Steps to Reproduce

Please tell us what you were doing...

Trying to implement a Slider that fires off an http post when the user stops interacting with the Slider. I see there's an 'onChanged' callback, but it's too rapid-fire for my purposes without implementing a clunky timeout mechanism. Ideally I could get a discreet callback when the touch/drag ends.

Flutter Doctor

flutter -v doctor
[✓] Flutter (Channel beta, v0.3.1, on Mac OS X 10.12.6 16G1314, locale en-US)
• Flutter version 0.3.1 at /Users/tony/afero/flutter
• Framework revision 12bbaba (12 days ago), 2018-04-19 23:36:15 -0700
• Engine revision 09d05a3
• Dart version 2.0.0-dev.48.0.flutter-fe606f890b

[✓] Android toolchain - develop for Android devices (Android SDK 27.0.3)
• Android SDK at /Users/tony/Library/Android/sdk
• Android NDK at /Users/tony/Library/Android/sdk/ndk-bundle
• Platform android-27, build-tools 27.0.3
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b01)
• All Android licenses accepted.

[✓] iOS toolchain - develop for iOS devices (Xcode 9.2)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 9.2, Build version 9C40b
• ios-deploy 1.9.2
• CocoaPods version 1.4.0

[✓] Android Studio (version 3.1)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin version 24.0.1
• Dart plugin version 173.4700
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b01)

[✓] Connected devices (1 available)
• Android SDK built for x86 • emulator-5554 • android-x86 • Android 8.0.0 (API 26) (emulator)
• No issues found!