Filter: prevent selection-change notifications in filter invalidation

Invalidating the filter can cause numerous selection-change notifications.
These cause a full UI reload. Therefore, go into "command" mode that was
implemented for the undo commands. Then, all selection-changes are
considered as "programmatical" and ignored.

At the end of filter invalidation, a filter-finished signal causes a
proper reload anyway.

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

qt-models/filtermodels.cpp

@@ -227,6 +227,16 @@ void MultiFilterSortModel::myInvalidate()
 	int i;
 	struct dive *d;
 
+	{
+		// This marker prevents the UI from getting notifications on selection changes.
+		// It is active until the end of the scope.
+		// This is actually meant for the undo-commands, so that they can do their work
+		// without having the UI updated.
+		// Here, it is used because invalidating the filter can generate numerous
+		// selection changes, which do full ui reloads. Instead, do that all at once
+		// as a consequence of the filterFinished signal right after the local scope.
+		auto marker = diveListNotifier.enterCommand();
+
 		divesDisplayed = 0;
 
 		// Apply filter for each dive
@@ -242,6 +252,8 @@ void MultiFilterSortModel::myInvalidate()
 		// Tell the dive trip model to update the displayed-counts
 		DiveTripModelBase::instance()->filterFinished();
 		countsChanged();
+	}
+
 	emit filterFinished();
 
 #if !defined(SUBSURFACE_MOBILE)