Accordion Sliver App Bar #

AccordionSliverAppBar is a customizable Flutter package that provides a SliverAppBar with dynamic accordion-style animations. It enables you to create SliverAppBars where sections can expand or collapse based on priorities, creating an engaging and responsive UI.

Demo #

Features #

• Accordion behavior for multiple stacked children
• Vanish animation for children that fade out when collapsed
• Static children that don't animate
• Optional overlay builder to layer a widget (e.g., color overlay) on top of the background

Installation #

Run command below to add package to pubspec.yaml:

flutter pub add accordion_sliver_app_bar

Usage #

For usage instructions and a complete example, check out the example project.

AccordionSliverAppBar Parameters #

• background: A widget placed at the very back of the stack (e.g., a colored container or image).
• children: A list of AccordionSliverChild objects to stack.
• backgroundOverlayBuilder: Optional function that takes a progress (0.0–1.0) and returns a widget overlaying the background.
• floating: Determines if the SliverAppBar should float.

AccordionSliverChild Parameters #

• expandedHeight: The height of the child when fully expanded.
• collapsedHeight: The height of the child when collapsed.
• priority: Higher priority children are placed nearer to the top of the stack (expanded first).
• wrapperBuilder: Wraps the child in any additional widgets (e.g., containers or scroll views).
• animatedBuilder: Receives a progress parameter from 0.0 (collapsed) to 1.0 (expanded). Use this to animate child widgets.
• clipBehavior: How to clip content (defaults to Clip.antiAlias).

AccordionSliverChild Additional factories #

• static: The child has the same height expanded or collapsed (no animation).
• staticVanish: The child is fully visible expanded, and hidden collapsed, without intermediate animation.
• vanish: The child animates its height and can fade out as it collapses.

Contributions #

Contributions are welcome! Feel free to submit issues, feature requests, or pull requests on the GitHub repository.

License #

This package is released under the MIT License. See the LICENSE file for details.

Support #

If you find this package helpful, please star the repository and share your feedback!