Opened 2 years ago

Last modified 3 months ago

#17610 new bug

WebPositive position:fixed/sticky elements jiggle while scrolling

Reported by: thebuck Owned by: pulkomandy
Priority: normal Milestone: Unscheduled
Component: Kits/Web Kit Version: R1/Development
Keywords: Cc:
Blocked By: Blocking:
Platform: All

Description

An intermediate state is rendered for a moment: page scrolled but fixed elements not yet anti-scrolled. The longer the redraw takes, the more prominent jumping can be observed.

Attachments (1)

position-fixed.html​ (863 bytes ) - added by thebuck 2 years ago.
Little testcase

Download all attachments as: .zip

Change History (3)

by thebuck, 2 years ago

Attachment: position-fixed.html​ added

Little testcase

comment:1 by pulkomandy, 2 years ago

I have already started reworking and simplifying the code in the work in progress version of haikuwebkit. Now it uses SetViewBitmap instead of DrawBitmap. However in the current state this only makes things worse. I need to implement BBitmap locking in app_server for non-overlay bitmaps, so that SetViewBitmap can be blocked until WebKit finishes drawing the bitmap.

Without this, we end up drawing to screen before the offscreen bitmap is completed.

This problem would also be solved by migrating to WebKit2, which has a completely different way to manage its offscreen bitmaps.

comment:2 by nephele, 3 months ago

Component: Applications/WebPositive → Kits/Web Kit
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