API to get what was changed with the last action (better GetProjectStateChangeCount)

[amagalma]

EDIT: Old title:
API: GetProjectStateChangeCount to return undo flags

It would be super-useful to know not only if something got changed in the project but also a hint to what it was (if not exactly what it was).

So, a second return value to show the flags for undo:

1: track configurations
2: track FX
4: track items
8: project states
16: freeze states

integer, flags = reaper.GetProjectStateChangeCount(ReaProject proj)
returns an integer that changes when the project state changes, and the undo flags associated with the change

Edit: New proposal at post #5

[Meo-Ada Mespotine]

I would prefer to enumerate the last x undostates, like

integer undoflags, string descchangename, string undo_statechunk_snippet =  reaper.Undo_GetState(integer idx)

parameters:
integer idx - the index of the undostate with 1 for the most recent

retvals:
integer undoflags - the undoflags set for this undostate
string descchangename - the "name" of the undostate, as shown in the undo-list/set by descchange in Undo_EndBlock
string undo_state_information - the change made by this undo-state, as shown by the context menu "Undo state information" in the Undo history-list.

This would be more versatile, especially, as you would probably want to know other undostates as well.

It would also allow us writing scripts, who analyze the undo-states and get all undostate-names, so Undo_OnStateChangeEx2 would benefit from it as well.

[amagalma]

This would be super! Especially the Undo Differences snippet!

I would prefer the enumeration to start with 0 for the last undo. 1 for the previous one, 2 for the previous before the previous etc
We might require a CountUndoStates function too..

But really, I would only care for the last undo. A function that returned the flags and the changed chunk snippet would be super for me! The name of the undo we can get it already with Undo_CanUndo2.

So, something like this would be super efficient for my needs:

integer undoflags, string undo_statechunk_snippet = reaper.Undo_GetLastUndoState(ReaProject proj)

[Meo-Ada Mespotine]

But sometimes, scripts produce numerous undo-states, as per behavior of some functions. So if your script creates one undo-state you're interested in and after that another one, getting the last undo-state would only give you the other one, not the one you were interested in. Getting more undo-states would give you full control, so some kind of index would be needed for that. Even if it's only optional with nil being the last one.

integer undoflags, string undo_statechunk_snippet = reaper.Undo_GetLastUndoState(ReaProject proj, optional integer undoindex)

[amagalma]

I am still thinking about this.. I am trying to create a Track Edit Groups script like in Pro Tools and I greatly need this to speed up things..

Would something like this make sense? :

integer changed_objects_count = reaper.CountLastUndoChanges(ReaProject proj)
returns the number of reaper objects that changed in the last undo

*void pointer, string "ctypename", string str = reaper.GetLastUndoChangeDetails(ReaProject proj, integer idx)

returns the pointer and type of object that changed with the last action, associated with the idx number.
Supported types are: "MediaTrack*", "MediaItem*", "MediaItem_Take*", "TrackEnvelope*" and "PCM_source*"
str holds the relative RPPXMLstate line(s) that changed

What do you think?

[vitalker]

+1 from me