1402197 - Add an option for GetTransformToAncestor to stop at stacking contexts and displayport

Status: RESOLVED FIXED

(Core :: Layout, enhancement, P3)

Description

[Matt Woodrow (:mattwoodrow)]

Attachment: transform-to-ancestor

Retained display lists wants a way to convert coordinates into the coordinate space of the nearest ancestor with a stacking context or displayport and this seemed the easiest way to achieve that.

Comment 1

[Markus Stange [:mstange]]

Comment on attachment 8911020 [details] [diff] [review]
transform-to-ancestor

Review of attachment 8911020 [details] [diff] [review]:
-----------------------------------------------------------------

::: layout/generic/nsFrame.cpp
@@ +10523,5 @@
> +}
> +
> +// If you change any of these, also change the computation in BuildDisplayListForChild
> +bool
> +nsIFrame::IsStackingContext() {

You could make these two functions take a bunch of optional arguments for the things that nsIFrame::BuildDisplayListForChild already has. The default value for those optional arguments would then do the manual lookups that you do here. Not sure if that will work, but if it does, then you can share the code and don't need the comments.

::: layout/generic/nsIFrame.h
@@ +2790,5 @@
>     *   into points in aOutAncestor's coordinate space.
>     */
> +  enum {
> +    IN_CSS_UNITS = (1 << 0),
> +    STOP_AT_STACKING_CONTEXT_AND_DISPLAY_PORT = (1 << 1)

no need for the parens

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/92dd76c32727
Add an option for GetTransformToAncestor to stop at stacking contexts and displayport. r=mstange

Comment 3

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/92dd76c32727