Add undo/redo for parameter changes

[GoogleCodeExporter]

I've always wanted the ability to undo/redo synth parameter changes when 
experimenting (without having to revert to a previously saved version of the 
preset).  I took a shot at implementing this for changes made using the GUI - 
attached is a patch against the latest commit.  

Let me know what you think!

Josh

Original issue reported on code.google.com by joshua.t...@gmail.com on 17 Feb 2014 at 4:03

Attachments:

• UndoRedo.diff

[GoogleCodeExporter]

Thanks for the patch, I've just tested it and it certainly seems to do the job!

Just one potential niggle - shouldn't the undo/redo buffer be reset after 
loading a new preset? Because undo/redo will no longer get you back to the 
sound you had before...

Original comment by nickdowell on 18 Feb 2014 at 6:17

• Changed state: Started
• Added labels: Type-Enhancement
• Removed labels: Type-Defect

[GoogleCodeExporter]

Thanks for checking it out!  I agree that the buffers should be cleared between 
presets, and that's how it behaves for me - the call to 
Preset::clearUndoStacks() that I put in the Preset = operator overload and 
Preset::fromString are there for that reason.  What behaviour are you seeing?  
(did I miss an edge case, or does it just never clear for you?)

Original comment by joshua.t...@gmail.com on 19 Feb 2014 at 12:53

[GoogleCodeExporter]

My bad; I think I got confused during testing.

What I think happened is I hit ctrl-R to randomize all the values (which is 
kind of like loading a new, albeit random, sound). In this case the undo buffer 
is not cleared but hitting undo will not go back to your previous sound.

What do you think should happen in this case? I think we should either clear 
the undo buffer (because it will not do what the user really wants it to do) or 
find a way to undo a randomize event - but I can see that's a little trickier 
to implement so don't mind either way.

Original comment by nickdowell on 19 Feb 2014 at 6:06

[GoogleCodeExporter]

Ahhhh, got it.  I think there's a lot of value in implementing undo for 
randomization as well (have you ever heard a really cool sound while 
randomizing and accidentally skipped past it?) - I'll provide a patch that 
handles this as soon as I can.

Original comment by joshua.t...@gmail.com on 21 Feb 2014 at 3:32

[GoogleCodeExporter]

This patch (also against the current public code) supports undo/redo for 
arbitrary sequences of parameter changes and randomisations.  The buffers clear 
when changing to a new preset (I've tried to address every possible way in 
which this can happen).  Let me know what you think!

Josh

Original comment by joshua.t...@gmail.com on 22 Feb 2014 at 5:54

Attachments:

• UndoRedoWithRandomise.diff

[GoogleCodeExporter]

Works like a charm; thanks!
Patch now applied to main repo.

Original comment by nickdowell on 1 Mar 2014 at 3:04

• Changed state: Fixed