[Lazarus] Undo/Redo in Form Designer

[Chavoux Luyt]

Hi

When I click the "Save all" button, don't Lazarus save only the files
that have changed since the last save? In that case, a "snapshot"
needs only store the information that will be saved when the "Save
all" button is clicked (and this information should be known somewhere
in Lazarus). AFAIK that will be diffs of the .pas, .lfm and possibly
the .lrs files of the current unit/form (and possibly of the project
file and other units if changes were made to more than 1 unit). The
point I am trying to make is that partial diffs of only the files that
were actually changed (in memory), will work.

How far back do we want undo/redo to go? Do we want to be able to
revert to a state from before the last "Save all"? Do we want to
revert to changes done before Lazarus was closed the previous time
(i.e. should these changes be saved when the project is closed)?

Cheers
Chavoux