Undo: select dives after add, remove, merge, split dive commands

Select the proper dives after the add, remove, split and merge
dives commands on undo *and* redo. Generally, select the added
dives. For undo of add, remember the pre-addition selection.
For redo of remove, select the closest dive to the first removed
dive.

The biggest part of the commit is the signal-interface between
the dive commands and the dive-list model and dive-list view.
This is done in two steps:
1) To the DiveTripModel in batches of trips. The dive trip model
   transforms the dives into indices.
2) To the DiveListView. The DiveListView has to translate the
   DiveTripModel indexes to actual indexes via its QSortFilterProxy-
   model.

For code-reuse, derive all divelist-changing commands from a new base-class,
which has a flag that describes whether the divelist changed. The helper
functions which add and remove dives are made members of the base class and
set the flag is a selected dive is added or removed.

To properly detect when the current dive was deleted it
became necessary to turn the current dive from an index
to a pointer, because indices are not stable.

Unfortunately, in some cases an index was expected and these
places now have to transform the dive into an index. These
should be converted in due course.

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

1 files changed, 14 insertions, 5 deletions

diff --git a/core/subsurface-qt/DiveListNotifier.h b/core/subsurface-qt/DiveListNotifier.h
index fe5ea0e22..35ecf108d 100644
--- a/core/subsurface-qt/DiveListNotifier.h
+++ b/core/subsurface-qt/DiveListNotifier.h
@@ -17,10 +17,10 @@ signals:
 	// Note that there are no signals for trips being added / created / time-shifted,
 	// because these events never happen without a dive being added / created / time-shifted.
 
-	// We send one divesAdded, divesDeleted, divesChanged and divesTimeChanged signal per trip
-	// (non-associated dives being considered part of the null trip). This is ideal for the
-	// tree-view, but might be not-so-perfect for the list view, if trips intermingle or
-	// the deletion spans multiple trips. But most of the time only dives of a single trip
+	// We send one divesAdded, divesDeleted, divesChanged and divesTimeChanged, divesSelected
+	// signal per trip (non-associated dives being considered part of the null trip). This is
+	// ideal for the tree-view, but might be not-so-perfect for the list view, if trips intermingle
+	// or the deletion spans multiple trips. But most of the time only dives of a single trip
 	// will be affected and trips don't overlap, so these considerations are moot.
 	// Notes:
 	// - The dives are always sorted by start-time.
@@ -31,7 +31,16 @@ signals:
 	void divesMovedBetweenTrips(dive_trip *from, dive_trip *to, bool deleteFrom, bool createTo, const QVector<dive *> &dives);
 	void divesTimeChanged(dive_trip *trip, timestamp_t delta, const QVector<dive *> &dives);
 
-	// This signal is sent if the selection of dives and/or the current dive changed
+	// Selection-signals come in two kinds:
+	//  - divesSelected, divesDeselected and currentDiveChanged are finer grained and are
+	//    called batch-wise per trip (except currentDiveChanged, of course). These signals
+	//    are used by the dive-list model and view to correctly highlight the correct dives.
+	//  - selectionChanged() is called once at the end of commands if either the selection
+	//    or the current dive changed. It is used by the main-window / profile to update
+	//    their data.
+	void divesSelected(dive_trip *trip, const QVector<dive *> &dives);
+	void divesDeselected(dive_trip *trip, const QVector<dive *> &dives);
+	void currentDiveChanged();
 	void selectionChanged();
 public:
 	// Desktop uses the QTreeView class to present the list of dives. The layout