X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/9766efc33f1dc1d9a9e03ea6eb37985f20b1dd06..c43507b0fed02bf204b524b953ce7c9794ed250f:/src/common/treebase.cpp

diff --git a/src/common/treebase.cpp b/src/common/treebase.cpp
index 38d242bf06..f10e2af927 100644
--- a/src/common/treebase.cpp
+++ b/src/common/treebase.cpp
@@ -162,7 +162,9 @@ wxSize wxTreeCtrlBase::DoGetBestSize() const
     else // use precise, if potentially slow, size computation method
     {
         // iterate over all items recursively
-        wxGetBestTreeSize(this, GetRootItem(), size);
+        wxTreeItemId idRoot = GetRootItem();
+        if ( idRoot.IsOk() )
+            wxGetBestTreeSize(this, idRoot, size);
     }
 
     // need some minimal size even for empty tree
@@ -181,6 +183,9 @@ wxSize wxTreeCtrlBase::DoGetBestSize() const
 
 void wxTreeCtrlBase::ExpandAll()
 {
+    if ( IsEmpty() )
+        return;
+
     ExpandAllChildren(GetRootItem());
 }
 
@@ -200,5 +205,33 @@ void wxTreeCtrlBase::ExpandAllChildren(const wxTreeItemId& item)
     }
 }
 
+void wxTreeCtrlBase::CollapseAll()
+{
+    if ( IsEmpty() )
+        return;
+
+    CollapseAllChildren(GetRootItem());
+}
+
+void wxTreeCtrlBase::CollapseAllChildren(const wxTreeItemId& item)
+{
+    // 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);
+}
+
+bool wxTreeCtrlBase::IsEmpty() const
+{
+    return !GetRootItem().IsOk();
+}
+
 #endif // wxUSE_TREECTRL