WindowsXP-SP1/windows/richedit/re41/_dragdrp.h
2020-09-30 16:53:49 +02:00

196 lines
4.6 KiB
C++

/*
* _DRAGDRP.H
*
* Purpose:
* class declarations for Richedit's OLE drop target and drop source
* objects.
*
* Author:
* alexgo (4/28/95)
*
*/
#ifndef __DRAGDRP_H__
#define __DRAGDRP_H__
#include "_osdc.h"
// DWORD packed flag values. These are assigned values such that they can
// be or'd with DataObjectInfo flags and not conflict. We are, in effect,
// overriding the DataObjectInfo flags.
#define DF_CLIENTCONTROL 0x80000000 // QueryAcceptData says the client
// will handle this drop.
#define DF_CANDROP 0x40000000 // We can handle the drop
#define DF_OVERSOURCE 0x20000000 // Drop target is within source range.
#define DF_RIGHTMOUSEDRAG 0x10000000 // doing a right mouse drag drop
// forward declaration.
class CCallMgr;
#define WIDTH_DROPCARET 2
/*
* CDropCaret
*
* Purpose:
* provides a caret for the location that drop will occur
*/
class CDropCaret
{
public:
CDropCaret(CTxtEdit *ped);
~CDropCaret();
BOOL Init();
void DrawCaret(LONG cpCur);
void ShowCaret(BOOL fShow);
void CancelRestoreCaretArea() {_dvp = -1;}
BOOL NoCaret() const {return -1 == _dvp;}
private:
CTxtEdit * _ped;
HDC _hdcWindow;
LONG _dvp;
POINTUV _ptCaret;
BOOL _fCaretOn;
};
/*
* CDropSource
*
* Purpose:
* provides drag drop feedback
*/
class CDropSource : public IDropSource
{
public:
// IUnknown methods
STDMETHOD(QueryInterface)(REFIID riid, void ** ppv);
STDMETHOD_(ULONG, AddRef)();
STDMETHOD_(ULONG, Release)();
// IDropSource methods
STDMETHOD(QueryContinueDrag)(BOOL fEscapePressed, DWORD grfKeyState);
STDMETHOD(GiveFeedback)(DWORD dwEffect);
CDropSource();
private:
// NOTE: private destructor, may not be allocated on the stack as
// this would break OLE's current object liveness rules
~CDropSource();
ULONG _crefs;
};
/*
* CDropTarget
*
* Purpose:
* an OLE drop-target object; provides a place for text to be "dropped"
*
*/
class CDropTarget : public IDropTarget
{
public:
// IUnknown methods
STDMETHOD(QueryInterface)(REFIID riid, void ** ppv);
STDMETHOD_(ULONG, AddRef)();
STDMETHOD_(ULONG, Release)();
// IDropTarget methods
STDMETHOD(DragEnter)(IDataObject *pdo, DWORD grfKeyState,
POINTL pt, DWORD *pdwEffect);
STDMETHOD(DragOver)(DWORD grfKeyState, POINTL pt, DWORD *pdwEffect);
STDMETHOD(DragLeave)();
STDMETHOD(Drop)(IDataObject *pdo, DWORD grfKeyState, POINTL pt,
DWORD *pdwEffect);
CDropTarget(CTxtEdit *ped);
// this method is used during drag drop to cache important information
void SetDragInfo( IUndoBuilder *publdr, LONG cpMin, LONG cpMax );
void Zombie(); //@cmember Nulls out the state of this object
BOOL fInDrag(); //@cmember Tells whether another app is dragging
// over us.
private:
// this class is used in CDropTarget::Drop to clean up at the end
// of the call.
class CDropCleanup
{
public:
CDropCleanup( CDropTarget *pdt )
{
_pdt = pdt;
}
~CDropCleanup()
{
delete _pdt->_pcallmgr;
_pdt->_pcallmgr = NULL;
delete _pdt->_pdrgcrt;
_pdt->_pdrgcrt = NULL;
}
private:
CDropTarget * _pdt;
};
friend class CDropCleanup;
// NOTE: private destructor, may not be allocated on the stack as
// this would break OLE's current object liveness rules
~CDropTarget();
void UpdateEffect(DWORD grfKeyState, POINTL pt, DWORD *pdwEffect);
void DrawFeedback(void);
void ConvertScreenPtToClientPt( POINTL *pptScreen, POINT *pptClient );
HRESULT HandleRightMouseDrop(IDataObject *pdo, POINTL ptl);
ULONG _crefs;
DWORD _dwFlags; // DataObjectInfo cache (e.g. DOI_CANPASTEPLAIN)
// and other flags.
CTxtEdit * _ped;
CCallMgr * _pcallmgr; // The call manager used during a drag drop operation.
// cached information for drag drop operations
IUndoBuilder *_publdr; // the undo builder for the drag operation
LONG _cpMin; // the min and max cp's for the range that is
LONG _cpMost; // being dragged so we can disable drag-onto-yourself!
LONG _cpSel; // active end and length for selection *before*
LONG _cchSel; // drag drop op occured (so we can restore it)
LONG _cpCur; // the cp that the mouse is currently over
CDropCaret *_pdrgcrt; // Object that implements the drop caret
};
/*
* CDropTarget::fInDrag ()
*
* Purpose:
* Tells interested parties whether a drag operation is occurring
*
*/
inline BOOL CDropTarget::fInDrag()
{
return _pcallmgr != NULL;
}
#endif // !__DRAGDRP_H__