Stroke order animator


This package implements stroke order animations and quizzes of Chinese characters based on the Make me a Hanzi data. That data is available under the ARPHIC public license.

The package uses a StrokeOrderAnimationController that handles the animation state and serves as an interface between your app and the stroke order animation. The stroke order data has to be passed in as a JSON string. In order to control animations, a TickerProvider must be passed to the controller, for example using a TickerProviderStateMixin. The controller is then passed as an argument to the StrokeOrderAnimator that displays the actual stroke order diagram.

When using the animations in a PageView or ListView, it is recommended to use a unique key for every StrokeOrderAnimator and cancel the animation when the selected page changes in order to avoid broken animation behaviour.

All attributes and actions of the stroke order diagram are controlled via the StrokeOrderAnimationController and can be changed anytime using the respective setter methods.


  • Animation speed of stroke animations and hints in quiz mode (3 is pretty fast)
  • Whether to show/hide strokes
  • Whether to show/hide outlines
  • Whether to show/hide medians
  • Whether to show/hide the correct strokes the user writes during a quiz
  • Whether to highlight radicals
  • Stroke color
  • Outline color
  • Median color
  • Radical color
  • Brush color in quiz mode
  • Brush thickness in quiz mode
  • Number of wrong strokes before showing a hint in quiz mode
  • Hint color in quiz mode


  • Start/stop animation
  • Start/stop quiz
  • Show next/previous stroke
  • Show full character
  • Reset animation/quiz


To better integrate the quizzes, three callbacks can be either passed to the StrokeOrderAnimationController during instantiation or afterwards using the add...Callback method:

  • onWrongStrokeCallback
  • onCorrectStrokeCallback
  • onQuizCompleteCallback

The onQuizCompleteCallback receives a Quizsummary containing the number of mistakes on a per-stroke basis and the paths of the correct strokes (in a 1024x1024 coordinate system). The other two callbacks receive the index of the stroke that was written (in-)correctly. All indices are zero-based.


To run an example showing several stroke order diagrams in a swipeable page view run the following:

git clone
cd stroke-order-animator/example/
flutter run

Issues and feature requests

Please file an issue on the project page if something doesn't work as expected or if you have a feature request.


Feel free to open a pull request. Just make sure to write extensive tests.