Option to opt out of repositioning Popover while open

[dcastil]

Hey Radix people! 👋

I'm using the Radix UI Popover and would like to suggest a prop for the PopoverContent component to opt out of repositioning while the popover is open. I have two use cases where not repositioning the popover is desirable:

1. When the anchor changes its size during the exit animation of the popover. The popover abruptly changes position during the animation which I'd like to prevent.

Screenshot.2022-05-11.at.22.05.59.mp4

2. When the content of the popover changes due to user input and the changed popover size leads to a repositioning. In this case I'd rather keep it in its original position to avoid disorientation, especially as the content only gets smaller.

Screenshot.2022-05-11.at.22.07.33.mp4

I think this could be implemented somewhat easily, too. It would require adding a boolean flag to useRect and useSize and drilling that prop through the PopperContent and PopoverContent.

primitives/packages/react/use-rect/src/useRect.tsx

Line 10 in 1096771

function useRect(measurable: Measurable | null) {

primitives/packages/react/use-size/src/useSize.tsx

Line 5 in 1096771

function useSize(element: HTMLElement | SVGElement | null) {

What do you think about it? I could also write the code for this.