Refactoring generic tree model behavior

scwx-qt/source/scwx/qt/model/tree_model.cpp

@@ -0,0 +1,145 @@
+#include <scwx/qt/model/tree_model.hpp>
+
+namespace scwx
+{
+namespace qt
+{
+namespace model
+{
+
+static const std::string logPrefix_ = "scwx::qt::model::tree_model";
+
+class TreeModelImpl
+{
+public:
+   explicit TreeModelImpl() = default;
+   ~TreeModelImpl()         = default;
+};
+
+TreeModel::TreeModel(QObject* parent) :
+    QAbstractTableModel(parent), p(std::make_unique<TreeModelImpl>())
+{
+}
+TreeModel::~TreeModel() = default;
+
+int TreeModel::rowCount(const QModelIndex& parent) const
+{
+   const TreeItem* parentItem;
+
+   if (parent.isValid())
+   {
+      parentItem = static_cast<const TreeItem*>(parent.constInternalPointer());
+   }
+   else
+   {
+      parentItem = root_item().get();
+   }
+
+   return parentItem->child_count();
+}
+
+int TreeModel::columnCount(const QModelIndex& parent) const
+{
+   const TreeItem* parentItem;
+
+   if (parent.isValid())
+   {
+      parentItem = static_cast<const TreeItem*>(parent.constInternalPointer());
+   }
+   else
+   {
+      parentItem = root_item().get();
+   }
+
+   return parentItem->column_count();
+}
+
+QVariant TreeModel::data(const QModelIndex& index, int role) const
+{
+   if (!index.isValid() || role != Qt::DisplayRole)
+   {
+      return QVariant();
+   }
+
+   const TreeItem* item = static_cast<const TreeItem*>(index.internalPointer());
+
+   return item->data(index.column());
+}
+
+Qt::ItemFlags TreeModel::flags(const QModelIndex& index) const
+{
+   Qt::ItemFlags flags;
+
+   if (!index.isValid())
+   {
+      flags = Qt::NoItemFlags;
+   }
+   else
+   {
+      flags = QAbstractItemModel::flags(index);
+   }
+
+   return flags;
+}
+
+QVariant
+TreeModel::headerData(int section, Qt::Orientation orientation, int role) const
+{
+   if (orientation == Qt::Horizontal && role == Qt::DisplayRole)
+   {
+      return root_item()->data(section);
+   }
+
+   return QVariant();
+}
+
+QModelIndex
+TreeModel::index(int row, int column, const QModelIndex& parent) const
+{
+   if (!hasIndex(row, column, parent))
+   {
+      return QModelIndex();
+   }
+
+   const TreeItem* parentItem;
+
+   if (!parent.isValid())
+   {
+      parentItem = root_item().get();
+   }
+   else
+   {
+      parentItem = static_cast<const TreeItem*>(parent.constInternalPointer());
+   }
+
+   const TreeItem* childItem = parentItem->child(row);
+   if (childItem)
+   {
+      return createIndex(row, column, childItem);
+   }
+
+   return QModelIndex();
+}
+
+QModelIndex TreeModel::parent(const QModelIndex& index) const
+{
+   if (!index.isValid())
+   {
+      return QModelIndex();
+   }
+
+   const TreeItem* childItem =
+      static_cast<const TreeItem*>(index.constInternalPointer());
+   const TreeItem* parentItem = childItem->parent_item();
+
+   if (parentItem == root_item().get())
+   {
+      return QModelIndex();
+   }
+
+   return createIndex(parentItem->row(), 0, parentItem);
+}
+
+} // namespace model
+} // namespace qt
+} // namespace scwx