1902325 - Remove z-index concept from views.

Status: RESOLVED FIXED

(Core :: Layout, task)

Comment 1

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 1902325 - Remove zIndex concept from views. r=tnikkel,#layout

This comes back to ~since forever, since absolutely positioned elements
used to have views. But now is basically only plumbed from
nsMenuPopupFrame to nsIWidget.

The main issue is that that concept is basically fiction nowadays:

• Wayland can't reorder popups.
• macOS doesn't implement it because SetZIndex calls PlaceBehind which
  only has a windows impl.
• Unclear whether it works properly on Windows as well.

Also, the front-end never sets it anyways.

So remove this fiction to simplify relevant code. We might want to
provide a z-ordering of popups somehow else, but it should probably live
in nsXULPopupManager etc rather than nsView.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/fc3e01bf7b80
Remove zIndex concept from views. r=tnikkel,layout-reviewers

Comment 3

[pstanciu]

https://hg.mozilla.org/mozilla-central/rev/fc3e01bf7b80