src/msw/ole/droptgt.cpp

///////////////////////////////////////////////////////////////////////////////
// Name:        src/msw/ole/droptgt.cpp
// Purpose:     wxDropTarget implementation
// Author:      Vadim Zeitlin
// Modified by:
// Created:
// RCS-ID:      $Id$
// Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
// Licence:     wxWindows licence
///////////////////////////////////////////////////////////////////////////////

// ============================================================================
// Declarations
// ============================================================================

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

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

#if defined(__BORLANDC__)
    #pragma hdrstop
#endif

#if wxUSE_OLE && wxUSE_DRAG_AND_DROP

#ifndef WX_PRECOMP
    #include "wx/log.h"
#endif

#include "wx/msw/private.h"

#ifdef __WXWINCE__
    #include <winreg.h>
    #include <ole2.h>
#endif

#ifdef __WIN32__
    #if !defined(__GNUWIN32__) || wxUSE_NORLANDER_HEADERS
        #if wxCHECK_W32API_VERSION( 1, 0 )
            #include "wx/msw/wrapwin.h"
        #endif
        #include <shlobj.h>            // for DROPFILES structure
    #endif
#else
    #include <shellapi.h>
#endif

#include "wx/dnd.h"

#include "wx/msw/ole/oleutils.h"

// ----------------------------------------------------------------------------
// IDropTarget interface: forward all interesting things to wxDropTarget
// (the name is unfortunate, but wx_I_DropTarget is not at all the same thing
//  as wxDropTarget which is 'public' class, while this one is private)
// ----------------------------------------------------------------------------

class wxIDropTarget : public IDropTarget
{
public:
    wxIDropTarget(wxDropTarget *p);
    virtual ~wxIDropTarget();

    // accessors for wxDropTarget
    void SetHwnd(HWND hwnd) { m_hwnd = hwnd; }

    // IDropTarget methods
    STDMETHODIMP DragEnter(LPDATAOBJECT, DWORD, POINTL, LPDWORD);
    STDMETHODIMP DragOver(DWORD, POINTL, LPDWORD);
    STDMETHODIMP DragLeave();
    STDMETHODIMP Drop(LPDATAOBJECT, DWORD, POINTL, LPDWORD);

    DECLARE_IUNKNOWN_METHODS;

protected:
    IDataObject  *m_pIDataObject; // !NULL between DragEnter and DragLeave/Drop
    wxDropTarget *m_pTarget;      // the real target (we're just a proxy)

    HWND          m_hwnd;         // window we're associated with

    // get default drop effect for given keyboard flags
    static inline DWORD GetDropEffect(DWORD flags, wxDragResult defaultAction);

    DECLARE_NO_COPY_CLASS(wxIDropTarget)
};

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

static wxDragResult ConvertDragEffectToResult(DWORD dwEffect);
static DWORD ConvertDragResultToEffect(wxDragResult result);

// ============================================================================
// wxIDropTarget implementation
// ============================================================================

// Name    : static wxIDropTarget::GetDropEffect
// Purpose : determine the drop operation from keyboard/mouse state.
// Returns : DWORD combined from DROPEFFECT_xxx constants
// Params  : [in] DWORD flags       kbd & mouse flags as passed to
//                                  IDropTarget methods
// Notes   : We do "move" normally and "copy" if <Ctrl> is pressed,
//           which is the standard behaviour (currently there is no
//           way to redefine it)
DWORD wxIDropTarget::GetDropEffect(DWORD flags, wxDragResult defaultAction)
{
  if (defaultAction == wxDragCopy)
    return flags & MK_SHIFT ? DROPEFFECT_MOVE : DROPEFFECT_COPY;
  return flags & MK_CONTROL ? DROPEFFECT_COPY : DROPEFFECT_MOVE;
}

wxIDropTarget::wxIDropTarget(wxDropTarget *pTarget)
{
  m_pTarget      = pTarget;
  m_pIDataObject = NULL;
}

wxIDropTarget::~wxIDropTarget()
{
}

BEGIN_IID_TABLE(wxIDropTarget)
  ADD_IID(Unknown)
  ADD_IID(DropTarget)
END_IID_TABLE;

IMPLEMENT_IUNKNOWN_METHODS(wxIDropTarget)

// Name    : wxIDropTarget::DragEnter
// Purpose : Called when the mouse enters the window (dragging something)
// Returns : S_OK
// Params  : [in] IDataObject *pIDataSource : source data
//           [in] DWORD        grfKeyState  : kbd & mouse state
//           [in] POINTL       pt           : mouse coordinates
//           [out]DWORD       *pdwEffect    : effect flag
// Notes   :
STDMETHODIMP wxIDropTarget::DragEnter(IDataObject *pIDataSource,
                                      DWORD        grfKeyState,
                                      POINTL       pt,
                                      DWORD       *pdwEffect)
{
    wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::DragEnter"));

    wxASSERT_MSG( m_pIDataObject == NULL,
                  _T("drop target must have data object") );

    // show the list of formats supported by the source data object for the
    // debugging purposes, this is quite useful sometimes - please don't remove
#if 0
    IEnumFORMATETC *penumFmt;
    if ( SUCCEEDED(pIDataSource->EnumFormatEtc(DATADIR_GET, &penumFmt)) )
    {
        FORMATETC fmt;
        while ( penumFmt->Next(1, &fmt, NULL) == S_OK )
        {
            wxLogDebug(_T("Drop source supports format %s"),
                       wxDataObject::GetFormatName(fmt.cfFormat));
        }

        penumFmt->Release();
    }
    else
    {
        wxLogLastError(_T("IDataObject::EnumFormatEtc"));
    }
#endif // 0

    if ( !m_pTarget->IsAcceptedData(pIDataSource) ) {
        // we don't accept this kind of data
        *pdwEffect = DROPEFFECT_NONE;

        return S_OK;
    }

    // get hold of the data object
    m_pIDataObject = pIDataSource;
    m_pIDataObject->AddRef();

    // we need client coordinates to pass to wxWin functions
    if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
    {
        wxLogLastError(wxT("ScreenToClient"));
    }

    // give some visual feedback
    *pdwEffect = ConvertDragResultToEffect(
        m_pTarget->OnEnter(pt.x, pt.y, ConvertDragEffectToResult(
            GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction()))
                    )
                 );

    return S_OK;
}

// Name    : wxIDropTarget::DragOver
// Purpose : Indicates that the mouse was moved inside the window represented
//           by this drop target.
// Returns : S_OK
// Params  : [in] DWORD   grfKeyState     kbd & mouse state
//           [in] POINTL  pt              mouse coordinates
//           [out]LPDWORD pdwEffect       effect flag
// Notes   : We're called on every WM_MOUSEMOVE, so this function should be
//           very efficient.
STDMETHODIMP wxIDropTarget::DragOver(DWORD   grfKeyState,
                                     POINTL  pt,
                                     LPDWORD pdwEffect)
{
    // there are too many of them... wxLogDebug("IDropTarget::DragOver");

    wxDragResult result;
    if ( m_pIDataObject ) {
        result = ConvertDragEffectToResult(
            GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction()));
    }
    else {
        // can't accept data anyhow normally
        result = wxDragNone;
    }

    // we need client coordinates to pass to wxWin functions
    if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
    {
        wxLogLastError(wxT("ScreenToClient"));
    }

    *pdwEffect = ConvertDragResultToEffect(
                    m_pTarget->OnDragOver(pt.x, pt.y, result)
                 );

    return S_OK;
}

// Name    : wxIDropTarget::DragLeave
// Purpose : Informs the drop target that the operation has left its window.
// Returns : S_OK
// Notes   : good place to do any clean-up
STDMETHODIMP wxIDropTarget::DragLeave()
{
  wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::DragLeave"));

  // remove the UI feedback
  m_pTarget->OnLeave();

  // release the held object
  RELEASE_AND_NULL(m_pIDataObject);

  return S_OK;
}

// Name    : wxIDropTarget::Drop
// Purpose : Instructs the drop target to paste data that was just now
//           dropped on it.
// Returns : S_OK
// Params  : [in] IDataObject *pIDataSource     the data to paste
//           [in] DWORD        grfKeyState      kbd & mouse state
//           [in] POINTL       pt               where the drop occurred?
//           [ouy]DWORD       *pdwEffect        operation effect
// Notes   :
STDMETHODIMP wxIDropTarget::Drop(IDataObject *pIDataSource,
                                 DWORD        grfKeyState,
                                 POINTL       pt,
                                 DWORD       *pdwEffect)
{
    wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::Drop"));

    // TODO I don't know why there is this parameter, but so far I assume
    //      that it's the same we've already got in DragEnter
    wxASSERT( m_pIDataObject == pIDataSource );

    // by default, nothing happens
    *pdwEffect = DROPEFFECT_NONE;

    // we need client coordinates to pass to wxWin functions
    if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
    {
        wxLogLastError(wxT("ScreenToClient"));
    }

    // first ask the drop target if it wants data
    if ( m_pTarget->OnDrop(pt.x, pt.y) ) {
        // it does, so give it the data source
        m_pTarget->SetDataSource(pIDataSource);

        // and now it has the data
        wxDragResult rc = ConvertDragEffectToResult(
            GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction()));
        rc = m_pTarget->OnData(pt.x, pt.y, rc);
        if ( wxIsDragResultOk(rc) ) {
            // operation succeeded
            *pdwEffect = ConvertDragResultToEffect(rc);
        }
        //else: *pdwEffect is already DROPEFFECT_NONE
    }
    //else: OnDrop() returned false, no need to copy data

    // release the held object
    RELEASE_AND_NULL(m_pIDataObject);

    return S_OK;
}

// ============================================================================
// wxDropTarget implementation
// ============================================================================

// ----------------------------------------------------------------------------
// ctor/dtor
// ----------------------------------------------------------------------------

wxDropTarget::wxDropTarget(wxDataObject *dataObj)
            : wxDropTargetBase(dataObj)
{
    // create an IDropTarget implementation which will notify us about d&d
    // operations.
    m_pIDropTarget = new wxIDropTarget(this);
    m_pIDropTarget->AddRef();
}

wxDropTarget::~wxDropTarget()
{
    ReleaseInterface(m_pIDropTarget);
}

// ----------------------------------------------------------------------------
// [un]register drop handler
// ----------------------------------------------------------------------------

bool wxDropTarget::Register(WXHWND hwnd)
{
    // FIXME
    // RegisterDragDrop not available on Windows CE >= 400?
    // Or maybe we can dynamically load them from ceshell.dll
    // or similar.
#if defined(__WXWINCE__) && _WIN32_WCE >= 400
    wxUnusedVar(hwnd);
    return false;
#else
    HRESULT hr;

    // May exist in later WinCE versions
#ifndef __WXWINCE__
    hr = ::CoLockObjectExternal(m_pIDropTarget, TRUE, FALSE);
    if ( FAILED(hr) ) {
        wxLogApiError(wxT("CoLockObjectExternal"), hr);
        return false;
    }
#endif

    hr = ::RegisterDragDrop((HWND) hwnd, m_pIDropTarget);
    if ( FAILED(hr) ) {
    // May exist in later WinCE versions
#ifndef __WXWINCE__
        ::CoLockObjectExternal(m_pIDropTarget, FALSE, FALSE);
#endif
        wxLogApiError(wxT("RegisterDragDrop"), hr);
        return false;
    }

    // we will need the window handle for coords transformation later
    m_pIDropTarget->SetHwnd((HWND)hwnd);

    return true;
#endif
}

void wxDropTarget::Revoke(WXHWND hwnd)
{
#if defined(__WXWINCE__) && _WIN32_WCE >= 400
    // Not available, see note above
    wxUnusedVar(hwnd);
#else
    HRESULT hr = ::RevokeDragDrop((HWND) hwnd);

    if ( FAILED(hr) ) {
        wxLogApiError(wxT("RevokeDragDrop"), hr);
    }

    // May exist in later WinCE versions
#ifndef __WXWINCE__
    ::CoLockObjectExternal(m_pIDropTarget, FALSE, TRUE);
#endif

    m_pIDropTarget->SetHwnd(0);
#endif
}

// ----------------------------------------------------------------------------
// base class pure virtuals
// ----------------------------------------------------------------------------

// OnDrop() is called only if we previously returned true from
// IsAcceptedData(), so no need to check anything here
bool wxDropTarget::OnDrop(wxCoord WXUNUSED(x), wxCoord WXUNUSED(y))
{
    return true;
}

// copy the data from the data source to the target data object
bool wxDropTarget::GetData()
{
    wxDataFormat format = GetSupportedFormat(m_pIDataSource);
    if ( format == wxDF_INVALID ) {
        // this is strange because IsAcceptedData() succeeded previously!
        wxFAIL_MSG(wxT("strange - did supported formats list change?"));

        return false;
    }

    STGMEDIUM stm;
    FORMATETC fmtMemory;
    fmtMemory.cfFormat  = format;
    fmtMemory.ptd       = NULL;
    fmtMemory.dwAspect  = DVASPECT_CONTENT;
    fmtMemory.lindex    = -1;
    fmtMemory.tymed     = TYMED_HGLOBAL;  // TODO to add other media

    bool rc = false;

    HRESULT hr = m_pIDataSource->GetData(&fmtMemory, &stm);
    if ( SUCCEEDED(hr) ) {
        IDataObject *dataObject = m_dataObject->GetInterface();

        hr = dataObject->SetData(&fmtMemory, &stm, TRUE);
        if ( SUCCEEDED(hr) ) {
            rc = true;
        }
        else {
            wxLogApiError(wxT("IDataObject::SetData()"), hr);
        }
    }
    else {
        wxLogApiError(wxT("IDataObject::GetData()"), hr);
    }

    return rc;
}

// ----------------------------------------------------------------------------
// callbacks used by wxIDropTarget
// ----------------------------------------------------------------------------

// we need a data source, so wxIDropTarget gives it to us using this function
void wxDropTarget::SetDataSource(IDataObject *pIDataSource)
{
    m_pIDataSource = pIDataSource;
}

// determine if we accept data of this type
bool wxDropTarget::IsAcceptedData(IDataObject *pIDataSource) const
{
    return GetSupportedFormat(pIDataSource) != wxDF_INVALID;
}

// ----------------------------------------------------------------------------
// helper functions
// ----------------------------------------------------------------------------

wxDataFormat wxDropTarget::GetSupportedFormat(IDataObject *pIDataSource) const
{
    // this strucutre describes a data of any type (first field will be
    // changing) being passed through global memory block.
    static FORMATETC s_fmtMemory = {
        0,
        NULL,
        DVASPECT_CONTENT,
        -1,
        TYMED_HGLOBAL       // TODO is it worth supporting other tymeds here?
    };

    // get the list of supported formats
    size_t nFormats = m_dataObject->GetFormatCount(wxDataObject::Set);
    wxDataFormat format;
    wxDataFormat *formats;
    formats = nFormats == 1 ? &format :  new wxDataFormat[nFormats];

    m_dataObject->GetAllFormats(formats, wxDataObject::Set);

    // cycle through all supported formats
    size_t n;
    for ( n = 0; n < nFormats; n++ ) {
        s_fmtMemory.cfFormat = formats[n];

        // NB: don't use SUCCEEDED macro here: QueryGetData returns S_FALSE
        //     for file drag and drop (format == CF_HDROP)
        if ( pIDataSource->QueryGetData(&s_fmtMemory) == S_OK ) {
            format = formats[n];

            break;
        }
    }

    if ( formats != &format ) {
        // free memory if we allocated it
        delete [] formats;
    }

    return n < nFormats ? format : wxFormatInvalid;
}

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

static wxDragResult ConvertDragEffectToResult(DWORD dwEffect)
{
    switch ( dwEffect ) {
        case DROPEFFECT_COPY:
            return wxDragCopy;

        case DROPEFFECT_LINK:
            return wxDragLink;

        case DROPEFFECT_MOVE:
            return wxDragMove;

        default:
            wxFAIL_MSG(wxT("invalid value in ConvertDragEffectToResult"));
            // fall through

        case DROPEFFECT_NONE:
            return wxDragNone;
    }
}

static DWORD ConvertDragResultToEffect(wxDragResult result)
{
    switch ( result ) {
        case wxDragCopy:
            return DROPEFFECT_COPY;

        case wxDragLink:
            return DROPEFFECT_LINK;

        case wxDragMove:
            return DROPEFFECT_MOVE;

        default:
            wxFAIL_MSG(wxT("invalid value in ConvertDragResultToEffect"));
            // fall through

        case wxDragNone:
            return DROPEFFECT_NONE;
    }
}

#endif // wxUSE_OLE && wxUSE_DRAG_AND_DROP
Commit	Line	Data
	1	///////////////////////////////////////////////////////////////////////////////
	2	// Name: src/msw/ole/droptgt.cpp
	3	// Purpose: wxDropTarget implementation
	4	// Author: Vadim Zeitlin
	5	// Modified by:
	6	// Created:
	7	// RCS-ID: $Id$
	8	// Copyright: (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
	9	// Licence: wxWindows licence
	10	///////////////////////////////////////////////////////////////////////////////
	11
	12	// ============================================================================
	13	// Declarations
	14	// ============================================================================
	15
	16	// ----------------------------------------------------------------------------
	17	// headers
	18	// ----------------------------------------------------------------------------
	19
	20	// For compilers that support precompilation, includes "wx.h".
	21	#include "wx/wxprec.h"
	22
	23	#if defined(__BORLANDC__)
	24	#pragma hdrstop
	25	#endif
	26
	27	#if wxUSE_OLE && wxUSE_DRAG_AND_DROP
	28
	29	#ifndef WX_PRECOMP
	30	#include "wx/log.h"
	31	#endif
	32
	33	#include "wx/msw/private.h"
	34
	35	#ifdef __WXWINCE__
	36	#include <winreg.h>
	37	#include <ole2.h>
	38	#endif
	39
	40	#ifdef __WIN32__
	41	#if !defined(__GNUWIN32__) \|\| wxUSE_NORLANDER_HEADERS
	42	#if wxCHECK_W32API_VERSION( 1, 0 )
	43	#include "wx/msw/wrapwin.h"
	44	#endif
	45	#include <shlobj.h> // for DROPFILES structure
	46	#endif
	47	#else
	48	#include <shellapi.h>
	49	#endif
	50
	51	#include "wx/dnd.h"
	52
	53	#include "wx/msw/ole/oleutils.h"
	54
	55	// ----------------------------------------------------------------------------
	56	// IDropTarget interface: forward all interesting things to wxDropTarget
	57	// (the name is unfortunate, but wx_I_DropTarget is not at all the same thing
	58	// as wxDropTarget which is 'public' class, while this one is private)
	59	// ----------------------------------------------------------------------------
	60
	61	class wxIDropTarget : public IDropTarget
	62	{
	63	public:
	64	wxIDropTarget(wxDropTarget *p);
	65	virtual ~wxIDropTarget();
	66
	67	// accessors for wxDropTarget
	68	void SetHwnd(HWND hwnd) { m_hwnd = hwnd; }
	69
	70	// IDropTarget methods
	71	STDMETHODIMP DragEnter(LPDATAOBJECT, DWORD, POINTL, LPDWORD);
	72	STDMETHODIMP DragOver(DWORD, POINTL, LPDWORD);
	73	STDMETHODIMP DragLeave();
	74	STDMETHODIMP Drop(LPDATAOBJECT, DWORD, POINTL, LPDWORD);
	75
	76	DECLARE_IUNKNOWN_METHODS;
	77
	78	protected:
	79	IDataObject *m_pIDataObject; // !NULL between DragEnter and DragLeave/Drop
	80	wxDropTarget *m_pTarget; // the real target (we're just a proxy)
	81
	82	HWND m_hwnd; // window we're associated with
	83
	84	// get default drop effect for given keyboard flags
	85	static inline DWORD GetDropEffect(DWORD flags, wxDragResult defaultAction);
	86
	87	DECLARE_NO_COPY_CLASS(wxIDropTarget)
	88	};
	89
	90	// ----------------------------------------------------------------------------
	91	// private functions
	92	// ----------------------------------------------------------------------------
	93
	94	static wxDragResult ConvertDragEffectToResult(DWORD dwEffect);
	95	static DWORD ConvertDragResultToEffect(wxDragResult result);
	96
	97	// ============================================================================
	98	// wxIDropTarget implementation
	99	// ============================================================================
	100
	101	// Name : static wxIDropTarget::GetDropEffect
	102	// Purpose : determine the drop operation from keyboard/mouse state.
	103	// Returns : DWORD combined from DROPEFFECT_xxx constants
	104	// Params : [in] DWORD flags kbd & mouse flags as passed to
	105	// IDropTarget methods
	106	// Notes : We do "move" normally and "copy" if <Ctrl> is pressed,
	107	// which is the standard behaviour (currently there is no
	108	// way to redefine it)
	109	DWORD wxIDropTarget::GetDropEffect(DWORD flags, wxDragResult defaultAction)
	110	{
	111	if (defaultAction == wxDragCopy)
	112	return flags & MK_SHIFT ? DROPEFFECT_MOVE : DROPEFFECT_COPY;
	113	return flags & MK_CONTROL ? DROPEFFECT_COPY : DROPEFFECT_MOVE;
	114	}
	115
	116	wxIDropTarget::wxIDropTarget(wxDropTarget *pTarget)
	117	{
	118	m_pTarget = pTarget;
	119	m_pIDataObject = NULL;
	120	}
	121
	122	wxIDropTarget::~wxIDropTarget()
	123	{
	124	}
	125
	126	BEGIN_IID_TABLE(wxIDropTarget)
	127	ADD_IID(Unknown)
	128	ADD_IID(DropTarget)
	129	END_IID_TABLE;
	130
	131	IMPLEMENT_IUNKNOWN_METHODS(wxIDropTarget)
	132
	133	// Name : wxIDropTarget::DragEnter
	134	// Purpose : Called when the mouse enters the window (dragging something)
	135	// Returns : S_OK
	136	// Params : [in] IDataObject *pIDataSource : source data
	137	// [in] DWORD grfKeyState : kbd & mouse state
	138	// [in] POINTL pt : mouse coordinates
	139	// [out]DWORD *pdwEffect : effect flag
	140	// Notes :
	141	STDMETHODIMP wxIDropTarget::DragEnter(IDataObject *pIDataSource,
	142	DWORD grfKeyState,
	143	POINTL pt,
	144	DWORD *pdwEffect)
	145	{
	146	wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::DragEnter"));
	147
	148	wxASSERT_MSG( m_pIDataObject == NULL,
	149	_T("drop target must have data object") );
	150
	151	// show the list of formats supported by the source data object for the
	152	// debugging purposes, this is quite useful sometimes - please don't remove
	153	#if 0
	154	IEnumFORMATETC *penumFmt;
	155	if ( SUCCEEDED(pIDataSource->EnumFormatEtc(DATADIR_GET, &penumFmt)) )
	156	{
	157	FORMATETC fmt;
	158	while ( penumFmt->Next(1, &fmt, NULL) == S_OK )
	159	{
	160	wxLogDebug(_T("Drop source supports format %s"),
	161	wxDataObject::GetFormatName(fmt.cfFormat));
	162	}
	163
	164	penumFmt->Release();
	165	}
	166	else
	167	{
	168	wxLogLastError(_T("IDataObject::EnumFormatEtc"));
	169	}
	170	#endif // 0
	171
	172	if ( !m_pTarget->IsAcceptedData(pIDataSource) ) {
	173	// we don't accept this kind of data
	174	*pdwEffect = DROPEFFECT_NONE;
	175
	176	return S_OK;
	177	}
	178
	179	// get hold of the data object
	180	m_pIDataObject = pIDataSource;
	181	m_pIDataObject->AddRef();
	182
	183	// we need client coordinates to pass to wxWin functions
	184	if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
	185	{
	186	wxLogLastError(wxT("ScreenToClient"));
	187	}
	188
	189	// give some visual feedback
	190	*pdwEffect = ConvertDragResultToEffect(
	191	m_pTarget->OnEnter(pt.x, pt.y, ConvertDragEffectToResult(
	192	GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction()))
	193	)
	194	);
	195
	196	return S_OK;
	197	}
	198
	199	// Name : wxIDropTarget::DragOver
	200	// Purpose : Indicates that the mouse was moved inside the window represented
	201	// by this drop target.
	202	// Returns : S_OK
	203	// Params : [in] DWORD grfKeyState kbd & mouse state
	204	// [in] POINTL pt mouse coordinates
	205	// [out]LPDWORD pdwEffect effect flag
	206	// Notes : We're called on every WM_MOUSEMOVE, so this function should be
	207	// very efficient.
	208	STDMETHODIMP wxIDropTarget::DragOver(DWORD grfKeyState,
	209	POINTL pt,
	210	LPDWORD pdwEffect)
	211	{
	212	// there are too many of them... wxLogDebug("IDropTarget::DragOver");
	213
	214	wxDragResult result;
	215	if ( m_pIDataObject ) {
	216	result = ConvertDragEffectToResult(
	217	GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction()));
	218	}
	219	else {
	220	// can't accept data anyhow normally
	221	result = wxDragNone;
	222	}
	223
	224	// we need client coordinates to pass to wxWin functions
	225	if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
	226	{
	227	wxLogLastError(wxT("ScreenToClient"));
	228	}
	229
	230	*pdwEffect = ConvertDragResultToEffect(
	231	m_pTarget->OnDragOver(pt.x, pt.y, result)
	232	);
	233
	234	return S_OK;
	235	}
	236
	237	// Name : wxIDropTarget::DragLeave
	238	// Purpose : Informs the drop target that the operation has left its window.
	239	// Returns : S_OK
	240	// Notes : good place to do any clean-up
	241	STDMETHODIMP wxIDropTarget::DragLeave()
	242	{
	243	wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::DragLeave"));
	244
	245	// remove the UI feedback
	246	m_pTarget->OnLeave();
	247
	248	// release the held object
	249	RELEASE_AND_NULL(m_pIDataObject);
	250
	251	return S_OK;
	252	}
	253
	254	// Name : wxIDropTarget::Drop
	255	// Purpose : Instructs the drop target to paste data that was just now
	256	// dropped on it.
	257	// Returns : S_OK
	258	// Params : [in] IDataObject *pIDataSource the data to paste
	259	// [in] DWORD grfKeyState kbd & mouse state
	260	// [in] POINTL pt where the drop occurred?
	261	// [ouy]DWORD *pdwEffect operation effect
	262	// Notes :
	263	STDMETHODIMP wxIDropTarget::Drop(IDataObject *pIDataSource,
	264	DWORD grfKeyState,
	265	POINTL pt,
	266	DWORD *pdwEffect)
	267	{
	268	wxLogTrace(wxTRACE_OleCalls, wxT("IDropTarget::Drop"));
	269
	270	// TODO I don't know why there is this parameter, but so far I assume
	271	// that it's the same we've already got in DragEnter
	272	wxASSERT( m_pIDataObject == pIDataSource );
	273
	274	// by default, nothing happens
	275	*pdwEffect = DROPEFFECT_NONE;
	276
	277	// we need client coordinates to pass to wxWin functions
	278	if ( !ScreenToClient(m_hwnd, (POINT *)&pt) )
	279	{
	280	wxLogLastError(wxT("ScreenToClient"));
	281	}
	282
	283	// first ask the drop target if it wants data
	284	if ( m_pTarget->OnDrop(pt.x, pt.y) ) {
	285	// it does, so give it the data source
	286	m_pTarget->SetDataSource(pIDataSource);
	287
	288	// and now it has the data
	289	wxDragResult rc = ConvertDragEffectToResult(
	290	GetDropEffect(grfKeyState, m_pTarget->GetDefaultAction()));
	291	rc = m_pTarget->OnData(pt.x, pt.y, rc);
	292	if ( wxIsDragResultOk(rc) ) {
	293	// operation succeeded
	294	*pdwEffect = ConvertDragResultToEffect(rc);
	295	}
	296	//else: *pdwEffect is already DROPEFFECT_NONE
	297	}
	298	//else: OnDrop() returned false, no need to copy data
	299
	300	// release the held object
	301	RELEASE_AND_NULL(m_pIDataObject);
	302
	303	return S_OK;
	304	}
	305
	306	// ============================================================================
	307	// wxDropTarget implementation
	308	// ============================================================================
	309
	310	// ----------------------------------------------------------------------------
	311	// ctor/dtor
	312	// ----------------------------------------------------------------------------
	313
	314	wxDropTarget::wxDropTarget(wxDataObject *dataObj)
	315	: wxDropTargetBase(dataObj)
	316	{
	317	// create an IDropTarget implementation which will notify us about d&d
	318	// operations.
	319	m_pIDropTarget = new wxIDropTarget(this);
	320	m_pIDropTarget->AddRef();
	321	}
	322
	323	wxDropTarget::~wxDropTarget()
	324	{
	325	ReleaseInterface(m_pIDropTarget);
	326	}
	327
	328	// ----------------------------------------------------------------------------
	329	// [un]register drop handler
	330	// ----------------------------------------------------------------------------
	331
	332	bool wxDropTarget::Register(WXHWND hwnd)
	333	{
	334	// FIXME
	335	// RegisterDragDrop not available on Windows CE >= 400?
	336	// Or maybe we can dynamically load them from ceshell.dll
	337	// or similar.
	338	#if defined(__WXWINCE__) && _WIN32_WCE >= 400
	339	wxUnusedVar(hwnd);
	340	return false;
	341	#else
	342	HRESULT hr;
	343
	344	// May exist in later WinCE versions
	345	#ifndef __WXWINCE__
	346	hr = ::CoLockObjectExternal(m_pIDropTarget, TRUE, FALSE);
	347	if ( FAILED(hr) ) {
	348	wxLogApiError(wxT("CoLockObjectExternal"), hr);
	349	return false;
	350	}
	351	#endif
	352
	353	hr = ::RegisterDragDrop((HWND) hwnd, m_pIDropTarget);
	354	if ( FAILED(hr) ) {
	355	// May exist in later WinCE versions
	356	#ifndef __WXWINCE__
	357	::CoLockObjectExternal(m_pIDropTarget, FALSE, FALSE);
	358	#endif
	359	wxLogApiError(wxT("RegisterDragDrop"), hr);
	360	return false;
	361	}
	362
	363	// we will need the window handle for coords transformation later
	364	m_pIDropTarget->SetHwnd((HWND)hwnd);
	365
	366	return true;
	367	#endif
	368	}
	369
	370	void wxDropTarget::Revoke(WXHWND hwnd)
	371	{
	372	#if defined(__WXWINCE__) && _WIN32_WCE >= 400
	373	// Not available, see note above
	374	wxUnusedVar(hwnd);
	375	#else
	376	HRESULT hr = ::RevokeDragDrop((HWND) hwnd);
	377
	378	if ( FAILED(hr) ) {
	379	wxLogApiError(wxT("RevokeDragDrop"), hr);
	380	}
	381
	382	// May exist in later WinCE versions
	383	#ifndef __WXWINCE__
	384	::CoLockObjectExternal(m_pIDropTarget, FALSE, TRUE);
	385	#endif
	386
	387	m_pIDropTarget->SetHwnd(0);
	388	#endif
	389	}
	390
	391	// ----------------------------------------------------------------------------
	392	// base class pure virtuals
	393	// ----------------------------------------------------------------------------
	394
	395	// OnDrop() is called only if we previously returned true from
	396	// IsAcceptedData(), so no need to check anything here
	397	bool wxDropTarget::OnDrop(wxCoord WXUNUSED(x), wxCoord WXUNUSED(y))
	398	{
	399	return true;
	400	}
	401
	402	// copy the data from the data source to the target data object
	403	bool wxDropTarget::GetData()
	404	{
	405	wxDataFormat format = GetSupportedFormat(m_pIDataSource);
	406	if ( format == wxDF_INVALID ) {
	407	// this is strange because IsAcceptedData() succeeded previously!
	408	wxFAIL_MSG(wxT("strange - did supported formats list change?"));
	409
	410	return false;
	411	}
	412
	413	STGMEDIUM stm;
	414	FORMATETC fmtMemory;
	415	fmtMemory.cfFormat = format;
	416	fmtMemory.ptd = NULL;
	417	fmtMemory.dwAspect = DVASPECT_CONTENT;
	418	fmtMemory.lindex = -1;
	419	fmtMemory.tymed = TYMED_HGLOBAL; // TODO to add other media
	420
	421	bool rc = false;
	422
	423	HRESULT hr = m_pIDataSource->GetData(&fmtMemory, &stm);
	424	if ( SUCCEEDED(hr) ) {
	425	IDataObject *dataObject = m_dataObject->GetInterface();
	426
	427	hr = dataObject->SetData(&fmtMemory, &stm, TRUE);
	428	if ( SUCCEEDED(hr) ) {
	429	rc = true;
	430	}
	431	else {
	432	wxLogApiError(wxT("IDataObject::SetData()"), hr);
	433	}
	434	}
	435	else {
	436	wxLogApiError(wxT("IDataObject::GetData()"), hr);
	437	}
	438
	439	return rc;
	440	}
	441
	442	// ----------------------------------------------------------------------------
	443	// callbacks used by wxIDropTarget
	444	// ----------------------------------------------------------------------------
	445
	446	// we need a data source, so wxIDropTarget gives it to us using this function
	447	void wxDropTarget::SetDataSource(IDataObject *pIDataSource)
	448	{
	449	m_pIDataSource = pIDataSource;
	450	}
	451
	452	// determine if we accept data of this type
	453	bool wxDropTarget::IsAcceptedData(IDataObject *pIDataSource) const
	454	{
	455	return GetSupportedFormat(pIDataSource) != wxDF_INVALID;
	456	}
	457
	458	// ----------------------------------------------------------------------------
	459	// helper functions
	460	// ----------------------------------------------------------------------------
	461
	462	wxDataFormat wxDropTarget::GetSupportedFormat(IDataObject *pIDataSource) const
	463	{
	464	// this strucutre describes a data of any type (first field will be
	465	// changing) being passed through global memory block.
	466	static FORMATETC s_fmtMemory = {
	467	0,
	468	NULL,
	469	DVASPECT_CONTENT,
	470	-1,
	471	TYMED_HGLOBAL // TODO is it worth supporting other tymeds here?
	472	};
	473
	474	// get the list of supported formats
	475	size_t nFormats = m_dataObject->GetFormatCount(wxDataObject::Set);
	476	wxDataFormat format;
	477	wxDataFormat *formats;
	478	formats = nFormats == 1 ? &format : new wxDataFormat[nFormats];
	479
	480	m_dataObject->GetAllFormats(formats, wxDataObject::Set);
	481
	482	// cycle through all supported formats
	483	size_t n;
	484	for ( n = 0; n < nFormats; n++ ) {
	485	s_fmtMemory.cfFormat = formats[n];
	486
	487	// NB: don't use SUCCEEDED macro here: QueryGetData returns S_FALSE
	488	// for file drag and drop (format == CF_HDROP)
	489	if ( pIDataSource->QueryGetData(&s_fmtMemory) == S_OK ) {
	490	format = formats[n];
	491
	492	break;
	493	}
	494	}
	495
	496	if ( formats != &format ) {
	497	// free memory if we allocated it
	498	delete [] formats;
	499	}
	500
	501	return n < nFormats ? format : wxFormatInvalid;
	502	}
	503
	504	// ----------------------------------------------------------------------------
	505	// private functions
	506	// ----------------------------------------------------------------------------
	507
	508	static wxDragResult ConvertDragEffectToResult(DWORD dwEffect)
	509	{
	510	switch ( dwEffect ) {
	511	case DROPEFFECT_COPY:
	512	return wxDragCopy;
	513
	514	case DROPEFFECT_LINK:
	515	return wxDragLink;
	516
	517	case DROPEFFECT_MOVE:
	518	return wxDragMove;
	519
	520	default:
	521	wxFAIL_MSG(wxT("invalid value in ConvertDragEffectToResult"));
	522	// fall through
	523
	524	case DROPEFFECT_NONE:
	525	return wxDragNone;
	526	}
	527	}
	528
	529	static DWORD ConvertDragResultToEffect(wxDragResult result)
	530	{
	531	switch ( result ) {
	532	case wxDragCopy:
	533	return DROPEFFECT_COPY;
	534
	535	case wxDragLink:
	536	return DROPEFFECT_LINK;
	537
	538	case wxDragMove:
	539	return DROPEFFECT_MOVE;
	540
	541	default:
	542	wxFAIL_MSG(wxT("invalid value in ConvertDragResultToEffect"));
	543	// fall through
	544
	545	case wxDragNone:
	546	return DROPEFFECT_NONE;
	547	}
	548	}
	549
	550	#endif // wxUSE_OLE && wxUSE_DRAG_AND_DROP