JavaScript function access from plain C++: An example

///-////////////////////////////////////////////////////////////////////////////////////////////////
///     Autor:  David Elias Flores Escalante
///     Company: TeleTracking SAC
///     URL: http://teletrackingsac.dnsalias.net
///     Date:   24/08/2008
///     File name: dWebCtrl.cpp
///     License: Free, but autor and company must be mentioned.
///-////////////////////////////////////////////////////////////////////////////////////////////////

#include "dWebCtrl.h"

extern char szDirectorioTrabajo[];

///-//////////////////////////////////////////////////////////////////////////////////////////
///    dWebCtrl OnResize
///-//////////////////////////////////////////////////////////////////////////////////////////
void dWebCtrl::Iniciar(HWND hwnd,HINSTANCE hInst)
{
    char pathtofile[512]="";
    BSTR buffer;

    memset(pathtofile,'\0',sizeof(pathtofile)-1);

    hWnd=CreateWindowEx( WS_EX_CLIENTEDGE,//|WS_EX_TOPMOST,///|WS_EX_DLGMODALFRAME,
                        "EDIT",
                        "",
                        WS_CHILD| WS_BORDER |WM_PAINT| WS_VISIBLE,///|WS_DLGFRAME,
                        0,0,0,0,
                        hwnd,
                        NULL,//(HMENU)idVentana,
                        hInst,
                        NULL);

    if (hWnd == NULL)
    {
         MessageBox(hwnd, "no window", "Error", MB_ICONEXCLAMATION | MB_OK);
         return;
    }

    VariantInit(&vEmpty);

    hWebInstance = LoadLibrary("atl.dll");

    wsprintf(pathtofile,"file:///%s/daveware.html",szDirectorioTrabajo);

    size = MultiByteToWideChar(CP_ACP, 0, pathtofile, -1, 0, 0);
    if (!(buffer = (wchar_t *)GlobalAlloc(GMEM_FIXED, sizeof(wchar_t)*size)))
        return;

    MultiByteToWideChar(CP_ACP, 0, pathtofile, -1, buffer, size);

    bstrURL = SysAllocString(buffer);

    SysFreeString(buffer);

    /// R�cup�rer l'adresse de la fonction "AtlAxAttachControl":
    PAttachControl AtlAxAttachControl = (PAttachControl) GetProcAddress(hWebInstance, "AtlAxAttachControl");

    hParent=hwnd;
    hInstance=hInst;

    /// Initialiser la librairie COM pour notre programme:
    OleInitialize(0);

    CoCreateInstance(CLSID_WebBrowser, NULL, CLSCTX_SERVER,IID_IWebBrowser2, (void**)&pIwb);


    if (pIwb)
    {
        VARIANT vEmpty;
        VARIANT_BOOL bBusy = VARIANT_TRUE;
        VariantInit(&vEmpty);

        AtlAxAttachControl(pIwb,hWnd,0);

        result=pIwb->Navigate(bstrURL, &vEmpty, &vEmpty, &vEmpty, &vEmpty);

        if (SUCCEEDED(result))
        {
            while(bBusy == VARIANT_TRUE)
            {
                Sleep(500);
                pIwb->get_Busy(&bBusy);
            }
        }

        pIwb->get_HWND ((long*)(&hWebCtrl));

        SysFreeString(bstrURL);
    }

}

///-//////////////////////////////////////////////////////////////////////////////////////////
///    Destructor
///-//////////////////////////////////////////////////////////////////////////////////////////
dWebCtrl::~dWebCtrl()
{
    pIwb->Quit();
	pIwb->Release();

    OleUninitialize();

	FreeLibrary(hWebInstance);
}

///-//////////////////////////////////////////////////////////////////////////////////////////
///    dWebCtrl OnResize
///-//////////////////////////////////////////////////////////////////////////////////////////
void dWebCtrl::OnResize(int x,int y)
{
    GetWindowRect(hParent,&rect);
    long ParentWidth=rect.right-rect.left;
    long ParentHeight=rect.bottom-rect.top;

    MoveWindow(hWnd,x,y,ParentWidth-8,ParentHeight-32,TRUE);

}

///-//////////////////////////////////////////////////////////////////////////////////////////
///    dWebCtrl get hWebCtrl
///-//////////////////////////////////////////////////////////////////////////////////////////
HWND dWebCtrl::GetWebHwnd()
{
    return(hWebCtrl);

}

///-//////////////////////////////////////////////////////////////////////////////////////////
///    Execute string "Script"
///-//////////////////////////////////////////////////////////////////////////////////////////
void dWebCtrl::ExecuteScript(char* Script)
{
    BSTR bstrScript;
    BSTR bufferScript;
    static DWORD size=0;
    char nameInput[256]={'\0'};

    memset(nameInput,'\0',sizeof(nameInput)-1);

    wsprintf(nameInput,"javascript:%s",Script);

    size = MultiByteToWideChar(CP_ACP, 0, nameInput, -1, 0, 0);
    if (!(bufferScript = (wchar_t *)GlobalAlloc(GMEM_FIXED, sizeof(wchar_t)*size)))
        return;

    MultiByteToWideChar(CP_ACP, 0, nameInput, -1, bufferScript, size);
    bstrScript = SysAllocString(bufferScript);

    SysFreeString(bufferScript);

    pIwb->Navigate(bstrScript, &vEmpty, &vEmpty, &vEmpty, &vEmpty);
    SysFreeString(bstrScript);

    return;
}