Tricks of the Windows Gam…ming Gurus (2nd Edition)/Disc2.iso/msdn_vcb/samples/vc98/sdk/com/inole2/chap05/polyline/ipolylin.cpp

C/C++ Source or Header | 1995-05-03 | 22.8 KB | 1,054 lines

/*
 * IPOLYLIN.CPP
 * Polyline Component Chapter 5
 *
 * Implementation of the IPolyline5 interface that we expose on the
 * CPolyline object.
 *
 * Copyright (c)1993-1995 Microsoft Corporation, All Rights Reserved
 *
 * Kraig Brockschmidt, Microsoft
 * Internet  :  [e-mail]
 * Compuserve:  >INTERNET:[e-mail]
 */


#include "polyline.h"


/*
 * CImpIPolyline:CImpIPolyline
 * CImpIPolyline::~CImpIPolyline
 *
 * Constructor Parameters:
 *  pObj            PCPolyline pointing to the object we live in.
 *  pUnkOuter       LPUNKNOWN of the controlling unknown.
 */

CImpIPolyline::CImpIPolyline(PCPolyline pObj, LPUNKNOWN pUnkOuter)
    {
    m_cRef=0;
    m_pObj=pObj;
    m_pUnkOuter=pUnkOuter;
    return;
    }


CImpIPolyline::~CImpIPolyline(void)
    {
    return;
    }




/*
 * CImpIPolyline::QueryInterface
 * CImpIPolyline::AddRef
 * CImpIPolyline::Release
 */

STDMETHODIMP CImpIPolyline::QueryInterface(REFIID riid, PPVOID ppv)
    {
    return m_pUnkOuter->QueryInterface(riid, ppv);
    }

STDMETHODIMP_(ULONG) CImpIPolyline::AddRef(void)
    {
    ++m_cRef;
    return m_pUnkOuter->AddRef();
    }

STDMETHODIMP_(ULONG) CImpIPolyline::Release(void)
    {
    --m_cRef;
    return m_pUnkOuter->Release();
    }





/*
 * CImpIPolyline::Init
 *
 * Purpose:
 *  Instantiates a polyline window within a given parent.  The
 *  parent may be a main application window, could be an MDI child
 *  window. We really do not care.
 *
 * Parameters:
 *  hWndParent      HWND of the parent of this window
 *  pRect           LPRECT that this window should occupy
 *  dwStyle         DWORD containing the window's style flags
 *  uID             UINT ID to associate with this window
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise E_OUTOFMEMORY
 */

STDMETHODIMP CImpIPolyline::Init(HWND hWndParent, LPRECT pRect
    , DWORD dwStyle, UINT uID)
    {
    SCODE           sc;

    m_pObj->m_hWnd=CreateWindowEx(WS_EX_NOPARENTNOTIFY
        , SZCLASSPOLYLINE, SZCLASSPOLYLINE, dwStyle, pRect->left
        , pRect->top, pRect->right-pRect->left
        , pRect->bottom-pRect->top, hWndParent, (HMENU)uID
        , m_pObj->m_hInst, m_pObj);

    sc=(NULL!=m_pObj->m_hWnd) ? S_OK : E_OUTOFMEMORY;
    return ResultFromScode(sc);
    }





/*
 * CImpIPolyline::ReadFromFile
 *
 * Purpose:
 *  Loads our current version data from a file.
 *
 * Parameters:
 *  pszFile         LPTSTR of the file to read.
 *
 * Return Value:
 *  HRESULT         NOERROR on success, error code otherwise.
 */

STDMETHODIMP CImpIPolyline::ReadFromFile(LPTSTR pszFile)
    {
    OFSTRUCT        of;
    HFILE           hFile;
    POLYLINEDATA    pl;
    UINT            cb;
   #ifdef UNICODE
    CHAR            szTemp[CCHPATHMAX];
   #endif

    if (NULL==pszFile)
        return ResultFromScode(POLYLINE_E_INVALIDPOINTER);

   #ifdef UNICODE
    UNICODETOANSI(pszFile, szTemp, CCHPATHMAX);
    hFile=OpenFile(szTemp, &of, OF_READ);
   #else
    hFile=OpenFile(pszFile, &of, OF_READ);
   #endif

    if (HFILE_ERROR==hFile)
        return ResultFromScode(POLYLINE_E_READFAILURE);

    //Since we only support one version, read all data we expect.

    //Read version numbers and seek back to file beginning.
    cb=_lread(hFile, &pl, CBPOLYLINEDATA);
    _lclose(hFile);

    if (CBPOLYLINEDATA!=cb)
        return ResultFromScode(POLYLINE_E_READFAILURE);

    /*
     * If we loaded successfully, make the data current.  By using
     * DataSet we centralize our version upgrading.  We size the
     * polyline window to the data AND notify the document so it
     * sizes to the polyline.
     */
    DataSet(&pl, TRUE, TRUE);
    m_pObj->m_fDirty=FALSE;
    return NOERROR;
    }






/*
 * CImpIPolyline::WriteToFile
 *
 * Purpose:
 *  Ignorantly writes our current data into a file overwriting
 *  previous contents.
 *
 * Parameters:
 *  pszFile         LPTSTR file in which to write.
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise a
 *                  POLYLINE_E_ value.
 */

STDMETHODIMP CImpIPolyline::WriteToFile(LPTSTR pszFile)
    {
    OFSTRUCT        of;
    HFILE           hFile;
    POLYLINEDATA    pl;
    UINT            cb;
   #ifdef UNICODE
    CHAR            szTemp[CCHPATHMAX];
   #endif

    if (NULL==pszFile)
        return ResultFromScode(POLYLINE_E_INVALIDPOINTER);

   #ifdef UNICODE
    UNICODETOANSI(pszFile, szTemp, CCHPATHMAX);
    hFile=OpenFile(szTemp, &of, OF_CREATE | OF_WRITE);
   #else
    hFile=OpenFile(pszFile, &of, OF_CREATE | OF_WRITE);
   #endif

    if (HFILE_ERROR==hFile)
        return ResultFromScode(POLYLINE_E_WRITEFAILURE);

    DataGet(&pl);
    cb=_lwrite(hFile, (LPCSTR)&pl, CBPOLYLINEDATA);
    _lclose(hFile);

    m_pObj->m_fDirty=!(CBPOLYLINEDATA==cb);

    return (!m_pObj->m_fDirty) ?
        NOERROR : ResultFromScode(POLYLINE_E_WRITEFAILURE);
    }









/*
 * CImpIPolyline::DataSet
 *
 * Purpose:
 *  Sets the current data in this Polyline to a given structure.
 *
 * Parameters:
 *  pplIn           PPOLYLINEDATA to initialize to.
 *  fSizeToData     BOOL indicating if we're to size to the data
 *                  or scale it.
 *  fNotify         BOOL indicating if we're to send an advise
 *                  on this change.
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise a
 *                  POLYLINE_E_ value.
 */

STDMETHODIMP CImpIPolyline::DataSet(PPOLYLINEDATA pplIn
    , BOOL fSizeToData, BOOL fNotify)
    {
    PPOLYLINEDATA   ppl=&m_pObj->m_pl;
    RECT            rc;

    /*
     * Copy the structure in pplIn and repaint to reflect the
     * new point set.  Note that unlike the RectSet message, we
     * do no scaling, assuming that the rect in the structure
     * is appropriate for the data.
     */

    if (NULL==pplIn)
        return ResultFromScode(POLYLINE_E_INVALIDPOINTER);

    *ppl=*pplIn;

    //Inform our parent of the data change
    if (NULL!=m_pObj->m_pAdv)
        {
        m_pObj->m_fDirty=TRUE;
        m_pObj->m_pAdv->OnDataChange();
        }

    /*
     * If we're scaling the window to fit the data, then use
     * RectSet passing our current rectangle as the new one.
     * That makes sure that the data won't change but that the
     * window is resized.
     */

    if (fSizeToData)
        {
        POINT       pt;

        /*
         * Get our offset in the parent window so we can RectSet
         * to the right place since RectSet expects rectangle in
         * parent coordinates and we get it in client coordinates.
         */
        GetWindowRect(m_pObj->m_hWnd, &rc);
        pt.x=rc.left;
        pt.y=rc.top;
        ScreenToClient(GetParent(m_pObj->m_hWnd), &pt);
        RECTSTORECT(ppl->rc, rc);
        OffsetRect(&rc, pt.x, pt.y);

        //This will also cause a repaint.
        RectSet(&rc, fNotify);
        }
    else
        {
        //Make sure we're updated.
        InvalidateRect(m_pObj->m_hWnd, NULL, TRUE);
        UpdateWindow(m_pObj->m_hWnd);
        }

    return NOERROR;
    }







/*
 * CImpIPolyline::DataGet
 *
 * Purpose:
 *  Retrieves the Polyline's current data.
 *
 * Parameters:
 *  pplIn           PPOLYLINEDATA into which we copy the data.
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise a
 *                  POLYLINE_E_ value.
 */

STDMETHODIMP CImpIPolyline::DataGet(PPOLYLINEDATA pplIn)
    {
    if (NULL==pplIn)
        return ResultFromScode(POLYLINE_E_INVALIDPOINTER);

    *pplIn=m_pObj->m_pl;
    return NOERROR;
    }







/*
 * CImpIPolyline::DataSetMem
 *
 * Purpose:
 *  Sets the Polyline's data using a global memory handle
 *  instead of a pointer.
 *
 * Parameters:
 *  hMem            HGLOBAL containing the data.
 *  fFree           BOOL indicating if we're to free the data.
 *                  The memory will be freed regardless of any
 *                  error returned from here.
 *  fSizeToData     BOOL indicating if we're to size to the data
 *                  or scale it.
 *  fNotify         BOOL indicating if we're to send an advise
 *                  on this change.
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise a
 *                  POLYLINE_E_ value.
 */

STDMETHODIMP CImpIPolyline::DataSetMem(HGLOBAL hMem, BOOL fFree
    , BOOL fSizeToData, BOOL fNotify)
    {
    PPOLYLINEDATA   ppl;
    HRESULT         hr=ResultFromScode(POLYLINE_E_INVALIDPOINTER);

    if (NULL!=hMem)
        {
        ppl=(PPOLYLINEDATA)GlobalLock(hMem);
        hr=DataSet(ppl, fSizeToData, fNotify);

        GlobalUnlock(hMem);

        if (fFree)
            GlobalFree(hMem);
        }

    return hr;
    }







/*
 * CImpIPolyline::DataGetMem
 *
 * Purpose:
 *  Retrieves the Polyline's data in a global memory handle.
 *
 * Parameters:
 *  phMem           HGLOBAL * in which to store the handle.
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise a
 *                  POLYLINE_E_ value.
 */

STDMETHODIMP CImpIPolyline::DataGetMem(HGLOBAL *phMem)
    {
    HGLOBAL         hMem;
    PPOLYLINEDATA   ppl;
    HRESULT         hr=ResultFromScode(POLYLINE_E_INVALIDPOINTER);

    if (NULL==phMem)
        return ResultFromScode(POLYLINE_E_INVALIDPOINTER);

    hMem=GlobalAlloc(GMEM_DDESHARE | GMEM_MOVEABLE, CBPOLYLINEDATA);

    if (NULL!=hMem)
        {
        ppl=(PPOLYLINEDATA)GlobalLock(hMem);
        hr=DataGet(ppl);

        GlobalUnlock(hMem);

        if (FAILED(hr))
            {
            GlobalFree(hMem);
            hMem=NULL;
            }
        }

    *phMem=hMem;
    return hr;
    }




/*
 * CImpIPolyline::RenderBitmap
 *
 * Purpose:
 *  Creates a bitmap image of the current Polyline.
 *
 * Parameters:
 *  phBmp           HBITMAP * in which to return the bitmap.
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise a
 *                  POLYLINE_E_ value.
 */

STDMETHODIMP CImpIPolyline::RenderBitmap(HBITMAP *phBmp)
    {
    HDC             hDC;
    HDC             hMemDC;
    HBITMAP         hBmp;
    RECT            rc;
    HGDIOBJ         hObj;

    if (NULL==phBmp)
        return ResultFromScode(POLYLINE_E_INVALIDPOINTER);

    //Render a bitmap the size of the current rectangle.
    hDC=GetDC(m_pObj->m_hWnd);
    hMemDC=CreateCompatibleDC(hDC);

    GetClientRect(m_pObj->m_hWnd, &rc);
    hBmp=CreateCompatibleBitmap(hDC, rc.right, rc.bottom);

    if (NULL!=hBmp)
        {
        //Draw the POLYLINEDATA into the bitmap.
        hObj=SelectObject(hMemDC, hBmp);
        m_pObj->Draw(hMemDC, FALSE, TRUE);
        SelectObject(hMemDC, hObj);
        }

    DeleteDC(hMemDC);
    ReleaseDC(m_pObj->m_hWnd, hDC);

    *phBmp=hBmp;
    return NOERROR;
    }







/*
 * CImpIPolyline::RenderMetafile
 *
 * Purpose:
 *  Renders the current image of the Polyline into a metafile.
 *
 * Parameters:
 *  phMF            HMETAFILE * in which to return the
 *                  new metafile.
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise a
 *                  POLYLINE_E_ value.
 */

STDMETHODIMP CImpIPolyline::RenderMetafile(HMETAFILE *phMF)
    {
    HDC             hDC;
    HMETAFILE       hMF;
    RECT            rc;

    if (NULL==phMF)
        return ResultFromScode(POLYLINE_E_INVALIDPOINTER);

    //Create a memory metafile and return its handle.
    hDC=(HDC)CreateMetaFile(NULL);
    hMF=NULL;

    if (NULL!=hDC)
        {
        /*
         * This is absolutely essential to the metafile so it
         * can be scaled in the clipboard and any destination
         * application.
         */
        SetMapMode(hDC, MM_ANISOTROPIC);
        GetClientRect(m_pObj->m_hWnd, &rc);
        SetWindowOrgEx(hDC, 0, 0, NULL);
        SetWindowExtEx(hDC, rc.right, rc.bottom, NULL);

        m_pObj->Draw(hDC, TRUE, TRUE);
        hMF=CloseMetaFile(hDC);
        }

    *phMF=hMF;
    return NOERROR;
    }






/*
 * CImpIPolyline::RenderMetafilePict
 *
 * Purpose:
 *  Renders the current Polyline into a METAFILEPICT structure in
 *  global memory.
 *
 * Parameters:
 *  phMem           HGLOBAL * in which to return the
 *                  METAFILEPICT.
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise a
 *                  POLYLINE_E_ value.
 */

STDMETHODIMP CImpIPolyline::RenderMetafilePict(HGLOBAL *phMem)
    {
    HGLOBAL         hMem;
    HMETAFILE       hMF;
    LPMETAFILEPICT  pMF;
    RECT            rc;
    HRESULT         hr;

    if (NULL==phMem)
        return ResultFromScode(POLYLINE_E_INVALIDPOINTER);

    //Get the metafile
    hr=RenderMetafile(&hMF);

    if (FAILED(hr))
        return hr;

    //Allocate the METAFILEPICT structure.
    hMem=GlobalAlloc(GMEM_DDESHARE | GMEM_MOVEABLE
        , sizeof(METAFILEPICT));

    if (NULL==hMem)
        {
        DeleteMetaFile(hMF);
        return ResultFromScode(E_FAIL);
        }

    /*
     * Global lock only fails in PMODE if the selector is invalid
     * (like it was discarded) or references a 0 length segment,
     * neither of which can happen here.
     */
    pMF=(LPMETAFILEPICT)GlobalLock(hMem);

    pMF->hMF=hMF;
    pMF->mm=MM_ANISOTROPIC;

    //Insert the extents in MM_HIMETRIC units.
    GetClientRect(m_pObj->m_hWnd, &rc);
    m_pObj->RectConvertMappings(&rc, FALSE);
    pMF->xExt=rc.right;
    pMF->yExt=rc.bottom;

    GlobalUnlock(hMem);

    *phMem=hMem;
    return NOERROR;
    }









/*
 * CImpIPolyline::New
 *
 * Purpose:
 *  Cleans out and reinitializes the data to defaults.
 *
 * Parameters:
 *  None
 *
 * Return Value:
 *  HRESULT         NOERROR always
 */

STDMETHODIMP CImpIPolyline::New(void)
    {
    PPOLYLINEDATA   ppl=&m_pObj->m_pl;
    UINT            i;
    RECT            rc;

    ppl->wVerMaj=VERSIONMAJOR;
    ppl->wVerMin=VERSIONMINOR;

    //Our rectangle is the size of our window's client area.
    GetClientRect(m_pObj->m_hWnd, &rc);
    RECTTORECTS(rc, ppl->rc);

    //Clean out the POLYLINEDATA structure and repaint the window.
    for (i=0; i< CPOLYLINEPOINTS; i++)
        {
        ppl->rgpt[i].x=0;
        ppl->rgpt[i].y=0;
        }

    ppl->cPoints      =0;
    ppl->rgbBackground=GetSysColor(COLOR_WINDOW);
    ppl->rgbLine      =GetSysColor(COLOR_WINDOWTEXT);
    ppl->iLineStyle   =PS_SOLID;

    InvalidateRect(m_pObj->m_hWnd, NULL, TRUE);
    UpdateWindow(m_pObj->m_hWnd);

    //Inform the advise sink of this data change.
    if (NULL!=m_pObj->m_pAdv)
        {
        m_pObj->m_fDirty=TRUE;
        m_pObj->m_pAdv->OnDataChange();
        }

    return NOERROR;
    }






/*
 * CImpIPolyline::Undo
 *
 * Purpose:
 *  Reverses previous actions in a Polyline.
 *
 * Parameters:
 *  None
 *
 * Return Value:
 *  HRESULT         S_OK if we can Undo more, S_FALSE otherwise.
 */

STDMETHODIMP CImpIPolyline::Undo(void)
    {
    SCODE           sc;

    //Decrement the number of active points and repaint.
    if (m_pObj->m_pl.cPoints > 0)
        {
        m_pObj->m_pl.cPoints--;
        InvalidateRect(m_pObj->m_hWnd, NULL, TRUE);
        UpdateWindow(m_pObj->m_hWnd);
        }

    if (NULL!=m_pObj->m_pAdv)
        {
        m_pObj->m_fDirty=TRUE;
        m_pObj->m_pAdv->OnPointChange();
        }

    //Return if we can undo any more.
    sc=(0!=m_pObj->m_pl.cPoints) ? S_OK : S_FALSE;
    return ResultFromScode(sc);
    }






/*
 * CImpIPolyline::Window
 *
 * Purpose:
 *  Returns the window handle associated with this polyline.
 *
 * Parameters:
 *  phWnd           HWND * in which to return the window handle.
 *
 * Return Value:
 *  HRESULT         NOERROR always.
 */

STDMETHODIMP CImpIPolyline::Window(HWND *phWnd)
    {
    *phWnd=m_pObj->m_hWnd;
    return NOERROR;
    }






/*
 * CImpIPolyline::RectGet
 *
 * Purpose:
 *  Returns the rectangle of the Polyline in parent coordinates.
 *
 * Parameters:
 *  pRect           LPRECT in which to return the rectangle.
 *
 * Return Value:
 *  HRESULT         NOERROR always
 */

STDMETHODIMP CImpIPolyline::RectGet(LPRECT pRect)
    {
    RECT            rc;
    POINT           pt;

    //Retrieve the size of our rectangle in parent coordinates.
    GetWindowRect(m_pObj->m_hWnd, &rc);
    pt.x=rc.left;
    pt.y=rc.top;
    ScreenToClient(GetParent(m_pObj->m_hWnd), &pt);

    SetRect(pRect, pt.x, pt.y, pt.x+(rc.right-rc.left)
        , pt.y+(rc.bottom-rc.top));

    return NOERROR;
    }





/*
 * CImpIPolyline::SizeGet
 *
 * Purpose:
 *  Retrieves the size of the Polyline in parent coordinates.
 *
 * Parameters:
 *  pRect           LPRECT in which to return the size.  The right
 *                  and bottom fields will contain the dimensions.
 *
 * Return Value:
 *  HRESULT         NOERROR always
 */

STDMETHODIMP CImpIPolyline::SizeGet(LPRECT pRect)
    {
    RectGet(pRect);
    return NOERROR;
    }






/*
 * CImpIPolyline::RectSet
 *
 * Purpose:
 *  Sets a new rectangle for the Polyline which sizes to fit.
 *
 * Parameters:
 *  pRect           LPRECT containing the new rectangle.
 *  fNotify         BOOL indicating if we're to notify anyone of
 *                  the change.
 *
 * Return Value:
 *  HRESULT         NOERROR always
 */

STDMETHODIMP CImpIPolyline::RectSet(LPRECT pRect, BOOL fNotify)
    {
    UINT            cx, cy;
    RECT            rc;

    //Scale the points from our current size to the new size
    cx=pRect->right-pRect->left;
    cy=pRect->bottom-pRect->top;

    SetWindowPos(m_pObj->m_hWnd, NULL, pRect->left, pRect->top
        , cx, cy, SWP_NOZORDER);

    SetRect(&rc, 0, 0, cx, cy);
    RECTTORECTS(rc, m_pObj->m_pl.rc);

    if (fNotify && NULL!=m_pObj->m_pAdv)
        {
        m_pObj->m_fDirty=TRUE;
        m_pObj->m_pAdv->OnSizeChange();
        }

    InvalidateRect(m_pObj->m_hWnd, NULL, TRUE);

    return NOERROR;
    }







/*
 * CImpIPolyline::SizeSet
 *
 * Purpose:
 *  Sets a new size for the Polyline which sizes to fit.
 *
 * Parameters:
 *  pRect           LPRECT containing the new rectangle.
 *  fNotify         BOOL indicating if we're to notify anyone of
 *                  the change.
 *
 * Return Value:
 *  HRESULT         NOERROR always
 */

STDMETHODIMP CImpIPolyline::SizeSet(LPRECT pRect, BOOL fNotify)
    {
    UINT            cx, cy;

    //Scale the points from our current size to the new size
    cx=pRect->right-pRect->left;
    cy=pRect->bottom-pRect->top;

    SetWindowPos(m_pObj->m_hWnd, NULL, 0, 0, (UINT)cx, (UINT)cy
        , SWP_NOMOVE | SWP_NOZORDER);

    if (fNotify && NULL!=m_pObj->m_pAdv)
        {
        m_pObj->m_fDirty=TRUE;
        m_pObj->m_pAdv->OnSizeChange();
        }

    InvalidateRect(m_pObj->m_hWnd, NULL, TRUE);

    return NOERROR;
    }






/*
 * CImpIPolyline::ColorSet
 *
 * Purpose:
 *  Changes for background or line color in the Polyline
 *
 * Parameters:
 *  iColor          UINT index of the color to change.
 *  cr              COLORREF new color to use.
 *  pcrPrev         COLORREF * in whch to store the
 *                  previous color.
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise a
 *                  POLYLINE_E_ value.
 */

STDMETHODIMP CImpIPolyline::ColorSet(UINT iColor, COLORREF cr
    , COLORREF *pcrPrev)
    {
    COLORREF        crRet;

    if (NULL==pcrPrev)
        return ResultFromScode(POLYLINE_E_INVALIDPOINTER);

    switch (iColor)
        {
        case POLYLINECOLOR_BACKGROUND:
            crRet=m_pObj->m_pl.rgbBackground;
            m_pObj->m_pl.rgbBackground=cr;
            break;

        case POLYLINECOLOR_LINE:
            crRet=m_pObj->m_pl.rgbLine;
            m_pObj->m_pl.rgbLine=cr;
            break;
        }

    //If the color changed, repaint
    if (crRet!=cr)
        {
        if (NULL!=m_pObj->m_pAdv)
            {
            m_pObj->m_fDirty=TRUE;
            m_pObj->m_pAdv->OnColorChange();
            }

        InvalidateRect(m_pObj->m_hWnd, NULL, TRUE);
        UpdateWindow(m_pObj->m_hWnd);
        }

    *pcrPrev=crRet;
    return NOERROR;
    }







/*
 * CImpIPolyline::ColorGet
 *
 * Purpose:
 *  Retrieves one of the colors currently in use by the Polyline.
 *
 * Parameters:
 *  iColor          UINT identifying the color of interest.
 *  pcr             COLORREF * in which to return the color.
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise a
 *                  POLYLINE_E_ value.
 */

STDMETHODIMP CImpIPolyline::ColorGet(UINT iColor, COLORREF *pcr)
    {
    COLORREF        crRet;

    if (NULL==pcr)
        return ResultFromScode(POLYLINE_E_INVALIDPOINTER);

    crRet=(POLYLINECOLOR_BACKGROUND==iColor)
        ? m_pObj->m_pl.rgbBackground : m_pObj->m_pl.rgbLine;

    *pcr=crRet;
    return NOERROR;
    }








/*
 * CImpIPolyline::LineStyleSet
 *
 * Purpose:
 *  Changes the line style in use by the Polyline
 *
 * Parameters:
 *  iStyle          UINT style of the line to use.
 *  piPrev          UINT * in which to store the previous style.
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise a
 *                  POLYLINE_E_ value.
 */

STDMETHODIMP CImpIPolyline::LineStyleSet(UINT iStyle, UINT *piPrev)
    {
    UINT            uRet;

    uRet=(UINT)m_pObj->m_pl.iLineStyle;

    if (NULL==piPrev)
        return ResultFromScode(POLYLINE_E_INVALIDPOINTER);

    //Validate the line style
    if (PS_SOLID==iStyle || PS_DASH==iStyle || PS_DOT==iStyle
        || PS_DASHDOT==iStyle || PS_DASHDOTDOT==iStyle)
        {
        m_pObj->m_pl.iLineStyle=iStyle;

        if (uRet!=(UINT)m_pObj->m_pl.iLineStyle)
            {
            if (NULL!=m_pObj->m_pAdv)
                {
                m_pObj->m_fDirty=TRUE;
                m_pObj->m_pAdv->OnLineStyleChange();
                }

            InvalidateRect(m_pObj->m_hWnd, NULL, TRUE);
            UpdateWindow(m_pObj->m_hWnd);
            }
        }

    *piPrev=uRet;
    return NOERROR;
    }







/*
 * CImpIPolyline::LineStyleGet
 *
 * Purpose:
 *  Retrieves the current line style in use in the Polyline
 *
 * Parameters:
 *  piStyle         UINT * in which to store the style.
 *
 * Return Value:
 *  HRESULT         NOERROR if successful, otherwise a
 *                  POLYLINE_E_ value.
 */

STDMETHODIMP CImpIPolyline::LineStyleGet(UINT *piStyle)
    {
    if (NULL==piStyle)
        return ResultFromScode(POLYLINE_E_INVALIDPOINTER);

    *piStyle=m_pObj->m_pl.iLineStyle;
    return NOERROR;
    }