I'm trying to make a button where when user hold it, there will be a progress, but if the user unpress the button before it finish, the progress will decrease. somthing like the one on the picture
In Flutter, progress can be displayed in two ways: CircularProgressIndicator: A CircularProgressIndicator is a widget that shows progress along a circle. It is a circular progress bar that spins to indicate that the application is busy or on hold.
You can customize the startAngle and endAngle properties of the radial axis to design full and semi-circular progress bars. To make a semi-circle progress bar, set the startAngle value to 180 and endAngle value to 0, as shown in the following code example.
You just need to make bool if its loading and getting data, the indicator shows up.
CircularProgressIndicator , 4dp indicator/track thickness is used without animation for visibility change. Without customization, primaryColor will be used as the indicator color; the track is transparent.
As said by Arnold Parge, you can use the GestureDetector and listen to onTapDown
and onTapUp
. To create your desired LoadingButton, you can use the following Widget Structure:
- GetureDetector
- Stack
- CircularProgressIndicator // background circle
- CircularProgressIndicator // foreground circle
- Icon
To create the animation, you can add an AnimationController and bind the value of the foreground CircularProgressIndicator
to AnimationController.value
. Now you'll just have to the add the two listeners to to the GestureDetector
:
onTapDown
: When tapping on the button, the animation should start. Therefore we call AnimationController.forward()
onTapUp
: When releasing the press, we want to check if the animation is already finished. We can use AnimationController.status to check the status. If it is AnimationStatus.forward
it is still running. Hence we want to reverse the animation with calling AnimationController.reverse()
.Here is the resulting button:
And the complete source code:
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData(),
home: Scaffold(
body: Center(child: LoadingButton()),
),
);
}
}
class LoadingButton extends StatefulWidget {
@override
LoadingButtonState createState() => LoadingButtonState();
}
class LoadingButtonState extends State<LoadingButton>
with SingleTickerProviderStateMixin {
AnimationController controller;
@override
void initState() {
super.initState();
controller =
AnimationController(vsync: this, duration: Duration(seconds: 1));
controller.addListener(() {
setState(() {});
});
}
@override
Widget build(BuildContext context) {
return GestureDetector(
onTapDown: (_) => controller.forward(),
onTapUp: (_) {
if (controller.status == AnimationStatus.forward) {
controller.reverse();
}
},
child: Stack(
alignment: Alignment.center,
children: <Widget>[
CircularProgressIndicator(
value: 1.0,
valueColor: AlwaysStoppedAnimation<Color>(Colors.grey),
),
CircularProgressIndicator(
value: controller.value,
valueColor: AlwaysStoppedAnimation<Color>(Colors.blue),
),
Icon(Icons.add)
],
),
);
}
}
Use GestureDetector.
Start the progress in onTapDown
and reverse the progress in onTapUp
if the progress is not complete or whatever your conditions are.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With