I’m working on a Flutter app and need to create an expandable connector interface similar to what I have in my UI mockup. The design shows two states - a collapsed state where the connector appears as a simple element, and an expanded state where it reveals additional connector options or details.
I’ve been experimenting with the ExpansionTile widget but I’m struggling to match the exact visual appearance I need. The design requires a specific layout where the connector elements have a particular styling and animation behavior.
Has anyone implemented something similar? What widgets or approach would work best for creating this type of expandable connector interface? I’m particularly interested in how to handle the visual transitions between the collapsed and expanded states while maintaining the connector-like appearance.
Any code examples or widget suggestions would be really helpful. I’m open to custom implementations if the built-in widgets aren’t sufficient for this design pattern.
I ran into the same issue building a data viz dashboard. Here’s what worked: I combined AnimatedContainer with AnimatedCrossFade instead of just using ExpansionTile. Built a custom widget that wrapped these around my connector elements - AnimatedContainer handled size changes, AnimatedCrossFade managed the content switching between collapsed/expanded states. For styling the connectors, I used CustomPainter to draw the lines and nodes. Gave me full control over how everything looked. 300ms animation duration felt right for the expansion. More work upfront than built-in widgets, but you get exactly the visual behavior and styling control you need for professional connectors.
I fixed this with a stateful widget that toggles between two layouts using AnimatedPositioned in a Stack. The trick was treating the connector as multiple positioned elements instead of animating one widget. I made separate widgets for the collapsed icon and expanded panel, then used AnimatedPositioned to slide them in while AnimatedOpacity handles the fade transitions. For styling, I went with DecoratedBox and custom BoxDecoration - way simpler than CustomPainter but you still get the visual control. Animation runs 250ms with Curves.fastOutSlowIn which feels right for this UI. You keep the connector look while having full control over how it expands.
I hit this exact problem building a workflow builder. AnimatedSize as the parent wrapper plus TweenAnimationBuilder saved me. AnimatedSize handles height changes automatically when content expands, and TweenAnimationBuilder lets you control custom stuff like connector line thickness or node spacing during animation. I used Path in a CustomPainter for the connector visuals - you get proper connection lines that actually look like connectors instead of styled containers. The trick was splitting expansion into two animations: one for container size, another for connector elements. I threw in AnimatedAlign to smoothly move connector endpoints during expansion. 400ms total animation time feels natural without being sluggish.
The problem with ExpansionTile is it locks you into a specific UI pattern that never matches custom designs. I’ve had better luck using AnimatedSwitcher with Transform widgets. AnimatedSwitcher handles smooth content transitions while Transform.scale or Transform.rotate gives you that connector-specific animation during state changes. For styling the connectors, I use Container with custom borders and Positioned widgets in a Stack - gives me exact control over visuals. Animation curves matter here. Curves.easeInOut works great for expansion, but Curves.elasticOut makes connectors feel more dynamic. I also throw in AnimatedOpacity to fade in secondary connector options. Takes more work than ExpansionTile, but you get exactly the visual behavior you want.
Skip the built-in widgets for this. I used AnimatedBuilder with a custom Tween - much more flexible than expansion tile. Wrap your connectors in SizeTransition and control everything with AnimationController. Use clipBehavior: Clip.hardEdge to prevent overflow during transitions. Add BoxShadow to your connectors to make them stand out.