undo: implement addBookmark undo command

Create a new translation unit for event-related undo commands.
Create a base class of commands that add events and one subclass
that adds a bookmark event.
Use this command in the profile-widget.

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

commands/command_event.cpp

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "command_event.h"
+#include "core/dive.h"
+#include "core/subsurface-qt/divelistnotifier.h"
+#include "core/libdivecomputer.h"
+
+namespace Command {
+
+AddEventBase::AddEventBase(struct dive *dIn, int dcNrIn, struct event *ev) :
+	d(dIn), dcNr(dcNrIn), eventToAdd(ev)
+{
+}
+
+bool AddEventBase::workToBeDone()
+{
+	return true;
+}
+
+void AddEventBase::redo()
+{
+	struct divecomputer *dc = get_dive_dc(d, dcNr);
+	eventToRemove = eventToAdd.get();
+	add_event_to_dc(dc, eventToAdd.release()); // return ownership to backend
+	invalidate_dive_cache(d);
+}
+
+void AddEventBase::undo()
+{
+	struct divecomputer *dc = get_dive_dc(d, dcNr);
+	remove_event_from_dc(dc, eventToRemove);
+	eventToAdd.reset(eventToRemove); // take ownership of event
+	eventToRemove = nullptr;
+	invalidate_dive_cache(d);
+}
+
+AddEventBookmark::AddEventBookmark(struct dive *d, int dcNr, int seconds) :
+	AddEventBase(d, dcNr, create_event(seconds, SAMPLE_EVENT_BOOKMARK, 0, 0, "bookmark"))
+{
+	setText(tr("Add bookmark"));
+}
+
+} // namespace Command