User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b) Gecko/20050125 Firefox/1.0+ Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b) Gecko/20050125 Firefox/1.0+ Testcase and screenshot coming up. Table with a css :hover rule to highlight table rows as the mouse passes over them. If I scroll whilst hovering (mousewheel), then some rows that were previously passed over contain partially coloured rows. Re-hovering over the rows statically (not scrolling) restore the proper colour. Regression from 1.7.5 Reproducible: Always Steps to Reproduce: 1. View testcase 2. Scroll whilst hovering over table 3. Watch as parts of table rows are 1 colour, other parts of the same row get a different background.
Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.8b) Gecko/20050127 it is easier seen on Firefox trunk but also reproducable on mozilla Trunk. I´ve used cursor keys or mousewheel to scroll while hovering, both was showing the bug.
I haven't seen this bug in a 2005-01-19 trunk build, but I can see it in a 2005-01-20 build. I think this could maybe be a regression from fixing bug 244366. Just scrolling with the mousewheel is enough for me to trigger the bug, although I have to repeat it a few times.
Hmm... I just tried the testcase in a 2005-01-25-06 Linux trunk build on Linux and I can't reproduce (scrolling with arrow keys, since I don't have a mousewheel). Same for a debug Firefox build from the 25th. So first of all, is anyone seeing this on a platform other than Windows?
Maybe you can reproduce it when you have smooth scrolling enabled? (I could not reproduce it with the arrow keys without smooth scrolling)
(In reply to comment #6) > Maybe you can reproduce it when you have smooth scrolling enabled? (I could not > reproduce it with the arrow keys without smooth scrolling) I don´t use smooth scrolling, as I´m on a slow celeron 333. I crashed on 2nd testcase by just loading it and going back. (used view-source inbetween )
interesting... without smooth scrolling, I can't reproduce this on linux/gtk2/trunk (checkout finish: Mo Jan 24 19:23:08 CET 2005), but with smooth scrolling I see it _sometimes_ (rarely). I only tried scrolling with mouse wheel in these experiments. Retesting using arrow keys and page up/down shows that this also works to reproduce this bug, when smooth scroll is enabled. since I needed to enable smooth scroll to enable this, maybe I'm seeing a different bug. on the other hand, maybe smooth scrolling only increases the chances of seeing this bug.
The initial report was performed with smooth scrolling enabled. I've retested with smooth scrolling disabled, and can still reproduce - but (a)not as often and (b)it's a whole row that is left painted wrongly, and not just little bits of several rows
So how does one go about enabling smooth scrolling in a Seamonkey build?
(In reply to comment #10) > So how does one go about enabling smooth scrolling in a Seamonkey build? It's on the very 1st Appearence tab under preferences IIRC.
Created attachment 172705 [details] [diff] [review] Maybe this would help I still can't reproduce this (keyboard scrolling, smooth scroll on and off, debug firefox or opt seamonkey build), but could someone who sees it try this patch? It might help.
notes: - I'm also seeing this on checkout finish: Fr Jan 28 21:59:05 CET 2005 (2.5 hours ago) - bz's patch does not seem to help for me
OK, I finally managed to reproduce this (had to find a debug GTK2 build to do so). As far as I can tell, it looks like the part of the patch to bug 244366 that "caused" this bug was removing the synchronous repaint in nsEventStateManager::PreHandleEvent. If I put this back in, things seem to get better. Also, if I force the "no scrollwidget" codepath in nsScrollPortView::Scroll, the bug seems to disappear. I'm guessing that the sequence of events here is the following: 1) The invalidates triggered by the style change are stored on the root view of the viewmanager in absolute coordinates. 2) When we bit-blit, we move the widget without invalidating it. 3) This ends up causing a style change, which stashes the area that stopped being hovered in the dirty region from step 1, and posts an event to invalidate later. 4) We scroll again, bit-blit again. 5) The invalidate is processed and invalidates the wrong part of the widget (since the right part has moved from the area that's marked as needing invalidation). Conclusion: It looks like the widget bit-blit needs to process pending updates, if there are any, before blitting. Robert, thoughts?
Created attachment 172817 [details] [diff] [review] Proposed patch
What makes you think that we won't scroll while refresh is disabled?
Nothing, unfortunately. We were already failing to handle this case, though... The problem is that at the moment we accumulate damage areas for all sorts of updates on the root view. Then when we invalidate we apply the damage to all the widgets. If one widget moves, we need to remember to apply the damage to that one widget in a different coordinate system from other widgets. I guess what I could do is that if a widget moves while refresh is disabled, the scrollable view accumulates all damage areas for all ancestors into its damage region and offsets it accordingly. This will cause us to do extra invalidates for scrolling while refresh is disabled, but it's the only way I see of getting this right given the current setup.
Yeah, that sounds OK.
Comment on attachment 172817 [details] [diff] [review] Proposed patch minusing for new patch
Another option is that when we scroll we walk through all views, and any dirty region that intersects the bounds of the scrollview gets copied, shifted by the scroll amount, and Or'ed with itself. I think that would also fix the correctness issue here. It'd make us do some extra painting, maybe, but maybe not...
So the difference between comment 20 and comment 17 is that we'd only shift the part of the region that overlapped the view bounds. Which we'd have to put in the same coordinate system as the region and all... Or is that adding in unnecessary complication?
Created attachment 173145 [details] [diff] [review] Patch per comment 20 Note that the sign of the point we offset the intersection by is the opposite of the nsScrollPortView.cpp code used to do. I'm convinced that that change is correct for two reasons: 1) The theoretical justification in the comment when the sign is flipped 2) The fact that without that change the bug didn't go away. ;)
Assignee: roc → bzbarsky
OS: Windows XP → All
Hardware: PC → All
Target Milestone: --- → mozilla1.8beta
Status: NEW → RESOLVED
Last Resolved: 14 years ago
Resolution: --- → FIXED
This may have fixed bug 201198
Confirming that today's Firefox nightly doesn't display the bug anymore. As an aside, it's actually improved over 1.7.5 - 1.7.5 disabled :hover effects whilst scroling, and only painted when scrolling ended - now the :hover paints during the scrolling as well. Thanks bz!
Status: RESOLVED → VERIFIED
This caused build bustage on VS6, which still is not fixed at least for Windows ME. See bug 281158.
Component: Layout: View Rendering → Layout: Web Painting
Product: Core → Core
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