Switching between sources causes a small popup to appear and disappear sometimes

[heartsucker]

STR

1. run rm -r ~/.securedrop_client in sd-app
2. run the qubes-installed client against a staging server with 100 sources (you probably don't need this much but this is what i tested with)
3. during the first sync, click on the first source in the sourcelist and hold the down arrow key until you get down to the bottom of the list

Expected

Smooth scrolling with a bit of a delay the longer the source list is

Actual

A small popup quickly appears and disappears (you might miss it so keep those eyes peeled).

Notes

This might have been introduced in #345, which removed changes that were put in to fix #185, because no one was able to see a reproduction of the issue and thought it had to do with using a tiling window manager. We could reapply the #185 fix to see if that resolves the issue now that we have an STR.

[redshiftzero]

no flicker is happening for me on sync or when switching conversations on master

[heartsucker]

I think the root cause is that I'm using a tiling window manager, so that when a widget disappears the WM tries to resize the window. This causes the flicker. This probably isn't a bug on normal WM's because they do not attempt to resize the window, and any manual resize done by the user would not occur in the split second where the widgets are being switched.

Given that no Qt / GTK apps I use with a tiling WM ever have this problem, it leads me to believe that we may be doing something wrong in our code. As we continue to write more code and do more complex things, potentially with very long conversations, these lags may become apparent to the user (or maybe not, I really don't know).

[emkll]

Confirming that this can also be reproduced (though is much less noticeable) in XFCE. when this occurs, there's a corresponding set of log messages in syslog:

Dec 10 13:54:45 localhost qubes-gui[500]: ERROR reading WM_HINTS
Dec 10 13:54:45 localhost qubes-gui[500]: got num_mfn=0x0 for window 0xc0001e (30797x-17260554)
Dec 10 13:54:45 localhost qubes-gui[500]: ERROR reading WM_HINTS

[eloquence]

Since Jen's comment in May I think many of us have seen the brief flicker of a window sometimes rapidly popping up and closing when switching between conversations, which may or may not be the same issue heartsucker originally reported. Either way, let's use this issue to track.

I've only been able to repro this in Qubes, and it's easiest to see by rapidly switching between a lot of sources.

I've not seen any similar issue with sync so added "needs repro" for that portion.

[eloquence]

This camera shot shows a small window being visible for a fraction of a second as I switch between sources in Qubes:

You can see it in real-time in this video):
https://youtu.be/UMBDIPFf5xY?t=5

[redshiftzero]

this is caused by deleting the entire conversation view and redrawing it on sync or source changed, see #473

[eloquence]

Thanks, #473 is in the backlog so removing this, but keeping it open until we confirm that the bug is indeed resolved by the implementation proposed there.

[eloquence]

Maybe because syncs are faster now, I am seeing this a lot more frequently.

[eloquence]

I still see this window flicker in Qubes even with #688 merged. I can most reliably reproduce it on the NY test instance by cursor-selecting through the source list while messages/replies are being downloaded. It now seems uncommon during normal use.

[eloquence]

Observed once today in 20200225-060103 nightly when cursor-selecting over sources.

[eloquence]

Sadly we're not completely rid of this issue yet.

STR that work for me reliably in 0.2.3-deb/0.2.3-rpm prod build:

1. Clear out data directory and DB in sd-app
2. Run the client
3. Switch between conversations during first sync

It is much less frequent now; I'm not seeing it during subsequent syncs without updates, or in normal conversation switching.

[eloquence]

Correction, after having the client up for a while, I was also able to see the flicker again intermittently, so it's not just on first sync.

[eloquence]

Also just saw flickering once in offline mode (switched to a source with a lot of widgets in the conversation view, if that makes a difference), though it's very elusive.

[sssoleileraaa]

I'll try to repro today. I thought by no longer deleting and adding widgets every time there is a sync or a source selection change we had fixed this. As far as the speech bubble widget flicker goes, that'll probably take a separate PR to fix since it's in a different area of the code, but I'll have to repro to get a better idea.

[eloquence]

Why does the creation of the ConversationView result in a full WM-decorated window popping up? Is there any way that we can reduce flicker by adjusting initial draw size, or otherwise suppress it?

If it's just on first load it's far less significant, of course. I'll see if I can still get the flicker after the first load on current builds.

[eloquence]

On re-reading your comment, the behavior I see in 0.2.5-deb prod build is consistent with what you're describing. I can see the flicker when viewing a source for the first time in a given session, but not on subsequent views of the same source.

That still translates to fairly frequent flickering during initial use of the client.

[sssoleileraaa]

STR that work for me reliably in 0.2.3-deb/0.2.3-rpm prod build:

1. Clear out data directory and DB in sd-app
2. Run the client
3. Switch between conversations during first sync

I am not seeing this on the client 0.2.0-dev-20200626-060133. Here's exactly what I did:

1. ran rm -r ~/.securedrop_client in sd-app
2. ran the qubes-installed client
3. during the first sync, clicked on different sources to view their conversations (on my staging instance i have about 5 sources)

[sssoleileraaa]

Also just tested with 100 sources and still can't repro. I have seen this in the past, so either it's been fixed or there is something not mentioned in the STR or our Qubes workstations are configured differently so that this issue shows up with your configuration but not mine. I think we should screen share if this does happen to you in a reproducible way.

[eloquence]

Yeah, it happens very reproducibly to me in a Qubes prod environment -- I just have to click on anywhere around ~1-20 sources after loading the client to see it. Happy to screen-share to figure out what might be causing the difference.

[sssoleileraaa]

After my screenshare with @eloquence he showed me a way to see the issue every time:

1. run rm -r ~/.securedrop_client in sd-app
2. run the qubes-installed client against a staging server with 100 sources (you probably don't need this much but this is what i tested with)
3. during the first sync, clicked on the first source in the sourcelist and hold the down arrow key until you get down to the bottom of the list and you should see a small popup quickly appear and disappear (you might miss it so keep those eyes peeled)

[emkll]

This issue seems to reliably occur for me when the source I am switching to has a large number (10?) files.

[eloquence]

Deferring again for now in favor of the slightly more troubling #1121 but will pick this up again soon.

[eloquence]

One day we will get back to you, bug #352! 👀

[sssoleileraaa]

Looks like only STR so far is still: #352 (comment)

[eloquence]

Anecdotally, it somewhat seems to correlate with the number of download widgets for a given source as well.

[sssoleileraaa]

Updated issue description to include an STR and notes