Undo: isolate undo-commands

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>

1 files changed, 3 insertions, 4 deletions

diff --git a/desktop-widgets/simplewidgets.cpp b/desktop-widgets/simplewidgets.cpp
index b7f985bc9..72a81d873 100644
--- a/desktop-widgets/simplewidgets.cpp
+++ b/desktop-widgets/simplewidgets.cpp
@@ -18,7 +18,7 @@
 #include "desktop-widgets/divelistview.h"
 #include "core/display.h"
 #include "profile-widget/profilewidget2.h"
-#include "desktop-widgets/undocommands.h"
+#include "desktop-widgets/command.h"
 #include "core/metadata.h"
 
 class MinMaxAvgWidgetPrivate {
@@ -171,8 +171,7 @@ void RenumberDialog::buttonClicked(QAbstractButton *button)
 				renumberedDives.append(QPair<int, int>(dive->id, newNr++));
 			}
 		}
-		UndoRenumberDives *undoCommand = new UndoRenumberDives(renumberedDives);
-		MainWindow::instance()->undoStack->push(undoCommand);
+		Command::renumberDives(renumberedDives);
 
 		mark_divelist_changed(true);
 		MainWindow::instance()->dive_list()->restoreSelection();
@@ -246,7 +245,7 @@ void ShiftTimesDialog::buttonClicked(QAbstractButton *button)
 				if (d->selected)
 					affectedDives.append(d);
 			}
-			MainWindow::instance()->undoStack->push(new UndoShiftTime(affectedDives, amount));
+			Command::shiftTime(affectedDives, amount);
 		}
 	}
 }