utils.cpp

/*****************************************************************************
 * utils.cpp: ActiveX control for VLC
 *****************************************************************************
 * Copyright (C) 2005 the VideoLAN team
 *
 * Authors: Damien Fouilleul <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

#include "utils.h"

/*
** conversion facilities
*/

using namespace std;

char *CStrFromBSTR(UINT codePage, BSTR bstr)
{
    UINT len = SysStringLen(bstr);
    if( len > 0 )
    {
        size_t mblen = WideCharToMultiByte(codePage,
                0, bstr, len, NULL, 0, NULL, NULL);
        if( mblen > 0 )
        {
            char *buffer = (char *)CoTaskMemAlloc(mblen+1);
            ZeroMemory(buffer, mblen+1);
            if( WideCharToMultiByte(codePage, 0, bstr, len, buffer, mblen, NULL, NULL) )
            {
                buffer[mblen] = '\0';
                return buffer;
            }
        }
    }
    return NULL;
};

BSTR BSTRFromCStr(UINT codePage, LPCSTR s)
{
    int wideLen = MultiByteToWideChar(codePage, 0, s, -1, NULL, 0);
    if( wideLen > 0 )
    {
        WCHAR* wideStr = (WCHAR*)CoTaskMemAlloc(wideLen*sizeof(WCHAR));
        if( NULL != wideStr )
        {
            BSTR bstr;

            ZeroMemory(wideStr, wideLen*sizeof(WCHAR));
            MultiByteToWideChar(codePage, 0, s, -1, wideStr, wideLen);
            bstr = SysAllocStringLen(wideStr, wideLen);
            free(wideStr);

            return bstr;
        }
    }
    return NULL;
};

/*
**  properties
*/

HRESULT GetObjectProperty(LPUNKNOWN object, DISPID dispID, VARIANT& v)
{
    IDispatch *pDisp;
    HRESULT hr = object->QueryInterface(IID_IDispatch, (LPVOID *)&pDisp);
    if( SUCCEEDED(hr) )
    {
        DISPPARAMS dispparamsNoArgs = {NULL, NULL, 0, 0};
        VARIANT vres;
        VariantInit(&vres);
        hr = pDisp->Invoke(dispID, IID_NULL, LOCALE_USER_DEFAULT,
                DISPATCH_PROPERTYGET, &dispparamsNoArgs, &vres, NULL, NULL);
        if( SUCCEEDED(hr) )
        {
            if( V_VT(&v) != V_VT(&vres) )
            {
                hr = VariantChangeType(&v, &vres, 0, V_VT(&v));
                VariantClear(&vres);
            }
            else
            {
                v = vres;
            }
        }
        pDisp->Release();
    }
    return hr;
};

HDC CreateDevDC(DVTARGETDEVICE *ptd)
{
        HDC hdc=NULL;
        LPDEVNAMES lpDevNames;
        LPDEVMODE lpDevMode;
        LPTSTR lpszDriverName;
        LPTSTR lpszDeviceName;
        LPTSTR lpszPortName;

        if (ptd == NULL) {
                hdc = CreateDC(TEXT("DISPLAY"), NULL, NULL, NULL);
                goto errReturn;
        }

        lpDevNames = (LPDEVNAMES) ptd; // offset for size field

        if (ptd->tdExtDevmodeOffset == 0) {
                lpDevMode = NULL;
        }else{
                lpDevMode  = (LPDEVMODE) ((LPTSTR)ptd + ptd->tdExtDevmodeOffset);
        }

        lpszDriverName = (LPTSTR) lpDevNames + ptd->tdDriverNameOffset;
        lpszDeviceName = (LPTSTR) lpDevNames + ptd->tdDeviceNameOffset;
        lpszPortName   = (LPTSTR) lpDevNames + ptd->tdPortNameOffset;

        hdc = CreateDC(lpszDriverName, lpszDeviceName, lpszPortName, lpDevMode);

errReturn:
        return hdc;
};

#define HIMETRIC_PER_INCH 2540

void DPFromHimetric(HDC hdc, LPPOINT pt, int count)
{
    LONG lpX = GetDeviceCaps(hdc, LOGPIXELSX);
    LONG lpY = GetDeviceCaps(hdc, LOGPIXELSY);
    while( count-- )
    {
        pt->x = pt->x*lpX/HIMETRIC_PER_INCH;
        pt->y = pt->y*lpY/HIMETRIC_PER_INCH;
        ++pt;
    }
};

void HimetricFromDP(HDC hdc, LPPOINT pt, int count)
{
    LONG lpX = GetDeviceCaps(hdc, LOGPIXELSX);
    LONG lpY = GetDeviceCaps(hdc, LOGPIXELSY);
    while( count-- )
    {
        pt->x = pt->x*HIMETRIC_PER_INCH/lpX;
        pt->y = pt->y*HIMETRIC_PER_INCH/lpY;
        ++pt;
    }
};

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