[OSM-dev] [GSoC] Improvements to Vespucci

Jan Schejbal jan.mailinglisten at googlemail.com
Wed Jul 25 15:05:35 BST 2012


Am 2012-07-25 15:29, schrieb Derick Rethans:
> Is Undo on your planning?

Yes. Appropriate TODO markers informing about the exact data that needs
to be saved on each action are already present in the code.

I plan to do the following:

* "Checkpoints" are created at appropriate intervals, e.g. before each
user-initiated action is actually performed

* Every time an element is changed (this includes creation and deletion,
iff the element is not yet included in the checkpoint, the current state
of the element is stored, including flags indicating if the element is
in currentStorage and apiStorage

On "Undo", a new checkpoint (the "redo" checkpoint) is created and for
each element in the last checkpoint (the "undo" checkpoint), the current
(i.e. changed) state of the element is stored in the redo checkpoint.
After this, the state described by the undo checkpoint is restored
(adding/deleting elements as required and changing the values of the
elements).

Kind regards,
Jan



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