Add Number of tracks to Tracks label in Library

[NeuroXS]

#13284

[JoergAtGithub]

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[NeuroXS]

Hey, I've signed the agreement :)

[ronso0]

This doesn't build if ENGINEPRIME is off.

You need to remove the #ifdef ENGINEPRIME around MixxxLibraryFeature::bindSidebarWidget(), move QPointer<WLibrarySidebar> m_pSidebarWidget; declaration etc.

Then it works.

[github-actions]

This PR is marked as stale because it has been open 90 days with no activity.

[ronso0]

While this is just a bandaid for a status bar #10382, it does job for Tracks (and works as expected).
What do you think @mixxxdj/developers ?

LGTM btw.
@NeuroXS Do you think you'll find time to finish this?
If yes, please squash the commits and rebase onto main (and resolve the conflicts).

[NeuroXS]

Hi, I have free time if you think there's something I can do related to this PR, would be cool to have my first merge in Mixxx :D

Last thing i did was solve the conflicts and do the change requested
Sorry, I'm new to github and this is my first PR, let me know if I'm doing a mistake :)

[ywwg]

looks good, congrats on your first contribution!

[ronso0]

Thanks. I took another look and like to improve this a bit.
(the repaint nit is just a question)

[ronso0]

repaint might be cheap, but is there another way to trigger repaint of just the Tracks item?

[ronso0]

Oh, and please rebase to give the actual track count commit a meaningful message ("Final commit" is .. not that helpful if you try to guess the change when looking at a git log ; )
-- drop the merge commit while doing so

[ronso0]

Thanks for the update, and sorry for kind of turning in circles here.
Turns out my performance concern was not relevant in the first place because Qt is smart and only repaints 'dirty' regions, no matter what we request to repaint.

• however, it does repaint the entire view if the changed track count label changes Tracks in a way that the tree width changes (determined by the widest item), which has been is "fixed" by Library sidebar: expand items to full width to maximize click-responsive area -- v2 #15330 btw, but this has not landed in main, yet.

TL;DR
The cleanest update request we can issue is
emit featureIsLoading(this, false /* don't re-select */);
This signal meant to update the sidebar title for Traktor, iTunes and other external features that do dynamic loading.

NeuroXS#1

---

Btw your current implementation won't work as intended.
TreeItem->parentRow() will return -1 for root items, so tracksIndex is invalid and thereby we'd still request to repaint the entire sidebar.

[ronso0]

LGTM, thanks!