Enable reordering of tracks in play queue

[phoerious]

Track entries can't be reordered in the play queue. Dragging them only creates a copy. This is very unintuitive. Dragging a track should move it, not duplicate it. Copying of entries could be implemented with Alt + drag similar to duplicating layers in Photoshop.

[luisegallego]

https://github.com/luisgmarine/nightingale-hacking/commit/c240dfb089ee0918d65e68480c9df17baa300826
The only problem that I am encountering is that when you reorder a track (click + drag) to the end of the play queue, the track entry is copied and not removed. Everywhere else the reordering of track(s) works just fine. In Addition, when you press (Alt + drag), the entire nightingale window is moved (this happens from any location within the UI). So maybe a different combination of keys is needed or perhaps there is a way to have (Alt + drag) duplicate track entries only when the event takes place within the play queue.

[freaktechnik]

Nice! Do you have an idea why that would be, as just from looking at the code it should always remove the original item.

EDIT: also, normally control duplicates items. Not sure if we have any duplication mechanism already in nightingale (for example in playlists). If we do, we should use the same technique.

[thebecwar]

Definitely should be ctrl to dup the item.

Also, does this method handle drag and drop from the OS, and if it does have you tested to make sure that it doesn't remove the selected item if it's a drop from outside the application?

[luisegallego]

@freaktechnik , no I don't have the slightest idea why it would not work for the last item. As for a copy mechanism I tried Ctrl + Drag in a regular playlist and nothing special happened. I would have to look at the code to confirm that such an option doesn't exist.

@thebecwar One of the main things I like to do with the play queue is drop new songs from my desktop ( I assume this would be drag and drop from the OS) to the play queue. This enables me to listen to all the tracks I want without having to actually import them to my library or physically move them to one of my watched folders (also adds them to my library).

[luisegallego]

The commit now reflects changes to fix the removal of the duplicate track entry when it is added to the end of the play queue. (Sorry if was obvious to other people :) ). Anyhow, I will try to add the ctrlKey feature to allow users to duplicate the tracks.

[freaktechnik]

Sorry @luisgmarine, but I was tempted to add the missing lines in order to fix this issue. As you can see the nsIDragSession (passed as aSession) contains information about what the intent of the session is.

[luisegallego]

No problem at all @freaktechnik. You actually taught me something so I am a happy camper!

[freaktechnik]

@luisgmarine Well, I had to dig deep into documentations and other code to find that, I don't know all the nsAPIs...