[Overlay] Expose this internal component

[stunaz]

Hi,
I would be nice to have a boolean property to show/hide an overlay with the popover.

[dano-giftbit]

We're looking at using the Overlay component with a custom Search component overlaid on it

To accomplish we're importing material-ui/internal/Overlay which works well but feels fragile with the "internal" nesting of the Overlay.

Given the various use cases, it might make sense to make Overlay a public component?

[oliviertassinari]

We do have an overlay component. I don't think that we should be backing it into the Popover. Still we could potentially move it out of the internal folder and document it.

[the-noob]

As far as I can see there is a backdrop with the Popover with alpha 1, it would be good to be able to control that as, in some cases, makes sense to let the user know any other interaction is disabled.

i.e. I have a colour palette with swatches that show edit/delete actions on hover and, when clicking edit, a Popover with a colour picker shows right beneath. At this point, as there is no visual clue that the Popover is a blocking action, users reported that hovering over other swatches doesn't work.

[oliviertassinari]

The Popover inherits the properties of the Modal component. You can already provide a BackdropInvisible, BackdropClassName and BackdropComponent property. I will work on exposing the Modal component to the public API so the feature is better documented.

The issue can be closed. Here is a demo: https://codesandbox.io/s/322l1n9ym6.