Have a working model for showing the namespaces in a tree with checkboxes.

The namespaces are currently spit into user and system. Later we might
add recognizing namespaces introduced by specific modules/extensions.

pglab/NamespaceItemModel.h

@@ -0,0 +1,126 @@
+#ifndef NAMESPACEITEMMODEL_H
+#define NAMESPACEITEMMODEL_H
+
+#include <QAbstractItemModel>
+#include "PgNamespace.h"
+#include <vector>
+
+class PgNamespaceContainer;
+
+class NamespaceItemModel: public QAbstractItemModel {
+public:
+	NamespaceItemModel(QObject *parent = 0);
+
+	void init(std::shared_ptr<const PgNamespaceContainer> ns);
+
+	virtual QModelIndex index(int row, int column,
+		const QModelIndex &parent = QModelIndex()) const override;
+	virtual QModelIndex parent(const QModelIndex &index) const override;
+
+	virtual int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+	virtual int columnCount(const QModelIndex &parent = QModelIndex()) const override;
+	virtual QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
+	virtual bool setData(const QModelIndex &index, const QVariant &value, int role) override;
+	virtual Qt::ItemFlags flags(const QModelIndex &index) const override;
+
+	//std::set<Oid> getCheckedNamespaces() const;
+
+private:
+//	using NsVec = std::vector<PgNamespace>;
+
+//	class Group {
+//	public:
+//		QString name;
+//		NsVec namespaces;
+//	};
+//	using GrpVec = std::vector<Group>;
+
+//	//std::shared_ptr<const PgNamespaceContainer> m_namespaces;
+//	GrpVec groups;
+
+
+	class Node {
+	public:
+
+		virtual ~Node() {}
+		virtual int getRowCount() const = 0;
+		virtual Qt::CheckState getCheckState() const = 0;
+
+	};
+	class GroupNode;
+
+	class LeafNode: public Node {
+	public:
+		std::weak_ptr<GroupNode> parent;
+		bool checked = false;
+
+		PgNamespace ns;
+		LeafNode(std::weak_ptr<GroupNode> p, const PgNamespace &nspace)
+			: parent(p)
+			, ns(nspace)
+		{}
+
+		virtual int getRowCount() const override
+		{
+			return 0;
+		}
+
+		virtual Qt::CheckState getCheckState() const override
+		{
+			return checked ? Qt::Checked : Qt::Unchecked;
+		}
+
+		bool operator < (const LeafNode &rhs) const
+		{
+			return ns.name < rhs.ns.name;
+		}
+	};
+
+	class GroupNode: public Node {
+	public:
+		using LeafVec = std::vector<std::shared_ptr<LeafNode>>;
+
+		QString name;
+		LeafVec leaves;
+
+		GroupNode(QString n)
+			: name(n)
+		{}
+		virtual int getRowCount() const override
+		{
+			return leaves.size();
+		}
+		void sortLeaves()
+		{
+			std::sort(leaves.begin(), leaves.end(),
+					  [] (auto l, auto r) -> bool { return *l < *r; });
+		}
+		virtual Qt::CheckState getCheckState() const override
+		{
+			bool some_checked = false;
+			bool some_unchecked = false;
+			for (auto l : leaves) {
+				if (l->checked)
+					some_checked = true;
+				else
+					some_unchecked = true;
+			}
+			Qt::CheckState result;
+			if (some_checked && some_unchecked)
+				result = Qt::PartiallyChecked;
+			else if (some_checked)
+				result = Qt::Checked;
+			else
+				result = Qt::Unchecked;
+
+			return result;
+		}
+	};
+
+	using GroupVec = std::vector<std::shared_ptr<GroupNode>>;
+
+	GroupVec groups;
+
+};
+
+#endif // NAMESPACEITEMMODEL_H