TreeModel: Clean up TreeItem API

isLazy/populate was the first incarnation of the canFetchMore/
fetchMore mechanism which now can take over completely. So:

- remove isLazy/populate
- the use in VariableChooser

Change-Id: I885d492c134fb6899759e19a73156b52df7a880a
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/libs/utils/treemodel.cpp

@@ -611,14 +611,12 @@ namespace Utils {
 // TreeItem
 //
 TreeItem::TreeItem()
-    : m_parent(0), m_model(0), m_displays(0), m_lazy(false), m_populated(false),
-      m_flags(Qt::ItemIsEnabled|Qt::ItemIsSelectable)
+    : m_parent(0), m_model(0), m_displays(0), m_flags(Qt::ItemIsEnabled|Qt::ItemIsSelectable)
 {
 }
 
 TreeItem::TreeItem(const QStringList &displays, int flags)
-    : m_parent(0), m_model(0), m_displays(new QStringList(displays)), m_lazy(false), m_populated(false),
-      m_flags(flags)
+    : m_parent(0), m_model(0), m_displays(new QStringList(displays)), m_flags(flags)
 {
 }
 
@@ -630,26 +628,15 @@ TreeItem::~TreeItem()
 
 TreeItem *TreeItem::child(int pos) const
 {
-    ensurePopulated();
     QTC_ASSERT(pos >= 0, return 0);
     return pos < m_children.size() ? m_children.at(pos) : 0;
 }
 
-bool TreeItem::isLazy() const
-{
-    return m_lazy;
-}
-
 int TreeItem::rowCount() const
 {
-    ensurePopulated();
     return m_children.size();
 }
 
-void TreeItem::populate()
-{
-}
-
 QVariant TreeItem::data(int column, int role) const
 {
     if (role == Qt::DisplayRole && m_displays && column >= 0 && column < m_displays->size())
@@ -696,7 +683,7 @@ void TreeItem::insertChild(int pos, TreeItem *item)
     QTC_CHECK(!item->parent());
     QTC_ASSERT(0 <= pos && pos <= m_children.size(), return); // '<= size' is intentional.
 
-    if (m_model && !m_lazy) {
+    if (m_model) {
         QModelIndex idx = index();
         m_model->beginInsertRows(idx, pos, pos);
         item->m_parent = this;
@@ -770,11 +757,6 @@ int TreeItem::level() const
     return l;
 }
 
-void TreeItem::setLazy(bool on)
-{
-    m_lazy = on;
-}
-
 void TreeItem::setFlags(Qt::ItemFlags flags)
 {
     m_flags = flags;
@@ -830,15 +812,6 @@ void TreeItem::expand()
     m_model->requestExpansion(index());
 }
 
-void TreeItem::ensurePopulated() const
-{
-    if (!m_populated) {
-        if (isLazy())
-            const_cast<TreeItem *>(this)->populate();
-        m_populated = true;
-    }
-}
-
 void TreeItem::propagateModel(TreeModel *m)
 {
     QTC_ASSERT(m, return);

src/libs/utils/treemodel.h

@@ -72,9 +72,7 @@ public:
 
     virtual TreeItem *parent() const { return m_parent; }
     virtual TreeItem *child(int pos) const;
-    virtual bool isLazy() const;
     virtual int rowCount() const;
-    virtual void populate();
 
     virtual QVariant data(int column, int role) const;
     virtual bool setData(int column, const QVariant &data, int role);
@@ -96,8 +94,6 @@ public:
     TreeItem *lastChild() const;
     int level() const;
 
-    void setLazy(bool on);
-    void setPopulated(bool on);
     void setFlags(Qt::ItemFlags flags);
     int childCount() const { return m_children.size(); }
     TreeItem *childAt(int index) const { return m_children.at(index); }
@@ -115,14 +111,12 @@ private:
     void operator=(const TreeItem &) Q_DECL_EQ_DELETE;
 
     void clear();
-    void ensurePopulated() const;
     void propagateModel(TreeModel *m);
 
     TreeItem *m_parent; // Not owned.
     TreeModel *m_model; // Not owned.
     QVector<TreeItem *> m_children; // Owned.
     QStringList *m_displays;
-    bool m_lazy;
     mutable bool m_populated;
     Qt::ItemFlags m_flags;
 

src/plugins/coreplugin/variablechooser.cpp

@@ -127,9 +127,8 @@ class VariableGroupItem : public TreeItem
 {
 public:
     VariableGroupItem()
-        : m_chooser(0)
+        : m_chooser(0), m_populated(false)
     {
-        setLazy(true);
     }
 
     QVariant data(int column, int role) const
@@ -143,16 +142,23 @@ public:
         return QVariant();
     }
 
-    void populate()
+    bool canFetchMore() const
+    {
+        return !m_populated;
+    }
+
+    void fetchMore()
     {
         if (MacroExpander *expander = m_provider())
             populateGroup(expander);
+        m_populated = true;
     }
 
     void populateGroup(MacroExpander *expander);
 
 public:
     VariableChooserPrivate *m_chooser; // Not owned.
+    bool m_populated;
     MacroExpanderProvider m_provider;
 };