(feat) Computer feature: use library data model if selected path is watched by library

[ronso0]

Fixes #14683
Related: #11026 #9897

TL:DR

If the selected path is watched by library, we show it like the other track views (Tracks, Crates, ..).
This gives us the same the view (colums) and editing capabilities.
Watched paths are currently marked with an orange cyan dot:

This is really handy if you want to browse your library by path!
Supposed to enhance the Sidebar Bookmarks use case #14508.

Details

If the path is watched, we use an alternative model (derived from LibraryTableModel, uses track data).
Luckily, LibraryTableModel already allows to use an extra search filter (not visible in the searchbox) which allows to filter tracks by directory. (such a filter is also used in Analyze view)
Since BrowseFeature tells the library to load its model on click, switching between the file / track model works flawlessly.

This also introduces SidebarItemDelegate to do the painting.

Note:
The header is different for the file / track views (eg. the file view does not have the rating column), but the views can be made somewhat similar by adjusting the headers once.

• adopt search query when switching between file / track model
• add subtle decoration if path item is watched (probably with sidebar delegate from (feat) add Library sidebar bookmarks #14508)
• cache isWatchedPath property to avoid string comparison when expanding the tree?
• don't rebuild child tree if watched path is expanded? (update on demand with "Refresh directory tree")
  try to adopt solution from (feat) add Library sidebar bookmarks #14508
• update TreeItems' isWatchedPath flag when directories have been added to or removed from library
• also switch view model in that case, if current view is affected?

TODO

• use ibrary view in Recording, too postponed, will happen as followup
• verify all commits build
• test on Linux
• test on Windows
• test on macOS
• test with watched network shares on all OS
• make it work with Tracks: allow saving & loading columns layout #14479, ie.

[ronso0]

Hehe, I tested this in a session with my personal branch (ie. on top of Sidebar Bookmakrs PR #14508) and it all works as expected!

[ronso0]

Cool, I merged this and #14508 Sidebar Bookmarks into my performace branch, and it works nicely!
Just had to adjust the columns, then I had the same tracks view as in Tracks.

[Eve00000]

Testing on Windows

• Quick Links & Devices only give a blue dot
• No data from dbase shown
  see image, properties window is opened from deck 2 genre & comment in dbase, not in trackview
  

[ronso0]

Hmm, weird.
Only the folder with the dot uses the library view.
But it should apply to all children since they are subfolders.

I'll check, maybe I messed up something during the rebase.

[ronso0]

No data from dbase shown [in subfolders]

Looks like I screwed that up with a fixup..
Fixed, please try again.

[Eve00000]

.. Fixed, please try again.

Looks like you fixed it, I only have blue dots, is that correct?

[ronso0]

Yes, that's it.
Root cause is that we extraFilter is wrapped into a SqlNode and SqlNode::match() always returns true.
Hence the check

bool shouldBeInResultSet = searchQuery.isEmpty() ||
        pQuery->match(pTrack);

that is supposed to add dirty tracks is pointless / counter-productive.

I'll file a separate issue if I don't find a quick fix myself.

edit fixed by #15597 in 2.5

[ronso0]

the Computer browse feature should be more of a raw view of the disk and only enhanced by library metadata. Maybe we could gray hidden tracks out?

FWIW hidden tracks are not filtered.
Run a library scan to see the true state of the directory in case you added/removed tracks.

[daschuer]

This is a 2.7 candidate.

[ronso0]

Great 🎉

This is a massive change set, so I understand that's it's been sitting so long.
I skimmed through the commits again and noticed I still need t clean up a few things and can improve comments.
I'll try to do that soonish and let you know when I'm done (remove Draft state).

Let me know if you wanna start reviewing before I'm done.