PICKED_ITEMS_LIST knows the architecture of the undo commands so
that it can delete those ITEMs which it owns. This represents poor
encapsulation so instead of adding yet another case, I added a
UR_TRANSIENT item flag which is set by callers whenever they create
new objects to “give to” the undo/redo stack. This allowed some
cleanup of other code, but cleaning up UR_DELETE and UR_WIRE_IMAGE
will be a bigger task and have to wait for another day.
Fixes: lp:1542018
* https://bugs.launchpad.net/kicad/+bug/1542018
The undo/redo operations are essentially the same as for
UR_CHANGED: we store both the origin marker item and a copy
of it and flip back and forth between the two. This also
required the implementation of clone() for the markers.
The ORIGIN_VIEWMARKER is moved from being a subclass of
EDA_ITEM to BOARD_ITEM to facilitate the use of a UR_CHANGE-
like implementation without having to know the internals
of the ORIGIN_VIEWMARKER.
In the command processors, the setting of the origins is
broken into two parts: one for UI-level access which includes
setting up undo, and one for low-level access which does not.
The undo/redo code itself of course uses the lower level.
Fixes: lp:1542018
* https://bugs.launchpad.net/kicad/+bug/1542018
Marek Roszko
Seth Hillbrand
Maciej Suminski
Jeff Young
Jon Evans
Tomasz Włostowski
Simon Richter
Brian Sidebotham