A possible alternative would be to have the main thread already paint a
displayport at the target position of a requested visual update as part of
the same transaction that requests the update.
There are a couple of reasons we may not want to do that:
1) APZ could reject the requested visual update under certain conditions,
e.g. if there is a higher-priority layout update.
2) It would break the property that the displayport in the main thread's
scroll metadata is relative to the scroll offset in said metadata.
Various places assume this and untangling that seems tricky.
This does mean that if the main thread requests a visual update to "far away"
(outside the existing displayport), we can get temporary checkerboarding
before the content at the target position is painted. However, it's
straightforward for callers to work around that, by changing the layout scroll
offset _and_ scheduling a visual update if they wish to visual-scroll far
away.
Differential Revision: https://phabricator.services.mozilla.com/D23902
--HG--
extra : moz-landing-system : lando
These macros tend to be handled quite poorly since the clang-format
tokenizer cannot figure out how to handle them.
Differential Revision: https://phabricator.services.mozilla.com/D13179
--HG--
extra : moz-landing-system : lando
This commit attempts to lower the pain of modifying FrameMetrics.h.
It looks like most includes really only want ViewID or
ScrollableLayerGuid, so this commit factors them out into a separate
header. In the process FrameMetrics::ViewID is changed to
ScrollableLayerGuid::ViewID, which personally seems like a better
place for it now that we have RepaintRequest. Unfortunately that
requires a lot of places to be updated.
After this commit there are still a couple of major places that
FrameMetrics is included.
* nsDisplayList.h
* nsIScrollableFrame.h
* Layers.h
Those are going to be more tricky or impossible to fix so they're
not in this commit.
Differential Revision: https://phabricator.services.mozilla.com/D10722
--HG--
rename : gfx/layers/FrameMetrics.h => gfx/layers/ScrollableLayerGuid.h
rename : gfx/layers/FrameMetrics.h => gfx/layers/ZoomConstraints.h
extra : rebase_source : 29ac79f91460a181bf7437af5c371207e22858e2
extra : source : c2e70e531075493fc6e374dcec862827f0bc6e77
FrameMetrics is currently used in about three ways.
1. Main thread to APZ transactions
2. Storing information in AsyncPanZoomController
3. APZ to main thread repaint requests
There's overlap in the use of fields in all these use cases, but it's not perfect. In a
following commit, I'd like to change the information used for (1) to support relative
scroll offset updates. This information isn't needed for (2) or (3), so it would be
good to refactor FrameMetrics out into these use cases.
This commit refactors out (3) as it is fairly easy to do. I'd like to refactor (2) out
as well, but that is trickier. I'd like to leave that for a future followup.
Differential Revision: https://phabricator.services.mozilla.com/D7127
--HG--
extra : rebase_source : f0be2be24fce7d0f0ed25f6f3bfab5f7f2864f23
extra : source : fc9898a9ab28cee292e201ddaf757ee267179433
extra : histedit_source : 35415d3dc2c0ae0f269994c385cceff75f150020
Botond Ballo
Sylvestre Ledru
Ehsan Akhgari
Ryan Hunt