Flutter AutoResizeTextView, setting high fontSize overflows - dart

In Android, we can use AutoResizeTextView and give it any text size of our choice, it will not flow out of its constraints, I was looking for similar solution in Flutter.
I tried following,
Container(
color: Colors.blue,
constraints: BoxConstraints(maxHeight: 200.0, minWidth: 600.0),
child: Text("8", style: TextStyle(fontSize: 400.0)),
);
Here is the ugly output. So, how can I force the Text to always stay inside the Container no matter how much fontSize is given to it

Thanks to pskink,
I need to wrap the Text inside FittedBox which is further wrapped inside a Container. Here is the solution.
Container(
color: Colors.blue,
constraints: BoxConstraints(maxHeight: 200.0, minWidth: 600.0),
child: FittedBox(child: Text("8", style: TextStyle(fontSize: 400.0))),
);

Related

Is there a more optimal way to space widgets within a column?

So i'm emulating an old app I have where the UI looks like this
Currently i'm focused on creating the UI layout for the purple side bar, I did that by creating a Container with a purple background. Within the container I created a column with multiple children and just used an empty SizedBox to create distance between one widget from another.
import 'package:flutter/material.dart';
class SignInPage extends StatelessWidget {
const SignInPage({super.key});
#override
Widget build(BuildContext context) {
return Scaffold(
// appBar: AppBar(
// title: Text('Sample Text'),
// elevation: 5.0,
// ),
body: _buildContent(),
);
}
Widget _buildContent() {
// private method
return Container(
color: Colors.deepPurpleAccent,
padding: EdgeInsets.all(16.0),
child: Column(
// crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Container(
color: Colors.orange,
child: SizedBox(
height: 100.0,
width: 80.0,
),
),
SizedBox(
height: 140.0,
),
Container(
color: Colors.red,
child: SizedBox(
height: 50.0,
width: 80.0,
),
),
SizedBox(
height: 8.0,
),
Container(
color: Colors.purple,
child: SizedBox(
height: 50.0,
width: 80.0,
),
),
],
),
);
}
}
I'm quite new to flutter so i'm wondering if there's a better way to structure my layout of the side bar? Also to think in the future, since the name "BagTrack" Is on the same level as "Analytic Overview" Should that just be one giant row"?
Actual answer
Method 1
#Mahfuzur Rahman answer is good, but to actually answer your question about other ways. Flex widgets (Column and Row extend the Flex widget), have both mainAxisAlignment and crossAxisAlignment, they can be used to align them more easily between different devices/screens sizes.
So maybe grouping your red and purple boxes in a Column with mainAxisSize set to MainAxisSize.min, and aligning the surrounding column with a specific size.
https://api.flutter.dev/flutter/widgets/Column-class.html
Method 2
Another way, if you would like some widget to occupy some percentage amount of space from it's parent, I suggest you look into Expanded widget, Flexible widget.
Method 3
Or even FractionallySizedBox could be a good widget for you, but then I would also look at this LayoutBuilder widget to solve the potential Unbounded Height/Width exception.
Second smaller question
It's entirely up to you to decide about your second question concerning the giant row. I wouldn't do it though. Probably would use a const SizedBox or const EdgeInsets (for Padding) and keep them at the same height this way.
Just complementing Flutter knowledge
PS: Since you are new to Flutter. As a suggestion for future performance: avoid the Container widget as much as you know, there are a lot of simpler widgets like SizedBox, ColoredBox, DecoratedBox and Padding that you can use in its place that could be marked as const sometimes and be less expensive.
For understanding final and const:
final is a variable that cannot be reassigned by accident inside your code. When you instantiate it you give it a value and that's it. (Using late changes that a bit but not much);
const is a variable assigned by the compiler, if you are familiar with C it's like #define but there is a little difference, every time you say const EdgeInsets.all(8) for example, the compiler will detect that and use the same variable, so you don't have to remember a specific constant variable name.
Yes there is. But using SizedBox also wont hurt.
I usually Prefer ListTile for each element in the drawer.
ListTile(
leading: GestureDetector(
behavior: HitTestBehavior.translucent,
onTap: () {},
child: Container(
width: 48,
height: 48,
padding: const EdgeInsets.symmetric(vertical: 4.0),
alignment: Alignment.center,
child: const CircleAvatar(),
),
),
title: const Text('title'),
dense: false,
)

Changing the color and styling of the Button in Flutter

I have migrated to Flutter 2.0 which is just the new release now. In my project I have used Flat Buttons but it got deprecated now in Flutter 2.0 and the suggestion pop up to use Text Button instead of Flat Buttons.
Now the problem is in Flat Buttons there are option directly to set the properties of button such as color, padding etc. but when I replaced it with Text Button there is error in using this properties. I have checked the documentation and found that there is the property of style: ButtonStyle(backgroundcolor: ____________). But when I have put Colors.blue in the backgroundcolor property it gives me error.
So I want to know that how is the behaviour of Buttons in Flutter 2.0 and how we can style the Buttons?
My snippet of code is here in which I want to style the button.
Container(
width: 200.0,
child: TextButton(
style: ButtonStyle(), // I want to style this.
onPressed: () => Navigator.pushNamed(context, SignupPage.id),
/*color: Colors.blue,
padding: const EdgeInsets.all(10.0),*/ //Commented code is deprecated in Flutter 2.0
child: Text(
'Create Account',
style: TextStyle(color: Colors.white, fontSize: 16.0),
),
The style argument with a backgroundcolor is the way to do it, but does not take a Color object, its type is MaterialStateProperty<Color?>? so you should provide an object of that type.
documentation is here https://api.flutter.dev/flutter/material/TextButton-class.html
and here https://api.flutter.dev/flutter/material/ButtonStyle-class.html
Buttons now have a state, so you have to define the colors for each state:
you can define one color for all the states.
ButtonStyle(
backgroundColor: MaterialStateProperty.all(Colors.green),
you can define a different color for each state.
ButtonStyle(
backgroundColor: MaterialStateProperty.resolveWith(
(Set states) {
if (states.contains(MaterialState.pressed))
return Theme.of(context).colorScheme.primary.withOpacity(0.5);
return null; // Use the component's default.
},
),
),

how to add Circular shape to a DropdownButton in flutter?

I want to know how to customize DropdownButton by adding circular shape border like below in the picture .
It's not possible to do that in a simple way. You have to edit the classes _DropdownMenuPainter and _DropdownMenuState from dropdrown.dart, which is part of the Flutter's material package.
In _DropdownMenuPainter, change the BoxDecoration radius set in constructor:
_DropdownMenuPainter({
...
this.resize,
}) : _painter = BoxDecoration(
...
borderRadius: BorderRadius.circular(16.0), // Set the radius you want here
boxShadow: kElevationToShadow[elevation],
).createBoxPainter(),
super(repaint: resize);
In _DropdownMenuState, inside the method build(), wrap the Material widget with a ClipRRect and set its borderRadius the same as you set for _DropdownMenuPainter:
return FadeTransition(
opacity: _fadeOpacity,
child: CustomPaint(
...
child: Semantics(
...
child: ClipRRect(
borderRadius: BorderRadius.circular(16.0), // This must be identical to the one set before
child: Material(
...
),
),
),
),
);
Notice that you'll lose those changes when you update Flutter.
Update:
I was going to make a PR to Flutter, but spent 1 hour trying to run the tests and had no success, so I'm not going to waste my time on this. Instead, I made a gist, so you can copy the whole file with the changes I made to your local Flutter copy.
https://gist.github.com/hugocbpassos/2a63594a21d7f231e97dd7dc1f18ee68
To use it, just set the radius property:
DropdownButton(
radius: 16,
items: [
...
],
);

Flutter: Constraints not constraining widget (explanation needed)

class Test extends StatelessWidget {
Widget build(BuildContext context) {
return UnconstrainedBox(
child: Container(
height: 250.0,
width: 250.0,
decoration:
BoxDecoration(shape: BoxShape.circle, color: Colors.red),
child: Opacity(
opacity: 0.5,
child: Container( // WIDGET IN QUESTION
constraints:
BoxConstraints.expand(width: 50.0, height: 50.0),
color: Colors.yellow))));
}
}
According to the Container class documentation...
If the widget has no child and no alignment, but a height, width, or constraints are provided, then the Container tries to be as small as possible given the combination of those constraints and the parent's constraints.
Instead, the widget is trying to be as large as possible (size of parent) rather than 50x50. I understand that I can use something like UnconstrainedBox, but I'm looking for an explanation of this behavior.
Looking for:
Currently getting:
The problem is your root Container.
By setting a width+height without an alignment, Container forces its child to fill the available space.
If you want that child take the least amount of space, you need to specify your root container how it should align its child within its bounds.
Container(
width: 250,
height: 250,
alignment: Alignment.center,
child: Whatever(),
);

Position widget in stack with percent

Let's say I want to position a widget inside a Stack but with a percent of the Stack position instead of a fixed size. How to do that in flutter ?
I'd expect that the Positionned.fromRelativeRect constructor would be the thing, using floats between 0 and 1. But seems like no.
Align allows to position the widget in percent. But heightFactor and widthFactor changes the Align size instead of the child size. Which is not what I want.
You can combine a Positioned.fill and LayoutBuilder to achieve such result.
new Stack(
children: <Widget>[
new Positioned.fill(
child: new LayoutBuilder(
builder: (context, constraints) {
return new Padding(
padding: new EdgeInsets.only(top: constraints.biggest.height * .59, bottom: constraints.biggest.height * .31),
child: new Text("toto", textAlign: TextAlign.center,),
);
},
),
)
],
),
one thing that i figured out not long ago is that you can position a widget on the screen using a container its alignment parameter with the help of the Alignment.lerp(x,y,z) function
//the widget will be placed in the center of the container
alignment: Alignment.lerp(Alignment.topCenter, Alignment.bottomCenter, 0),
//the widget will be placed in the bottom of the container
alignment: Alignment.lerp(Alignment.topCenter, Alignment.bottomCenter, 1),
//the widget will be placed in the bottom quarter of the container
alignment: Alignment.lerp(Alignment.topCenter, Alignment.bottomCenter, 0.5),
//the widget will be placed in the top quarter of the container
alignment: Alignment.lerp(Alignment.topCenter, Alignment.bottomCenter, -0.5),
use FractionalOffset & FractionallySizedBox it's very simple in contrast
around no unnecessary code like Positioned.fill
no no extra calculations like Alignment
...
Container(
color: Colors.blue[200],
alignment: FractionalOffset(0.7, 0.6),
child: FractionallySizedBox(
widthFactor: 0.1,
heightFactor: 1/3,
child: Container(color: Colors.red[900])
),
),
...
If you want to use LayoutBuilder then do without Positioned.fill, like this:
you need one LayoutBuilder, no need to turn around every elements and use Transform.translate instead of Padding.
new LayoutBuilder(
builder: (context, constraints) {
return Stack(
children: <Widget>[
Transform.translate(
offset: Offset(
constraints.biggest.width * left,
constraints.biggest.height * top),
child: new Text("toto", textAlign: TextAlign.center,),
),
...
],
);
}
)

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