Filter: separate backend from frontend logic

The filter code was an unholy intermixture of backend and frontend
logic, which made it hard to access it from outside of the UI.
Notably, it expected that Qt would call filterAcceptsRow on all rows.
For trip-view, apparently the filter functions were called twice
(once for filtering the trip, then for filtering the individual dives).

Make the filtering explicit, by calling showDive() for all dives in
MultiFilterSortModel::myInvalidate(), setting the hidden_by_filter
flags accordingly and ultimately invalidating the filter.

The UI code only accesses the hidden_by_filter flag set previously.

The "justCleared" flag can then be removed, since accessing the filter
does not have side effects. Moreover, there is no noticeable performance
gain by returning out early.

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

qt-models/filtermodels.cpp

@@ -362,7 +362,6 @@ void LocationFilterModel::addName(const QString &newName)
 
 MultiFilterSortModel::MultiFilterSortModel(QObject *parent) : QSortFilterProxyModel(parent),
 	divesDisplayed(0),
-	justCleared(false),
 	curr_dive_site(NULL)
 {
 }
@@ -376,7 +375,7 @@ bool MultiFilterSortModel::showDive(const struct dive *d) const
 		return same_string(ds->name, curr_dive_site->name) || ds->uuid == curr_dive_site->uuid;
 	}
 
-	if (justCleared || models.isEmpty())
+	if (models.isEmpty())
 		return true;
 
 	for (const FilterModelBase *model: models) {
@@ -393,42 +392,23 @@ bool MultiFilterSortModel::filterAcceptsRow(int source_row, const QModelIndex &s
 	QVariant diveVariant = sourceModel()->data(index0, DiveTripModel::DIVE_ROLE);
 	struct dive *d = (struct dive *)diveVariant.value<void *>();
 
-	if (d) {
+	// For dives, simply check the hidden_by_filter flag
-		// Current row is a dive
+	if (d)
-		bool show = showDive(d);
+		return !d->hidden_by_filter;
-		filter_dive(d, show);
-		return show;
-	}
 
-	// From here on, the current row is a trip
+	// Since this is not a dive, it must be a trip
-	if (curr_dive_site) {
+	QVariant tripVariant = sourceModel()->data(index0, DiveTripModel::TRIP_ROLE);
-		bool showTrip = false;
+	dive_trip *trip = (dive_trip *)tripVariant.value<void *>();
-		for (int i = 0; i < sourceModel()->rowCount(index0); i++) {
-			QModelIndex child = sourceModel()->index(i, 0, index0);
-			d = (struct dive *)sourceModel()->data(child, DiveTripModel::DIVE_ROLE).value<void *>();
-			dive_site *ds = get_dive_site_by_uuid(d->dive_site_uuid);
-			if (!ds)
-				continue;
-			if (same_string(ds->name, curr_dive_site->name) || ds->uuid == curr_dive_site->uuid) {
-				if (ds->uuid != curr_dive_site->uuid) {
-					qWarning() << "Warning, two different dive sites with same name have a different id"
-						   << ds->uuid << "and" << curr_dive_site->uuid;
-				}
-				showTrip = true; // do not shortcircuit the loop or the counts will be wrong
-			}
-		}
-		return showTrip;
-	}
 
-	if (justCleared || models.isEmpty())
+	if (!trip)
-		return true;
+		return false; // Oops. Neither dive nor trip, something is seriously wrong.
 
-	bool showTrip = false;
+	// Show the trip if any dive is visible
-	for (int i = 0; i < sourceModel()->rowCount(index0); i++) {
+	for (d = trip->dives; d; d = d->next) {
-		if (filterAcceptsRow(i, index0))
+		if (!d->hidden_by_filter)
-			showTrip = true; // do not shortcircuit the loop or the counts will be wrong
+			return true;
 	}
-	return showTrip;
+	return false;
 }
 
 void MultiFilterSortModel::myInvalidate()
@@ -440,6 +420,14 @@ void MultiFilterSortModel::myInvalidate()
 
 	divesDisplayed = 0;
 
+	// Apply filter for each dive
+	for_each_dive (i, d) {
+		bool show = showDive(d);
+		filter_dive(d, show);
+		if (show)
+			divesDisplayed++;
+	}
+
 	invalidateFilter();
 
 	// first make sure the trips are no longer shown as selected
@@ -464,11 +452,6 @@ void MultiFilterSortModel::myInvalidate()
 		dlv->selectDives(curSelectedDives);
 	}
 
-	for_each_dive (i, d) {
-		if (!d->hidden_by_filter)
-			divesDisplayed++;
-	}
-
 	emit filterFinished();
 
 	if (curr_dive_site) {
@@ -491,11 +474,9 @@ void MultiFilterSortModel::removeFilterModel(FilterModelBase *model)
 
 void MultiFilterSortModel::clearFilter()
 {
-	justCleared = true;
 	Q_FOREACH (FilterModelBase *iface, models) {
 		iface->clearFilter();
 	}
-	justCleared = false;
 	myInvalidate();
 }
 

qt-models/filtermodels.h

@@ -111,7 +111,6 @@ signals:
 private:
 	MultiFilterSortModel(QObject *parent = 0);
 	QList<FilterModelBase *> models;
-	bool justCleared;
 	struct dive_site *curr_dive_site;
 };