+void wxTreeCtrlBase::ExpandAll()
+{
+ if ( IsEmpty() )
+ return;
+
+ ExpandAllChildren(GetRootItem());
+}
+
+void wxTreeCtrlBase::ExpandAllChildren(const wxTreeItemId& item)
+{
+ Freeze();
+ // expand this item first, this might result in its children being added on
+ // the fly
+ if ( item != GetRootItem() || !HasFlag(wxTR_HIDE_ROOT) )
+ Expand(item);
+ //else: expanding hidden root item is unsupported and unnecessary
+
+ // then (recursively) expand all the children
+ wxTreeItemIdValue cookie;
+ for ( wxTreeItemId idCurr = GetFirstChild(item, cookie);
+ idCurr.IsOk();
+ idCurr = GetNextChild(item, cookie) )
+ {
+ ExpandAllChildren(idCurr);
+ }
+ Thaw();
+}
+
+void wxTreeCtrlBase::CollapseAll()
+{
+ if ( IsEmpty() )
+ return;
+
+ CollapseAllChildren(GetRootItem());
+}
+
+void wxTreeCtrlBase::CollapseAllChildren(const wxTreeItemId& item)
+{
+ Freeze();
+ // first (recursively) collapse all the children
+ wxTreeItemIdValue cookie;
+ for ( wxTreeItemId idCurr = GetFirstChild(item, cookie);
+ idCurr.IsOk();
+ idCurr = GetNextChild(item, cookie) )
+ {
+ CollapseAllChildren(idCurr);
+ }
+
+ // then collapse this element too
+ Collapse(item);
+ Thaw();
+}
+
+bool wxTreeCtrlBase::IsEmpty() const
+{
+ return !GetRootItem().IsOk();
+}
+