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>

4 files changed, 49 insertions, 9 deletions

diff --git a/commands/command.cpp b/commands/command.cpp
index c173494c0..33c866e72 100644
--- a/commands/command.cpp
+++ b/commands/command.cpp
@@ -304,9 +304,9 @@ int removeCylinder(int index, bool currentDiveOnly)
 	return execute_edit(new RemoveCylinder(index, currentDiveOnly));
 }
 
-int editCylinder(int index, cylinder_t cyl, bool currentDiveOnly)
+int editCylinder(int index, cylinder_t cyl, EditCylinderType type, bool currentDiveOnly)
 {
-	return execute_edit(new EditCylinder(index, cyl, currentDiveOnly));
+	return execute_edit(new EditCylinder(index, cyl, type, currentDiveOnly));
 }
 
 // Trip editing related commands
diff --git a/commands/command.h b/commands/command.h
index 66122ac99..fc1ddf582 100644
--- a/commands/command.h
+++ b/commands/command.h
@@ -92,7 +92,12 @@ int removeWeight(int index, bool currentDiveOnly);
 int editWeight(int index, weightsystem_t ws, bool currentDiveOnly);
 int addCylinder(bool currentDiveOnly);
 int removeCylinder(int index, bool currentDiveOnly);
-int editCylinder(int index, cylinder_t cyl, bool currentDiveOnly);
+enum class EditCylinderType {
+	TYPE,
+	PRESSURE,
+	GASMIX
+};
+int editCylinder(int index, cylinder_t cyl, EditCylinderType type, bool currentDiveOnly);
 #ifdef SUBSURFACE_MOBILE
 // Edits a dive and creates a divesite (if createDs != NULL) or edits a divesite (if changeDs != NULL).
 // Takes ownership of newDive and createDs!
diff --git a/commands/command_edit.cpp b/commands/command_edit.cpp
index d5e2d12d0..c81e67394 100644
--- a/commands/command_edit.cpp
+++ b/commands/command_edit.cpp
@@ -1151,9 +1151,23 @@ void RemoveCylinder::redo()
 	}
 }
 
+static int editCylinderTypeToFlags(EditCylinderType type)
+{
+	switch (type) {
+	default:
+	case EditCylinderType::TYPE:
+		return SAME_TYPE | SAME_SIZE;
+	case EditCylinderType::PRESSURE:
+		return SAME_PRESS;
+	case EditCylinderType::GASMIX:
+		return SAME_GAS;
+	}
+}
+
 // ***** Edit Cylinder *****
-EditCylinder::EditCylinder(int index, cylinder_t cylIn, bool currentDiveOnly) :
-	EditCylinderBase(index, currentDiveOnly, false, SAME_TYPE | SAME_PRESS | SAME_GAS)
+EditCylinder::EditCylinder(int index, cylinder_t cylIn, EditCylinderType typeIn, bool currentDiveOnly) :
+	EditCylinderBase(index, currentDiveOnly, false, editCylinderTypeToFlags(typeIn)),
+	type(typeIn)
 {
 	if (dives.empty())
 		return;
@@ -1184,9 +1198,23 @@ EditCylinder::EditCylinder(int index, cylinder_t cylIn, bool currentDiveOnly) :
 
 	// The base class copied the cylinders for us, let's edit them
 	for (int i = 0; i < (int)indexes.size(); ++i) {
-		free_cylinder(cyl[i]);
-		cyl[i] = cylIn;
-		cyl[i].type.description = copy_qstring(description);
+		switch (type) {
+		case EditCylinderType::TYPE:
+			free((void *)cyl[i].type.description);
+			cyl[i].type = cylIn.type;
+			cyl[i].type.description = copy_qstring(description);
+			cyl[i].cylinder_use = cylIn.cylinder_use;
+			break;
+		case EditCylinderType::PRESSURE:
+			cyl[i].start.mbar = cylIn.start.mbar;
+			cyl[i].end.mbar = cylIn.end.mbar;
+			break;
+		case EditCylinderType::GASMIX:
+			cyl[i].gasmix = cylIn.gasmix;
+			cyl[i].bestmix_o2 = cylIn.bestmix_o2;
+			cyl[i].bestmix_he = cylIn.bestmix_he;
+			break;
+		}
 	}
 }
 
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;
 };