simpletreemodel example: rename parent() to parentItem() for clarity

I show this example during trainings, and parent() is too much like
QObject::parent(), QModelIndex::parent() and our model's parent()
[which calls this method], so it's less confusing if this is called
something clearer like parentItem().

Change-Id: I101342051349d94c4a3bc3d4bc332194d6779293
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>

examples/widgets/itemviews/simpletreemodel/treeitem.cpp

@@ -51,65 +51,65 @@
 //! [0]
 TreeItem::TreeItem(const QList<QVariant> &data, TreeItem *parent)
 {
-    parentItem = parent;
-    itemData = data;
+    m_parentItem = parent;
+    m_itemData = data;
 }
 //! [0]
 
 //! [1]
 TreeItem::~TreeItem()
 {
-    qDeleteAll(childItems);
+    qDeleteAll(m_childItems);
 }
 //! [1]
 
 //! [2]
 void TreeItem::appendChild(TreeItem *item)
 {
-    childItems.append(item);
+    m_childItems.append(item);
 }
 //! [2]
 
 //! [3]
 TreeItem *TreeItem::child(int row)
 {
-    return childItems.value(row);
+    return m_childItems.value(row);
 }
 //! [3]
 
 //! [4]
 int TreeItem::childCount() const
 {
-    return childItems.count();
+    return m_childItems.count();
 }
 //! [4]
 
 //! [5]
 int TreeItem::columnCount() const
 {
-    return itemData.count();
+    return m_itemData.count();
 }
 //! [5]
 
 //! [6]
 QVariant TreeItem::data(int column) const
 {
-    return itemData.value(column);
+    return m_itemData.value(column);
 }
 //! [6]
 
 //! [7]
-TreeItem *TreeItem::parent()
+TreeItem *TreeItem::parentItem()
 {
-    return parentItem;
+    return m_parentItem;
 }
 //! [7]
 
 //! [8]
 int TreeItem::row() const
 {
-    if (parentItem)
-        return parentItem->childItems.indexOf(const_cast<TreeItem*>(this));
+    if (m_parentItem)
+        return m_parentItem->m_childItems.indexOf(const_cast<TreeItem*>(this));
 
     return 0;
 }

examples/widgets/itemviews/simpletreemodel/treeitem.h

@@ -48,7 +48,7 @@
 class TreeItem
 {
 public:
-    explicit TreeItem(const QList<QVariant> &data, TreeItem *parent = 0);
+    explicit TreeItem(const QList<QVariant> &data, TreeItem *parentItem = 0);
     ~TreeItem();
 
     void appendChild(TreeItem *child);
@@ -58,12 +58,12 @@ public:
     int columnCount() const;
     QVariant data(int column) const;
     int row() const;
-    TreeItem *parent();
+    TreeItem *parentItem();
 
 private:
-    QList<TreeItem*> childItems;
-    QList<QVariant> itemData;
-    TreeItem *parentItem;
+    QList<TreeItem*> m_childItems;
+    QList<QVariant> m_itemData;
+    TreeItem *m_parentItem;
 };
 //! [0]
 

examples/widgets/itemviews/simpletreemodel/treemodel.cpp

@@ -143,7 +143,7 @@ QModelIndex TreeModel::parent(const QModelIndex &index) const
         return QModelIndex();
 
     TreeItem *childItem = static_cast<TreeItem*>(index.internalPointer());
-    TreeItem *parentItem = childItem->parent();
+    TreeItem *parentItem = childItem->parentItem();
 
     if (parentItem == rootItem)
         return QModelIndex();