Filter: Make filters aware of added / removed dives

Instead of reloading all the filter, only increment / decrement the
count of the entries of added / removed dives.

Originally, this was planned to be done via the signals from the
divelist, but it turned out that this was suboptimal, because
if the filter decides that the new item is selected, this has to
be done *before* adding the dive. Otherwise, it wouldn't be shown.

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

1 files changed, 154 insertions, 5 deletions

diff --git a/qt-models/filtermodels.cpp b/qt-models/filtermodels.cpp
index f6ff5ea69..1491dbacf 100644
--- a/qt-models/filtermodels.cpp
+++ b/qt-models/filtermodels.cpp
@@ -4,6 +4,7 @@
 #include "core/display.h"
 #include "core/qthelper.h"
 #include "core/subsurface-string.h"
+#include "core/subsurface-qt/DiveListNotifier.h"
 #include "qt-models/divetripmodel.h"
 
 #if !defined(SUBSURFACE_MOBILE)
@@ -159,6 +160,58 @@ void FilterModelBase::updateList(QStringList &newList)
 	endResetModel();
 }
 
+// Decrease count of entry with given name. Remove if count reaches zero.
+// Exception: Don't remove the "Show Empty Tags" entry.
+void FilterModelBase::decreaseCount(const QString &name)
+{
+	if (name.isEmpty()) {
+		// Decrease the "Show Empty Tags" entry. Keep it even if count reaches 0.
+		if (items.empty() || items.back().count <= 0)
+			return; // Shouldn't happen!
+		--items.back().count;
+		int idx = items.size() - 1;
+		dataChanged(createIndex(idx, 0), createIndex(idx, 0));
+		return;
+	}
+
+	int idx = indexOf(name);
+	if (idx < 0 || items[idx].count <= 0)
+		return; // Shouldn't happen
+
+	if(--items[idx].count == 0) {
+		beginRemoveRows(QModelIndex(), idx, idx);
+		items.erase(items.begin() + idx);
+		endRemoveRows();
+	} else {
+		dataChanged(createIndex(idx, 0), createIndex(idx, 0));
+	}
+}
+
+// Increase count of entry with given name. If entry doesn't yet exist, add it.
+void FilterModelBase::increaseCount(const QString &name)
+{
+	if (name.isEmpty()) {
+		// Increase the "Show Empty Tags" entry. Keep it even if count reaches 0.
+		if (items.empty())
+			return; // Shouldn't happen!
+		++items.back().count;
+		int idx = items.size() - 1;
+		dataChanged(createIndex(idx, 0), createIndex(idx, 0));
+		return;
+	}
+
+	int idx = indexOf(name);
+	if (idx < 0) {
+		idx = findInsertionIndex(name);
+		beginInsertRows(QModelIndex(), idx, idx);
+		items.insert(items.begin() + idx, { name, anyChecked, 1 });
+		endInsertRows();
+	} else {
+		++items[idx].count;
+		dataChanged(createIndex(idx, 0), createIndex(idx, 0));
+	}
+}
+
 Qt::ItemFlags FilterModelBase::flags(const QModelIndex &index) const
 {
 	return QAbstractListModel::flags(index) | Qt::ItemIsUserCheckable;
@@ -258,6 +311,16 @@ bool SuitsFilterModel::doFilter(const dive *d) const
 	return negate;
 }
 
+void SuitsFilterModel::diveAdded(const dive *d)
+{
+	increaseCount(QString(d->suit));
+}
+
+void SuitsFilterModel::diveDeleted(const dive *d)
+{
+	decreaseCount(QString(d->suit));
+}
+
 void SuitsFilterModel::repopulate()
 {
 	QStringList list;
@@ -322,6 +385,33 @@ bool TagFilterModel::doFilter(const dive *d) const
 	return negate;
 }
 
+void TagFilterModel::diveAdded(const dive *d)
+{
+	struct tag_entry *head = d->tag_list;
+	if (!head) {
+		increaseCount(QString());
+		return;
+	}
+	while (head) {
+		increaseCount(QString());
+		increaseCount(QString(head->tag->name));
+		head = head->next;
+	}
+}
+
+void TagFilterModel::diveDeleted(const dive *d)
+{
+	struct tag_entry *head = d->tag_list;
+	if (!head) {
+		decreaseCount(QString());
+		return;
+	}
+	while (head) {
+		decreaseCount(QString(head->tag->name));
+		head = head->next;
+	}
+}
+
 BuddyFilterModel::BuddyFilterModel(QObject *parent) : FilterModelBase(parent)
 {
 }
@@ -331,6 +421,15 @@ int BuddyFilterModel::countDives(const char *s) const
 	return count_dives_with_person(s);
 }
 
+static QStringList getDiveBuddies(const dive *d)
+{
+	QString persons = QString(d->buddy) + "," + QString(d->divemaster);
+	QStringList personsList = persons.split(',', QString::SkipEmptyParts);
+	for (QString &s: personsList)
+		s = s.trimmed();
+	return personsList;
+}
+
 bool BuddyFilterModel::doFilter(const dive *d) const
 {
 	// If there's nothing checked, this should show everything
@@ -339,11 +438,7 @@ bool BuddyFilterModel::doFilter(const dive *d) const
 	if (!anyChecked || rowCount() == 0)
 		return true;
 
-	// Checked means 'Show', Unchecked means 'Hide'.
-	QString persons = QString(d->buddy) + "," + QString(d->divemaster);
-	QStringList personsList = persons.split(',', QString::SkipEmptyParts);
-	for (QString &s: personsList)
-		s = s.trimmed();
+	QStringList personsList = getDiveBuddies(d);
 	// only show empty buddie dives if the user checked that.
 	if (personsList.isEmpty())
 		return items[rowCount() - 1].checked != negate;
@@ -357,6 +452,28 @@ bool BuddyFilterModel::doFilter(const dive *d) const
 	return negate;
 }
 
+void BuddyFilterModel::diveAdded(const dive *d)
+{
+	QStringList buddies = getDiveBuddies(d);
+	if (buddies.empty()) {
+		increaseCount(QString());
+		return;
+	}
+	for(const QString &buddy: buddies)
+		increaseCount(buddy);
+}
+
+void BuddyFilterModel::diveDeleted(const dive *d)
+{
+	QStringList buddies = getDiveBuddies(d);
+	if (buddies.empty()) {
+		decreaseCount(QString());
+		return;
+	}
+	for(const QString &buddy: buddies)
+		decreaseCount(buddy);
+}
+
 void BuddyFilterModel::repopulate()
 {
 	QStringList list;
@@ -406,6 +523,16 @@ bool LocationFilterModel::doFilter(const dive *d) const
 	return negate;
 }
 
+void LocationFilterModel::diveAdded(const dive *d)
+{
+	increaseCount(get_dive_location(d));
+}
+
+void LocationFilterModel::diveDeleted(const dive *d)
+{
+	decreaseCount(get_dive_location(d));
+}
+
 void LocationFilterModel::repopulate()
 {
 	QStringList list;
@@ -437,6 +564,28 @@ MultiFilterSortModel::MultiFilterSortModel(QObject *parent) : QSortFilterProxyMo
 {
 }
 
+void MultiFilterSortModel::divesAdded(const QVector<dive *> &dives)
+{
+	// TODO: We call diveAdded for every dive and model.
+	// If multiple dives are added (e.g. import dive) this will lead to a large
+	// number of model changes and might be a pessimization compared to a full
+	// model reload. Instead, the models should take the vector, calculate the
+	// new fields and add them at once.
+	for (FilterModelBase *model: models) {
+		for (const dive *d: dives)
+			model->diveAdded(d);
+	}
+}
+
+void MultiFilterSortModel::divesDeleted(const QVector<dive *> &dives)
+{
+	// TODO: See comment for divesDeleted
+	for (FilterModelBase *model: models) {
+		for (const dive *d: dives)
+			model->diveDeleted(d);
+	}
+}
+
 bool MultiFilterSortModel::showDive(const struct dive *d) const
 {
 	if (curr_dive_site) {