PAGE.CPP
/* 
 * PAGE.CPP 
 * Patron Chapter 7 
 * 
 * Implementation of parts of the CPage class; those member 
 * functions dealing with mouse events are in PAGEMOUS.CPP. 
 * 
 * Copyright (c)1993-1996 Microsoft Corporation, All Rights Reserved 
 * 
 * Kraig Brockschmidt, Software Design Engineer 
 * Microsoft Systems Developer Relations 
 * 
 * Internet  :  kraigb@microsoft.com 
 * Compuserve:  >INTERNET:kraigb@microsoft.com 
 */ 
 
 
#include "patron.h" 
 
 
/* 
 * CPage::CPage 
 * CPage::~CPage 
 * 
 * Constructor Parameters: 
 *  dwID            DWORD identifier for this page. 
 *  hWnd            HWND of the pages window (for repaints, etc). 
 *  pPG             PCPages to the Pages window. 
 */ 
 
//CHAPTER7MOD 
CPage::CPage(DWORD dwID, HWND hWnd, PCPages pPG) 
//End CHAPTER7MOD 
    { 
    m_dwID     =dwID; 
    m_pIStorage=NULL; 
 
    //CHAPTER7MOD 
    m_cOpens=0; 
    m_hWnd=hWnd; 
    m_pPG=pPG; 
 
    m_dwIDNext      =0; 
    m_cTenants      =0; 
    m_hWndTenantList=NULL; 
    m_iTenantCur    =NOVALUE;   //Tenants are zero indexed. 
    m_pTenantCur    =NULL; 
 
    m_uHTCode=HTNOWHERE; 
    m_uSizingFlags=0; 
    m_fTracking=FALSE; 
    m_hDC=NULL; 
 
    m_fSizePending=FALSE; 
    m_fTimer=FALSE; 
 
    //These will be read from WIN.INI in Chapter 8. 
    m_cxyDist=2; 
    m_cDelay=200; 
    //End CHAPTER7MOD 
 
    return; 
    } 
 
 
CPage::~CPage(void) 
    { 
    //CHAPTER7MOD 
    if (m_fTimer) 
        KillTimer(m_hWnd, IDTIMER_DEBOUNCE); 
    //End CHAPTER7MOD 
 
    m_hWnd=NULL; 
    Close(FALSE); 
    return; 
    } 
 
 
 
/* 
 * CPage::GetID 
 * 
 * Return Value: 
 *  DWORD           dwID field in this page.  This function is only 
 *                  here to avoid hiding inline implementations 
 *                  in pages.h 
 */ 
 
DWORD CPage::GetID(void) 
    { 
    return m_dwID; 
    } 
 
 
 
 
 
/* 
 * CPage::FOpen 
 * 
 * Purpose: 
 *  Retrieves the IStorage associated with this page.  The IStorage 
 *  is owned by the page and thus the page always holds a reference 
 *  count.  The caller should call Close or delete this page to 
 *  match this open. 
 * 
 *  This function may be called multiple times resulting in 
 *  additional reference counts on the storage each of which must be 
 *  matched with a call to Close.  The last Close can be done 
 *  through delete. 
 * 
 * Parameters: 
 *  pIStorage       LPSTORAGE in which this page lives. 
 * 
 * Return Value: 
 *  BOOL            TRUE if opening succeeds, FALSE otherwise. 
 */ 
 
BOOL CPage::FOpen(LPSTORAGE pIStorage) 
    { 
    //CHAPTER7MOD 
    HRESULT         hr=NOERROR; 
    LPSTREAM        pIStream; 
    DWORD           dwMode; 
    TCHAR           szTemp[32]; 
    BOOL            fNew; 
    BOOL            fCreated=FALSE; 
    TENANTLIST      tl; 
    PTENANTINFO     pti; 
    ULONG           cb; 
    LPMALLOC        pIMalloc; 
    UINT            i; 
    PCTenant        pTenant; 
 
    fNew=(NULL==m_pIStorage); 
 
    if (!fNew) 
        { 
        m_cOpens++; 
        m_pIStorage->AddRef(); 
        return TRUE; 
        } 
 
    if (NULL==pIStorage) 
        return FALSE; 
 
    /* 
     * Attempt to open the storage under this ID.  If none, 
     * create one.  In either case, the IStorage is either 
     * saved in pPage or released. 
     */ 
 
    GetStorageName(szTemp); 
    dwMode=STGM_TRANSACTED | STGM_READWRITE | STGM_SHARE_EXCLUSIVE; 
 
    OLECHAR pwcsTemp[MAX_PATH]; 
#if defined(WIN32) && !defined(UNICODE) 
    mbstowcs(pwcsTemp, szTemp, MAX_PATH); 
#else 
    pwcsTemp = szTemp; 
#endif 
    hr=pIStorage->OpenStorage(pwcsTemp, NULL, dwMode, NULL, 0 
        , &m_pIStorage); 
 
    if (FAILED(hr)) 
        { 
        hr=pIStorage->CreateStorage(pwcsTemp, dwMode, 0, 0 
            , &m_pIStorage); 
        fCreated=TRUE; 
        } 
 
    if (FAILED(hr)) 
        return FALSE; 
 
    m_cOpens++; 
 
    if (NULL==m_hWndTenantList) 
        { 
        /* 
         * The first time we open this page, create the hidden 
         * listbox we'll use to track tenants.  We give it the 
         * owner-draw style so we can just store pointers in it. 
         */ 
        m_hWndTenantList=CreateWindow(TEXT("listbox") 
            , TEXT("Tenant List"), WS_POPUP | LBS_OWNERDRAWFIXED 
            , 0, 0, 100, 100, HWND_DESKTOP, NULL 
            , m_pPG->m_hInst, NULL); 
 
        if (NULL==m_hWndTenantList) 
            return FALSE; 
        } 
 
 
    //If this is brand-new, we're done. 
    if (fCreated) 
        return TRUE; 
 
 
    /* 
     * Now open the stream we saved in Close and load all the 
     * tenants listed in there.  If there are none, then we don't 
     * have to load squat. 
     */ 
 
    hr=m_pIStorage->OpenStream(SZSTREAMTENANTLIST, NULL, STGM_DIRECT 
        | STGM_READ | STGM_SHARE_EXCLUSIVE, 0, &pIStream); 
 
    if (FAILED(hr)) 
        return FALSE; 
 
    if (SUCCEEDED(CoGetMalloc(MEMCTX_TASK, &pIMalloc))) 
        { 
        pIStream->Read(&tl, sizeof(tl), NULL); 
        m_cTenants=tl.cTenants; 
        m_dwIDNext=tl.dwIDNext; 
        m_iTenantCur=0; 
 
        cb=tl.cTenants*sizeof(TENANTINFO); 
 
        if (0!=cb) 
            { 
            pti=(PTENANTINFO)pIMalloc->Alloc(cb); 
 
            if (NULL!=pti) 
                { 
                pIStream->Read(pti, cb, NULL); 
 
                for (i=0; i < m_cTenants; i++) 
                    { 
                    if (FTenantAdd(NOVALUE, (pti+i)->dwID, &pTenant)) 
                        pTenant->FLoad(m_pIStorage, (pti+i)); 
                    } 
 
                pIMalloc->Free(pti); 
                } 
            } 
 
        pIMalloc->Release(); 
        } 
 
    pIStream->Release(); 
 
    //Get and select the first tenant 
    if (FTenantGet(0, &m_pTenantCur, FALSE)) 
        m_pTenantCur->Select(TRUE); 
 
    return TRUE; 
    //End CHAPTER7MOD 
    } 
 
 
 
 
 
/* 
 * CPage::Close 
 * 
 * Purpose: 
 *  Possibly commits the storage, then releases it reversing the 
 *  reference count from FOpen. 
 * 
 * Parameters: 
 *  fCommit         BOOL indicating if we're to commit. 
 * 
 * Return Value: 
 *  None 
 */ 
 
void CPage::Close(BOOL fCommit) 
    { 
    if (NULL==m_pIStorage) 
        return; 
 
    if (fCommit) 
        Update(); 
 
    //CHAPTER7MOD 
    m_pIStorage->Release(); 
 
    //If this was the last close, make all tenants loaded->passive 
    if (0==--m_cOpens) 
        { 
        UINT        i; 
        PCTenant    pTenant; 
 
        m_pIStorage=NULL; 
 
        for (i=0; i < m_cTenants; i++) 
            { 
            if (FTenantGet(i, &pTenant, FALSE)) 
                { 
                if (NULL!=m_hWnd) 
                    { 
                    //FOpen may select again, so this repaints. 
                    pTenant->Select(FALSE); 
                    } 
 
                pTenant->Close(FALSE); 
                delete pTenant; 
                } 
            } 
 
        DestroyWindow(m_hWndTenantList); 
        m_hWndTenantList=NULL; 
        } 
    //End CHAPTER7MOD 
 
    return; 
    } 
 
 
 
 
/* 
 * CPage::Update 
 * 
 * Purpose: 
 *  Forces a common on the page if it's open. 
 * 
 * Parameters: 
 *  None 
 * 
 * Return Value: 
 *  BOOL            TRUE if there are any open objects on this page, 
 *                  that is, we should remain open. 
 */ 
 
BOOL CPage::Update(void) 
    { 
    //CHAPTER7MOD 
    BOOL            fOpen=FALSE; 
    UINT            i; 
    PCTenant        pTenant; 
    HRESULT         hr; 
    LPSTREAM        pIStream; 
    TENANTLIST      tl; 
    PTENANTINFO     pti; 
    ULONG           cb; 
    LPMALLOC        pIMalloc; 
 
    //Walk the list of objects and update them all as well. 
    for (i=0; i < m_cTenants; i++) 
        { 
        if (FTenantGet(i, &pTenant, FALSE)) 
            fOpen |= pTenant->Update(); 
        } 
 
    //Now write our own stream containing the tenant list. 
    hr=m_pIStorage->CreateStream(SZSTREAMTENANTLIST, STGM_CREATE 
        | STGM_WRITE| STGM_DIRECT | STGM_SHARE_EXCLUSIVE, 0, 0 
        , &pIStream); 
 
    if (FAILED(hr)) 
        return fOpen; 
 
    if (SUCCEEDED(CoGetMalloc(MEMCTX_TASK, &pIMalloc))) 
        { 
        tl.cTenants=m_cTenants; 
        tl.dwIDNext=m_dwIDNext; 
 
        pIStream->Write(&tl, sizeof(TENANTLIST), &cb); 
 
        cb=m_cTenants*sizeof(TENANTINFO); 
        pti=(PTENANTINFO)pIMalloc->Alloc(cb); 
 
        if (NULL!=pti) 
            { 
            for (i=0; i < m_cTenants; i++) 
                { 
                FTenantGet(i, &pTenant, FALSE); 
                pTenant->GetInfo((pti+i)); 
                } 
 
            pIStream->Write(pti, cb, &cb); 
            pIMalloc->Free(pti); 
            } 
 
        pIMalloc->Release(); 
        } 
 
    pIStream->Release(); 
 
    //Now commit the whole mess and we're done 
    if (NULL!=m_pIStorage) 
        m_pIStorage->Commit(STGC_ONLYIFCURRENT); 
 
    return fOpen; 
    //End CHAPTER7MOD 
    } 
 
 
 
 
 
/* 
 * CPage::Destroy 
 * 
 * Purpose: 
 *  Removes this page from the given storage.  The caller should 
 *  eventually delete this Page object to free the storage. 
 * 
 * Parameters: 
 *  pIStorage       LPSTORAGE contianing this page on which to call 
 *                  DestroyElement 
 * 
 * Return Value: 
 *  None 
 */ 
 
void CPage::Destroy(LPSTORAGE pIStorage) 
    { 
    if (NULL!=pIStorage) 
        { 
        TCHAR   szTemp[32]; 
 
        Close(FALSE); 
        GetStorageName(szTemp); 
#if defined(WIN32) && !defined(UNICODE) 
        OLECHAR pwcsTemp[32]; 
        mbstowcs(pwcsTemp, szTemp, 32); 
        pIStorage->DestroyElement(pwcsTemp); 
#else 
        pIStorage->DestroyElement(szTemp); 
#endif 
        } 
 
    return; 
    } 
 
 
 
 
/* 
 * CPage::GetStorageName 
 * 
 * Parameters: 
 *  pszName         LPTSTR to a buffer in which to store the storage 
 *                  name for this page. 
 * 
 * Return Value: 
 *  UINT            Number of characters stored. 
 */ 
 
UINT CPage::GetStorageName(LPTSTR pszName) 
    { 
    return wsprintf(pszName, TEXT("Page %lu"), m_dwID); 
    } 
 
 
 
//CHAPTER7MOD 
 
 
/* 
 * CPage::Draw 
 * 
 * Purpose: 
 *  Draws the objects on this page to the given hDC. 
 * 
 * Parameters: 
 *  hDC             HDC on which to draw. 
 *  xOff, yOff      int offsets for the page. 
 *  fNoColor        BOOL indicating black & white screen rendering. 
 *  fPrinter        BOOL indicating hDC is on the printer. 
 * 
 * Return Value: 
 *  None 
 */ 
 
void CPage::Draw(HDC hDC, int xOff, int yOff, BOOL fNoColor 
    , BOOL fPrinter) 
    { 
    int                 i; 
    PCTenant            pTenant; 
    HDC                 hIC=NULL; 
    PCOMBINEDEVICE      pcd=NULL; 
    DVTARGETDEVICE     *ptd=NULL; 
 
    /* 
     * If printing, tell the tenant to forget the borders. Otherwise 
     * we leave xOff and yOff the same to account for scrolling. 
     */ 
    if (fPrinter) 
        { 
        xOff=LOMETRIC_BORDER+m_pPG->m_xMarginLeft; 
        yOff=-LOMETRIC_BORDER-m_pPG->m_yMarginTop; 
 
        /* 
         * Get device information.  If this fails, ptd is 
         * NULL which is acceptable. 
         */ 
        if (m_pPG->DevReadConfig(&pcd, &hIC)) 
            ptd=&(pcd->td); 
        } 
 
    for (i=(int)m_cTenants-1; i >=0; i--) 
        { 
        if (FTenantGet(i, &pTenant, FALSE)) 
            { 
            RECT        rc, rcWin; 
            RECTL       rcl; 
 
            //Paint this tenant only if visible. 
            pTenant->RectGet(&rcl, TRUE); 
            RECTFROMRECTL(rc, rcl); 
            OffsetRect(&rc, -(int)m_pPG->m_xPos 
                , -(int)m_pPG->m_yPos); 
            GetClientRect(m_hWnd, &rcWin); 
 
            if (IntersectRect(&rc, &rc, &rcWin)) 
                { 
                pTenant->Draw(hDC, ptd, hIC, xOff, yOff 
                    , fNoColor, fPrinter); 
                } 
            } 
        } 
 
    //Free whatever CPages::DevReadConfig returned. 
    if (NULL!=pcd) 
        { 
        LPMALLOC    pIMalloc; 
 
        if (SUCCEEDED(CoGetMalloc(MEMCTX_TASK, &pIMalloc))) 
            { 
            pIMalloc->Free(pcd); 
            pIMalloc->Release(); 
            } 
        } 
 
    if (NULL!=hIC) 
        DeleteDC(hIC); 
 
    return; 
    } 
 
 
 
 
 
 
/* 
 * CPage::TenantCreate 
 * 
 * Purpose: 
 *  Creates a new tenant of a specific type. 
 * 
 * Parameters: 
 *  tType           TENANTTYPE to create. 
 *  pv              LPVOID providing information for the new 
 *                  object creation. 
 *  pFE             LPFORMATETC describing how we want this 
 *                  rendered. 
 *  ppo             PPATRONOBJECT with placement data. 
 *  dwData          DWORD extra data to pass to the tenant. 
 * 
 * Return Value: 
 *  None 
 */ 
 
BOOL CPage::TenantCreate(TENANTTYPE tType, LPVOID pv 
    , LPFORMATETC pFE, PPATRONOBJECT ppo, DWORD dwData) 
    { 
    PCTenant    pTenant; 
    UINT        uRet; 
    int         x, y; 
    int         h, v; 
    POINTL      ptl; 
    SIZEL       szl; 
    RECTL       rcl; 
    RECT        rc; 
 
    //New tenants go at top of the pile; zero index to FTenantAdd. 
    if (!FTenantAdd(0, m_dwIDNext, &pTenant)) 
        return FALSE; 
 
    uRet=pTenant->UCreate(tType, pv, pFE, &ptl, &szl, m_pIStorage 
        , ppo, dwData); 
 
    if (UCREATE_FAILED==uRet) 
        { 
        //Reverse UCreate AND FTenantAdd 
        SendMessage(m_hWndTenantList, LB_DELETESTRING, 0, 0L); 
        pTenant->Destroy(m_pIStorage); 
 
        delete pTenant; 
        return FALSE; 
        } 
 
    m_dwIDNext++; 
    m_cTenants++; 
 
    if (NULL!=m_pTenantCur) 
        m_pTenantCur->Select(FALSE); 
 
    m_iTenantCur=0;             //First one in the list now. 
    m_pTenantCur=pTenant; 
 
    //Tell the tenant where it lives, default is (0,0) in print area 
    x=LOMETRIC_BORDER+m_pPG->m_xMarginLeft; 
    y=-LOMETRIC_BORDER-m_pPG->m_yMarginTop; 
 
    h=x; 
    v=y; 
 
    if (UCREATE_PLACEDOBJECT==uRet) 
        { 
        SetRect(&rc, 3*CXYHANDLE, 3*CXYHANDLE, 0, 0); 
        RectConvertMappings(&rc, NULL, FALSE); 
 
        //Make sure place point is on page, otherwise go to (0,0) 
        if (((int)ptl.x > x) 
            && ((int)ptl.x < x+(int)m_pPG->m_cx-rc.left)) 
            x=(int)ptl.x; 
 
        //m_pPG->m_cy is absolute 
        if (((int)ptl.y < y) 
            && ((int)ptl.y > y-(int)m_pPG->m_cy-rc.top)) 
            y=(int)ptl.y; 
        } 
 
    //Bounds check size of the object and fit to page as necessary. 
    if (x+(int)szl.cx > (int)(h+m_pPG->m_cx)) 
        szl.cx=h+m_pPG->m_cx-x; 
 
    //Remember that szl we get from UCreate is absolute 
    if (y-(int)szl.cy < (int)(v-m_pPG->m_cy)) 
        szl.cy=-(int)(v-m_pPG->m_cy-y); 
 
    SETRECTL(rcl, x, y, x+szl.cx, y-szl.cy); 
    m_pTenantCur->RectSet(&rcl, FALSE); 
 
    //Force a repaint on this new guy 
    m_pTenantCur->Invalidate(); 
    UpdateWindow(m_hWnd); 
 
    m_pTenantCur->Select(TRUE); 
    return TRUE; 
    } 
 
 
 
 
 
 
/* 
 * CPage::TenantDestroy 
 * 
 * Purpose: 
 *  Destroys the currently selected tenant on this page. 
 * 
 * Parameters: 
 *  None 
 * 
 * Return Value: 
 *  None 
 */ 
 
BOOL CPage::TenantDestroy(void) 
    { 
    if (NULL==m_pTenantCur) 
        { 
        MessageBeep(0); 
        return FALSE; 
        } 
 
    SendMessage(m_hWndTenantList, LB_DELETESTRING 
        , m_iTenantCur, 0L); 
 
    m_pTenantCur->Invalidate(); 
    m_pTenantCur->Destroy(m_pIStorage); 
 
    delete m_pTenantCur; 
    m_pTenantCur=NULL; 
 
    //Update counts, etc., and select the next tenant in the list. 
    if (m_iTenantCur==m_cTenants-1) 
        m_iTenantCur--; 
 
    if (0==--m_cTenants) 
        m_pTenantCur=NULL; 
    else 
        { 
        FTenantGet(m_iTenantCur, &m_pTenantCur, TRUE); 
        m_pTenantCur->Select(TRUE); 
        } 
 
    UpdateWindow(m_hWnd); 
    return TRUE; 
    } 
 
 
 
 
 
/* 
 * CPage::TenantClip 
 * 
 * Purpose: 
 *  Copies or cuts the currently selected tenant to the clipoard. 
 * 
 * Parameters: 
 *  fCut            BOOL TRUE to cut the object, FALSE to copy. 
 * 
 * Return Value: 
 *  BOOL            TRUE if successful, FALSE otherwise. 
 */ 
 
BOOL CPage::TenantClip(BOOL fCut) 
    { 
    LPDATAOBJECT    pIDataObject; 
    BOOL            fRet=FALSE; 
 
    if (NULL==m_pTenantCur) 
        return FALSE; 
 
    /* 
     * To perform a data transfer operation, we need to create a 
     * data object with the selected object's data inside. To do 
     * this we CoCreateInstance on CLSID_DataTransferObject 
     * (Also implemented in this chapter), retrieve data from the 
     * object we have, stuff that data into the transfer object, 
     * then stick that object on the clipboard. 
     * 
     * Since we'll want an identical object at other times, like for 
     * drag-drop, we use a private function to actually create it. 
     */ 
 
    pIDataObject=TransferObjectCreate(NULL); 
 
    if (NULL!=pIDataObject) 
        { 
        if (SUCCEEDED(OleSetClipboard(pIDataObject))) 
            { 
            if (fCut) 
                TenantDestroy(); 
 
            fRet=TRUE; 
            } 
 
        pIDataObject->Release(); 
        } 
 
    return fRet; 
    } 
 
 
 
 
 
/* 
 * CPage::FQueryObjectSelected 
 * 
 * Purpose: 
 *  Returns whether or not there is an object selected on this 
 *  page for Cut, Copy, Delete functions. 
 * 
 * Parameters: 
 *  hMenu           HMENU of the Edit menu. 
 * 
 * Return Value: 
 *  BOOL            TRUE if we have an object, FALSE otherwise. 
 */ 
 
BOOL CPage::FQueryObjectSelected(HMENU hMenu) 
    { 
    return (NULL!=m_pTenantCur); 
    } 
 
 
 
 
 
 
/* 
 * CPages::FTenantGet 
 * (Protected) 
 * 
 * Purpose: 
 *  Returns a tenant of a given index returning a BOOL so it's 
 *  simple to use this function inside if statements. 
 * 
 * Parameters: 
 *  iTenant         UINT tenant to retrieve 0 based. 
 *  ppTenant        PCPage * in which to return the tenant 
 *                  pointer 
 *  fOpen           BOOL indicating if we should open this 
 *                  tenant as well. 
 * 
 * Return Value: 
 *  BOOL            TRUE if successful, FALSE otherwise. 
 */ 
 
BOOL CPage::FTenantGet(UINT iTenant, PCTenant *ppTenant 
    , BOOL fOpen) 
    { 
    if (NULL==ppTenant) 
        return FALSE; 
 
    if (LB_ERR!=SendMessage(m_hWndTenantList, LB_GETTEXT 
        , iTenant, (LONG)ppTenant)) 
        { 
        if (fOpen) 
            (*ppTenant)->FOpen(m_pIStorage); 
 
        return TRUE; 
        } 
 
    return FALSE; 
    } 
 
 
 
 
 
 
 
/* 
 * CPage::FTenantAdd 
 * (Protected) 
 * 
 * Purpose: 
 *  Creates a new tenant initialized to the given values.  The new 
 *  tenants's storage is created if it does not already exist.  If 
 *  fOpenStorage is set the the tenants's storage is opened and left 
 *  opened. 
 * 
 * Parameters: 
 *  iTenant         UINT Location at which to insert tenant; new 
 *                  tenant is inserted after this position.  NOVALUE 
 *                  for the end. 
 *  dwID            DWORD ID for this tenant. 
 *  ppNew           PCTenant * in which to store the new tenant. 
 * 
 * Return Value: 
 *  BOOL            TRUE if the function succeeded, FALSE otherwise. 
 */ 
 
BOOL CPage::FTenantAdd(UINT iTenant, DWORD dwID 
    , PCTenant *ppNew) 
    { 
    PCTenant    pTenant; 
    LRESULT     lr; 
 
    if (NULL!=ppNew) 
        *ppNew=NULL; 
 
    pTenant=new CTenant(dwID, m_hWnd, m_pPG); 
 
    if (NULL==pTenant) 
        return FALSE; 
 
    //Now try to add to the listbox. 
    lr=SendMessage(m_hWndTenantList, LB_INSERTSTRING, iTenant 
        , (LONG)pTenant); 
 
    if (lr < 0) 
        { 
        delete pTenant; 
        return FALSE; 
        } 
 
    *ppNew=pTenant; 
    return TRUE; 
    } 
 
 
 
 
 
/* 
 * CPage::TransferObjectCreate 
 * (Protected) 
 * 
 * Purpose: 
 *  Creates a DataTransferObject and stuff the current selection's 
 *  data into it. 
 * 
 * Parameters: 
 *  pptl            LPPOINTL containing the pick point in device 
 *                  units applicable only to drag-drop; since 
 *                  drag-drop is inherently mouse oriented, we use 
 *                  device units for the point.  Ignored if NULL. 
 * 
 * Return Value: 
 *  LPDATAOBJECT    Pointer to the object created, NULL on failure 
 */ 
 
LPDATAOBJECT CPage::TransferObjectCreate(LPPOINTL pptl) 
    { 
    LPDATAOBJECT    pIDataObject; 
    LPDATAOBJECT    pIDataT; 
    PPATRONOBJECT   ppo; 
    RECTL           rcl; 
    LPUNKNOWN       pObj; 
    FORMATETC       fe; 
    STGMEDIUM       stm; 
    HRESULT         hr; 
 
    m_pTenantCur->ObjectGet(&pObj); 
 
    hr=CoCreateInstance(CLSID_DataTransferObject, NULL 
        , CLSCTX_INPROC_SERVER, IID_IDataObject 
        , (PPVOID)&pIDataObject); 
 
    if (FAILED(hr)) 
        return NULL; 
 
    //Go get the data we should hold on to. 
    hr=pObj->QueryInterface(IID_IDataObject, (PPVOID)&pIDataT); 
 
    if (FAILED(hr)) 
        { 
        pIDataObject->Release(); 
        pObj->Release(); 
        return NULL; 
        } 
 
    //Copy from known obj into transfer obj.  Ordering is important! 
 
    //Generate placeable object structure 
    stm.tymed=TYMED_HGLOBAL; 
    stm.pUnkForRelease=NULL; 
    stm.hGlobal=GlobalAlloc(GHND, sizeof(PATRONOBJECT)); 
 
    if (NULL==stm.hGlobal) 
        { 
        pIDataObject->Release(); 
        pObj->Release(); 
        return NULL; 
        } 
 
    ppo=(PPATRONOBJECT)GlobalLock(stm.hGlobal); 
 
    m_pTenantCur->SizeGet(&ppo->szl, FALSE); 
    ppo->szl.cy=-ppo->szl.cy; //Negate to make absolute size 
 
    m_pTenantCur->RectGet(&rcl, FALSE); 
    ppo->ptl.x=rcl.left; 
    ppo->ptl.y=rcl.top; 
 
    if (NULL==pptl) 
        { 
        ppo->ptlPick.x=0; 
        ppo->ptlPick.y=0; 
        } 
    else 
        ppo->ptlPick=*pptl; 
 
    m_pTenantCur->FormatEtcGet(&ppo->fe, FALSE); 
 
    GlobalUnlock(stm.hGlobal); 
 
    SETDefFormatEtc(fe, m_pPG->m_cf, TYMED_HGLOBAL); 
    pIDataObject->SetData(&fe, &stm, TRUE); 
 
 
    //Copy the actual presentation. 
    m_pTenantCur->FormatEtcGet(&fe, TRUE); 
    pIDataT->GetData(&fe, &stm); 
    pIDataObject->SetData(&fe, &stm, TRUE); 
 
    pIDataT->Release(); 
 
    pObj->Release(); 
    return pIDataObject;    //Caller now responsible 
    } 
 
 
//End CHAPTER7MOD