MicroWindows mods

[wxWidgets.git] / src / msw / treectrl.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        src/msw/treectrl.cpp
// Purpose:     wxTreeCtrl
// Author:      Julian Smart
// Modified by: Vadim Zeitlin to be less MSW-specific on 10.10.98
// Created:     1997
// RCS-ID:      $Id$
// Copyright:   (c) Julian Smart
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

// ============================================================================
// declarations
// ============================================================================

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

#ifdef __GNUG__
    #pragma implementation "treectrl.h"
#endif

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
    #pragma hdrstop
#endif

#if wxUSE_TREECTRL

#include "wx/msw/private.h"

// Set this to 1 to be _absolutely_ sure that repainting will work for all
// comctl32.dll versions
#define wxUSE_COMCTL32_SAFELY 0

// Mingw32 is a bit mental even though this is done in winundef
#ifdef GetFirstChild
    #undef GetFirstChild
#endif

#ifdef GetNextSibling
    #undef GetNextSibling
#endif

#if defined(__WIN95__)

#include "wx/app.h"
#include "wx/log.h"
#include "wx/dynarray.h"
#include "wx/imaglist.h"
#include "wx/settings.h"
#include "wx/msw/treectrl.h"
#include "wx/msw/dragimag.h"

#ifdef __GNUWIN32_OLD__
    #include "wx/msw/gnuwin32/extra.h"
#endif

#if defined(__WIN95__) && !((defined(__GNUWIN32_OLD__) || defined(__TWIN32__)) && !defined(__CYGWIN10__))
    #include <commctrl.h>
#endif

// Bug in headers, sometimes
#ifndef TVIS_FOCUSED
    #define TVIS_FOCUSED            0x0001
#endif

#ifndef TV_FIRST
    #define TV_FIRST                0x1100
#endif

#ifndef TVS_CHECKBOXES
    #define TVS_CHECKBOXES          0x0100
#endif

#ifndef TVS_FULLROWSELECT
    #define TVS_FULLROWSELECT       0x1000
#endif

// old headers might miss these messages (comctl32.dll 4.71+ only)
#ifndef TVM_SETBKCOLOR
    #define TVM_SETBKCOLOR          (TV_FIRST + 29)
    #define TVM_SETTEXTCOLOR        (TV_FIRST + 30)
#endif

// a macro to hide the ugliness of nested casts
#define HITEM(item)     (HTREEITEM)(WXHTREEITEM)(item)

// the native control doesn't support multiple selections under MSW and we
// have 2 ways to emulate them: either using TVS_CHECKBOXES style and let
// checkboxes be the selection status (checked == selected) or by really
// emulating everything, i.e. intercepting mouse and key events &c. The first
// approach is much easier but doesn't work with comctl32.dll < 4.71 and also
// looks quite ugly.
#define wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE 0


// ----------------------------------------------------------------------------
// private functions
// ----------------------------------------------------------------------------

// wrapper for TreeView_HitTest
static HTREEITEM GetItemFromPoint(HWND hwndTV, int x, int y)
{
    TV_HITTESTINFO tvht;
    tvht.pt.x = x;
    tvht.pt.y = y;

    return (HTREEITEM)TreeView_HitTest(hwndTV, &tvht);
}

#if !wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE

// wrappers for TreeView_GetItem/TreeView_SetItem
static bool IsItemSelected(HWND hwndTV, HTREEITEM hItem)
{
    TV_ITEM tvi;
    tvi.mask = TVIF_STATE | TVIF_HANDLE;
    tvi.stateMask = TVIS_SELECTED;
    tvi.hItem = hItem;

    if ( !TreeView_GetItem(hwndTV, &tvi) )
    {
        wxLogLastError(wxT("TreeView_GetItem"));
    }

    return (tvi.state & TVIS_SELECTED) != 0;
}

static void SelectItem(HWND hwndTV, HTREEITEM hItem, bool select = TRUE)
{
    TV_ITEM tvi;
    tvi.mask = TVIF_STATE | TVIF_HANDLE;
    tvi.stateMask = TVIS_SELECTED;
    tvi.state = select ? TVIS_SELECTED : 0;
    tvi.hItem = hItem;

    if ( TreeView_SetItem(hwndTV, &tvi) == -1 )
    {
        wxLogLastError(wxT("TreeView_SetItem"));
    }
}

static inline void UnselectItem(HWND hwndTV, HTREEITEM htItem)
{
    SelectItem(hwndTV, htItem, FALSE);
}

static inline void ToggleItemSelection(HWND hwndTV, HTREEITEM htItem)
{
    SelectItem(hwndTV, htItem, !IsItemSelected(hwndTV, htItem));
}

// helper function which selects all items in a range and, optionally,
// unselects all others
static void SelectRange(HWND hwndTV,
                        HTREEITEM htFirst,
                        HTREEITEM htLast,
                        bool unselectOthers = TRUE)
{
    // find the first (or last) item and select it
    bool cont = TRUE;
    HTREEITEM htItem = (HTREEITEM)TreeView_GetRoot(hwndTV);
    while ( htItem && cont )
    {
        if ( (htItem == htFirst) || (htItem == htLast) )
        {
            if ( !IsItemSelected(hwndTV, htItem) )
            {
                SelectItem(hwndTV, htItem);
            }

            cont = FALSE;
        }
        else
        {
            if ( unselectOthers && IsItemSelected(hwndTV, htItem) )
            {
                UnselectItem(hwndTV, htItem);
            }
        }

        htItem = (HTREEITEM)TreeView_GetNextVisible(hwndTV, htItem);
    }

    // select the items in range
    cont = htFirst != htLast;
    while ( htItem && cont )
    {
        if ( !IsItemSelected(hwndTV, htItem) )
        {
            SelectItem(hwndTV, htItem);
        }

        cont = (htItem != htFirst) && (htItem != htLast);

        htItem = (HTREEITEM)TreeView_GetNextVisible(hwndTV, htItem);
    }

    // unselect the rest
    if ( unselectOthers )
    {
        while ( htItem )
        {
            if ( IsItemSelected(hwndTV, htItem) )
            {
                UnselectItem(hwndTV, htItem);
            }

            htItem = (HTREEITEM)TreeView_GetNextVisible(hwndTV, htItem);
        }
    }

    // seems to be necessary - otherwise the just selected items don't always
    // appear as selected
    UpdateWindow(hwndTV);
}

// helper function which tricks the standard control into changing the focused
// item without changing anything else (if someone knows why Microsoft doesn't
// allow to do it by just setting TVIS_FOCUSED flag, please tell me!)
static void SetFocus(HWND hwndTV, HTREEITEM htItem)
{
    // the current focus
    HTREEITEM htFocus = (HTREEITEM)TreeView_GetSelection(hwndTV);

    if ( htItem )
    {
        // set the focus
        if ( htItem != htFocus )
        {
            // remember the selection state of the item
            bool wasSelected = IsItemSelected(hwndTV, htItem);

            if ( htFocus && IsItemSelected(hwndTV, htFocus) )
            {
                // prevent the tree from unselecting the old focus which it
                // would do by default (TreeView_SelectItem unselects the
                // focused item)
                TreeView_SelectItem(hwndTV, 0);
                SelectItem(hwndTV, htFocus);
            }

            TreeView_SelectItem(hwndTV, htItem);

            if ( !wasSelected )
            {
                // need to clear the selection which TreeView_SelectItem() gave
                // us
                UnselectItem(hwndTV, htItem);
            }
            //else: was selected, still selected - ok
        }
        //else: nothing to do, focus already there
    }
    else
    {
        if ( htFocus )
        {
            bool wasFocusSelected = IsItemSelected(hwndTV, htFocus);

            // just clear the focus
            TreeView_SelectItem(hwndTV, 0);

            if ( wasFocusSelected )
            {
                // restore the selection state
                SelectItem(hwndTV, htFocus);
            }
        }
        //else: nothing to do, no focus already
    }
}

#endif // wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE

// ----------------------------------------------------------------------------
// private classes
// ----------------------------------------------------------------------------

// a convenient wrapper around TV_ITEM struct which adds a ctor
#ifdef __VISUALC__
#pragma warning( disable : 4097 ) // inheriting from typedef
#endif

struct wxTreeViewItem : public TV_ITEM
{
    wxTreeViewItem(const wxTreeItemId& item,    // the item handle
                   UINT mask_,                  // fields which are valid
                   UINT stateMask_ = 0)         // for TVIF_STATE only
    {
        // hItem member is always valid
        mask = mask_ | TVIF_HANDLE;
        stateMask = stateMask_;
        hItem = HITEM(item);
    }
};

#ifdef __VISUALC__
#pragma warning( default : 4097 )
#endif

// a class which encapsulates the tree traversal logic: it vists all (unless
// OnVisit() returns FALSE) items under the given one
class wxTreeTraversal
{
public:
    wxTreeTraversal(const wxTreeCtrl *tree)
    {
        m_tree = tree;
    }

    // do traverse the tree: visit all items (recursively by default) under the
    // given one; return TRUE if all items were traversed or FALSE if the
    // traversal was aborted because OnVisit returned FALSE
    bool DoTraverse(const wxTreeItemId& root, bool recursively = TRUE);

    // override this function to do whatever is needed for each item, return
    // FALSE to stop traversing
    virtual bool OnVisit(const wxTreeItemId& item) = 0;

protected:
    const wxTreeCtrl *GetTree() const { return m_tree; }

private:
    bool Traverse(const wxTreeItemId& root, bool recursively);

    const wxTreeCtrl *m_tree;
};

// internal class for getting the selected items
class TraverseSelections : public wxTreeTraversal
{
public:
    TraverseSelections(const wxTreeCtrl *tree,
                       wxArrayTreeItemIds& selections)
        : wxTreeTraversal(tree), m_selections(selections)
        {
            m_selections.Empty();

            DoTraverse(tree->GetRootItem());
        }

    virtual bool OnVisit(const wxTreeItemId& item)
    {
#if wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE
        if ( GetTree()->IsItemChecked(item) )
#else
        if ( ::IsItemSelected(GetHwndOf(GetTree()), HITEM(item)) )
#endif
        {
            m_selections.Add(item);
        }

        return TRUE;
    }

    size_t GetCount() const { return m_selections.GetCount(); }

private:
    wxArrayTreeItemIds& m_selections;
};

// internal class for counting tree items
class TraverseCounter : public wxTreeTraversal
{
public:
    TraverseCounter(const wxTreeCtrl *tree,
                    const wxTreeItemId& root,
                    bool recursively)
        : wxTreeTraversal(tree)
        {
            m_count = 0;

            DoTraverse(root, recursively);
        }

    virtual bool OnVisit(const wxTreeItemId& WXUNUSED(item))
    {
        m_count++;

        return TRUE;
    }

    size_t GetCount() const { return m_count; }

private:
    size_t m_count;
};

// ----------------------------------------------------------------------------
// This class is needed for support of different images: the Win32 common
// control natively supports only 2 images (the normal one and another for the
// selected state). We wish to provide support for 2 more of them for folder
// items (i.e. those which have children): for expanded state and for expanded
// selected state. For this we use this structure to store the additional items
// images.
//
// There is only one problem with this: when we retrieve the item's data, we
// don't know whether we get a pointer to wxTreeItemData or
// wxTreeItemIndirectData. So we have to maintain a list of all items which
// have indirect data inside the listctrl itself.
// ----------------------------------------------------------------------------

class wxTreeItemIndirectData
{
public:
    // ctor associates this data with the item and the real item data becomes
    // available through our GetData() method
    wxTreeItemIndirectData(wxTreeCtrl *tree, const wxTreeItemId& item)
    {
        for ( size_t n = 0; n < WXSIZEOF(m_images); n++ )
        {
            m_images[n] = -1;
        }

        // save the old data
        m_data = tree->GetItemData(item);

        // and set ourselves as the new one
        tree->SetIndirectItemData(item, this);
    }

    // dtor deletes the associated data as well
    ~wxTreeItemIndirectData() { delete m_data; }

    // accessors
        // get the real data associated with the item
    wxTreeItemData *GetData() const { return m_data; }
        // change it
    void SetData(wxTreeItemData *data) { m_data = data; }

        // do we have such image?
    bool HasImage(wxTreeItemIcon which) const { return m_images[which] != -1; }
        // get image
    int GetImage(wxTreeItemIcon which) const { return m_images[which]; }
        // change it
    void SetImage(int image, wxTreeItemIcon which) { m_images[which] = image; }

private:
    // all the images associated with the item
    int m_images[wxTreeItemIcon_Max];

    wxTreeItemData *m_data;
};

// ----------------------------------------------------------------------------
// wxWin macros
// ----------------------------------------------------------------------------

IMPLEMENT_DYNAMIC_CLASS(wxTreeCtrl, wxControl)

// ----------------------------------------------------------------------------
// variables
// ----------------------------------------------------------------------------

// handy table for sending events
static wxEventType g_events[2][2] =
{
    { wxEVT_COMMAND_TREE_ITEM_COLLAPSED, wxEVT_COMMAND_TREE_ITEM_COLLAPSING },
    { wxEVT_COMMAND_TREE_ITEM_EXPANDED,  wxEVT_COMMAND_TREE_ITEM_EXPANDING  }
};

// ============================================================================
// implementation
// ============================================================================

// ----------------------------------------------------------------------------
// tree traversal
// ----------------------------------------------------------------------------

bool wxTreeTraversal::DoTraverse(const wxTreeItemId& root, bool recursively)
{
    if ( !OnVisit(root) )
        return FALSE;

    return Traverse(root, recursively);
}

bool wxTreeTraversal::Traverse(const wxTreeItemId& root, bool recursively)
{
    long cookie;
    wxTreeItemId child = m_tree->GetFirstChild(root, cookie);
    while ( child.IsOk() )
    {
        // depth first traversal
        if ( recursively && !Traverse(child, TRUE) )
            return FALSE;

        if ( !OnVisit(child) )
            return FALSE;

        child = m_tree->GetNextChild(root, cookie);
    }

    return TRUE;
}

// ----------------------------------------------------------------------------
// construction and destruction
// ----------------------------------------------------------------------------

void wxTreeCtrl::Init()
{
    m_imageListNormal = NULL;
    m_imageListState = NULL;
    m_ownsImageListNormal = m_ownsImageListState = FALSE;
    m_textCtrl = NULL;
    m_hasAnyAttr = FALSE;
    m_dragImage = NULL;
    m_htSelStart = 0;

    // Initialize static array of events, because with the new event system,
    // they may not be initialized yet.

    g_events[0][0] = wxEVT_COMMAND_TREE_ITEM_COLLAPSED;
    g_events[0][1] = wxEVT_COMMAND_TREE_ITEM_COLLAPSING;
    g_events[1][0] = wxEVT_COMMAND_TREE_ITEM_EXPANDED;
    g_events[1][1] = wxEVT_COMMAND_TREE_ITEM_EXPANDING;
}

bool wxTreeCtrl::Create(wxWindow *parent,
                        wxWindowID id,
                        const wxPoint& pos,
                        const wxSize& size,
                        long style,
                        const wxValidator& validator,
                        const wxString& name)
{
    Init();

    if ( !CreateControl(parent, id, pos, size, style, validator, name) )
        return FALSE;

    DWORD wstyle = WS_VISIBLE | WS_CHILD | WS_TABSTOP |
                   TVS_SHOWSELALWAYS;

    if ( m_windowStyle & wxCLIP_SIBLINGS )
        wstyle |= WS_CLIPSIBLINGS;

    if ((m_windowStyle & wxTR_NO_LINES) == 0)
        wstyle |= TVS_HASLINES;
    if ( m_windowStyle & wxTR_HAS_BUTTONS )
        wstyle |= TVS_HASBUTTONS;

    if ( m_windowStyle & wxTR_EDIT_LABELS )
        wstyle |= TVS_EDITLABELS;

    if ( m_windowStyle & wxTR_LINES_AT_ROOT )
        wstyle |= TVS_LINESATROOT;
    
    if ( m_windowStyle & wxTR_FULL_ROW_HIGHLIGHT )
    {    
        if ( wxTheApp->GetComCtl32Version() >= 471 )
            wstyle |= TVS_FULLROWSELECT;
    }


    // using TVS_CHECKBOXES for emulation of a multiselection tree control
    // doesn't work without the new enough headers
#if wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE && \
    !defined( __GNUWIN32_OLD__ ) && \
    !defined( __BORLANDC__ ) && \
    !defined( __WATCOMC__ ) && \
    (!defined(__VISUALC__) || (__VISUALC__ > 1010))

    // we emulate the multiple selection tree controls by using checkboxes: set
    // up the image list we need for this if we do have multiple selections
    if ( m_windowStyle & wxTR_MULTIPLE )
        wstyle |= TVS_CHECKBOXES;
#endif // wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE

    // Create the tree control.
    if ( !MSWCreateControl(WC_TREEVIEW, wstyle) )
        return FALSE;

#if wxUSE_COMCTL32_SAFELY
    wxWindow::SetBackgroundColour(wxSystemSettings::GetSystemColour(wxSYS_COLOUR_WINDOW));
    wxWindow::SetForegroundColour(wxWindow::GetParent()->GetForegroundColour());
#elif 1
    SetBackgroundColour(wxSystemSettings::GetSystemColour(wxSYS_COLOUR_WINDOW));
    SetForegroundColour(wxWindow::GetParent()->GetForegroundColour());
#else
    // This works around a bug in the Windows tree control whereby for some versions
    // of comctrl32, setting any colour actually draws the background in black.
    // This will initialise the background to the system colour.
    // THIS FIX NOW REVERTED since it caused problems on _other_ systems.
    // Assume the user has an updated comctl32.dll.
    ::SendMessage(GetHwnd(), TVM_SETBKCOLOR, 0,-1);
    wxWindow::SetBackgroundColour(wxSystemSettings::GetSystemColour(wxSYS_COLOUR_WINDOW));
    SetForegroundColour(wxWindow::GetParent()->GetForegroundColour());
#endif


    // VZ: this is some experimental code which may be used to get the
    //     TVS_CHECKBOXES style functionality for comctl32.dll < 4.71.
    //     AFAIK, the standard DLL does about the same thing anyhow.
#if 0
    if ( m_windowStyle & wxTR_MULTIPLE )
    {
        wxBitmap bmp;

        // create the DC compatible with the current screen
        HDC hdcMem = CreateCompatibleDC(NULL);

        // create a mono bitmap of the standard size
        int x = GetSystemMetrics(SM_CXMENUCHECK);
        int y = GetSystemMetrics(SM_CYMENUCHECK);
        wxImageList imagelistCheckboxes(x, y, FALSE, 2);
        HBITMAP hbmpCheck = CreateBitmap(x, y,   // bitmap size
                                         1,      // # of color planes
                                         1,      // # bits needed for one pixel
                                         0);     // array containing colour data
        SelectObject(hdcMem, hbmpCheck);

        // then draw a check mark into it
        RECT rect = { 0, 0, x, y };
        if ( !::DrawFrameControl(hdcMem, &rect,
                                 DFC_BUTTON,
                                 DFCS_BUTTONCHECK | DFCS_CHECKED) )
        {
            wxLogLastError(wxT("DrawFrameControl(check)"));
        }

        bmp.SetHBITMAP((WXHBITMAP)hbmpCheck);
        imagelistCheckboxes.Add(bmp);

        if ( !::DrawFrameControl(hdcMem, &rect,
                                 DFC_BUTTON,
                                 DFCS_BUTTONCHECK) )
        {
            wxLogLastError(wxT("DrawFrameControl(uncheck)"));
        }

        bmp.SetHBITMAP((WXHBITMAP)hbmpCheck);
        imagelistCheckboxes.Add(bmp);

        // clean up
        ::DeleteDC(hdcMem);

        // set the imagelist
        SetStateImageList(&imagelistCheckboxes);
    }
#endif // 0

    SetSize(pos.x, pos.y, size.x, size.y);

    return TRUE;
}

wxTreeCtrl::~wxTreeCtrl()
{
    // delete any attributes
    if ( m_hasAnyAttr )
    {
        for ( wxNode *node = m_attrs.Next(); node; node = m_attrs.Next() )
        {
            delete (wxTreeItemAttr *)node->Data();
        }

        // prevent TVN_DELETEITEM handler from deleting the attributes again!
        m_hasAnyAttr = FALSE;
    }

    DeleteTextCtrl();

    // delete user data to prevent memory leaks
    DeleteAllItems();

    if (m_ownsImageListNormal) delete m_imageListNormal;
    if (m_ownsImageListState) delete m_imageListState;
}

// ----------------------------------------------------------------------------
// accessors
// ----------------------------------------------------------------------------

// simple wrappers which add error checking in debug mode

bool wxTreeCtrl::DoGetItem(wxTreeViewItem* tvItem) const
{
    if ( !TreeView_GetItem(GetHwnd(), tvItem) )
    {
        wxLogLastError(wxT("TreeView_GetItem"));

        return FALSE;
    }

    return TRUE;
}

void wxTreeCtrl::DoSetItem(wxTreeViewItem* tvItem)
{
    if ( TreeView_SetItem(GetHwnd(), tvItem) == -1 )
    {
        wxLogLastError(wxT("TreeView_SetItem"));
    }
}

size_t wxTreeCtrl::GetCount() const
{
    return (size_t)TreeView_GetCount(GetHwnd());
}

unsigned int wxTreeCtrl::GetIndent() const
{
    return TreeView_GetIndent(GetHwnd());
}

void wxTreeCtrl::SetIndent(unsigned int indent)
{
    TreeView_SetIndent(GetHwnd(), indent);
}

wxImageList *wxTreeCtrl::GetImageList() const
{
    return m_imageListNormal;
}

wxImageList *wxTreeCtrl::GetStateImageList() const
{
    return m_imageListNormal;
}

void wxTreeCtrl::SetAnyImageList(wxImageList *imageList, int which)
{
    // no error return
    TreeView_SetImageList(GetHwnd(),
                          imageList ? imageList->GetHIMAGELIST() : 0,
                          which);
}

void wxTreeCtrl::SetImageList(wxImageList *imageList)
{
    if (m_ownsImageListNormal) delete m_imageListNormal;
    SetAnyImageList(m_imageListNormal = imageList, TVSIL_NORMAL);
    m_ownsImageListNormal = FALSE;
}

void wxTreeCtrl::SetStateImageList(wxImageList *imageList)
{
    if (m_ownsImageListState) delete m_imageListState;
    SetAnyImageList(m_imageListState = imageList, TVSIL_STATE);
    m_ownsImageListState = FALSE;
}

void wxTreeCtrl::AssignImageList(wxImageList *imageList)
{
    SetImageList(imageList);
    m_ownsImageListNormal = TRUE;
}

void wxTreeCtrl::AssignStateImageList(wxImageList *imageList)
{
    SetStateImageList(imageList);
    m_ownsImageListState = TRUE;
}

size_t wxTreeCtrl::GetChildrenCount(const wxTreeItemId& item,
                                    bool recursively) const
{
    TraverseCounter counter(this, item, recursively);

    return counter.GetCount() - 1;
}

// ----------------------------------------------------------------------------
// control colours
// ----------------------------------------------------------------------------

bool wxTreeCtrl::SetBackgroundColour(const wxColour &colour)
{
#if !wxUSE_COMCTL32_SAFELY
    if ( !wxWindowBase::SetBackgroundColour(colour) )
        return FALSE;

    SendMessage(GetHwnd(), TVM_SETBKCOLOR, 0, colour.GetPixel());
#endif

    return TRUE;
}

bool wxTreeCtrl::SetForegroundColour(const wxColour &colour)
{
#if !wxUSE_COMCTL32_SAFELY
    if ( !wxWindowBase::SetForegroundColour(colour) )
        return FALSE;

    SendMessage(GetHwnd(), TVM_SETTEXTCOLOR, 0, colour.GetPixel());
#endif

    return TRUE;
}

// ----------------------------------------------------------------------------
// Item access
// ----------------------------------------------------------------------------

wxString wxTreeCtrl::GetItemText(const wxTreeItemId& item) const
{
    wxChar buf[512];  // the size is arbitrary...

    wxTreeViewItem tvItem(item, TVIF_TEXT);
    tvItem.pszText = buf;
    tvItem.cchTextMax = WXSIZEOF(buf);
    if ( !DoGetItem(&tvItem) )
    {
        // don't return some garbage which was on stack, but an empty string
        buf[0] = wxT('\0');
    }

    return wxString(buf);
}

void wxTreeCtrl::SetItemText(const wxTreeItemId& item, const wxString& text)
{
    wxTreeViewItem tvItem(item, TVIF_TEXT);
    tvItem.pszText = (wxChar *)text.c_str();  // conversion is ok
    DoSetItem(&tvItem);
}

int wxTreeCtrl::DoGetItemImageFromData(const wxTreeItemId& item,
                                       wxTreeItemIcon which) const
{
    wxTreeViewItem tvItem(item, TVIF_PARAM);
    if ( !DoGetItem(&tvItem) )
    {
        return -1;
    }

    return ((wxTreeItemIndirectData *)tvItem.lParam)->GetImage(which);
}

void wxTreeCtrl::DoSetItemImageFromData(const wxTreeItemId& item,
                                        int image,
                                        wxTreeItemIcon which) const
{
    wxTreeViewItem tvItem(item, TVIF_PARAM);
    if ( !DoGetItem(&tvItem) )
    {
        return;
    }

    wxTreeItemIndirectData *data = ((wxTreeItemIndirectData *)tvItem.lParam);

    data->SetImage(image, which);

    // make sure that we have selected images as well
    if ( which == wxTreeItemIcon_Normal &&
         !data->HasImage(wxTreeItemIcon_Selected) )
    {
        data->SetImage(image, wxTreeItemIcon_Selected);
    }

    if ( which == wxTreeItemIcon_Expanded &&
         !data->HasImage(wxTreeItemIcon_SelectedExpanded) )
    {
        data->SetImage(image, wxTreeItemIcon_SelectedExpanded);
    }
}

void wxTreeCtrl::DoSetItemImages(const wxTreeItemId& item,
                                 int image,
                                 int imageSel)
{
    wxTreeViewItem tvItem(item, TVIF_IMAGE | TVIF_SELECTEDIMAGE);
    tvItem.iSelectedImage = imageSel;
    tvItem.iImage = image;
    DoSetItem(&tvItem);
}

int wxTreeCtrl::GetItemImage(const wxTreeItemId& item,
                             wxTreeItemIcon which) const
{
    if ( HasIndirectData(item) )
    {
        return DoGetItemImageFromData(item, which);
    }

    UINT mask;
    switch ( which )
    {
        default:
            wxFAIL_MSG( wxT("unknown tree item image type") );

        case wxTreeItemIcon_Normal:
            mask = TVIF_IMAGE;
            break;

        case wxTreeItemIcon_Selected:
            mask = TVIF_SELECTEDIMAGE;
            break;

        case wxTreeItemIcon_Expanded:
        case wxTreeItemIcon_SelectedExpanded:
            return -1;
    }

    wxTreeViewItem tvItem(item, mask);
    DoGetItem(&tvItem);

    return mask == TVIF_IMAGE ? tvItem.iImage : tvItem.iSelectedImage;
}

void wxTreeCtrl::SetItemImage(const wxTreeItemId& item, int image,
                              wxTreeItemIcon which)
{
    int imageNormal, imageSel;
    switch ( which )
    {
        default:
            wxFAIL_MSG( wxT("unknown tree item image type") );

        case wxTreeItemIcon_Normal:
            imageNormal = image;
            imageSel = GetItemSelectedImage(item);
            break;

        case wxTreeItemIcon_Selected:
            imageNormal = GetItemImage(item);
            imageSel = image;
            break;

        case wxTreeItemIcon_Expanded:
        case wxTreeItemIcon_SelectedExpanded:
            if ( !HasIndirectData(item) )
            {
                // we need to get the old images first, because after we create
                // the wxTreeItemIndirectData GetItemXXXImage() will use it to
                // get the images
                imageNormal = GetItemImage(item);
                imageSel = GetItemSelectedImage(item);

                // if it doesn't have it yet, add it
                wxTreeItemIndirectData *data = new
                    wxTreeItemIndirectData(this, item);

                // copy the data to the new location
                data->SetImage(imageNormal, wxTreeItemIcon_Normal);
                data->SetImage(imageSel, wxTreeItemIcon_Selected);
            }

            DoSetItemImageFromData(item, image, which);

            // reset the normal/selected images because we won't use them any
            // more - now they're stored inside the indirect data
            imageNormal =
            imageSel = I_IMAGECALLBACK;
            break;
    }

    // NB: at least in version 5.00.0518.9 of comctl32.dll we need to always
    //     change both normal and selected image - otherwise the change simply
    //     doesn't take place!
    DoSetItemImages(item, imageNormal, imageSel);
}

wxTreeItemData *wxTreeCtrl::GetItemData(const wxTreeItemId& item) const
{
    wxTreeViewItem tvItem(item, TVIF_PARAM);
    if ( !DoGetItem(&tvItem) )
    {
        return NULL;
    }

    if ( HasIndirectData(item) )
    {
        return ((wxTreeItemIndirectData *)tvItem.lParam)->GetData();
    }
    else
    {
        return (wxTreeItemData *)tvItem.lParam;
    }
}

void wxTreeCtrl::SetItemData(const wxTreeItemId& item, wxTreeItemData *data)
{
    // first, associate this piece of data with this item
    if ( data )
    {
        data->SetId(item);
    }

    wxTreeViewItem tvItem(item, TVIF_PARAM);

    if ( HasIndirectData(item) )
    {
        if ( DoGetItem(&tvItem) )
        {
            ((wxTreeItemIndirectData *)tvItem.lParam)->SetData(data);
        }
        else
        {
            wxFAIL_MSG( wxT("failed to change tree items data") );
        }
    }
    else
    {
        tvItem.lParam = (LPARAM)data;
        DoSetItem(&tvItem);
    }
}

void wxTreeCtrl::SetIndirectItemData(const wxTreeItemId& item,
                                     wxTreeItemIndirectData *data)
{
    // this should never happen because it's unnecessary and will probably lead
    // to crash too because the code elsewhere supposes that the pointer the
    // wxTreeItemIndirectData has is a real wxItemData and not
    // wxTreeItemIndirectData as well
    wxASSERT_MSG( !HasIndirectData(item), wxT("setting indirect data twice?") );

    SetItemData(item, (wxTreeItemData *)data);

    m_itemsWithIndirectData.Add(item);
}

bool wxTreeCtrl::HasIndirectData(const wxTreeItemId& item) const
{
    return m_itemsWithIndirectData.Index(item) != wxNOT_FOUND;
}

void wxTreeCtrl::SetItemHasChildren(const wxTreeItemId& item, bool has)
{
    wxTreeViewItem tvItem(item, TVIF_CHILDREN);
    tvItem.cChildren = (int)has;
    DoSetItem(&tvItem);
}

void wxTreeCtrl::SetItemBold(const wxTreeItemId& item, bool bold)
{
    wxTreeViewItem tvItem(item, TVIF_STATE, TVIS_BOLD);
    tvItem.state = bold ? TVIS_BOLD : 0;
    DoSetItem(&tvItem);
}

void wxTreeCtrl::SetItemDropHighlight(const wxTreeItemId& item, bool highlight)
{
    wxTreeViewItem tvItem(item, TVIF_STATE, TVIS_DROPHILITED);
    tvItem.state = highlight ? TVIS_DROPHILITED : 0;
    DoSetItem(&tvItem);
}

void wxTreeCtrl::RefreshItem(const wxTreeItemId& item)
{
    wxRect rect;
    if ( GetBoundingRect(item, rect) )
    {
        RefreshRect(rect);
    }
}

void wxTreeCtrl::SetItemTextColour(const wxTreeItemId& item,
                                   const wxColour& col)
{
    m_hasAnyAttr = TRUE;

    long id = (long)(WXHTREEITEM)item;
    wxTreeItemAttr *attr = (wxTreeItemAttr *)m_attrs.Get(id);
    if ( !attr )
    {
        attr = new wxTreeItemAttr;
        m_attrs.Put(id, (wxObject *)attr);
    }

    attr->SetTextColour(col);

    RefreshItem(item);
}

void wxTreeCtrl::SetItemBackgroundColour(const wxTreeItemId& item,
                                         const wxColour& col)
{
    m_hasAnyAttr = TRUE;

    long id = (long)(WXHTREEITEM)item;
    wxTreeItemAttr *attr = (wxTreeItemAttr *)m_attrs.Get(id);
    if ( !attr )
    {
        attr = new wxTreeItemAttr;
        m_attrs.Put(id, (wxObject *)attr);
    }

    attr->SetBackgroundColour(col);

    RefreshItem(item);
}

void wxTreeCtrl::SetItemFont(const wxTreeItemId& item, const wxFont& font)
{
    m_hasAnyAttr = TRUE;

    long id = (long)(WXHTREEITEM)item;
    wxTreeItemAttr *attr = (wxTreeItemAttr *)m_attrs.Get(id);
    if ( !attr )
    {
        attr = new wxTreeItemAttr;
        m_attrs.Put(id, (wxObject *)attr);
    }

    attr->SetFont(font);

    RefreshItem(item);
}

// ----------------------------------------------------------------------------
// Item status
// ----------------------------------------------------------------------------

bool wxTreeCtrl::IsVisible(const wxTreeItemId& item) const
{
    // Bug in Gnu-Win32 headers, so don't use the macro TreeView_GetItemRect
    RECT rect;

    // this ugliness comes directly from MSDN - it *is* the correct way to pass
    // the HTREEITEM with TVM_GETITEMRECT
    *(WXHTREEITEM *)&rect = (WXHTREEITEM)item;

    // FALSE means get item rect for the whole item, not only text
    return SendMessage(GetHwnd(), TVM_GETITEMRECT, FALSE, (LPARAM)&rect) != 0;
}

bool wxTreeCtrl::ItemHasChildren(const wxTreeItemId& item) const
{
    wxTreeViewItem tvItem(item, TVIF_CHILDREN);
    DoGetItem(&tvItem);

    return tvItem.cChildren != 0;
}

bool wxTreeCtrl::IsExpanded(const wxTreeItemId& item) const
{
    // probably not a good idea to put it here
    //wxASSERT( ItemHasChildren(item) );

    wxTreeViewItem tvItem(item, TVIF_STATE, TVIS_EXPANDED);
    DoGetItem(&tvItem);

    return (tvItem.state & TVIS_EXPANDED) != 0;
}

bool wxTreeCtrl::IsSelected(const wxTreeItemId& item) const
{
    wxTreeViewItem tvItem(item, TVIF_STATE, TVIS_SELECTED);
    DoGetItem(&tvItem);

    return (tvItem.state & TVIS_SELECTED) != 0;
}

bool wxTreeCtrl::IsBold(const wxTreeItemId& item) const
{
    wxTreeViewItem tvItem(item, TVIF_STATE, TVIS_BOLD);
    DoGetItem(&tvItem);

    return (tvItem.state & TVIS_BOLD) != 0;
}

// ----------------------------------------------------------------------------
// navigation
// ----------------------------------------------------------------------------

wxTreeItemId wxTreeCtrl::GetRootItem() const
{
    return wxTreeItemId((WXHTREEITEM) TreeView_GetRoot(GetHwnd()));
}

wxTreeItemId wxTreeCtrl::GetSelection() const
{
    wxCHECK_MSG( !(m_windowStyle & wxTR_MULTIPLE), (long)(WXHTREEITEM)0,
                 wxT("this only works with single selection controls") );

    return wxTreeItemId((WXHTREEITEM) TreeView_GetSelection(GetHwnd()));
}

wxTreeItemId wxTreeCtrl::GetParent(const wxTreeItemId& item) const
{
    return wxTreeItemId((WXHTREEITEM) TreeView_GetParent(GetHwnd(), HITEM(item)));
}

wxTreeItemId wxTreeCtrl::GetFirstChild(const wxTreeItemId& item,
                                       long& _cookie) const
{
    // remember the last child returned in 'cookie'
    _cookie = (long)TreeView_GetChild(GetHwnd(), HITEM(item));

    return wxTreeItemId((WXHTREEITEM)_cookie);
}

wxTreeItemId wxTreeCtrl::GetNextChild(const wxTreeItemId& WXUNUSED(item),
                                      long& _cookie) const
{
    wxTreeItemId l = wxTreeItemId((WXHTREEITEM)TreeView_GetNextSibling(GetHwnd(),
                                   HITEM(_cookie)));
    _cookie = (long)l;

    return l;
}

wxTreeItemId wxTreeCtrl::GetLastChild(const wxTreeItemId& item) const
{
    // can this be done more efficiently?
    long cookie;

    wxTreeItemId childLast,
    child = GetFirstChild(item, cookie);
    while ( child.IsOk() )
    {
        childLast = child;
        child = GetNextChild(item, cookie);
    }

    return childLast;
}

wxTreeItemId wxTreeCtrl::GetNextSibling(const wxTreeItemId& item) const
{
    return wxTreeItemId((WXHTREEITEM) TreeView_GetNextSibling(GetHwnd(), HITEM(item)));
}

wxTreeItemId wxTreeCtrl::GetPrevSibling(const wxTreeItemId& item) const
{
    return wxTreeItemId((WXHTREEITEM) TreeView_GetPrevSibling(GetHwnd(), HITEM(item)));
}

wxTreeItemId wxTreeCtrl::GetFirstVisibleItem() const
{
    return wxTreeItemId((WXHTREEITEM) TreeView_GetFirstVisible(GetHwnd()));
}

wxTreeItemId wxTreeCtrl::GetNextVisible(const wxTreeItemId& item) const
{
    wxASSERT_MSG( IsVisible(item), wxT("The item you call GetNextVisible() for must be visible itself!"));

    return wxTreeItemId((WXHTREEITEM) TreeView_GetNextVisible(GetHwnd(), HITEM(item)));
}

wxTreeItemId wxTreeCtrl::GetPrevVisible(const wxTreeItemId& item) const
{
    wxASSERT_MSG( IsVisible(item), wxT("The item you call GetPrevVisible() for must be visible itself!"));

    return wxTreeItemId((WXHTREEITEM) TreeView_GetPrevVisible(GetHwnd(), HITEM(item)));
}

// ----------------------------------------------------------------------------
// multiple selections emulation
// ----------------------------------------------------------------------------

bool wxTreeCtrl::IsItemChecked(const wxTreeItemId& item) const
{
    // receive the desired information.
    wxTreeViewItem tvItem(item, TVIF_STATE, TVIS_STATEIMAGEMASK);
    DoGetItem(&tvItem);

    // state image indices are 1 based
    return ((tvItem.state >> 12) - 1) == 1;
}

void wxTreeCtrl::SetItemCheck(const wxTreeItemId& item, bool check)
{
    // receive the desired information.
    wxTreeViewItem tvItem(item, TVIF_STATE, TVIS_STATEIMAGEMASK);

    // state images are one-based
    tvItem.state = (check ? 2 : 1) << 12;

    DoSetItem(&tvItem);
}

size_t wxTreeCtrl::GetSelections(wxArrayTreeItemIds& selections) const
{
    TraverseSelections selector(this, selections);

    return selector.GetCount();
}

// ----------------------------------------------------------------------------
// Usual operations
// ----------------------------------------------------------------------------

wxTreeItemId wxTreeCtrl::DoInsertItem(const wxTreeItemId& parent,
                                      wxTreeItemId hInsertAfter,
                                      const wxString& text,
                                      int image, int selectedImage,
                                      wxTreeItemData *data)
{
    wxCHECK_MSG( parent.IsOk() || !TreeView_GetRoot(GetHwnd()),
                 wxTreeItemId(),
                 _T("can't have more than one root in the tree") );

    TV_INSERTSTRUCT tvIns;
    tvIns.hParent = HITEM(parent);
    tvIns.hInsertAfter = HITEM(hInsertAfter);

    // this is how we insert the item as the first child: supply a NULL
    // hInsertAfter
    if ( !tvIns.hInsertAfter )
    {
        tvIns.hInsertAfter = TVI_FIRST;
    }

    UINT mask = 0;
    if ( !text.IsEmpty() )
    {
        mask |= TVIF_TEXT;
        tvIns.item.pszText = (wxChar *)text.c_str();  // cast is ok
    }
    else
    {
        tvIns.item.pszText = NULL;
        tvIns.item.cchTextMax = 0;
    }

    if ( image != -1 )
    {
        mask |= TVIF_IMAGE;
        tvIns.item.iImage = image;

        if ( selectedImage == -1 )
        {
            // take the same image for selected icon if not specified
            selectedImage = image;
        }
    }

    if ( selectedImage != -1 )
    {
        mask |= TVIF_SELECTEDIMAGE;
        tvIns.item.iSelectedImage = selectedImage;
    }

    if ( data != NULL )
    {
        mask |= TVIF_PARAM;
        tvIns.item.lParam = (LPARAM)data;
    }

    tvIns.item.mask = mask;

    HTREEITEM id = (HTREEITEM) TreeView_InsertItem(GetHwnd(), &tvIns);
    if ( id == 0 )
    {
        wxLogLastError(wxT("TreeView_InsertItem"));
    }

    if ( data != NULL )
    {
        // associate the application tree item with Win32 tree item handle
        data->SetId((WXHTREEITEM)id);
    }

    return wxTreeItemId((WXHTREEITEM)id);
}

// for compatibility only
wxTreeItemId wxTreeCtrl::InsertItem(const wxTreeItemId& parent,
                                    const wxString& text,
                                    int image, int selImage,
                                    long insertAfter)
{
    return DoInsertItem(parent, (WXHTREEITEM)insertAfter, text,
                        image, selImage, NULL);
}

wxTreeItemId wxTreeCtrl::AddRoot(const wxString& text,
                                 int image, int selectedImage,
                                 wxTreeItemData *data)
{
    return DoInsertItem(wxTreeItemId((long) (WXHTREEITEM) 0), (long)(WXHTREEITEM) 0,
                        text, image, selectedImage, data);
}

wxTreeItemId wxTreeCtrl::PrependItem(const wxTreeItemId& parent,
                                     const wxString& text,
                                     int image, int selectedImage,
                                     wxTreeItemData *data)
{
    return DoInsertItem(parent, (WXHTREEITEM) TVI_FIRST,
                        text, image, selectedImage, data);
}

wxTreeItemId wxTreeCtrl::InsertItem(const wxTreeItemId& parent,
                                    const wxTreeItemId& idPrevious,
                                    const wxString& text,
                                    int image, int selectedImage,
                                    wxTreeItemData *data)
{
    return DoInsertItem(parent, idPrevious, text, image, selectedImage, data);
}

wxTreeItemId wxTreeCtrl::InsertItem(const wxTreeItemId& parent,
                                    size_t index,
                                    const wxString& text,
                                    int image, int selectedImage,
                                    wxTreeItemData *data)
{
    // find the item from index
    long cookie;
    wxTreeItemId idPrev, idCur = GetFirstChild(parent, cookie);
    while ( index != 0 && idCur.IsOk() )
    {
        index--;

        idPrev = idCur;
        idCur = GetNextChild(parent, cookie);
    }

    // assert, not check: if the index is invalid, we will append the item
    // to the end
    wxASSERT_MSG( index == 0, _T("bad index in wxTreeCtrl::InsertItem") );

    return DoInsertItem(parent, idPrev, text, image, selectedImage, data);
}

wxTreeItemId wxTreeCtrl::AppendItem(const wxTreeItemId& parent,
                                    const wxString& text,
                                    int image, int selectedImage,
                                    wxTreeItemData *data)
{
    return DoInsertItem(parent, (WXHTREEITEM) TVI_LAST,
                        text, image, selectedImage, data);
}

void wxTreeCtrl::Delete(const wxTreeItemId& item)
{
    if ( !TreeView_DeleteItem(GetHwnd(), HITEM(item)) )
    {
        wxLogLastError(wxT("TreeView_DeleteItem"));
    }
}

// delete all children (but don't delete the item itself)
void wxTreeCtrl::DeleteChildren(const wxTreeItemId& item)
{
    long cookie;

    wxArrayLong children;
    wxTreeItemId child = GetFirstChild(item, cookie);
    while ( child.IsOk() )
    {
        children.Add((long)(WXHTREEITEM)child);

        child = GetNextChild(item, cookie);
    }

    size_t nCount = children.Count();
    for ( size_t n = 0; n < nCount; n++ )
    {
        if ( !TreeView_DeleteItem(GetHwnd(), (HTREEITEM)children[n]) )
        {
            wxLogLastError(wxT("TreeView_DeleteItem"));
        }
    }
}

void wxTreeCtrl::DeleteAllItems()
{
    if ( !TreeView_DeleteAllItems(GetHwnd()) )
    {
        wxLogLastError(wxT("TreeView_DeleteAllItems"));
    }
}

void wxTreeCtrl::DoExpand(const wxTreeItemId& item, int flag)
{
    wxASSERT_MSG( flag == TVE_COLLAPSE ||
                  flag == (TVE_COLLAPSE | TVE_COLLAPSERESET) ||
                  flag == TVE_EXPAND   ||
                  flag == TVE_TOGGLE,
                  wxT("Unknown flag in wxTreeCtrl::DoExpand") );

    // TreeView_Expand doesn't send TVN_ITEMEXPAND(ING) messages, so we must
    // emulate them. This behaviour has changed slightly with comctl32.dll
    // v 4.70 - now it does send them but only the first time. To maintain
    // compatible behaviour and also in order to not have surprises with the
    // future versions, don't rely on this and still do everything ourselves.
    // To avoid that the messages be sent twice when the item is expanded for
    // the first time we must clear TVIS_EXPANDEDONCE style manually.

    wxTreeViewItem tvItem(item, TVIF_STATE, TVIS_EXPANDEDONCE);
    tvItem.state = 0;
    DoSetItem(&tvItem);

    if ( TreeView_Expand(GetHwnd(), HITEM(item), flag) != 0 )
    {
        wxTreeEvent event(wxEVT_NULL, m_windowId);
        event.m_item = item;

        bool isExpanded = IsExpanded(item);

        event.SetEventObject(this);

        // FIXME return value of {EXPAND|COLLAPS}ING event handler is discarded
        event.SetEventType(g_events[isExpanded][TRUE]);
        GetEventHandler()->ProcessEvent(event);

        event.SetEventType(g_events[isExpanded][FALSE]);
        GetEventHandler()->ProcessEvent(event);
    }
    //else: change didn't took place, so do nothing at all
}

void wxTreeCtrl::Expand(const wxTreeItemId& item)
{
    DoExpand(item, TVE_EXPAND);
}

void wxTreeCtrl::Collapse(const wxTreeItemId& item)
{
    DoExpand(item, TVE_COLLAPSE);
}

void wxTreeCtrl::CollapseAndReset(const wxTreeItemId& item)
{
    DoExpand(item, TVE_COLLAPSE | TVE_COLLAPSERESET);
}

void wxTreeCtrl::Toggle(const wxTreeItemId& item)
{
    DoExpand(item, TVE_TOGGLE);
}

void wxTreeCtrl::ExpandItem(const wxTreeItemId& item, int action)
{
    DoExpand(item, action);
}

void wxTreeCtrl::Unselect()
{
    wxASSERT_MSG( !(m_windowStyle & wxTR_MULTIPLE),
                  wxT("doesn't make sense, may be you want UnselectAll()?") );

    // just remove the selection
    SelectItem(wxTreeItemId((long) (WXHTREEITEM) 0));
}

void wxTreeCtrl::UnselectAll()
{
    if ( m_windowStyle & wxTR_MULTIPLE )
    {
        wxArrayTreeItemIds selections;
        size_t count = GetSelections(selections);
        for ( size_t n = 0; n < count; n++ )
        {
#if wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE
            SetItemCheck(selections[n], FALSE);
#else // !wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE
            ::UnselectItem(GetHwnd(), HITEM(selections[n]));
#endif // wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE/!wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE
        }
    }
    else
    {
        // just remove the selection
        Unselect();
    }
}

void wxTreeCtrl::SelectItem(const wxTreeItemId& item)
{
    if ( m_windowStyle & wxTR_MULTIPLE )
    {
#if wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE
        // selecting the item means checking it
        SetItemCheck(item);
#else // !wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE
        ::SelectItem(GetHwnd(), HITEM(item));
#endif // wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE/!wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE
    }
    else
    {
        // inspite of the docs (MSDN Jan 99 edition), we don't seem to receive
        // the notification from the control (i.e. TVN_SELCHANG{ED|ING}), so
        // send them ourselves

        wxTreeEvent event(wxEVT_NULL, m_windowId);
        event.m_item = item;
        event.SetEventObject(this);

        event.SetEventType(wxEVT_COMMAND_TREE_SEL_CHANGING);
        if ( !GetEventHandler()->ProcessEvent(event) || event.IsAllowed() )
        {
            if ( !TreeView_SelectItem(GetHwnd(), HITEM(item)) )
            {
                wxLogLastError(wxT("TreeView_SelectItem"));
            }
            else
            {
                event.SetEventType(wxEVT_COMMAND_TREE_SEL_CHANGED);
                (void)GetEventHandler()->ProcessEvent(event);
            }
        }
        //else: program vetoed the change
    }
}

void wxTreeCtrl::EnsureVisible(const wxTreeItemId& item)
{
    // no error return
    TreeView_EnsureVisible(GetHwnd(), HITEM(item));
}

void wxTreeCtrl::ScrollTo(const wxTreeItemId& item)
{
    if ( !TreeView_SelectSetFirstVisible(GetHwnd(), HITEM(item)) )
    {
        wxLogLastError(wxT("TreeView_SelectSetFirstVisible"));
    }
}

wxTextCtrl* wxTreeCtrl::GetEditControl() const
{
    // normally, we could try to do something like this to return something
    // even when the editing was started by the user and not by calling
    // EditLabel() - but as nobody has asked for this so far and there might be
    // problems in the code below, I leave it disabled for now (VZ)
#if 0
    if ( !m_textCtrl )
    {
        HWND hwndText = TreeView_GetEditControl(GetHwnd());
        if ( hwndText )
        {
            m_textCtrl = new wxTextCtrl(this, -1);
            m_textCtrl->Hide();
            m_textCtrl->SetHWND((WXHWND)hwndText);
        }
        //else: not editing label right now
    }
#endif // 0

    return m_textCtrl;
}

void wxTreeCtrl::DeleteTextCtrl()
{
    if ( m_textCtrl )
    {
        // the HWND corresponding to this control is deleted by the tree
        // control itself and we don't know when exactly this happens, so check
        // if the window still exists before calling UnsubclassWin()
        if ( !::IsWindow(GetHwndOf(m_textCtrl)) )
        {
            m_textCtrl->SetHWND(0);
        }

        m_textCtrl->UnsubclassWin();
        m_textCtrl->SetHWND(0);
        delete m_textCtrl;
        m_textCtrl = NULL;
    }
}

wxTextCtrl* wxTreeCtrl::EditLabel(const wxTreeItemId& item,
                                  wxClassInfo* textControlClass)
{
    wxASSERT( textControlClass->IsKindOf(CLASSINFO(wxTextCtrl)) );

    DeleteTextCtrl();

    HWND hWnd = (HWND) TreeView_EditLabel(GetHwnd(), HITEM(item));

    // this is not an error - the TVN_BEGINLABELEDIT handler might have
    // returned FALSE
    if ( !hWnd )
    {
        return NULL;
    }

    m_textCtrl = (wxTextCtrl *)textControlClass->CreateObject();
    m_textCtrl->SetParent(this);
    m_textCtrl->SetHWND((WXHWND)hWnd);
    m_textCtrl->SubclassWin((WXHWND)hWnd);

    return m_textCtrl;
}

// End label editing, optionally cancelling the edit
void wxTreeCtrl::EndEditLabel(const wxTreeItemId& WXUNUSED(item), bool discardChanges)
{
    TreeView_EndEditLabelNow(GetHwnd(), discardChanges);

    DeleteTextCtrl();
}

wxTreeItemId wxTreeCtrl::HitTest(const wxPoint& point, int& flags)
{
    TV_HITTESTINFO hitTestInfo;
    hitTestInfo.pt.x = (int)point.x;
    hitTestInfo.pt.y = (int)point.y;

    TreeView_HitTest(GetHwnd(), &hitTestInfo);

    flags = 0;

    // avoid repetition
    #define TRANSLATE_FLAG(flag) if ( hitTestInfo.flags & TVHT_##flag ) \
                                    flags |= wxTREE_HITTEST_##flag

    TRANSLATE_FLAG(ABOVE);
    TRANSLATE_FLAG(BELOW);
    TRANSLATE_FLAG(NOWHERE);
    TRANSLATE_FLAG(ONITEMBUTTON);
    TRANSLATE_FLAG(ONITEMICON);
    TRANSLATE_FLAG(ONITEMINDENT);
    TRANSLATE_FLAG(ONITEMLABEL);
    TRANSLATE_FLAG(ONITEMRIGHT);
    TRANSLATE_FLAG(ONITEMSTATEICON);
    TRANSLATE_FLAG(TOLEFT);
    TRANSLATE_FLAG(TORIGHT);

    #undef TRANSLATE_FLAG

    return wxTreeItemId((WXHTREEITEM) hitTestInfo.hItem);
}

bool wxTreeCtrl::GetBoundingRect(const wxTreeItemId& item,
                                 wxRect& rect,
                                 bool textOnly) const
{
    RECT rc;
    if ( TreeView_GetItemRect(GetHwnd(), HITEM(item),
                              &rc, textOnly) )
    {
        rect = wxRect(wxPoint(rc.left, rc.top), wxPoint(rc.right, rc.bottom));

        return TRUE;
    }
    else
    {
        // couldn't retrieve rect: for example, item isn't visible
        return FALSE;
    }
}

// ----------------------------------------------------------------------------
// sorting stuff
// ----------------------------------------------------------------------------

static int CALLBACK TreeView_CompareCallback(wxTreeItemData *pItem1,
                                             wxTreeItemData *pItem2,
                                             wxTreeCtrl *tree)
{
    wxCHECK_MSG( pItem1 && pItem2, 0,
                 wxT("sorting tree without data doesn't make sense") );

    return tree->OnCompareItems(pItem1->GetId(), pItem2->GetId());
}

int wxTreeCtrl::OnCompareItems(const wxTreeItemId& item1,
                               const wxTreeItemId& item2)
{
    return wxStrcmp(GetItemText(item1), GetItemText(item2));
}

void wxTreeCtrl::SortChildren(const wxTreeItemId& item)
{
    // rely on the fact that TreeView_SortChildren does the same thing as our
    // default behaviour, i.e. sorts items alphabetically and so call it
    // directly if we're not in derived class (much more efficient!)
    if ( GetClassInfo() == CLASSINFO(wxTreeCtrl) )
    {
        TreeView_SortChildren(GetHwnd(), HITEM(item), 0);
    }
    else
    {
        TV_SORTCB tvSort;
        tvSort.hParent = HITEM(item);
        tvSort.lpfnCompare = (PFNTVCOMPARE)TreeView_CompareCallback;
        tvSort.lParam = (LPARAM)this;
        TreeView_SortChildrenCB(GetHwnd(), &tvSort, 0 /* reserved */);
    }
}

// ----------------------------------------------------------------------------
// implementation
// ----------------------------------------------------------------------------

bool wxTreeCtrl::MSWCommand(WXUINT cmd, WXWORD id)
{
    if ( cmd == EN_UPDATE )
    {
        wxCommandEvent event(wxEVT_COMMAND_TEXT_UPDATED, id);
        event.SetEventObject( this );
        ProcessCommand(event);
    }
    else if ( cmd == EN_KILLFOCUS )
    {
        wxCommandEvent event(wxEVT_KILL_FOCUS, id);
        event.SetEventObject( this );
        ProcessCommand(event);
    }
    else
    {
        // nothing done
        return FALSE;
    }

    // command processed
    return TRUE;
}

// we hook into WndProc to process WM_MOUSEMOVE/WM_BUTTONUP messages - as we
// only do it during dragging, minimize wxWin overhead (this is important for
// WM_MOUSEMOVE as they're a lot of them) by catching Windows messages directly
// instead of passing by wxWin events
long wxTreeCtrl::MSWWindowProc(WXUINT nMsg, WXWPARAM wParam, WXLPARAM lParam)
{
    bool processed = FALSE;
    long rc = 0;
    bool isMultiple = (GetWindowStyle() & wxTR_MULTIPLE) != 0;

    if ( (nMsg >= WM_MOUSEFIRST) && (nMsg <= WM_MOUSELAST) )
    {
        // we only process mouse messages here and these parameters have the same
        // meaning for all of them
        int x = GET_X_LPARAM(lParam),
            y = GET_Y_LPARAM(lParam);
        HTREEITEM htItem = GetItemFromPoint(GetHwnd(), x, y);

        switch ( nMsg )
        {
#if !wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE
            case WM_LBUTTONDOWN:
                if ( htItem && isMultiple )
                {
                    if ( wParam & MK_CONTROL )
                    {
                        SetFocus();

                        // toggle selected state
                        ToggleItemSelection(GetHwnd(), htItem);

                        ::SetFocus(GetHwnd(), htItem);

                        // reset on any click without Shift
                        m_htSelStart = 0;

                        processed = TRUE;
                    }
                    else if ( wParam & MK_SHIFT )
                    {
                        // this selects all items between the starting one and
                        // the current

                        if ( !m_htSelStart )
                        {
                            // take the focused item
                            m_htSelStart = (WXHTREEITEM)
                                TreeView_GetSelection(GetHwnd());
                        }

                        SelectRange(GetHwnd(), HITEM(m_htSelStart), htItem,
                                    !(wParam & MK_CONTROL));

                        ::SetFocus(GetHwnd(), htItem);

                        processed = TRUE;
                    }
                    else // normal click
                    {
                        // clear the selection and then let the default handler
                        // do the job
                        UnselectAll();

                        // prevent the click from starting in-place editing
                        // when there was no selection in the control
                        TreeView_SelectItem(GetHwnd(), 0);

                        // reset on any click without Shift
                        m_htSelStart = 0;
                    }
                }
                break;
#endif // wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE

            case WM_MOUSEMOVE:
                if ( m_dragImage )
                {
                    m_dragImage->Move(wxPoint(x, y));
                    if ( htItem )
                    {
                        // highlight the item as target (hiding drag image is
                        // necessary - otherwise the display will be corrupted)
                        m_dragImage->Hide();
                        TreeView_SelectDropTarget(GetHwnd(), htItem);
                        m_dragImage->Show();
                    }
                }
                break;

            case WM_LBUTTONUP:
            case WM_RBUTTONUP:
                if ( m_dragImage )
                {
                    m_dragImage->EndDrag();
                    delete m_dragImage;
                    m_dragImage = NULL;

                    // generate the drag end event
                    wxTreeEvent event(wxEVT_COMMAND_TREE_END_DRAG, m_windowId);

                    event.m_item = (WXHTREEITEM)htItem;
                    event.m_pointDrag = wxPoint(x, y);
                    event.SetEventObject(this);

                    (void)GetEventHandler()->ProcessEvent(event);

                    // if we don't do it, the tree seems to think that 2 items
                    // are selected simultaneously which is quite weird
                    TreeView_SelectDropTarget(GetHwnd(), 0);
                }
                break;
        }
    }
#if !wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE
    else if ( (nMsg == WM_SETFOCUS || nMsg == WM_KILLFOCUS) && isMultiple )
    {
        // the tree control greys out the selected item when it loses focus and
        // paints it as selected again when it regains it, but it won't do it
        // for the other items itself - help it
        wxArrayTreeItemIds selections;
        size_t count = GetSelections(selections);
        RECT rect;
        for ( size_t n = 0; n < count; n++ )
        {
            // TreeView_GetItemRect() will return FALSE if item is not visible,
            // which may happen perfectly well
            if ( TreeView_GetItemRect(GetHwnd(), HITEM(selections[n]),
                                      &rect, TRUE) )
            {
                ::InvalidateRect(GetHwnd(), &rect, FALSE);
            }
        }
    }
    else if ( nMsg == WM_KEYDOWN && isMultiple )
    {
        bool bCtrl = wxIsCtrlDown(),
             bShift = wxIsShiftDown();

        // we handle.arrows and space, but not page up/down and home/end: the
        // latter should be easy, but not the former

        HTREEITEM htSel = (HTREEITEM)TreeView_GetSelection(GetHwnd());
        if ( !m_htSelStart )
        {
            m_htSelStart = (WXHTREEITEM)htSel;
        }

        if ( wParam == VK_SPACE )
        {
            if ( bCtrl )
            {
                ToggleItemSelection(GetHwnd(), htSel);
            }
            else
            {
                UnselectAll();

                ::SelectItem(GetHwnd(), htSel);
            }

            processed = TRUE;
        }
        else if ( wParam == VK_UP || wParam == VK_DOWN )
        {
            if ( !bCtrl && !bShift )
            {
                // no modifiers, just clear selection and then let the default
                // processing to take place
                UnselectAll();
            }
            else if ( htSel )
            {
                (void)wxControl::MSWWindowProc(nMsg, wParam, lParam);

                HTREEITEM htNext = (HTREEITEM)(wParam == VK_UP
                                    ? TreeView_GetPrevVisible(GetHwnd(), htSel)
                                    : TreeView_GetNextVisible(GetHwnd(), htSel));

                if ( !htNext )
                {
                    // at the top/bottom
                    htNext = htSel;
                }

                if ( bShift )
                {
                    SelectRange(GetHwnd(), HITEM(m_htSelStart), htNext);
                }
                else // bCtrl
                {
                    // without changing selection
                    ::SetFocus(GetHwnd(), htNext);
                }

                processed = TRUE;
            }
        }
    }
#endif // !wxUSE_CHECKBOXES_IN_MULTI_SEL_TREE
    if ( !processed )
        rc = wxControl::MSWWindowProc(nMsg, wParam, lParam);

    return rc;
}

// process WM_NOTIFY Windows message
bool wxTreeCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
{
    wxTreeEvent event(wxEVT_NULL, m_windowId);
    wxEventType eventType = wxEVT_NULL;
    NMHDR *hdr = (NMHDR *)lParam;

    switch ( hdr->code )
    {
        case TVN_BEGINDRAG:
            eventType = wxEVT_COMMAND_TREE_BEGIN_DRAG;
            // fall through

        case TVN_BEGINRDRAG:
            {
                if ( eventType == wxEVT_NULL )
                    eventType = wxEVT_COMMAND_TREE_BEGIN_RDRAG;
                //else: left drag, already set above

                NM_TREEVIEW *tv = (NM_TREEVIEW *)lParam;

                event.m_item = (WXHTREEITEM) tv->itemNew.hItem;
                event.m_pointDrag = wxPoint(tv->ptDrag.x, tv->ptDrag.y);

                // don't allow dragging by default: the user code must
                // explicitly say that it wants to allow it to avoid breaking
                // the old apps
                event.Veto();
            }
            break;

        case TVN_BEGINLABELEDIT:
            {
                eventType = wxEVT_COMMAND_TREE_BEGIN_LABEL_EDIT;
                TV_DISPINFO *info = (TV_DISPINFO *)lParam;

                event.m_item = (WXHTREEITEM) info->item.hItem;
                event.m_label = info->item.pszText;
            }
            break;

        case TVN_DELETEITEM:
            {
                eventType = wxEVT_COMMAND_TREE_DELETE_ITEM;
                NM_TREEVIEW *tv = (NM_TREEVIEW *)lParam;

                event.m_item = (WXHTREEITEM)tv->itemOld.hItem;

                if ( m_hasAnyAttr )
                {
                    delete (wxTreeItemAttr *)m_attrs.
                                Delete((long)tv->itemOld.hItem);
                }
            }
            break;

        case TVN_ENDLABELEDIT:
            {
                eventType = wxEVT_COMMAND_TREE_END_LABEL_EDIT;
                TV_DISPINFO *info = (TV_DISPINFO *)lParam;

                event.m_item = (WXHTREEITEM)info->item.hItem;
                event.m_label = info->item.pszText;
                if (info->item.pszText == NULL)
                    return FALSE;
                break;
            }

        case TVN_GETDISPINFO:
            eventType = wxEVT_COMMAND_TREE_GET_INFO;
            // fall through

        case TVN_SETDISPINFO:
            {
                if ( eventType == wxEVT_NULL )
                    eventType = wxEVT_COMMAND_TREE_SET_INFO;
                //else: get, already set above

                TV_DISPINFO *info = (TV_DISPINFO *)lParam;

                event.m_item = (WXHTREEITEM) info->item.hItem;
                break;
            }

        case TVN_ITEMEXPANDING:
        case TVN_ITEMEXPANDED:
            {
                NM_TREEVIEW* tv = (NM_TREEVIEW*)lParam;

                bool expand = FALSE;
                switch ( tv->action )
                {
                    case TVE_EXPAND:
                        expand = TRUE;
                        break;

                    case TVE_COLLAPSE:
                        expand = FALSE;
                        break;

                    default:
                        wxLogDebug(wxT("unexpected code %d in TVN_ITEMEXPAND message"), tv->action);
                }

                bool ing = ((int)hdr->code == TVN_ITEMEXPANDING);
                eventType = g_events[expand][ing];

                event.m_item = (WXHTREEITEM) tv->itemNew.hItem;
            }
            break;

        case TVN_KEYDOWN:
            {
                eventType = wxEVT_COMMAND_TREE_KEY_DOWN;
                TV_KEYDOWN *info = (TV_KEYDOWN *)lParam;

                // we pass 0 as last CreateKeyEvent() parameter because we
                // don't have access to the real key press flags here - but as
                // it is only used to determin wxKeyEvent::m_altDown flag it's
                // not too bad
                event.m_evtKey = CreateKeyEvent(wxEVT_KEY_DOWN,
                                                wxCharCodeMSWToWX(info->wVKey),
                                                0);

                // a separate event for Space/Return
                if ( !wxIsCtrlDown() && !wxIsShiftDown() &&
                     ((info->wVKey == VK_SPACE) || (info->wVKey == VK_RETURN)) )
                {
                    wxTreeEvent event2(wxEVT_COMMAND_TREE_ITEM_ACTIVATED,
                                       m_windowId);
                    event2.SetEventObject(this);
                    if ( !(GetWindowStyle() & wxTR_MULTIPLE) )
                    {
                        event2.m_item = GetSelection();
                    }
                    //else: don't know how to get it

                    (void)GetEventHandler()->ProcessEvent(event2);
                }
            }
            break;

        case TVN_SELCHANGED:
            eventType = wxEVT_COMMAND_TREE_SEL_CHANGED;
            // fall through

        case TVN_SELCHANGING:
            {
                if ( eventType == wxEVT_NULL )
                    eventType = wxEVT_COMMAND_TREE_SEL_CHANGING;
                //else: already set above

                NM_TREEVIEW* tv = (NM_TREEVIEW *)lParam;

                event.m_item = (WXHTREEITEM) tv->itemNew.hItem;
                event.m_itemOld = (WXHTREEITEM) tv->itemOld.hItem;
            }
            break;

#if defined(_WIN32_IE) && _WIN32_IE >= 0x300 && !wxUSE_COMCTL32_SAFELY && !( defined(__GNUWIN32__) && !wxCHECK_W32API_VERSION( 1, 0 ) )
        case NM_CUSTOMDRAW:
            {
                LPNMTVCUSTOMDRAW lptvcd = (LPNMTVCUSTOMDRAW)lParam;
                NMCUSTOMDRAW& nmcd = lptvcd->nmcd;
                switch ( nmcd.dwDrawStage )
                {
                    case CDDS_PREPAINT:
                        // if we've got any items with non standard attributes,
                        // notify us before painting each item
                        *result = m_hasAnyAttr ? CDRF_NOTIFYITEMDRAW
                                               : CDRF_DODEFAULT;
                        break;

                    case CDDS_ITEMPREPAINT:
                        {
                            wxTreeItemAttr *attr =
                                (wxTreeItemAttr *)m_attrs.Get(nmcd.dwItemSpec);

                            if ( !attr )
                            {
                                // nothing to do for this item
                                *result = CDRF_DODEFAULT;
                                break;
                            }

                            HFONT hFont;
                            wxColour colText, colBack;
                            if ( attr->HasFont() )
                            {
                                wxFont font = attr->GetFont();
                                hFont = (HFONT)font.GetResourceHandle();
                            }
                            else
                            {
                                hFont = 0;
                            }

                            if ( attr->HasTextColour() )
                            {
                                colText = attr->GetTextColour();
                            }
                            else
                            {
                                colText = GetForegroundColour();
                            }

                            // selection colours should override ours
                            if ( nmcd.uItemState & CDIS_SELECTED )
                            {
                                DWORD clrBk = ::GetSysColor(COLOR_HIGHLIGHT);
                                lptvcd->clrTextBk = clrBk;

                                // try to make the text visible
                                lptvcd->clrText = wxColourToRGB(colText);
                                lptvcd->clrText |= ~clrBk;
                                lptvcd->clrText &= 0x00ffffff;
                            }
                            else
                            {
                                if ( attr->HasBackgroundColour() )
                                {
                                    colBack = attr->GetBackgroundColour();
                                }
                                else
                                {
                                    colBack = GetBackgroundColour();
                                }

                                lptvcd->clrText = wxColourToRGB(colText);
                                lptvcd->clrTextBk = wxColourToRGB(colBack);
                            }

                            // note that if we wanted to set colours for
                            // individual columns (subitems), we would have
                            // returned CDRF_NOTIFYSUBITEMREDRAW from here
                            if ( hFont )
                            {
                                ::SelectObject(nmcd.hdc, hFont);

                                *result = CDRF_NEWFONT;
                            }
                            else
                            {
                                *result = CDRF_DODEFAULT;
                            }
                        }
                        break;

                    default:
                        *result = CDRF_DODEFAULT;
                }
            }

            // we always process it
            return TRUE;
#endif // _WIN32_IE >= 0x300

        case NM_DBLCLK:
        case NM_RCLICK:
            {
                TV_HITTESTINFO tvhti;
                ::GetCursorPos(&tvhti.pt);
                ::ScreenToClient(GetHwnd(), &tvhti.pt);
                if ( TreeView_HitTest(GetHwnd(), &tvhti) )
                {
                    if ( tvhti.flags & TVHT_ONITEM )
                    {
                        event.m_item = (WXHTREEITEM) tvhti.hItem;
                        eventType = (int)hdr->code == NM_DBLCLK
                                    ? wxEVT_COMMAND_TREE_ITEM_ACTIVATED
                                    : wxEVT_COMMAND_TREE_ITEM_RIGHT_CLICK;

                        event.m_pointDrag.x = tvhti.pt.x;
                        event.m_pointDrag.y = tvhti.pt.y;
                    }

                    break;
                }
            }
            // fall through

        default:
            return wxControl::MSWOnNotify(idCtrl, lParam, result);
    }

    event.SetEventObject(this);
    event.SetEventType(eventType);

    bool processed = GetEventHandler()->ProcessEvent(event);

    // post processing
    switch ( hdr->code )
    {
        case NM_DBLCLK:
            // we translate NM_DBLCLK into ACTIVATED event, so don't interpret
            // the return code of this event handler as the return value for
            // NM_DBLCLK - otherwise, double clicking the item to toggle its
            // expanded status would never work
            *result = FALSE;
            break;

        case TVN_BEGINDRAG:
        case TVN_BEGINRDRAG:
            if ( event.IsAllowed() )
            {
                // normally this is impossible because the m_dragImage is
                // deleted once the drag operation is over
                wxASSERT_MSG( !m_dragImage, _T("starting to drag once again?") );

                m_dragImage = new wxDragImage(*this, event.m_item);
                m_dragImage->BeginDrag(wxPoint(0, 0), this);
                m_dragImage->Show();
            }
            break;

        case TVN_DELETEITEM:
            {
                // NB: we might process this message using wxWindows event
                //     tables, but due to overhead of wxWin event system we
                //     prefer to do it here ourself (otherwise deleting a tree
                //     with many items is just too slow)
                NM_TREEVIEW* tv = (NM_TREEVIEW *)lParam;

                wxTreeItemId item = event.m_item;
                if ( HasIndirectData(item) )
                {
                    wxTreeItemIndirectData *data = (wxTreeItemIndirectData *)
                                                        tv->itemOld.lParam;
                    delete data; // can't be NULL here

                    m_itemsWithIndirectData.Remove(item);
#if 0
                    int iIndex = m_itemsWithIndirectData.Index(item);
                    wxASSERT( iIndex != wxNOT_FOUND) ;
                    m_itemsWithIndirectData.wxBaseArray::RemoveAt((size_t)iIndex);
#endif
                }
                else
                {
                    wxTreeItemData *data = (wxTreeItemData *)tv->itemOld.lParam;
                    delete data; // may be NULL, ok
                }

                processed = TRUE; // Make sure we don't get called twice
            }
            break;

        case TVN_BEGINLABELEDIT:
            // return TRUE to cancel label editing
            *result = !event.IsAllowed();
            break;

        case TVN_ENDLABELEDIT:
            // return TRUE to set the label to the new string: note that we
            // also must pretend that we did process the message or it is going
            // to be passed to DefWindowProc() which will happily return FALSE
            // cancelling the label change
            *result = event.IsAllowed();
            processed = TRUE;

            // ensure that we don't have the text ctrl which is going to be
            // deleted any more
            DeleteTextCtrl();
            break;

        case TVN_SELCHANGING:
        case TVN_ITEMEXPANDING:
            // return TRUE to prevent the action from happening
            *result = !event.IsAllowed();
            break;

        case TVN_GETDISPINFO:
            // NB: so far the user can't set the image himself anyhow, so do it
            //     anyway - but this may change later
//          if ( /* !processed && */ 1 )
            {
                wxTreeItemId item = event.m_item;
                TV_DISPINFO *info = (TV_DISPINFO *)lParam;
                if ( info->item.mask & TVIF_IMAGE )
                {
                    info->item.iImage =
                        DoGetItemImageFromData
                        (
                         item,
                         IsExpanded(item) ? wxTreeItemIcon_Expanded
                                          : wxTreeItemIcon_Normal
                        );
                }
                if ( info->item.mask & TVIF_SELECTEDIMAGE )
                {
                    info->item.iSelectedImage =
                        DoGetItemImageFromData
                        (
                         item,
                         IsExpanded(item) ? wxTreeItemIcon_SelectedExpanded
                                          : wxTreeItemIcon_Selected
                        );
                }
			}
            break;

        //default:
            // for the other messages the return value is ignored and there is
            // nothing special to do
    }
    return processed;
}

#endif // __WIN95__

#endif // wxUSE_TREECTRL