Cylinders: Add CylindersModelFiltered

When the show_unused_cylinders flag is not set, the cylinder tables
in the equipment tab and the planner should not show unused cylinders.
However, the code in CylindersModel is fundamentally broken if the
unused cylinders are not at the end of the list: The correct number
of cylinders is shown, but not the correct cylinders.

Therefore, add a higher-level CylindersModelFiltered model on top
of CylindersModel that does the actual filtering. Some calls are
routed through to the base model (notably those that take indexes,
as these have to be mapped), for some calls the caller has to get
access to the source model first. We might want to adjust this.

For filtering, reuse the already existing show_cylinder function
and export it via CylindersModel.

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

3 files changed, 114 insertions, 52 deletions

diff --git a/qt-models/cylindermodel.cpp b/qt-models/cylindermodel.cpp
index b1d744c27..c5a0d2272 100644
--- a/qt-models/cylindermodel.cpp
+++ b/qt-models/cylindermodel.cpp
@@ -14,9 +14,9 @@ CylindersModel::CylindersModel(QObject *parent) :
 	changed(false),
 	rows(0)
 {
-	//	enum {REMOVE, TYPE, SIZE, WORKINGPRESS, START, END, O2, HE, DEPTH, MOD, MND, USE};
+	//	enum {REMOVE, TYPE, SIZE, WORKINGPRESS, START, END, O2, HE, DEPTH, MOD, MND, USE, IS_USED};
 	setHeaderDataStrings(QStringList() << "" << tr("Type") << tr("Size") << tr("Work press.") << tr("Start press.") << tr("End press.") << tr("O₂%") << tr("He%")
-						 << tr("Deco switch at") <<tr("Bot. MOD") <<tr("MND") << tr("Use"));
+						 << tr("Deco switch at") <<tr("Bot. MOD") <<tr("MND") << tr("Use") << "Is used");
 
 	connect(&diveListNotifier, &DiveListNotifier::cylindersReset, this, &CylindersModel::cylindersReset);
 }
@@ -29,12 +29,6 @@ QVariant CylindersModel::headerData(int section, Qt::Orientation orientation, in
 		return CleanerTableModel::headerData(section, orientation, role);
 }
 
-CylindersModel *CylindersModel::instance()
-{
-	static CylindersModel self;
-	return &self;
-}
-
 static QString get_cylinder_string(const cylinder_t *cyl)
 {
 	QString unit;
@@ -129,6 +123,28 @@ static QVariant percent_string(fraction_t fraction)
 	return QString("%L1%").arg(permille / 10.0, 0, 'f', 1);
 }
 
+bool CylindersModel::cylinderUsed(int i) const
+{
+	const struct dive *dive = &displayed_dive;
+	if (i < 0 || i >= dive->cylinders.nr)
+		return false;
+	if (is_cylinder_used(dive, i))
+		return true;
+
+	cylinder_t *cyl = get_cylinder(dive, i);
+	if (cyl->start.mbar || cyl->sample_start.mbar ||
+	    cyl->end.mbar || cyl->sample_end.mbar)
+		return true;
+	if (cyl->manually_added)
+		return true;
+
+	/*
+	 * The cylinder has some data, but none of it is very interesting,
+	 * it has no pressures and no gas switches. Do we want to show it?
+	 */
+	return false;
+}
+
 QVariant CylindersModel::data(const QModelIndex &index, int role) const
 {
 	if (!index.isValid() || index.row() >= rows)
@@ -447,40 +463,13 @@ void CylindersModel::clear()
 	}
 }
 
-static bool show_cylinder(struct dive *dive, int i)
-{
-	if (i < 0 || i >= dive->cylinders.nr)
-		return false;
-	if (is_cylinder_used(dive, i))
-		return true;
-
-	cylinder_t *cyl = get_cylinder(dive, i);
-	if (cyl->start.mbar || cyl->sample_start.mbar ||
-	    cyl->end.mbar || cyl->sample_end.mbar)
-		return true;
-	if (cyl->manually_added)
-		return true;
-
-	/*
-	 * The cylinder has some data, but none of it is very interesting,
-	 * it has no pressures and no gas switches. Do we want to show it?
-	 */
-	return prefs.display_unused_tanks;
-}
-
 void CylindersModel::updateDive()
 {
 #ifdef DEBUG_CYL
 	dump_cylinders(&displayed_dive, true);
 #endif
 	beginResetModel();
-	// TODO: this is fundamentally broken - it assumes that unused cylinders are at
-	// the end. Fix by using a QSortFilterProxyModel.
-	rows = 0;
-	for (int i = 0; i < displayed_dive.cylinders.nr; ++i) {
-		if (show_cylinder(&displayed_dive, i))
-			++rows;
-	}
+	rows = displayed_dive.cylinders.nr;
 	endResetModel();
 }
 
@@ -493,7 +482,6 @@ Qt::ItemFlags CylindersModel::flags(const QModelIndex &index) const
 
 void CylindersModel::remove(QModelIndex index)
 {
-
 	if (index.column() == USE) {
 		cylinder_t *cyl = cylinderAt(index);
 		if (cyl->cylinder_use == OC_GAS)
@@ -622,3 +610,54 @@ void CylindersModel::cylindersReset(const QVector<dive *> &dives)
 	// And update the model..
 	updateDive();
 }
+
+CylindersModelFiltered *CylindersModelFiltered::instance()
+{
+	static CylindersModelFiltered self;
+	return &self;
+}
+
+CylindersModelFiltered::CylindersModelFiltered(QObject *parent) : QSortFilterProxyModel(parent)
+{
+	setSourceModel(&source);
+}
+
+void CylindersModelFiltered::updateDive()
+{
+	source.updateDive();
+}
+
+void CylindersModelFiltered::clear()
+{
+	source.clear();
+}
+
+void CylindersModelFiltered::add()
+{
+	source.add();
+}
+
+CylindersModel *CylindersModelFiltered::model()
+{
+	return &source;
+}
+
+void CylindersModelFiltered::remove(QModelIndex index)
+{
+	source.remove(mapToSource(index));
+}
+
+void CylindersModelFiltered::passInData(const QModelIndex &index, const QVariant &value)
+{
+	source.passInData(mapToSource(index), value);
+}
+
+cylinder_t *CylindersModelFiltered::cylinderAt(const QModelIndex &index)
+{
+	return source.cylinderAt(mapToSource(index));
+}
+
+bool CylindersModelFiltered::filterAcceptsRow(int source_row, const QModelIndex &source_parent) const
+{
+	return prefs.display_unused_tanks || source.cylinderUsed(source_row);
+}
diff --git a/qt-models/cylindermodel.h b/qt-models/cylindermodel.h
index 9f9abc836..66f51acca 100644
--- a/qt-models/cylindermodel.h
+++ b/qt-models/cylindermodel.h
@@ -2,6 +2,8 @@
 #ifndef CYLINDERMODEL_H
 #define CYLINDERMODEL_H
 
+#include <QSortFilterProxyModel>
+
 #include "cleanertablemodel.h"
 #include "core/dive.h"
 
@@ -27,7 +29,6 @@ public:
 	};
 
 	explicit CylindersModel(QObject *parent = 0);
-	static CylindersModel *instance();
 	QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
 	int rowCount(const QModelIndex &parent = QModelIndex()) const override;
 	Qt::ItemFlags flags(const QModelIndex &index) const override;
@@ -44,6 +45,7 @@ public:
 	bool changed;
 	QVariant headerData(int section, Qt::Orientation orientation, int role) const override;
 	bool updateBestMixes();
+	bool cylinderUsed(int i) const;
 
 public
 slots:
@@ -54,4 +56,25 @@ private:
 	int rows;
 };
 
+// Cylinder model that hides unused cylinders if the pref.show_unused_cylinders flag is not set
+class CylindersModelFiltered : public QSortFilterProxyModel {
+	Q_OBJECT
+public:
+	CylindersModelFiltered(QObject *parent = 0);
+	static CylindersModelFiltered *instance();
+	CylindersModel *model(); // Access to unfiltered base model
+
+	void clear();
+	void add();
+	void updateDive();
+	cylinder_t *cylinderAt(const QModelIndex &index);
+	void passInData(const QModelIndex &index, const QVariant &value);
+public
+slots:
+	void remove(QModelIndex index);
+private:
+	CylindersModel source;
+	bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const override;
+};
+
 #endif
diff --git a/qt-models/diveplannermodel.cpp b/qt-models/diveplannermodel.cpp
index 65773e13c..3d3f1d0bc 100644
--- a/qt-models/diveplannermodel.cpp
+++ b/qt-models/diveplannermodel.cpp
@@ -37,7 +37,7 @@ void DivePlannerPointsModel::removeSelectedPoints(const QVector<int> &rows)
 		divepoints.remove(v2[i]);
 	}
 	endRemoveRows();
-	CylindersModel::instance()->updateTrashIcon();
+	CylindersModelFiltered::instance()->model()->updateTrashIcon();
 }
 
 void DivePlannerPointsModel::createSimpleDive()
@@ -89,7 +89,7 @@ void DivePlannerPointsModel::loadFromDive(dive *d)
 	const struct event *evd = NULL;
 	enum divemode_t current_divemode = UNDEF_COMP_TYPE;
 	recalc = false;
-	CylindersModel::instance()->updateDive();
+	CylindersModelFiltered::instance()->updateDive();
 	duration_t lasttime = { 0 };
 	duration_t lastrecordedtime = {};
 	duration_t newtime = {};
@@ -162,7 +162,7 @@ void DivePlannerPointsModel::setupCylinders()
 		reset_cylinders(&displayed_dive, true);
 
 		if (displayed_dive.cylinders.nr > 0) {
-			CylindersModel::instance()->updateDive();
+			CylindersModelFiltered::instance()->updateDive();
 			return;		// We have at least one cylinder
 		}
 	}
@@ -180,7 +180,7 @@ void DivePlannerPointsModel::setupCylinders()
 		add_to_cylinder_table(&displayed_dive.cylinders, 0, cyl);
 	}
 	reset_cylinders(&displayed_dive, false);
-	CylindersModel::instance()->updateDive();
+	CylindersModelFiltered::instance()->updateDive();
 }
 
 // Update the dive's maximum depth.  Returns true if max. depth changed
@@ -209,7 +209,7 @@ void DivePlannerPointsModel::removeDeco()
 
 void DivePlannerPointsModel::addCylinder_clicked()
 {
-	CylindersModel::instance()->add();
+	CylindersModelFiltered::instance()->add();
 }
 
 
@@ -317,7 +317,7 @@ bool DivePlannerPointsModel::setData(const QModelIndex &index, const QVariant &v
 			if (value.toInt() >= 0) {
 				p.depth = units_to_depth(value.toInt());
 				if (updateMaxDepth())
-					CylindersModel::instance()->updateBestMixes();
+					CylindersModelFiltered::instance()->model()->updateBestMixes();
 			}
 			break;
 		case RUNTIME:
@@ -343,8 +343,8 @@ bool DivePlannerPointsModel::setData(const QModelIndex &index, const QVariant &v
 				p.cylinderid = value.toInt();
 			/* Did we change the start (dp 0) cylinder to another cylinderid than 0? */
 			if (value.toInt() != 0 && index.row() == 0)
-				CylindersModel::instance()->moveAtFirst(value.toInt());
-			CylindersModel::instance()->updateTrashIcon();
+				CylindersModelFiltered::instance()->model()->moveAtFirst(value.toInt());
+			CylindersModelFiltered::instance()->model()->updateTrashIcon();
 			break;
 		case DIVEMODE:
 			if (value.toInt() < FREEDIVE) {
@@ -799,9 +799,9 @@ void DivePlannerPointsModel::editStop(int row, divedatapoint newData)
 	divepoints[row] = newData;
 	std::sort(divepoints.begin(), divepoints.end(), divePointsLessThan);
 	if (updateMaxDepth())
-		CylindersModel::instance()->updateBestMixes();
+		CylindersModelFiltered::instance()->model()->updateBestMixes();
 	if (divepoints[0].cylinderid != old_first_cylid)
-		CylindersModel::instance()->moveAtFirst(divepoints[0].cylinderid);
+		CylindersModelFiltered::instance()->model()->moveAtFirst(divepoints[0].cylinderid);
 	emitDataChanged();
 }
 
@@ -850,9 +850,9 @@ void DivePlannerPointsModel::remove(const QModelIndex &index)
 		divepoints.remove(index.row());
 	}
 	endRemoveRows();
-	CylindersModel::instance()->updateTrashIcon();
+	CylindersModelFiltered::instance()->model()->updateTrashIcon();
 	if (divepoints[0].cylinderid != old_first_cylid)
-		CylindersModel::instance()->moveAtFirst(divepoints[0].cylinderid);
+		CylindersModelFiltered::instance()->model()->moveAtFirst(divepoints[0].cylinderid);
 }
 
 struct diveplan &DivePlannerPointsModel::getDiveplan()
@@ -907,13 +907,13 @@ void DivePlannerPointsModel::clear()
 {
 	bool oldRecalc = setRecalc(false);
 
-	CylindersModel::instance()->updateDive();
+	CylindersModelFiltered::instance()->updateDive();
 	if (rowCount() > 0) {
 		beginRemoveRows(QModelIndex(), 0, rowCount() - 1);
 		divepoints.clear();
 		endRemoveRows();
 	}
-	CylindersModel::instance()->clear();
+	CylindersModelFiltered::instance()->clear();
 	setRecalc(oldRecalc);
 }