Slow switching of Views - Long thread

[JimmXinu]

Thanks! I haven't been following qt6 dev very much.

Attached is a VM test version with the change.

Posted test version in PI thread.

[chaley]

FWIW: you can easily determine whether apply_state() has the save_state named parameter.

        import inspect
        x = inspect.signature(self.gui.library_view.apply_state)
        has_save_state = 'save_state' in x.parameters

inspect.signature() appeared in python 3 so this won't work on calibre 4 and earlier, so your exception method might be a better solution. Or directly checking the calibre version.

[chaley]

Originally Posted by JimmXinu

Thanks! I haven't been following qt6 dev very much.

Attached is a VM test version with the change.

It works. save_state() is called only once, regardless of how I change VLs.

[BetterRed]

FTR - last evening my time, I ripped the custom columns out of jnikkir's library. That had some effect but it was still slower than I would have expected, given the one column sort sequence didn't change and VL switching was instant.

@JimmXinu - I'll do some tests of the new VM plugin in my 5.38 install, and when Kovid posts a new portable 5.99 beta I'll test it under that too. Be interesting to see if the small delays I get with VM switching are reduced, I've assumed they were due to my multi-column sort sequences - which are my raison d'être for using VM.

@jnikkir - thanks for your cooperation & perseverance, without it the 'bug' would not have been fixed.

BR

[chaley]

Originally Posted by BetterRed

@JimmXinu - I'll do some tests of the new VM plugin in my 5.38 install, and when Kovid posts a new portable 5.99 beta I'll test it under that too. Be interesting to see if the small delays I get with VM switching are reduced, I've assumed they were due to my multi-column sort sequences - which are my raison d'être for using VM.

There won't be any performance change in 5.38 unless you are running from source.

[BetterRed]

Originally Posted by chaley

There won't be any performance change in 5.38 unless you are running from source.

Installing it under 5.38 is for 'backward compatibility' testing

Installing it under next portable 5.99 beta will tell us if it your changes improves my non-problematic View switching performance - or has any unwanted side-effects

BR

[nikosan]

Originally Posted by BetterRed

@jnikkir - thanks for your cooperation & perseverance, without it the 'bug' would not have been fixed.

No way, you guys are the heroes! I really appreciate all the back & forth as we worked through this.

Originally Posted by chaley

There won't be any performance change in 5.38 unless you are running from source.

I am indeed using 5.38 and didn't see a change with VM 1.7.1, so I'm going to show my ignorance one more time by asking... what does "running from source" mean? What's the best way to get this up and running? =S

[ownedbycats]

It means setting up a development environment, downloading Calibre's source code, and running from that. You don't necessarily need to be a dev -- I do it myself for new features and bugfixes.

https://manual.calibre-ebook.com/develop.html

If you go this path, I recommend SourceTree -- I believe chaley uses it too.

[nikosan]

Originally Posted by ownedbycats

It means setting up a development environment, downloading Calibre's source code, and running from that. You don't necessarily need to be a dev -- I do it myself for new features and bugfixes.

https://manual.calibre-ebook.com/develop.html

If you go this path, I recommend SourceTree -- I believe chaley uses it too.

Thank you! I'm going to look into that. Is there another way to get this working, or is running from source the only option?

[JimmXinu]

The other option is just to wait for the next Calibre version release.

[BetterRed]

Originally Posted by JimmXinu

The other option is just to wait for the next Calibre version release.

. . . on Friday of next week.

Or, if it comes sooner, you could get a sneak peek by installing the portable edition of the next version 6 beta, see ==>> Plugin devs: Upcoming migration to Qt 6

BR

[JimmXinu]

qt6 beta 5.99.8 doesn't have that change yet.

[nikosan]

Originally Posted by JimmXinu

The other option is just to wait for the next Calibre version release.

Originally Posted by BetterRed

. . . on Friday of next week.

Or, if it comes sooner, you could get a sneak peek by installing the portable edition of the next version 6 beta, see ==>> Plugin devs: Upcoming migration to Qt 6

Oh that's soon!! Okay... I am going to try and be patient and wait for the next release, but I might keep an eye on that beta page anyway. Thank you, all!

[nikosan]

Just wanted to pop back into this thread and say, all delays in loading VM Views are, indeed, totally gone now (at least when I'm not relying on Action Chains to change the VM view). After updating to Calibre 5.39.0 and installing View Manager 1.7.1, I set each VM view to switch to a specific virtual library, and now CTRL+Tabbing between them instantly loads the correct VL and VM column layout. Yay!!

Using Action Chains (set to change VM views when clicking on a VL tab) does reintroduce some delay. As chaley mentioned earlier, apparently that delay is intentional to "improve performance." So I'm trying to rely less on clicking a tab and having Action Chains change the VM view, and more on using CTRL+Tab to switch VLs/VM views.

I kind of wish there was a shortcut to load the previous VM view, in addition to CTRL+Tab which loads "next view," but that's a not a huge deal.

Thanks again to everyone who helped figure out what was up with those delays. It makes switching between VM views so much smoother.

[JimmXinu]

I've posted a VM test version with Previous View action. Note that you have to set your own hotkeys.