Yesterday I landed in Subversion a branch of
Tasks I've been working on to
remove all confirmation dialogs and replace them with infinite
undo/redo. I'm really pleased with the end result, there are no more
dialogs getting in the way and every action is undoable. To implement
this I adapted MarlinUndoManager from
Marlin by the most excellent Iain
Holmes.
The basic design is that the application has a global undo
context. When an operation which should be undoable occurs, you
start the context, add as many undoables as
required, and then end the context. Allowing a single
undoable action to consist of multiple undoables lets the application
reuse fine-grained logic to build coarse user-level actions (in Tasks
this is used to build the Remove Completed action from multiple Delete
Task actions). To make integrating this into applications even easier, I
wrote a GtkAction which reflects the state of an undo context, so it
is trivial to add redo/undo to the interface.
There is one remaining task left before this is ready to be released: undo support in the edit dialog entries. Once this is done, the next release of Tasks will be announced. I also plan to work with Iain on cleaning up this code and submitting it for inclusion into GTK+.
NP: Money Jungle, Duke Ellington, Charles Mingus, Max Roach