undo: more fine-grained editing of cylinder

Don't overwrite the full cylinder when editing a single field.
Implement three "modes": editing of type, pressure and gasmix.

Don't consider individual fields, because some of them are
related. E.g. you can change the gasmix by setting the MOD.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

1 files changed, 8 insertions, 1 deletions

diff --git a/commands/command_edit.h b/commands/command_edit.h
index d7c31f7f2..ab842a13c 100644
--- a/commands/command_edit.h
+++ b/commands/command_edit.h
@@ -5,6 +5,7 @@
 #define COMMAND_EDIT_H
 
 #include "command_base.h"
+#include "command.h" // for EditCylinderType
 #include "core/subsurface-qt/divelistnotifier.h"
 
 #include <QVector>
@@ -406,10 +407,16 @@ private:
 	void redo() override;
 };
 
+// Instead of implementing an undo command for every single field in a cylinder,
+// we only have one and pass an edit "type". We either edit the type, pressure
+// or gasmix fields. This has mostly historical reasons rooted in the way the
+// CylindersModel code works. The model works for undo and also in the planner
+// without undo. Having a single undo-command simplifies the code there.
 class EditCylinder : public EditCylinderBase {
 public:
-	EditCylinder(int index, cylinder_t cyl, bool currentDiveOnly); // Clones cylinder
+	EditCylinder(int index, cylinder_t cyl, EditCylinderType type, bool currentDiveOnly); // Clones cylinder
 private:
+	EditCylinderType type;
 	void undo() override;
 	void redo() override;
 };