Add origin-aware animations CSS variable to the popover components based on the `placement` prop

[sadeghbarati]

Provide a general summary of the feature here

Just like the radix-ui, it would be nice to have --radix-popper-transform-origin CSS variable for these component

• Popover
  • Combobox
  • Menu
  • Select
  • DatePicker/DateRangePicker
• Tooltip

🤔 Expected Behavior?

Please check this shadcn PR video

shadcn-ui/ui#6945

😯 Current Behavior

Components are doesn't have origin aware animations

💁 Possible Solution

No response

🔦 Context

For context please check the radix-ui popper component

https://github.com/radix-ui/primitives/blob/main/packages/react/popper/src/popper.tsx#L241C11-L244C23

💻 Examples

No response

🧢 Your Company/Team

No response

🕷 Tracking Issue

No response

[sadeghbarati]

function getPopoverAnimationClassName(values: PopoverRenderProps): string {
  return clsx(
    "fill-mode-forwards",
    values.placement &&
      {
        bottom: "origin-top",
        top: "origin-bottom",
        left: "origin-right",
        right: "origin-left",
        center: "origin-center",
      }[values.placement],
    values.isEntering && "animate-in fade-in",
    values.isExiting && "animate-out fade-out zoom-out-95",
  );
}

Found this in argos-ci which is using statis TailwindCSS origin classes based on the placement props which is good but,

I need transform-origin value be more accurate

[devongovett]

This should already be possible with the data-placement attribute, or placement render prop. https://react-spectrum.adobe.com/react-aria/Popover.html#popover-2

.react-aria-Popover {
  &[data-placement=top] {
    transform-origin: bottom;
  }
}

[sadeghbarati]

appreciate for the response 🌻

[OliverJAsh]

Unfortunately data-placement doesn't provide the full placement (e.g. bottom right), only the placement axis (e.g. bottom): #6825

@devongovett Would be great to get your thoughts on that issue.

[OliverJAsh]

In my work at Unsplash, I'm trying to implement a popover enter/exit animation that makes the popover appear to "pop in" and slide-in from the anchor point where it's attached to the trigger. See this reduced test case for example. It works in my reduced test case, but it's not origin-aware, meaning it won't work with different placements. To solve this I think React Aria might need something like a data-crossplacement attribute to go along with data-placement (#8163).

For comparison, here's what Radix is doing. It exposes a CSS variable.

I also encountered other issues whilst attempting to implement this animation. It seems to require an extra child element for the scale transform, and I couldn't get [data-entering] to work on the child, rather I had to use @starting-style instead. See this reduced test case for example. I would appreciate any input on this.

I've already shipped this to production at Unsplash using a patch for #8163. One thing I noticed is that data-crossplacement unfortunately falls short when the cross placement is adjusted to prevent collisions. For example, here we specify placement={"top end"}. Due to collision prevention the popover appears in the top start position, however data-crossplacement is still right, meaning the animation appears to have the wrong origin.

Screen.Recording.2025-05-01.at.07.43.47.mov