Initial commit.

src/core/mergedproxymodel.h

@@ -0,0 +1,110 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef MERGEDPROXYMODEL_H
+#define MERGEDPROXYMODEL_H
+
+#include "config.h"
+
+#include <memory>
+
+#include <QAbstractProxyModel>
+
+std::size_t hash_value(const QModelIndex& index);
+
+class MergedProxyModelPrivate;
+
+class MergedProxyModel : public QAbstractProxyModel {
+  Q_OBJECT
+
+ public:
+  explicit MergedProxyModel(QObject* parent = nullptr);
+  ~MergedProxyModel();
+
+  // Make another model appear as a child of the given item in the source model.
+  void AddSubModel(const QModelIndex& source_parent, QAbstractItemModel* submodel);
+  void RemoveSubModel(const QModelIndex& source_parent);
+
+  // Find the item in the source model that is the parent of the model
+  // containing proxy_index.  If proxy_index is in the source model, then
+  // this just returns mapToSource(proxy_index).
+  QModelIndex FindSourceParent(const QModelIndex& proxy_index) const;
+
+  // QAbstractItemModel
+  QModelIndex index(int row, int column, const QModelIndex& parent) const;
+  QModelIndex parent(const QModelIndex& child) const;
+  int rowCount(const QModelIndex& parent) const;
+  int columnCount(const QModelIndex& parent) const;
+  QVariant data(const QModelIndex &proxyIndex, int role = Qt::DisplayRole) const;
+  bool hasChildren(const QModelIndex& parent) const;
+  QMap<int, QVariant> itemData(const QModelIndex& proxyIndex) const;
+  Qt::ItemFlags flags(const QModelIndex& index) const;
+  bool setData(const QModelIndex& index, const QVariant& value, int role);
+  QStringList mimeTypes() const;
+  QMimeData* mimeData(const QModelIndexList& indexes) const;
+  bool dropMimeData(const QMimeData* data, Qt::DropAction action, int row, int column, const QModelIndex& parent);
+  bool canFetchMore(const QModelIndex& parent) const;
+  void fetchMore(const QModelIndex& parent);
+
+  // QAbstractProxyModel
+  // Note that these implementations of map{To,From}Source will not always
+  // give you an index in sourceModel(), you might get an index in one of the
+  // child models instead.
+  QModelIndex mapFromSource(const QModelIndex& sourceIndex) const;
+  QModelIndex mapToSource(const QModelIndex& proxyIndex) const;
+  void setSourceModel(QAbstractItemModel* sourceModel);
+
+  // Convenience functions that call map{To,From}Source multiple times.
+  QModelIndexList mapFromSource(const QModelIndexList& source_indexes) const;
+  QModelIndexList mapToSource(const QModelIndexList& proxy_indexes) const;
+
+signals:
+  void SubModelReset(const QModelIndex& root, QAbstractItemModel* model);
+
+ private slots:
+  void SourceModelReset();
+  void SubModelReset();
+
+  void RowsAboutToBeInserted(const QModelIndex& source_parent, int start, int end);
+  void RowsInserted(const QModelIndex& source_parent, int start, int end);
+  void RowsAboutToBeRemoved(const QModelIndex& source_parent, int start, int end);
+  void RowsRemoved(const QModelIndex& source_parent, int start, int end);
+  void DataChanged(const QModelIndex& top_left, const QModelIndex& bottom_right);
+
+  void LayoutAboutToBeChanged();
+  void LayoutChanged();
+
+ private:
+  QModelIndex GetActualSourceParent(const QModelIndex& source_parent,
+                                    QAbstractItemModel* model) const;
+  QAbstractItemModel* GetModel(const QModelIndex& source_index) const;
+  void DeleteAllMappings();
+  bool IsKnownModel(const QAbstractItemModel* model) const;
+
+  QMap<QAbstractItemModel*, QPersistentModelIndex> merge_points_;
+  QAbstractItemModel* resetting_model_;
+
+  QMap<QAbstractItemModel*, QModelIndex> old_merge_points_;
+
+  std::unique_ptr<MergedProxyModelPrivate> p_;
+};
+
+#endif  // MERGEDPROXYMODEL_H
+