Remove TabParent::mChildProcessOffsetAtTouchStart

RESOLVED FIXED in Firefox 40

Status

()

Core
DOM: Content Processes
RESOLVED FIXED
3 years ago
3 years ago

People

(Reporter: kats, Assigned: kats)

Tracking

unspecified
mozilla40
Points:
---

Firefox Tracking Flags

(firefox40 fixed)

Details

Attachments

(1 attachment)

TabParent::mChildProcessOffsetAtTouchStart was added back in bug 833795 when things were quite different, and input events would go through the APZ fairly late in the flow. This variable was added to make sure that input events were in a consistent coordinate system. However, things have changed quite a bit since then (in particular input events go through APZ much earlier) and so we should not need this variable any more. Instead it can just be replaced by calls to GetChildProcessOffset().
Attachment #8586180 - Flags: review?(botond)
Comment on attachment 8586180 [details] [diff] [review]
Patch

Review of attachment 8586180 [details] [diff] [review]:
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The exact history of this code is too nebulous to trace in detail, but on a high level:

   - at one point, TabChild would feed APZ events that were transformed by this cached offset
       - there was a corresponding un-transform in the Recv*Tap functions
   - today, TabChild no longer applies this transformation by the cached offset 
       - (rather, an equivalent transformation by the up-to-date offset is done in APZCTreeManager)
       - so it doesn't make sense to keeping un-transforming by the cached offset in Recv*Tap, either
Attachment #8586180 - Flags: review?(botond) → review+
https://hg.mozilla.org/mozilla-central/rev/28de2ef94e20
Status: NEW → RESOLVED
Last Resolved: 3 years ago
status-firefox40: --- → fixed
Resolution: --- → FIXED
Target Milestone: --- → mozilla40
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