Range Slider: Rounding error causes values.end to exceed max #180984
Description
Steps to reproduce
- Start the example app from the issue with Emulator Medium_Phone Android 36.1 with Google Play in debug mode
- Slide the left thumb of the RangeSlider to the right till it overlaps with the right Thumb
- Slide the right thumb now
Expected results
values should always be in range with valid visuals
Actual results
- Red Screen is shown
Code sample
Code sample
import 'package:flutter/material.dart';
void main() {
runApp(const MainApp());
}
class MainApp extends StatefulWidget {
const MainApp({super.key});
@override
State<MainApp> createState() => _MainAppState();
}
class _MainAppState extends State<MainApp> {
RangeValues _currentRangeValues = const RangeValues(0, 200);
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: Center(
child: RangeSlider(
min: 0,
max: 200,
values: _currentRangeValues,
onChanged: (RangeValues values) {
setState(() {
_currentRangeValues = values;
});
},
),
),
),
);
}
}
[range_slider_bug_github.zip](https://github.com/user-attachments/files/24620974/range_slider_bug_github.zip)Screenshots or Video
Screenshots / Video demonstration
Logs
Logs
════════ Exception caught by widgets library ═══════════════════════════════════
The following assertion was thrown building MainApp(dirty, state: _MainAppState#db0da):
'package:flutter/src/material/range_slider.dart': Failed assertion: line 179 pos 15: 'values.end >= min && values.end <= max': is not true.
The relevant error-causing widget was:
MainApp MainApp:file:///Users/christophprenissl/range_slider_bug/lib/main.dart:4:16
When the exception was thrown, this was the stack:
#2 new RangeSlider (package:flutter/src/material/range_slider.dart:179:15)
range_slider.dart:179
#3 _MainAppState.build (package:range_slider_bug/main.dart:22:18)
main.dart:22
#4 StatefulElement.build (package:flutter/src/widgets/framework.dart:5931:27)
framework.dart:5931
#5 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5817:15)
framework.dart:5817
#6 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5982:11)
framework.dart:5982
#7 Element.rebuild (package:flutter/src/widgets/framework.dart:5529:7)
framework.dart:5529
#8 BuildScope._tryRebuild (package:flutter/src/widgets/framework.dart:2750:15)
framework.dart:2750
#9 BuildScope._flushDirtyElements (package:flutter/src/widgets/framework.dart:2807:11)
framework.dart:2807
#10 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:3111:18)
framework.dart:3111
#11 WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:1267:21)
binding.dart:1267
#12 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:495:5)
binding.dart:495
#13 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1430:15)
binding.dart:1430
#14 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1345:9)
binding.dart:1345
#15 SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:1198:5)
binding.dart:1198
#16 _invoke (dart:ui/hooks.dart:356:13)
hooks.dart:356
#17 PlatformDispatcher._drawFrame (dart:ui/platform_dispatcher.dart:444:5)
platform_dispatcher.dart:444
#18 _drawFrame (dart:ui/hooks.dart:328:31)
hooks.dart:328
(elided 2 frames from class _AssertionError)
Flutter Doctor output
Doctor output
[✓] Flutter (Channel master, 3.40.0-1.0.pre-573, on macOS 26.2 25C56 darwin-arm64, locale de-DE) [1.900ms]
• Flutter version 3.40.0-1.0.pre-573 on channel master at /Users/christophprenissl/Projects/flutter/flutter
• Upstream repository [email protected]:flutter/flutter.git
• Framework revision 5e417dc812 (3 hours ago), 2026-01-14 15:58:57 +0100
• Engine revision bc63dfe662
• Dart version 3.12.0 (build 3.12.0-17.0.dev)
• DevTools version 2.54.0
• Feature flags: enable-web, enable-linux-desktop, enable-macos-desktop, enable-windows-desktop, enable-android, enable-ios, cli-animations, enable-native-assets, omit-legacy-version-file, enable-lldb-debugging, enable-uiscene-migration, enable-riscv64
[✓] Android toolchain - develop for Android devices (Android SDK version 36.0.0) [1.999ms]
• Android SDK at /Users/christophprenissl/Library/Android/sdk
• Emulator version 36.3.10.0 (build_id 14472402) (CL:N/A)
• Platform android-36, build-tools 36.0.0
• ANDROID_HOME = /Users/christophprenissl/Library/Android/sdk
• Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
This is the JDK bundled with the latest Android Studio installation on this machine.
To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
• Java version OpenJDK Runtime Environment (build 21.0.8+-14196175-b1038.72)
• All Android licenses accepted.
[✓] Xcode - develop for iOS and macOS (Xcode 26.2) [4,5s]
• Xcode at /Applications/Xcode-26.2.0.app/Contents/Developer
• Build 17C52
• CocoaPods version 1.16.2
[✓] Chrome - develop for the web [6ms]
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
[✓] Connected device (4 available) [6,7s]
• sdk gphone64 arm64 (mobile) • emulator-5554 • android-arm64 • Android 16 (API 36) (emulator)
• SnakePT (wireless) (mobile) • 00008150-000104890204401C • ios • iOS 26.2 23C55
• macOS (desktop) • macos • darwin-arm64 • macOS 26.2 25C56 darwin-arm64
• Chrome (web) • chrome • web-javascript • Google Chrome 143.0.7499.193
! Error: Browsing on the local area network for SnakePT. Ensure the device is unlocked and attached with a cable or associated with the same local area network as this Mac.
The device must be opted into Developer Mode to connect wirelessly. (code -27)
[✓] Network resources [250ms]
• All expected network resources are available.
• No issues found!