Don't block the main UI thread while generating completions in wxMSW.

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

///////////////////////////////////////////////////////////////////////////////
// Name:        src/msw/textentry.cpp
// Purpose:     wxTextEntry implementation for wxMSW
// Author:      Vadim Zeitlin
// Created:     2007-09-26
// RCS-ID:      $Id$
// Copyright:   (c) 2007 Vadim Zeitlin <vadim@wxwindows.org>
// Licence:     wxWindows licence
///////////////////////////////////////////////////////////////////////////////

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

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

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

#ifdef __BORLANDC__
    #pragma hdrstop
#endif

#ifndef WX_PRECOMP
    #include "wx/arrstr.h"
    #include "wx/string.h"
#endif // WX_PRECOMP

#if wxUSE_TEXTCTRL || wxUSE_COMBOBOX

#include "wx/textentry.h"
#include "wx/textcompleter.h"
#include "wx/dynlib.h"

#include "wx/msw/private.h"

#if wxUSE_UXTHEME
    #include "wx/msw/uxtheme.h"
#endif

#define GetEditHwnd() ((HWND)(GetEditHWND()))

// ----------------------------------------------------------------------------
// Classes used by auto-completion implementation.
// ----------------------------------------------------------------------------

// standard VC6 SDK (WINVER == 0x0400) does not know about IAutoComplete
#if wxUSE_OLE && (WINVER >= 0x0500)
    #define HAS_AUTOCOMPLETE
#endif

#ifdef HAS_AUTOCOMPLETE

#include "wx/msw/ole/oleutils.h"
#include <shldisp.h>
#include <shobjidl.h>

#if defined(__MINGW32__) || defined (__WATCOMC__) || defined(__CYGWIN__)
    // needed for IID_IAutoComplete, IID_IAutoComplete2 and ACO_AUTOSUGGEST
    #include <shlguid.h>
#endif

#ifndef ACO_UPDOWNKEYDROPSLIST
    #define ACO_UPDOWNKEYDROPSLIST 0x20
#endif

#ifndef SHACF_FILESYS_ONLY
    #define SHACF_FILESYS_ONLY 0x00000010
#endif

DEFINE_GUID(CLSID_AutoComplete,
    0x00bb2763, 0x6a77, 0x11d0, 0xa5, 0x35, 0x00, 0xc0, 0x4f, 0xd7, 0xd0, 0x62);

namespace
{

// Small helper class which can be used to ensure thread safety even when
// wxUSE_THREADS==0 (and hence wxCriticalSection does nothing).
class CSLock
{
public:
    CSLock(CRITICAL_SECTION& cs) : m_cs(&cs)
    {
        ::EnterCriticalSection(m_cs);
    }

    ~CSLock()
    {
        ::LeaveCriticalSection(m_cs);
    }

private:
    CRITICAL_SECTION * const m_cs;

    wxDECLARE_NO_COPY_CLASS(CSLock);
};

} // anonymity namespace

// Implementation of string enumerator used by wxTextAutoCompleteData. This
// class simply iterates over its strings except that it also can be told to
// update them from the custom completer if one is used.
//
// Notice that Next() method of this class is called by IAutoComplete
// background thread and so we must care about thread safety here.
class wxIEnumString : public IEnumString
{
public:
    wxIEnumString()
    {
        Init();

        m_index = 0;
    }

    wxIEnumString(const wxIEnumString& other)
        : m_strings(other.m_strings),
          m_index(other.m_index)
    {
        Init();
    }

    void ChangeStrings(const wxArrayString& strings)
    {
        CSLock lock(m_csStrings);

        m_strings = strings;
        m_index = 0;
    }

    void UpdateStringsFromCompleter(wxTextCompleter *completer,
                                    const wxString& prefix)
    {
        CSLock lock(m_csUpdate);

        // We simply store the pointer here and will really update during the
        // next call to our Next() method as we want to call GetCompletions()
        // from the worker thread to prevent the main UI thread from blocking
        // while the completions are generated.
        m_completer = completer;
        m_prefix = prefix;
    }

    virtual HRESULT STDMETHODCALLTYPE Next(ULONG celt,
                                           LPOLESTR *rgelt,
                                           ULONG *pceltFetched)
    {
        if ( !rgelt || (!pceltFetched && celt > 1) )
            return E_POINTER;

        ULONG pceltFetchedDummy;
        if ( !pceltFetched )
            pceltFetched = &pceltFetchedDummy;

        *pceltFetched = 0;

        CSLock lock(m_csStrings);

        DoUpdateIfNeeded();

        for ( const unsigned count = m_strings.size(); celt--; ++m_index )
        {
            if ( m_index == count )
                return S_FALSE;

            const wxWX2WCbuf wcbuf = m_strings[m_index].wc_str();
            const size_t size = (wcslen(wcbuf) + 1)*sizeof(wchar_t);
            void *olestr = CoTaskMemAlloc(size);
            if ( !olestr )
                return E_OUTOFMEMORY;

            memcpy(olestr, wcbuf, size);

            *rgelt++ = static_cast<LPOLESTR>(olestr);

            ++(*pceltFetched);
        }

        return S_OK;
    }

    virtual HRESULT STDMETHODCALLTYPE Skip(ULONG celt)
    {
        CSLock lock(m_csStrings);

        m_index += celt;
        if ( m_index > m_strings.size() )
        {
            m_index = m_strings.size();
            return S_FALSE;
        }

        return S_OK;
    }

    virtual HRESULT STDMETHODCALLTYPE Reset()
    {
        {
            CSLock lock(m_csUpdate);

            if ( m_completer )
            {
                // We will update the string from completer soon (or maybe are
                // already in process of doing it) so don't do anything now, it
                // is useless at best and could also result in a deadlock if
                // m_csStrings is already locked by Next().
                return S_OK;
            }
        }

        CSLock lock(m_csStrings);

        m_index = 0;

        return S_OK;
    }

    virtual HRESULT STDMETHODCALLTYPE Clone(IEnumString **ppEnum)
    {
        if ( !ppEnum )
            return E_POINTER;

        CSLock lock(m_csStrings);

        wxIEnumString *e = new wxIEnumString(*this);

        e->AddRef();
        *ppEnum = e;

        return S_OK;
    }

    DECLARE_IUNKNOWN_METHODS;

private:
    // dtor doesn't have to be virtual as we're only ever deleted from our own
    // Release() and are not meant to be derived form anyhow, but making it
    // virtual silences gcc warnings; making it private makes it impossible to
    // (mistakenly) delete us directly instead of calling Release()
    virtual ~wxIEnumString()
    {
        ::DeleteCriticalSection(&m_csStrings);
        ::DeleteCriticalSection(&m_csUpdate);
    }

    // Common part of all ctors.
    void Init()
    {
        ::InitializeCriticalSection(&m_csUpdate);
        ::InitializeCriticalSection(&m_csStrings);

        m_completer = NULL;
    }

    void DoUpdateIfNeeded()
    {
        wxTextCompleter *completer;
        wxString prefix;
        {
            CSLock lock(m_csUpdate);

            completer = m_completer;
            if ( !completer )
                return;

            prefix = m_prefix;
        } // Unlock m_csUpdate to allow the main thread to call our
          // UpdateStringsFromCompleter() without blocking while we are
          // generating completions.

        // Notice that m_csStrings is locked by our caller already so no need
        // to enter it again.
        m_index = 0;
        m_strings.clear();
        completer->GetCompletions(prefix, m_strings);

        {
            CSLock lock(m_csUpdate);

            if ( m_completer == completer && m_prefix == prefix )
            {
                // There were no calls to UpdateStringsFromCompleter() while we
                // generated the completions, so our completions are still
                // pertinent.
                m_completer = NULL;
                return;
            }
            //else: Our completions are already out of date, regenerate them
            //      once again.
        }
    }


    // Critical section protecting m_strings and m_index.
    CRITICAL_SECTION m_csStrings;

    // The strings we iterate over and the current iteration index.
    wxArrayString m_strings;
    unsigned m_index;

    // This one protects just m_completer, it is different from m_csStrings
    // because the main thread should be able to update our completer prefix
    // without blocking (as this would freeze the UI) even while we're inside a
    // possibly long process of updating m_strings.
    CRITICAL_SECTION m_csUpdate;

    // If completer pointer is non-NULL, we must use it by calling its
    // GetCompletions() method with the specified prefix to update the list of
    // strings we iterate over when our Next() is called the next time.
    wxTextCompleter *m_completer;
    wxString m_prefix;


    wxDECLARE_NO_ASSIGN_CLASS(wxIEnumString);
};

BEGIN_IID_TABLE(wxIEnumString)
    ADD_IID(Unknown)
    ADD_IID(EnumString)
END_IID_TABLE;

IMPLEMENT_IUNKNOWN_METHODS(wxIEnumString)


// This class gathers the auto-complete-related we use. It is allocated on
// demand by wxTextEntry when AutoComplete() is called.
class wxTextAutoCompleteData wxBIND_OR_CONNECT_HACK_ONLY_BASE_CLASS
{
public:
    // The constructor associates us with the given text entry.
    wxTextAutoCompleteData(wxTextEntry *entry)
        : m_entry(entry),
          m_win(entry->GetEditableWindow())
    {
        m_autoComplete = NULL;
        m_autoCompleteDropDown = NULL;
        m_enumStrings = NULL;
        m_customCompleter = NULL;

        m_connectedCharEvent = false;

        // Create an object exposing IAutoComplete interface which we'll later
        // use to get IAutoComplete2 as the latter can't be created directly,
        // apparently.
        HRESULT hr = CoCreateInstance
                     (
                        CLSID_AutoComplete,
                        NULL,
                        CLSCTX_INPROC_SERVER,
                        IID_IAutoComplete,
                        reinterpret_cast<void **>(&m_autoComplete)
                     );
        if ( FAILED(hr) )
        {
            wxLogApiError(wxT("CoCreateInstance(CLSID_AutoComplete)"), hr);
            return;
        }

        // Create a string enumerator and initialize the completer with it.
        m_enumStrings = new wxIEnumString;
        m_enumStrings->AddRef();
        hr = m_autoComplete->Init(m_entry->GetEditHWND(), m_enumStrings,
                                  NULL, NULL);
        if ( FAILED(hr) )
        {
            wxLogApiError(wxT("IAutoComplete::Init"), hr);

            m_enumStrings->Release();
            m_enumStrings = NULL;

            return;
        }

        // As explained in DoRefresh(), we need to call IAutoCompleteDropDown::
        // ResetEnumerator() if we want to be able to change the completions on
        // the fly. In principle we could live without it, i.e. return true
        // from IsOk() even if this QueryInterface() fails, but it doesn't look
        // like this is ever going to have in practice anyhow as the shell-
        // provided IAutoComplete always implements IAutoCompleteDropDown too.
        hr = m_autoComplete->QueryInterface
                             (
                               IID_IAutoCompleteDropDown,
                               reinterpret_cast<void **>(&m_autoCompleteDropDown)
                             );
        if ( FAILED(hr) )
        {
            wxLogApiError(wxT("IAutoComplete::QI(IAutoCompleteDropDown)"), hr);
            return;
        }

        // Finally set the completion options using IAutoComplete2.
        IAutoComplete2 *pAutoComplete2 = NULL;
        hr = m_autoComplete->QueryInterface
                             (
                               IID_IAutoComplete2,
                               reinterpret_cast<void **>(&pAutoComplete2)
                             );
        if ( SUCCEEDED(hr) )
        {
            pAutoComplete2->SetOptions(ACO_AUTOSUGGEST |
                                       ACO_AUTOAPPEND |
                                       ACO_UPDOWNKEYDROPSLIST);
            pAutoComplete2->Release();
        }
    }

    ~wxTextAutoCompleteData()
    {
        delete m_customCompleter;

        if ( m_enumStrings )
            m_enumStrings->Release();
        if ( m_autoCompleteDropDown )
            m_autoCompleteDropDown->Release();
        if ( m_autoComplete )
            m_autoComplete->Release();
    }

    // Must be called after creating this object to verify if initializing it
    // succeeded.
    bool IsOk() const
    {
        return m_autoComplete && m_autoCompleteDropDown && m_enumStrings;
    }

    void ChangeStrings(const wxArrayString& strings)
    {
        m_enumStrings->ChangeStrings(strings);

        DoRefresh();
    }

    // Takes ownership of the pointer if it is non-NULL.
    bool ChangeCustomCompleter(wxTextCompleter *completer)
    {
        delete m_customCompleter;
        m_customCompleter = completer;

        if ( m_customCompleter )
        {
            // We postpone connecting to this event until we really need to do
            // it (however we don't disconnect from it when we don't need it
            // any more because we don't have wxUNBIND_OR_DISCONNECT_HACK...).
            if ( !m_connectedCharEvent )
            {
                m_connectedCharEvent = true;

                // Use the special wxEVT_AFTER_CHAR and not the usual
                // wxEVT_CHAR here because we need to have the updated value of
                // the text control in this handler in order to provide
                // completions for the correct prefix and unfortunately we
                // don't have any way to let DefWindowProc() run from our
                // wxEVT_CHAR handler (as we must also let the other handlers
                // defined at wx level run first).
                //
                // Notice that we can't use wxEVT_COMMAND_TEXT_UPDATED here
                // neither as, due to our use of ACO_AUTOAPPEND, we get
                // EN_CHANGE notifications from the control every time
                // IAutoComplete auto-appends something to it.
                wxBIND_OR_CONNECT_HACK(m_win, wxEVT_AFTER_CHAR,
                                        wxKeyEventHandler,
                                        wxTextAutoCompleteData::OnAfterChar,
                                        this);
            }

            UpdateStringsFromCustomCompleter();
        }

        return true;
    }

    void DisableCompletion()
    {
        // We currently simply reset the list of possible strings as this seems
        // to effectively disable auto-completion just fine. We could (and
        // probably should) use IAutoComplete::Enable(FALSE) for this too but
        // then we'd need to call Enable(TRUE) to turn it on back again later.

        m_enumStrings->ChangeStrings(wxArrayString());

        ChangeCustomCompleter(NULL);
    }

private:
    // Must be called after changing wxIEnumString::m_strings to really make
    // the changes stick.
    void DoRefresh()
    {
        m_enumStrings->Reset();

        // This is completely and utterly not documented and in fact the
        // current MSDN seems to try to discourage us from using it by saying
        // that "there is no reason to use this method unless the drop-down
        // list is currently visible" but actually we absolutely must call it
        // to force the auto-completer (and not just its drop-down!) to refresh
        // the list of completions which could have changed now. Without this
        // call the new choices returned by GetCompletions() that hadn't been
        // returned by it before are simply silently ignored.
        m_autoCompleteDropDown->ResetEnumerator();
    }

    // Update the strings returned by our string enumerator to correspond to
    // the currently valid choices according to the custom completer.
    void UpdateStringsFromCustomCompleter()
    {
        // As we use ACO_AUTOAPPEND, the selected part of the text is usually
        // the one appended by us so don't consider it as part of the
        // user-entered prefix.
        long from, to;
        m_entry->GetSelection(&from, &to);

        if ( to == from )
            from = m_entry->GetLastPosition(); // Take all if no selection.

        const wxString prefix = m_entry->GetRange(0, from);

        m_enumStrings->UpdateStringsFromCompleter(m_customCompleter, prefix);

        DoRefresh();
    }

    void OnAfterChar(wxKeyEvent& event)
    {
        // Notice that we must not refresh the completions when the user
        // presses Backspace as this would result in adding back the just
        // erased character(s) because of ACO_AUTOAPPEND option we use.
        if ( m_customCompleter && event.GetKeyCode() != WXK_BACK )
            UpdateStringsFromCustomCompleter();

        event.Skip();
    }


    // The text entry we're associated with.
    wxTextEntry * const m_entry;

    // The window of this text entry.
    wxWindow * const m_win;

    // The auto-completer object itself.
    IAutoComplete *m_autoComplete;

    // Its IAutoCompleteDropDown interface needed for ResetEnumerator() call.
    IAutoCompleteDropDown *m_autoCompleteDropDown;

    // Enumerator for strings currently used for auto-completion.
    wxIEnumString *m_enumStrings;

    // Custom completer or NULL if none.
    wxTextCompleter *m_customCompleter;

    // Initially false, set to true after connecting OnTextChanged() handler.
    bool m_connectedCharEvent;


    wxDECLARE_NO_COPY_CLASS(wxTextAutoCompleteData);
};

#endif // HAS_AUTOCOMPLETE

// ============================================================================
// wxTextEntry implementation
// ============================================================================

// ----------------------------------------------------------------------------
// initialization and destruction
// ----------------------------------------------------------------------------

wxTextEntry::wxTextEntry()
{
#ifdef HAS_AUTOCOMPLETE
    m_autoCompleteData = NULL;
#endif // HAS_AUTOCOMPLETE
}

wxTextEntry::~wxTextEntry()
{
#ifdef HAS_AUTOCOMPLETE
    delete m_autoCompleteData;
#endif // HAS_AUTOCOMPLETE
}

// ----------------------------------------------------------------------------
// operations on text
// ----------------------------------------------------------------------------

void wxTextEntry::WriteText(const wxString& text)
{
    ::SendMessage(GetEditHwnd(), EM_REPLACESEL, 0, (LPARAM)text.wx_str());
}

wxString wxTextEntry::DoGetValue() const
{
    return wxGetWindowText(GetEditHWND());
}

void wxTextEntry::Remove(long from, long to)
{
    DoSetSelection(from, to, SetSel_NoScroll);
    WriteText(wxString());
}

// ----------------------------------------------------------------------------
// clipboard operations
// ----------------------------------------------------------------------------

void wxTextEntry::Copy()
{
    ::SendMessage(GetEditHwnd(), WM_COPY, 0, 0);
}

void wxTextEntry::Cut()
{
    ::SendMessage(GetEditHwnd(), WM_CUT, 0, 0);
}

void wxTextEntry::Paste()
{
    ::SendMessage(GetEditHwnd(), WM_PASTE, 0, 0);
}

// ----------------------------------------------------------------------------
// undo/redo
// ----------------------------------------------------------------------------

void wxTextEntry::Undo()
{
    ::SendMessage(GetEditHwnd(), EM_UNDO, 0, 0);
}

void wxTextEntry::Redo()
{
    // same as Undo, since Undo undoes the undo
    Undo();
    return;
}

bool wxTextEntry::CanUndo() const
{
    return ::SendMessage(GetEditHwnd(), EM_CANUNDO, 0, 0) != 0;
}

bool wxTextEntry::CanRedo() const
{
    // see comment in Redo()
    return CanUndo();
}

// ----------------------------------------------------------------------------
// insertion point and selection
// ----------------------------------------------------------------------------

void wxTextEntry::SetInsertionPoint(long pos)
{
    // calling DoSetSelection(-1, -1) would select everything which is not what
    // we want here
    if ( pos == -1 )
        pos = GetLastPosition();

    // be careful to call DoSetSelection() which is overridden in wxTextCtrl
    // and not just SetSelection() here
    DoSetSelection(pos, pos);
}

long wxTextEntry::GetInsertionPoint() const
{
    long from;
    GetSelection(&from, NULL);
    return from;
}

long wxTextEntry::GetLastPosition() const
{
    return ::SendMessage(GetEditHwnd(), EM_LINELENGTH, 0, 0);
}

void wxTextEntry::DoSetSelection(long from, long to, int WXUNUSED(flags))
{
    // if from and to are both -1, it means (in wxWidgets) that all text should
    // be selected, translate this into Windows convention
    if ( (from == -1) && (to == -1) )
    {
        from = 0;
    }

    ::SendMessage(GetEditHwnd(), EM_SETSEL, from, to);
}

void wxTextEntry::GetSelection(long *from, long *to) const
{
    DWORD dwStart, dwEnd;
    ::SendMessage(GetEditHwnd(), EM_GETSEL, (WPARAM)&dwStart, (LPARAM)&dwEnd);

    if ( from )
        *from = dwStart;
    if ( to )
        *to = dwEnd;
}

// ----------------------------------------------------------------------------
// auto-completion
// ----------------------------------------------------------------------------

#if wxUSE_OLE

#ifdef HAS_AUTOCOMPLETE

bool wxTextEntry::DoAutoCompleteFileNames()
{
    typedef HRESULT (WINAPI *SHAutoComplete_t)(HWND, DWORD);
    static SHAutoComplete_t s_pfnSHAutoComplete = (SHAutoComplete_t)-1;
    static wxDynamicLibrary s_dllShlwapi;
    if ( s_pfnSHAutoComplete == (SHAutoComplete_t)-1 )
    {
        if ( !s_dllShlwapi.Load(wxT("shlwapi.dll"), wxDL_VERBATIM | wxDL_QUIET) )
        {
            s_pfnSHAutoComplete = NULL;
        }
        else
        {
            wxDL_INIT_FUNC(s_pfn, SHAutoComplete, s_dllShlwapi);
        }
    }

    if ( !s_pfnSHAutoComplete )
        return false;

    HRESULT hr = (*s_pfnSHAutoComplete)(GetEditHwnd(), SHACF_FILESYS_ONLY);
    if ( FAILED(hr) )
    {
        wxLogApiError(wxT("SHAutoComplete()"), hr);

        return false;
    }

    // Disable the other kinds of completion now that we use the built-in file
    // names completion.
    if ( m_autoCompleteData )
        m_autoCompleteData->DisableCompletion();

    return true;
}

wxTextAutoCompleteData *wxTextEntry::GetOrCreateCompleter()
{
    if ( !m_autoCompleteData )
    {
        wxTextAutoCompleteData * const ac = new wxTextAutoCompleteData(this);
        if ( ac->IsOk() )
            m_autoCompleteData = ac;
        else
            delete ac;
    }

    return m_autoCompleteData;
}

bool wxTextEntry::DoAutoCompleteStrings(const wxArrayString& choices)
{
    wxTextAutoCompleteData * const ac = GetOrCreateCompleter();
    if ( !ac )
        return false;

    ac->ChangeStrings(choices);

    return true;
}

bool wxTextEntry::DoAutoCompleteCustom(wxTextCompleter *completer)
{
    // First deal with the case when we just want to disable auto-completion.
    if ( !completer )
    {
        if ( m_autoCompleteData )
            m_autoCompleteData->DisableCompletion();
        //else: Nothing to do, we hadn't used auto-completion even before.
    }
    else // Have a valid completer.
    {
        wxTextAutoCompleteData * const ac = GetOrCreateCompleter();
        if ( !ac )
        {
            // Delete the custom completer for consistency with the case when
            // we succeed to avoid memory leaks in user code.
            delete completer;
            return false;
        }

        // This gives ownership of the custom completer to m_autoCompleteData.
        if ( !ac->ChangeCustomCompleter(completer) )
            return false;
    }

    return true;
}

#else // !HAS_AUTOCOMPLETE

// We still need to define stubs as we declared these overrides in the header.

bool wxTextEntry::DoAutoCompleteFileNames()
{
    return wxTextEntryBase::DoAutoCompleteFileNames();
}

bool wxTextEntry::DoAutoCompleteStrings(const wxArrayString& choices)
{
    return wxTextEntryBase::DoAutoCompleteStrings(choices);
}

#endif // HAS_AUTOCOMPLETE/!HAS_AUTOCOMPLETE

#endif // wxUSE_OLE

// ----------------------------------------------------------------------------
// editable state
// ----------------------------------------------------------------------------

bool wxTextEntry::IsEditable() const
{
    return !(::GetWindowLong(GetEditHwnd(), GWL_STYLE) & ES_READONLY);
}

void wxTextEntry::SetEditable(bool editable)
{
    ::SendMessage(GetEditHwnd(), EM_SETREADONLY, !editable, 0);
}

// ----------------------------------------------------------------------------
// max length
// ----------------------------------------------------------------------------

void wxTextEntry::SetMaxLength(unsigned long len)
{
    if ( len >= 0xffff )
    {
        // this will set it to a platform-dependent maximum (much more
        // than 64Kb under NT)
        len = 0;
    }

    ::SendMessage(GetEditHwnd(), EM_LIMITTEXT, len, 0);
}

// ----------------------------------------------------------------------------
// hints
// ----------------------------------------------------------------------------

#if wxUSE_UXTHEME

#ifndef EM_SETCUEBANNER
    #define EM_SETCUEBANNER 0x1501
    #define EM_GETCUEBANNER 0x1502
#endif

bool wxTextEntry::SetHint(const wxString& hint)
{
    if ( wxUxThemeEngine::GetIfActive() )
    {
        // notice that this message always works with Unicode strings
        //
        // we always use TRUE for wParam to show the hint even when the window
        // has focus, otherwise there would be no way to show the hint for the
        // initially focused window
        if ( ::SendMessage(GetEditHwnd(), EM_SETCUEBANNER,
                             TRUE, (LPARAM)(const wchar_t *)hint.wc_str()) )
            return true;
    }

    return wxTextEntryBase::SetHint(hint);
}

wxString wxTextEntry::GetHint() const
{
    if ( wxUxThemeEngine::GetIfActive() )
    {
        wchar_t buf[256];
        if ( ::SendMessage(GetEditHwnd(), EM_GETCUEBANNER,
                            (WPARAM)buf, WXSIZEOF(buf)) )
            return wxString(buf);
    }

    return wxTextEntryBase::GetHint();
}


#endif // wxUSE_UXTHEME

// ----------------------------------------------------------------------------
// margins support
// ----------------------------------------------------------------------------

bool wxTextEntry::DoSetMargins(const wxPoint& margins)
{
#if !defined(__WXWINCE__)
    bool res = true;

    if ( margins.x != -1 )
    {
        // left margin
        ::SendMessage(GetEditHwnd(), EM_SETMARGINS,
                      EC_LEFTMARGIN, MAKELONG(margins.x, 0));
    }

    if ( margins.y != -1 )
    {
        res = false;
    }

    return res;
#else
    return false;
#endif
}

wxPoint wxTextEntry::DoGetMargins() const
{
#if !defined(__WXWINCE__)
    LRESULT lResult = ::SendMessage(GetEditHwnd(), EM_GETMARGINS,
                                    0, 0);
    int left = LOWORD(lResult);
    int top = -1;
    return wxPoint(left, top);
#else
    return wxPoint(-1, -1);
#endif
}

#endif // wxUSE_TEXTCTRL || wxUSE_COMBOBOX