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Cover image for React Draggable Bottom Panel
Josiah Bryan
Josiah Bryan

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React Draggable Bottom Panel

TL;DR: Source for BottomPanel.jsx and BottomPanel.module.scss is at
https://gist.github.com/josiahbryan/c220708256f7c8d79760aff37f64948f.

Live Demo: https://josiahbryan.com/#/bottompanel-demo

I've been working on a couple of different projects lately, one involves working on the next-generation marketplace for fringe.us, and the other project is an app for a luxury driving service.

Both of these projects called for a bottom panel that can be partially exposed and then dragged/swiped up to reveal content.

I searched high and low and could not find any acceptable implementations of just such a UI component in React - which was rather shocking, I thought surely someone had solved this rather common UI paradigm already for React!

I found many implementations of the paradigm in non-web-React formats, here's a couple examples that show what I wanted:

Both of those packages look beautiful and I would love to use them! However, the projects I'm working on require React in a browser, so those packages are not options.

I almost gave up on finding a solution, but yesterday I decided to give it one last try. I thought surely I can implement it myself! I first tried extracting the SwipeableDrawer component from @material-ui's source, but that proved incredibly painful and never got that working.

Then I tried writing a simple implementation of a drawer myself using react-swipeable's awesome hook. That worked okay, but the FPS (especially on mobile) was HORRIBLE. I'm talking ~10-~12 fps when dragging. NOT accetable.

Then, almost as if by providence, I stumbled upon this section in react-swipeable's docs: https://github.com/FormidableLabs/react-swipeable#how-to-use-touch-action-to-prevent-scrolling - that mentioned a package I hadn't looked at yet, use-gesture. By this point, I was exhausted from reading docs and thought that I would just glance at that package, but didn't think anything would be useful. Boy, was I wrong.

I read the docs in use-gesture and was subtly impressed. Then I found their examples page, which led me to their example for an "Action Sheet": https://codesandbox.io/embed/zuwji?file=/src/index.js&codemirror=1 - needless to say, I was incredibly impressed!

I set about porting their code with very minimal tweaks into a reusable BottomDrawer component that had the various extra niceties I wanted:

  • Drag handle at the top
  • Customizable open size / closed size
  • Scrollable content area inside the sheet

After a good two hours of banging my head against the keyboard, I finally solved all the things I needed and created the following beautiful component (screenshot is at the top of this post). I call it <BottomPanel> - I know, so original - my excuse is I like to KISS.

To see a live working example of this component, head over to my website:

https://josiahbryan.com/#/bottompanel-demo

Example of <BottomPanel> closed:
BottomPanel Closed

Example of <BottomPanel> open:
BottomPanel Open
Usable like this:

<BottomPanel
    maxOpenHeight={window.innerHeight * 0.8} // px
    closedPanelSize={200} // px
>
    <LoremIpsum />
</BottomPanel>
Enter fullscreen mode Exit fullscreen mode

You can find the full source for BottomPanel.jsx and the required styles (BottomPanel.module.scss) in the following gist:
https://gist.github.com/josiahbryan/c220708256f7c8d79760aff37f64948f.

Cheers!
-Josiah Bryan

Discussion (2)

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Supportic

I like the animation. It's so smooth 😊

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Josiah Bryan Author

Thanks!! I certainly can't take (much) credit for the animation - 95% of the animation-critical code came from the original CodePen! But yes, it does look amazingly beautiful!