change frozen style like google spreadsheet

[xianzhi3]

Hi, @ndrsn I changed the frozen style like google spreadsheet.
You can have a test at the link below.
https://90zfd.csb.app/demo.html

[ndrsn]

Hi @xianzhi3 thanks for this. I believe I've discovered two bugs/quirks. For now I can only reproduce the one below here:

I'll see if I can narrow down the other later this week.

[xianzhi3]

@ndrsn I fixed the quirks bug

[ndrsn]

Hi! Great! I managed to reproduce the other one. The recording is a bit long, because I'm not sure which parts of it are relevant, but here is the weird behavior:

[xianzhi3]

@ndrsn I fixed the recording issue. You can test it at the same link.

[mdebrauw]

Hi @xianzhi3 I (visually) tested this too using the link you provided.

Still seeing some weird behaviour, sudden and fast mouse movements seem to make the grid disappear for a moment.

[xianzhi3]

It works well in my end. What is your computer OS?

[mdebrauw]

Chrome Version 98.0.4758.80 (Official Build) (arm64) on macOs Monetery (12.0)

Also tests on Safari (Version 15.0 (17612.1.29.5))

[ndrsn]

I can reproduce this as well — see the white screen near the end of the animation. Only once I move the mouse again the grid re-renders:

(I am on macOS as well, for the record)

[ndrsn]

Another one:

[hangxingliu]

I think the key to reproduce this bug is:

You drag the frozen marker and let your mouse leave the browser, then backed to the grid.

And the grid is empty(only has white background) until you move your mouse to trigger next render.

[ndrsn]

You drag the frozen marker and let your mouse leave the browser, then backed to the grid.

Maybe that's one edge-case as well, but in this example I don't leave the browser boundaries with my cursor:

And here's another (longer) recording, taken after I've left this tab open for a few hours (not sure if that's relevant, but my perception is that the issue becomes more frequent in this recording):

(Apologies for the million open tabs, I am seeking professional help)

[hangxingliu]

@ndrsn can you have a test on this demo: https://9l3dgo.csb.app/

the changes between the demo and the latest commit of this PR are here:

(btw, you may can try the extension named OneTab or Better OneTab for organizing the tabs)

[ndrsn]

@hangxingliu that seemed to work, thanks! But why, though? The behaviour seemed a little flaky/inconsistent, and it's not clear to me how this fix explains what was happening.

I'll be happy to merge this (including your fix), and don't want to cause anyone more work, but if you or @xianzhi3 can explain what the bug was and why this change is the fix we need, I'll be a little more confident in merging :-)

[hangxingliu]

@ndrsn I am not 100 percent sure my guess is correct. If I need to explain to you, I need another test for this bug. But I am working on the refactoring of self.selections for performance purpose (On another branch with unstaged changes). I can test it again and tell you after I finished the util functions of it.

[ndrsn]

@hangxingliu That sounds reasonable! Do you suggest we merge this now? If this is part of the code you guys will be touching anyway, I trust any lingering bugs will be ironed out anyway :-)

[hangxingliu]

@ndrsn The investigation of this bug is almost done, I will write it in the Slack channel one message by one message. I think you can merge this PR and the patch after you read them.

[ndrsn]

Alright! @xianzhi3 can you fix the merge conflicts? Then I'll merge right after.

Update: noticed some things in the diff which I can't quite link to the frozen style change proposed — not sure if they're GitHub messing up the diff (it does that some times), or if they're unrelated changes that somehow snuck into the PR. @xianzhi3 , do you know? Perhaps a rebase is in order?

[ndrsn]

Great work @xianzhi3 and @hangxingliu, thanks a lot!