after a seek, reset error if error==EOF

[wxWidgets.git] / samples / treectrl / treetest.cpp

diff --git a/samples/treectrl/treetest.cpp b/samples/treectrl/treetest.cpp
index 93d51cd80d74f6ea7d720625933e76a78f4f8815..6e8dc94fd08ac85b589d7adaddfc4b8e21699794 100644 (file)
--- a/samples/treectrl/treetest.cpp
+++ b/samples/treectrl/treetest.cpp
@@ -25,22 +25,34 @@
   #include "wx/wx.h"
 #endif
 
   #include "wx/wx.h"
 #endif
 

-// under Windows the icons are in the .rc file
-#ifndef __WXMSW__
-  #include "icon1.xpm"
-  #include "icon2.xpm"
-  #include "mondrian.xpm"
-#endif
-

 #include "wx/log.h"
 
 #include "wx/log.h"
 

+#include "wx/image.h"

 #include "wx/imaglist.h"
 #include "wx/treectrl.h"
 
 #include "math.h"
 
 #include "wx/imaglist.h"
 #include "wx/treectrl.h"
 
 #include "math.h"
 

+#ifdef __WXMSW__
+    // comment out this line to test multiple selection even under MSW (where
+    // it looks ugly - but works)
+    #define NO_MULTIPLE_SELECTION
+#endif
+
+#define NO_VARIABLE_HEIGHT
+

 #include "treetest.h"
 
 #include "treetest.h"
 

+// under Windows the icons are in the .rc file
+#ifndef __WXMSW__
+  #include "icon1.xpm"
+  #include "icon2.xpm"
+  #include "icon3.xpm"
+  #include "icon4.xpm"
+  #include "icon5.xpm"
+  #include "mondrian.xpm"
+#endif
+

 // verify that the item is ok and insult the user if it is not
 #define CHECK_ITEM( item ) if ( !item.IsOk() ) {                            \
                              wxMessageBox("Please select some item first!", \
 // verify that the item is ok and insult the user if it is not
 #define CHECK_ITEM( item ) if ( !item.IsOk() ) {                            \
                              wxMessageBox("Please select some item first!", \


@@ -54,7 +66,14 @@ BEGIN_EVENT_TABLE(MyFrame, wxFrame)
     EVT_MENU(TreeTest_Quit, MyFrame::OnQuit)
     EVT_MENU(TreeTest_About, MyFrame::OnAbout)
     EVT_MENU(TreeTest_Dump, MyFrame::OnDump)
     EVT_MENU(TreeTest_Quit, MyFrame::OnQuit)
     EVT_MENU(TreeTest_About, MyFrame::OnAbout)
     EVT_MENU(TreeTest_Dump, MyFrame::OnDump)

+#ifndef NO_MULTIPLE_SELECTION
+    EVT_MENU(TreeTest_DumpSelected, MyFrame::OnDumpSelected)
+    EVT_MENU(TreeTest_Select, MyFrame::OnSelect)
+    EVT_MENU(TreeTest_Unselect, MyFrame::OnUnselect)
+#endif // NO_MULTIPLE_SELECTION

     EVT_MENU(TreeTest_Rename, MyFrame::OnRename)
     EVT_MENU(TreeTest_Rename, MyFrame::OnRename)

+    EVT_MENU(TreeTest_Count, MyFrame::OnCount)
+    EVT_MENU(TreeTest_CountRec, MyFrame::OnCountRec)

     EVT_MENU(TreeTest_Sort, MyFrame::OnSort)
     EVT_MENU(TreeTest_SortRev, MyFrame::OnSortRev)
     EVT_MENU(TreeTest_Bold, MyFrame::OnSetBold)
     EVT_MENU(TreeTest_Sort, MyFrame::OnSort)
     EVT_MENU(TreeTest_SortRev, MyFrame::OnSortRev)
     EVT_MENU(TreeTest_Bold, MyFrame::OnSetBold)


@@ -70,6 +89,7 @@ BEGIN_EVENT_TABLE(MyFrame, wxFrame)
     EVT_MENU(TreeTest_DecIndent, MyFrame::OnDecIndent)
     EVT_MENU(TreeTest_IncSpacing, MyFrame::OnIncSpacing)
     EVT_MENU(TreeTest_DecSpacing, MyFrame::OnDecSpacing)
     EVT_MENU(TreeTest_DecIndent, MyFrame::OnDecIndent)
     EVT_MENU(TreeTest_IncSpacing, MyFrame::OnIncSpacing)
     EVT_MENU(TreeTest_DecSpacing, MyFrame::OnDecSpacing)

+    EVT_MENU(TreeTest_ToggleIcon, MyFrame::OnToggleIcon)

 END_EVENT_TABLE()
 
 BEGIN_EVENT_TABLE(MyTreeCtrl, wxTreeCtrl)
 END_EVENT_TABLE()
 
 BEGIN_EVENT_TABLE(MyTreeCtrl, wxTreeCtrl)


@@ -78,7 +98,9 @@ BEGIN_EVENT_TABLE(MyTreeCtrl, wxTreeCtrl)
     EVT_TREE_BEGIN_LABEL_EDIT(TreeTest_Ctrl, MyTreeCtrl::OnBeginLabelEdit)
     EVT_TREE_END_LABEL_EDIT(TreeTest_Ctrl, MyTreeCtrl::OnEndLabelEdit)
     EVT_TREE_DELETE_ITEM(TreeTest_Ctrl, MyTreeCtrl::OnDeleteItem)
     EVT_TREE_BEGIN_LABEL_EDIT(TreeTest_Ctrl, MyTreeCtrl::OnBeginLabelEdit)
     EVT_TREE_END_LABEL_EDIT(TreeTest_Ctrl, MyTreeCtrl::OnEndLabelEdit)
     EVT_TREE_DELETE_ITEM(TreeTest_Ctrl, MyTreeCtrl::OnDeleteItem)

+#if 0       // there are so many of those that logging them causes flicker

     EVT_TREE_GET_INFO(TreeTest_Ctrl, MyTreeCtrl::OnGetInfo)
     EVT_TREE_GET_INFO(TreeTest_Ctrl, MyTreeCtrl::OnGetInfo)

+#endif

     EVT_TREE_SET_INFO(TreeTest_Ctrl, MyTreeCtrl::OnSetInfo)
     EVT_TREE_ITEM_EXPANDED(TreeTest_Ctrl, MyTreeCtrl::OnItemExpanded)
     EVT_TREE_ITEM_EXPANDING(TreeTest_Ctrl, MyTreeCtrl::OnItemExpanding)
     EVT_TREE_SET_INFO(TreeTest_Ctrl, MyTreeCtrl::OnSetInfo)
     EVT_TREE_ITEM_EXPANDED(TreeTest_Ctrl, MyTreeCtrl::OnItemExpanded)
     EVT_TREE_ITEM_EXPANDING(TreeTest_Ctrl, MyTreeCtrl::OnItemExpanding)


@@ -135,6 +157,9 @@ MyFrame::MyFrame(const wxString& title, int x, int y, int w, int h)
     tree_menu->Append(TreeTest_DeleteChildren, "Delete &children");
     tree_menu->Append(TreeTest_DeleteAll, "Delete &all items");
     tree_menu->AppendSeparator();
     tree_menu->Append(TreeTest_DeleteChildren, "Delete &children");
     tree_menu->Append(TreeTest_DeleteAll, "Delete &all items");
     tree_menu->AppendSeparator();

+    tree_menu->Append(TreeTest_Count, "Count children of current item");
+    tree_menu->Append(TreeTest_CountRec, "Recursively count children of current item");
+    tree_menu->AppendSeparator();

     tree_menu->Append(TreeTest_Sort, "Sort children of current item");
     tree_menu->Append(TreeTest_SortRev, "Sort in reversed order");
     tree_menu->AppendSeparator();
     tree_menu->Append(TreeTest_Sort, "Sort children of current item");
     tree_menu->Append(TreeTest_SortRev, "Sort in reversed order");
     tree_menu->AppendSeparator();


@@ -147,11 +172,20 @@ MyFrame::MyFrame(const wxString& title, int x, int y, int w, int h)
     tree_menu->Append(TreeTest_DecSpacing, "Reduce spacing by 5 points\tCtrl-R");
 
     item_menu->Append(TreeTest_Dump, "&Dump item children");
     tree_menu->Append(TreeTest_DecSpacing, "Reduce spacing by 5 points\tCtrl-R");
 
     item_menu->Append(TreeTest_Dump, "&Dump item children");

-    item_menu->AppendSeparator();

     item_menu->Append(TreeTest_Rename, "&Rename item...");
     item_menu->Append(TreeTest_Rename, "&Rename item...");

+

     item_menu->AppendSeparator();
     item_menu->Append(TreeTest_Bold, "Make item &bold");
     item_menu->Append(TreeTest_UnBold, "Make item &not bold");
     item_menu->AppendSeparator();
     item_menu->Append(TreeTest_Bold, "Make item &bold");
     item_menu->Append(TreeTest_UnBold, "Make item &not bold");

+    item_menu->AppendSeparator();
+    item_menu->Append(TreeTest_ToggleIcon, "Toggle the items &icon");
+
+#ifndef NO_MULTIPLE_SELECTION
+    item_menu->AppendSeparator();
+    item_menu->Append(TreeTest_DumpSelected, "Dump selected items\tAlt-D");
+    item_menu->Append(TreeTest_Select, "Select current item\tAlt-S");
+    item_menu->Append(TreeTest_Unselect, "Unselect everything\tAlt-U");
+#endif

 
     wxMenuBar *menu_bar = new wxMenuBar;
     menu_bar->Append(file_menu, "&File");
 
     wxMenuBar *menu_bar = new wxMenuBar;
     menu_bar->Append(file_menu, "&File");


@@ -161,9 +195,15 @@ MyFrame::MyFrame(const wxString& title, int x, int y, int w, int h)
 
     m_treeCtrl = new MyTreeCtrl(this, TreeTest_Ctrl,
                                 wxDefaultPosition, wxDefaultSize,
 
     m_treeCtrl = new MyTreeCtrl(this, TreeTest_Ctrl,
                                 wxDefaultPosition, wxDefaultSize,

-                                wxTR_HAS_BUTTONS | wxSUNKEN_BORDER
-                               | wxTR_MULTIPLE
-                               );
+                                wxTR_HAS_BUTTONS |
+                                wxTR_EDIT_LABELS |
+#ifndef NO_MULTIPLE_SELECTION
+                                wxTR_MULTIPLE |
+#endif
+#ifndef NO_VARIABLE_HEIGHT
+                                wxTR_HAS_VARIABLE_ROW_HEIGHT |
+#endif
+                                wxSUNKEN_BORDER);

     wxTextCtrl *textCtrl = new wxTextCtrl(this, -1, "",
                                 wxDefaultPosition, wxDefaultSize,
                                 wxTE_MULTILINE | wxSUNKEN_BORDER);
     wxTextCtrl *textCtrl = new wxTextCtrl(this, -1, "",
                                 wxDefaultPosition, wxDefaultSize,
                                 wxTE_MULTILINE | wxSUNKEN_BORDER);


@@ -211,8 +251,7 @@ void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 {
     wxMessageBox("Tree test sample\n"
 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 {
     wxMessageBox("Tree test sample\n"

-                 "Julian Smart (c) 1997,\n"
-                 "Vadim Zeitlin (c) 1998",
+                 "(c) Julian Smart 1997, Vadim Zeitlin 1998",

                  "About tree test",
                  wxOK | wxICON_INFORMATION, this);
 }
                  "About tree test",
                  wxOK | wxICON_INFORMATION, this);
 }


@@ -223,6 +262,8 @@ void MyFrame::OnRename(wxCommandEvent& WXUNUSED(event))
 
     CHECK_ITEM( item );
 
 
     CHECK_ITEM( item );
 

+    // old code - now we edit in place
+#if 0

     static wxString s_text;
     s_text = wxGetTextFromUser("New name: ", "Tree sample question",
             s_text, this);
     static wxString s_text;
     s_text = wxGetTextFromUser("New name: ", "Tree sample question",
             s_text, this);


@@ -230,6 +271,32 @@ void MyFrame::OnRename(wxCommandEvent& WXUNUSED(event))
     {
         m_treeCtrl->SetItemText(item, s_text);
     }
     {
         m_treeCtrl->SetItemText(item, s_text);
     }

+#endif // 0
+
+    // TODO demonstrate creating a custom edit control...
+    (void)m_treeCtrl->EditLabel(item);
+}
+
+void MyFrame::OnCount(wxCommandEvent& WXUNUSED(event))
+{
+    wxTreeItemId item = m_treeCtrl->GetSelection();
+
+    CHECK_ITEM( item );
+
+    int i = m_treeCtrl->GetChildrenCount( item, FALSE );
+    
+    wxLogMessage(_T("%d children"), i);
+}
+
+void MyFrame::OnCountRec(wxCommandEvent& WXUNUSED(event))
+{
+    wxTreeItemId item = m_treeCtrl->GetSelection();
+
+    CHECK_ITEM( item );
+
+    int i = m_treeCtrl->GetChildrenCount( item );
+    
+    wxLogMessage(_T("%d children"), i);

 }
 
 void MyFrame::DoSort(bool reverse)
 }
 
 void MyFrame::DoSort(bool reverse)


@@ -250,6 +317,33 @@ void MyFrame::OnDump(wxCommandEvent& WXUNUSED(event))
     m_treeCtrl->GetItemsRecursively(root, -1);
 }
 
     m_treeCtrl->GetItemsRecursively(root, -1);
 }
 

+#ifndef NO_MULTIPLE_SELECTION
+
+void MyFrame::OnDumpSelected(wxCommandEvent& WXUNUSED(event))
+{
+    wxArrayTreeItemIds array;
+
+    size_t count = m_treeCtrl->GetSelections(array);
+    wxLogMessage(_T("%u items selected"), count);
+
+    for ( size_t n = 0; n < count; n++ )
+    {
+        wxLogMessage("\t%s", m_treeCtrl->GetItemText(array.Item(n)).c_str());
+    }
+}
+
+void MyFrame::OnSelect(wxCommandEvent& event)
+{
+    m_treeCtrl->SelectItem(m_treeCtrl->GetSelection());
+}
+
+void MyFrame::OnUnselect(wxCommandEvent& event)
+{
+    m_treeCtrl->UnselectAll();
+}
+
+#endif // NO_MULTIPLE_SELECTION
+

 void MyFrame::DoSetBold(bool bold)
 {
     wxTreeItemId item = m_treeCtrl->GetSelection();
 void MyFrame::DoSetBold(bool bold)
 {
     wxTreeItemId item = m_treeCtrl->GetSelection();


@@ -306,8 +400,8 @@ void MyFrame::OnAddItem(wxCommandEvent& WXUNUSED(event))
     text.Printf("Item #%d", ++s_num);
 
     m_treeCtrl->AppendItem(m_treeCtrl->GetRootItem(),
     text.Printf("Item #%d", ++s_num);
 
     m_treeCtrl->AppendItem(m_treeCtrl->GetRootItem(),

-                           text,
-                           MyTreeCtrl::TreeCtrlIcon_File);
+                           text /*,
+                           MyTreeCtrl::TreeCtrlIcon_File */ );

 }
 
 void MyFrame::OnIncIndent(wxCommandEvent& WXUNUSED(event))
 }
 
 void MyFrame::OnIncIndent(wxCommandEvent& WXUNUSED(event))


@@ -338,6 +432,15 @@ void MyFrame::OnDecSpacing(wxCommandEvent& WXUNUSED(event))
         m_treeCtrl->SetSpacing( indent-5 );
 }
 
         m_treeCtrl->SetSpacing( indent-5 );
 }
 

+void MyFrame::OnToggleIcon(wxCommandEvent& WXUNUSED(event))
+{
+    wxTreeItemId item = m_treeCtrl->GetSelection();
+
+    CHECK_ITEM( item );
+
+    m_treeCtrl->DoToggleIcon(item);
+}
+

 // MyTreeCtrl implementation
 IMPLEMENT_DYNAMIC_CLASS(MyTreeCtrl, wxTreeCtrl)
 
 // MyTreeCtrl implementation
 IMPLEMENT_DYNAMIC_CLASS(MyTreeCtrl, wxTreeCtrl)
 


@@ -346,6 +449,15 @@ MyTreeCtrl::MyTreeCtrl(wxWindow *parent, const wxWindowID id,
                        long style)
           : wxTreeCtrl(parent, id, pos, size, style)
 {
                        long style)
           : wxTreeCtrl(parent, id, pos, size, style)
 {

+#ifndef NO_VARIABLE_HEIGHT
+#if wxUSE_LIBJPEG
+    wxImage::AddHandler(new wxJPEGHandler);
+    wxImage image;
+
+    image.LoadFile(wxString("horse.jpg"), wxBITMAP_TYPE_JPEG );
+#endif
+#endif
+

     m_reverseSort = FALSE;
 
     // Make an image list containing small icons
     m_reverseSort = FALSE;
 
     // Make an image list containing small icons


@@ -355,11 +467,25 @@ MyTreeCtrl::MyTreeCtrl(wxWindow *parent, const wxWindowID id,
 #if defined(__WXMSW__) && defined(__WIN16__)
     // This is required in 16-bit Windows mode only because we can't load a specific (16x16)
     // icon image, so it comes out stretched
 #if defined(__WXMSW__) && defined(__WIN16__)
     // This is required in 16-bit Windows mode only because we can't load a specific (16x16)
     // icon image, so it comes out stretched

+#  ifndef NO_VARIABLE_HEIGHT
+    m_imageListNormal->Add(image.ConvertToBitmap());
+#  else

     m_imageListNormal->Add(wxBitmap("bitmap1", wxBITMAP_TYPE_BMP_RESOURCE));
     m_imageListNormal->Add(wxBitmap("bitmap1", wxBITMAP_TYPE_BMP_RESOURCE));

+#  endif

     m_imageListNormal->Add(wxBitmap("bitmap2", wxBITMAP_TYPE_BMP_RESOURCE));
     m_imageListNormal->Add(wxBitmap("bitmap2", wxBITMAP_TYPE_BMP_RESOURCE));

+    m_imageListNormal->Add(wxBitmap("bitmap3", wxBITMAP_TYPE_BMP_RESOURCE));
+    m_imageListNormal->Add(wxBitmap("bitmap4", wxBITMAP_TYPE_BMP_RESOURCE));
+    m_imageListNormal->Add(wxBitmap("bitmap5", wxBITMAP_TYPE_BMP_RESOURCE));

 #else
 #else

+#  ifndef NO_VARIABLE_HEIGHT
+    m_imageListNormal->Add(image.ConvertToBitmap());
+#  else

     m_imageListNormal->Add(wxICON(icon1));
     m_imageListNormal->Add(wxICON(icon1));

+#  endif

     m_imageListNormal->Add(wxICON(icon2));
     m_imageListNormal->Add(wxICON(icon2));

+    m_imageListNormal->Add(wxICON(icon3));
+    m_imageListNormal->Add(wxICON(icon4));
+    m_imageListNormal->Add(wxICON(icon5));

 #endif
 
     SetImageList(m_imageListNormal);
 #endif
 
     SetImageList(m_imageListNormal);


@@ -394,21 +520,32 @@ void MyTreeCtrl::AddItemsRecursively(const wxTreeItemId& idParent,
 {
     if ( depth > 0 )
     {
 {
     if ( depth > 0 )
     {

+        bool hasChildren = depth > 1;
+

         wxString str;
         for ( size_t n = 0; n < numChildren; n++ )
         {
             // at depth 1 elements won't have any more children
         wxString str;
         for ( size_t n = 0; n < numChildren; n++ )
         {
             // at depth 1 elements won't have any more children

-            if (depth == 1)
-                str.Printf("%s child %d.%d", "File", folder, n + 1);
-            else
+            if ( hasChildren )

                 str.Printf("%s child %d", "Folder", n + 1);
                 str.Printf("%s child %d", "Folder", n + 1);

+            else
+                str.Printf("%s child %d.%d", "File", folder, n + 1);

 
 

+            // here we pass to AppendItem() normal and selected item images (we
+            // suppose that selected image follows the normal one in the enum)

             int image = depth == 1 ? TreeCtrlIcon_File : TreeCtrlIcon_Folder;
             int image = depth == 1 ? TreeCtrlIcon_File : TreeCtrlIcon_Folder;

-            wxTreeItemId id = AppendItem(idParent, str, image, image,
+            wxTreeItemId id = AppendItem(idParent, str, image, image + 1,

                                          new MyTreeItemData(str));
 
                                          new MyTreeItemData(str));
 

+            // and now we also set the expanded one (only for the folders)
+            if ( hasChildren )
+            {
+                SetItemImage(id, TreeCtrlIcon_FolderOpened,
+                             wxTreeItemIcon_Expanded);
+            }
+

             // remember the last child for OnEnsureVisible()
             // remember the last child for OnEnsureVisible()

-            if ( depth == 1 && n == numChildren - 1 )
+            if ( !hasChildren && n == numChildren - 1 )

             {
                 m_lastItem = id;
             }
             {
                 m_lastItem = id;
             }


@@ -425,6 +562,7 @@ void MyTreeCtrl::AddTestItemsToTree(size_t numChildren,
     wxTreeItemId rootId = AddRoot("Root",
                                   TreeCtrlIcon_Folder, TreeCtrlIcon_Folder,
                                   new MyTreeItemData("Root item"));
     wxTreeItemId rootId = AddRoot("Root",
                                   TreeCtrlIcon_Folder, TreeCtrlIcon_Folder,
                                   new MyTreeItemData("Root item"));

+    SetItemImage(rootId, TreeCtrlIcon_FolderOpened, wxTreeItemIcon_Expanded);

 
     AddItemsRecursively(rootId, numChildren, depth, 0);
 }
 
     AddItemsRecursively(rootId, numChildren, depth, 0);
 }


@@ -441,7 +579,7 @@ void MyTreeCtrl::GetItemsRecursively(const wxTreeItemId& idParent, long cookie)
     if(id <= 0)
         return;
 
     if(id <= 0)
         return;
 

-    wxString text=GetItemText(id);
+    wxString text = GetItemText(id);

     wxLogMessage(text);
 
     if (ItemHasChildren(id))
     wxLogMessage(text);
 
     if (ItemHasChildren(id))


@@ -450,6 +588,14 @@ void MyTreeCtrl::GetItemsRecursively(const wxTreeItemId& idParent, long cookie)
     GetItemsRecursively(idParent, cookie);
 }
 
     GetItemsRecursively(idParent, cookie);
 }
 

+void MyTreeCtrl::DoToggleIcon(const wxTreeItemId& item)
+{
+    int image = GetItemImage(item) == TreeCtrlIcon_Folder ? TreeCtrlIcon_File
+                                                          : TreeCtrlIcon_Folder;
+
+    SetItemImage(item, image);
+}
+

 
 // avoid repetition
 #define TREE_EVENT_HANDLER(name)                            \
 
 // avoid repetition
 #define TREE_EVENT_HANDLER(name)                            \


@@ -460,8 +606,6 @@ void MyTreeCtrl::name(wxTreeEvent& WXUNUSED(event))         \
 
 TREE_EVENT_HANDLER(OnBeginDrag)
 TREE_EVENT_HANDLER(OnBeginRDrag)
 
 TREE_EVENT_HANDLER(OnBeginDrag)
 TREE_EVENT_HANDLER(OnBeginRDrag)

-TREE_EVENT_HANDLER(OnBeginLabelEdit)
-TREE_EVENT_HANDLER(OnEndLabelEdit)

 TREE_EVENT_HANDLER(OnDeleteItem)
 TREE_EVENT_HANDLER(OnGetInfo)
 TREE_EVENT_HANDLER(OnSetInfo)
 TREE_EVENT_HANDLER(OnDeleteItem)
 TREE_EVENT_HANDLER(OnGetInfo)
 TREE_EVENT_HANDLER(OnSetInfo)


@@ -473,13 +617,40 @@ TREE_EVENT_HANDLER(OnSelChanging)
 
 #undef TREE_EVENT_HANDLER
 
 
 #undef TREE_EVENT_HANDLER
 

+void MyTreeCtrl::OnBeginLabelEdit(wxTreeEvent& event)
+{
+    wxLogMessage("OnBeginLabelEdit");
+
+    // for testing, prevent this items label editing
+    wxTreeItemId itemId = event.GetItem();
+    if ( IsTestItem(itemId) )
+    {
+        wxMessageBox("You can't edit this item.");
+
+        event.Veto();
+    }
+}
+
+void MyTreeCtrl::OnEndLabelEdit(wxTreeEvent& event)
+{
+    wxLogMessage("OnEndLabelEdit");
+
+    // don't allow anything except letters in the labels
+    if ( !event.GetLabel().IsWord() )
+    {
+        wxMessageBox("The label should contain only letters.");
+
+        event.Veto();
+    }
+}
+

 void MyTreeCtrl::OnItemCollapsing(wxTreeEvent& event)
 {
     wxLogMessage("OnItemCollapsing");
 
     // for testing, prevent the user from collapsing the first child folder
     wxTreeItemId itemId = event.GetItem();
 void MyTreeCtrl::OnItemCollapsing(wxTreeEvent& event)
 {
     wxLogMessage("OnItemCollapsing");
 
     // for testing, prevent the user from collapsing the first child folder
     wxTreeItemId itemId = event.GetItem();

-    if ( GetParent(itemId) == GetRootItem() && !GetPrevSibling(itemId) )
+    if ( IsTestItem(itemId) )

     {
         wxMessageBox("You can't collapse this item.");
 
     {
         wxMessageBox("You can't collapse this item.");