Bug 88700 – Fix RenderLayerCompositor::recursiveRepaintLayerRect to respect transform

• Component: Layout and Rendering
• Status: RESOLVED WONTFIX

[Tien-Ren Chen]

Fix RenderLayerCompositor::recursiveRepaintLayerRect to respect transform

[Tien-Ren Chen]

Created attachment 146686 [details]
Patch

[WebKit Review Bot]

Attachment 146686 [details] did not pass style-queue:

Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/WebCore/ChangeLog', u'Source/WebCor..." exit_code: 1
Source/WebCore/ChangeLog:8:  You should remove the 'No new tests' and either add and list tests, or explain why no new tests were possible.  [changelog/nonewtests] [5]
Total errors found: 1 in 2 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Tien-Ren Chen]

This should fix the bug that text box carets doesn't blink in transformed elements.

As I'll be OOO for 2 weeks, could aelias@ or jknotten@ help me finish the patch? Thanks!

[Adam Barth]

@trchen: Is this patch still current?

[Brent Fulgham]

I would love to r+ this patch, but it's not clear what tests we would look at to confirm it was doing what was expected.

Can you please update the ChangeLog with the relevant tests we should use for this change?

[Tien-Ren Chen]

(In reply to comment #5)
> I would love to r+ this patch, but it's not clear what tests we would look at to confirm it was doing what was expected.
> 
> Can you please update the ChangeLog with the relevant tests we should use for this change?

Test is one issue... Another issue is the algorithmic complexity. The original code applies layer offset incrementally. It takes O(1) to enter a sub-tree. My patch re-runs the transformation chain when arriving every node, taking O(H) to enter a sub-tree at depth H. This makes tree traversal worse than O(H^2)

I'd like to make this patch to do incremental transformation, but it needs to be very careful about fixed position elements. Hopefully we can make use some of the existing code. (RenderGeometryMap looks like what we need)

[Tien-Ren Chen]

The only user of this function is the caret, and now carets are container-aware. Planning to remove the function.