ..relativeLineTo(-headSize, headSize)
            ..relativeLineTo(-headSize, -headSize)
            ..relativeLineTo(headSize, 0.0)
            ..moveTo(offset.dx + size.width / 2.0, offset.dy + size.height)
            ..relativeLineTo(0.0, -childParentData.offset.dy + headSize)
            ..relativeLineTo(headSize, 0.0)
            ..relativeLineTo(-headSize, -headSize)
            ..relativeLineTo(-headSize, headSize)
            ..relativeLineTo(headSize, 0.0);
          context.canvas.drawPath(path, paint);
        }
        if (childParentData.offset.dx > 0.0) {
          // horizontal alignment arrows
          final double headSize =
              math.min(childParentData.offset.dx * 0.2, 10.0);
          path
            ..moveTo(offset.dx, offset.dy + size.height / 2.0)
            ..relativeLineTo(childParentData.offset.dx - headSize, 0.0)
            ..relativeLineTo(0.0, headSize)
            ..relativeLineTo(headSize, -headSize)
            ..relativeLineTo(-headSize, -headSize)
            ..relativeLineTo(0.0, headSize)
            ..moveTo(offset.dx + size.width, offset.dy + size.height / 2.0)
            ..relativeLineTo(-childParentData.offset.dx + headSize, 0.0)
            ..relativeLineTo(0.0, headSize)
            ..relativeLineTo(-headSize, -headSize)
            ..relativeLineTo(headSize, -headSize)
            ..relativeLineTo(0.0, headSize);
          context.canvas.drawPath(path, paint);
        }
      } else {
        paint = Paint()..color = const Color(0x90909090);
        context.canvas.drawRect(offset & size, paint);
      }
      return true;
    }());
  }

  @override
  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
    super.debugFillProperties(properties);
    properties
        .add(DoubleProperty('widthFactor', _widthFactor, ifNull: 'expand'));
    properties
        .add(DoubleProperty('heightFactor', _heightFactor, ifNull: 'expand'));
  }
}

CopsOnRoad · Accepted Answer · 2020-04-08 12:47:11Z

-2

You can try this too:

Center(
  child: Stack(
    children: [],
  ),
)

answered Apr 8, 2020 at 12:47

CopsOnRoad

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Flutter position stack widget in center

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Probably the most elegant way.

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Probably the most elegant way.

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