SingleDepthTreeModelHelper: new tree model helper class

src/utils/CMakeLists.txt

@@ -20,5 +20,7 @@ set(MR_TIMETABLE_PLANNER_SOURCES
   utils/rs_utils.h
   utils/rs_utils.cpp
 
+  utils/singledepthtreemodelhelper.h
+
   PARENT_SCOPE
 )

src/utils/singledepthtreemodelhelper.h

@@ -0,0 +1,136 @@
+#ifndef SINGLEDEPTHREEMODELHELPER_H
+#define SINGLEDEPTHREEMODELHELPER_H
+
+#include <QAbstractItemModel>
+
+/*!
+ * \brief The SingleDepthTreeModelHelper class
+ *
+ * Helper class to implement single depth tree model like:
+ *
+ * Root
+ * - TopLevel 1
+ *   - Child 1
+ *   - Child 2
+ * - TopLevel 2
+ *   - Child 1
+ *
+ * \tparam Super is the model itself, must have constant NCols
+ * \tparam ModelData must have getTopLevelAtRow(), topLevelCount(), getParentRow(), getParent()
+ * \tparam RowData must have childCount() and ptrForRow()
+ */
+template <typename Super, typename ModelData, typename RowData>
+class SingleDepthTreeModelHelper : public QAbstractItemModel
+{
+public:
+    SingleDepthTreeModelHelper(QObject *p = nullptr) : QAbstractItemModel(p) {}
+
+    // Basic functionality:
+    QModelIndex index(int row, int column,
+                      const QModelIndex &p = QModelIndex()) const override
+    {
+        if(p.isValid())
+        {
+            if(p.row() >= m_data.topLevelCount() || p.internalPointer())
+                return QModelIndex(); //Out of bound or child-most
+
+            auto topLevel = m_data.getTopLevelAtRow(p.row());
+            if(row >= topLevel->childCount())
+                return QModelIndex();
+
+            void *ptr = const_cast<void *>(static_cast<const void *>(topLevel->ptrForRow(row)));
+            return createIndex(row, column, ptr);
+        }
+
+        if(row >= m_data.topLevelCount())
+            return QModelIndex();
+
+        return createIndex(row, column, nullptr);
+    }
+
+    QModelIndex parent(const QModelIndex &idx) const override
+    {
+        if(!idx.isValid())
+            return QModelIndex();
+
+        RowData *item = static_cast<RowData*>(idx.internalPointer());
+        if(!item) //Caption, it's toplevel so no parent
+            return QModelIndex();
+
+        int topLevelRow = m_data.getParentRow(item);
+        if(topLevelRow < 0)
+            return QModelIndex();
+        return index(topLevelRow, 0);
+    }
+
+    int rowCount(const QModelIndex &p) const override
+    {
+        if(p.isValid())
+        {
+            if(p.internalPointer())
+                return 0; //Child most, no childs below so 0 rows
+
+            auto topLevel = m_data.getTopLevelAtRow(p.row());
+            return topLevel->childCount();
+        }
+
+        return m_data.topLevelCount();
+    }
+
+    int columnCount(const QModelIndex &p) const override
+    {
+        return p.isValid() ? 1 : Super::NCols;
+    }
+
+    bool hasChildren(const QModelIndex &p) const override
+    {
+        if(p.isValid())
+        {
+            if(p.internalPointer() || p.row() >= m_data.topLevelCount())
+                return false;
+
+            //Every tree has always childrens otherwhise gets removed
+            return true;
+        }
+
+        return m_data.topLevelCount() > 0;
+    }
+
+    QModelIndex sibling(int row, int column, const QModelIndex &idx) const override
+    {
+        if(!idx.isValid())
+            return QModelIndex();
+
+        if(idx.internalPointer())
+        {
+            //It's a row inside a toplevel tree
+            if(column >= Super::NCols)
+                return QModelIndex();
+
+            void *ptr = idx.internalPointer();
+            if(row != idx.row())
+            {
+                //Calculate new ptr for row
+                RowData *item = static_cast<RowData*>(idx.internalPointer());
+                auto topLevel = m_data.getParent(item);
+                if(!topLevel || row >= topLevel->childCount())
+                    return QModelIndex(); //Out of bound child row
+                ptr = const_cast<void *>(static_cast<const void *>(topLevel->ptrForRow(row)));
+            }
+
+            return createIndex(row, column, ptr);
+        }
+
+        if(column > 0 || row >= m_data.topLevelCount())
+            return QModelIndex(); //Parents (RS Items) have only column zero
+
+        return createIndex(row, 0, nullptr);
+    }
+
+    inline const RowData *getItem(const QModelIndex& idx) const { return static_cast<const RowData*>(idx.internalPointer()); }
+
+protected:
+    ModelData m_data;
+};
+
+#endif // SINGLEDEPTHREEMODELHELPER_H