This refactors the undo-commands (which are now only "commands").
- Move everything in namespace Command. This allows shortening of
names without polluting the global namespace. Moreover, the prefix
Command:: will immediately signal that the undo-machinery is
invoked. This is more terse than UndoCommands::instance()->...
- Remove the Undo in front of the class-names. Creating an "UndoX"
object to do "X" is paradoxical.
- Create a base class for all commands that defines the Qt-translation
functions. Thus all translations end up in the "Command" context.
- Add a workToBeDone() function, which signals whether this should be
added to the UndoStack. Thus the caller doesn't have to check itself
whether this any work will be done. Note: Qt5.9 introduces "setObsolete"
which does the same.
- Split into public and internal header files. In the public header
file only export the function calls, thus hiding all implementation
details from the caller.
- Split in different translation units: One for the stubs, one for
the base classes and one for groups of commands. Currently, there
is only one class of commands: divelist-commands.
- Move the undoStack from the MainWindow class into commands_base.cpp.
If we want to implement MDI, this can easily be moved into an
appropriate Document class.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
