GDragAndDrop.h

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#ifndef __DRAG_AND_DROP
#define __DRAG_AND_DROP

#include "GVariant.h"

#if WIN32NATIVE

#include <shlobj.h>
#include "GCom.h"

#else

#ifndef S_OK
#define S_OK                                0
#endif
#define DROPEFFECT_NONE                     0x0
#define DROPEFFECT_COPY                     0x1
#define DROPEFFECT_MOVE                     0x2
#define DROPEFFECT_LINK                     0x4

#endif

// int <-> char* format conversions
#if defined WIN32

#endif


class LgiClass GDragDropSource
#if WIN32NATIVE
    : public IDropSource, public IEnumFORMATETC
#endif
{
    friend class GDataObject;

protected:
    class GDndSourcePriv *d;
    
    #if WIN32NATIVE
    int Index;

    // IUnknown
    ULONG STDMETHODCALLTYPE AddRef();
    ULONG STDMETHODCALLTYPE Release();
    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, void **ppv);

    // IEnumFORMATETC
    HRESULT STDMETHODCALLTYPE Next(ULONG celt, FORMATETC *rgelt, ULONG *pceltFetched);
    HRESULT STDMETHODCALLTYPE Skip(ULONG celt);
    HRESULT STDMETHODCALLTYPE Reset();
    HRESULT STDMETHODCALLTYPE Clone(IEnumFORMATETC **ppenum);

    // IDropSource
    HRESULT STDMETHODCALLTYPE QueryContinueDrag(BOOL fEscapePressed, DWORD InputState);
    HRESULT STDMETHODCALLTYPE GiveFeedback(DWORD dwEffect);
    #endif

    bool CreateFileDrop(GVariant *Var, GMouse &m, List<char> &Files);

    #ifdef XWIN
    // void OnSelectionRequest(Display *Dsp, XEvent &Event, XWidget *W, Atom XdndSelection); 
    #endif
    
public:
    GDragDropSource();
    ~GDragDropSource();

    int Drag(GView *SourceWnd, int Effect);

    virtual void OnRegister(bool Suc) {}
    virtual void OnStartData() {}
    virtual void OnEndData() {}
    
    virtual bool GetData
    (
        GVariant *Data,
        char *Format
    )
    { return false; }

    virtual bool GetFormats
    (
        List<char> &Formats
    )
    { return false; }
};

class LgiClass GDragDropTarget
#if WIN32NATIVE
    : public IDropTarget
#endif
{
private:
    GView *To;
    uchar *DragDropData;
    int DragDropLength;
    List<char> Formats;

    #if WIN32NATIVE
    // IUnknown
    ULONG STDMETHODCALLTYPE AddRef();
    ULONG STDMETHODCALLTYPE Release();
    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, void **ppv);

    // IDropTarget
    HRESULT STDMETHODCALLTYPE DragEnter(IDataObject *pDataObject, DWORD grfKeyState, POINTL pt, DWORD *pdwEffect);
    HRESULT STDMETHODCALLTYPE DragOver(DWORD grfKeyState, POINTL pt, DWORD *pdwEffect);
    HRESULT STDMETHODCALLTYPE DragLeave(void);
    HRESULT STDMETHODCALLTYPE Drop(IDataObject *pDataObject, DWORD grfKeyState, POINTL pt, DWORD *pdwEffect);

    #endif

protected:
    #if WIN32NATIVE
    // Data elements
    IDataObject *DataObject;

    // Tools
    bool OnDropFileGroupDescriptor(FILEGROUPDESCRIPTOR *Data, GArray<char*> &Files);
    #endif

public:
    GDragDropTarget();
    ~GDragDropTarget();

    void SetWindow(GView *To);

    // Override these

    virtual void OnDragInit(bool Suc) {}
    virtual void OnDragEnter() {}
    virtual void OnDragExit() {}

    virtual int WillAccept
    (
        List<char> &Formats,
        GdcPt2 Pt,
        int KeyState
    ) { return DROPEFFECT_NONE; }

    virtual int OnDrop
    (
        char *Format,
        GVariant *Data,
        GdcPt2 Pt,
        int KeyState
    ) { return DROPEFFECT_NONE; }
};

#endif

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