mobile/divelist: implement model that shows all dives in trip-order

MobileSwipeModel is probably not an ideal name, but all I could come up with.

One of the main complications here is that our list is reversed with respect to
the source model. We should change that one day.  Probably by moving the
sorting down to the core-model.

Since looking up the source row is somewhat expensive, the lookup is cached for
a single entry because accesses come in bursts for a single dive. This should
be a good compromise and avoids keeping track of a full row-to-dive array.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 56 insertions, 1 deletions

diff --git a/qt-models/mobilelistmodel.h b/qt-models/mobilelistmodel.h
index f5214d9bd..2ec8cbd8c 100644
--- a/qt-models/mobilelistmodel.h
+++ b/qt-models/mobilelistmodel.h
@@ -4,7 +4,7 @@
 // MobileListModel presents a list of trips and optionally the dives of
 // one expanded trip. It is used for quick navigation through trips.
 //
-// MobileDiveListModel gives a linearized view of all dives, sorted by
+// MobileSwipeModel gives a linearized view of all dives, sorted by
 // trip. Even if there is temporal overlap of trips, all dives of
 // a trip are listed in a contiguous block. This model is used for
 // swiping through dives.
@@ -109,18 +109,73 @@ private slots:
 	void changed(const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector<int> &roles);
 };
 
+class MobileSwipeModel : public MobileListModelBase {
+	Q_OBJECT
+public:
+	MobileSwipeModel(DiveTripModelBase *source);
+	static MobileSwipeModel *instance();
+	void resetModel(DiveTripModelBase::Layout layout);	// Switch between tree and list view
+private:
+	struct IndexRange {
+		int first, last;
+	};
+	std::vector<IndexRange> rangeStack;
+	std::vector<int> firstElement; // First element of top level item.
+	int rows;
+	QVariant data(const QModelIndex &index, int role) const override;
+	int rowCount(const QModelIndex &parent) const override;
+
+	// Since accesses to data come in bursts, we cache map-to-source lookup.
+	// Note that this is not thread safe. We suppose that the model is only ever accessed from the UI thread.
+	mutable int cachedRow = -1;
+	mutable QModelIndex cacheSourceParent;
+	mutable int cacheSourceRow = -1;
+
+	// Translate indexes from/to source
+	int topLevelRowCountInSource(int sourceRow) const;
+	QModelIndex mapToSource(const QModelIndex &index) const;
+	int mapTopLevelFromSource(int row) const;
+	int mapTopLevelFromSourceForInsert(int row) const;
+	int elementCountInTopLevel(int row) const;
+	int mapRowFromSource(const QModelIndex &parent, int row) const;
+	int mapRowFromSource(const QModelIndex &parent) const;
+	int mapRowFromSourceForInsert(const QModelIndex &parent, int row) const;
+	IndexRange mapRangeFromSource(const QModelIndex &parent, int first, int last) const;
+	void invalidateSourceRowCache() const;
+	void updateSourceRowCache(int row) const;
+
+	// Update elements
+	void initData();
+	int removeTopLevel(int begin, int end);
+	void addTopLevel(int row, std::vector<int> items);
+	void updateTopLevel(int row, int delta);
+signals:
+	void currentDiveChanged(QModelIndex index);
+private slots:
+	void doneReset();
+	void prepareRemove(const QModelIndex &parent, int first, int last);
+	void doneRemove(const QModelIndex &parent, int first, int last);
+	void prepareInsert(const QModelIndex &parent, int first, int last);
+	void doneInsert(const QModelIndex &parent, int first, int last);
+	void prepareMove(const QModelIndex &parent, int first, int last, const QModelIndex &dest, int destRow);
+	void doneMove(const QModelIndex &parent, int first, int last, const QModelIndex &dest, int destRow);
+	void changed(const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector<int> &roles);
+};
+
 // This convenience class provides access to the two mobile models.
 // Moreover, it provides an interface to the source trip-model.
 class MobileModels {
 public:
 	static MobileModels *instance();
 	MobileListModel *listModel();
+	MobileSwipeModel *swipeModel();
 	void clear(); // Clear all dive data
 	void reset(); // Reset model after having reloaded the core data
 private:
 	MobileModels();
 	DiveTripModelTree source;
 	MobileListModel lm;
+	MobileSwipeModel sm;
 };
 
 // Helper functions - these are actually defined in DiveObjectHelper.cpp. Why declare them here?