C++ MHUnion类代码示例

// Return a bool value.  May throw an exception if it isn't the correct type.
static bool GetBool(MHParameter *parm, MHEngine *engine)
{
    MHUnion un;
    un.GetValueFrom(*parm, engine);
    un.CheckType(MHUnion::U_Bool);
    return un.m_fBoolVal;
}

// Extract a string value.
static void GetString(MHParameter *parm, MHOctetString &str, MHEngine *engine)
{
    MHUnion un;
    un.GetValueFrom(*parm, engine);
    un.CheckType(MHUnion::U_String);
    str.Copy(un.m_StrVal);
}

// Return the value, looking up any indirect ref.
void MHGenericOctetString::GetValue(MHOctetString &str, MHEngine *engine) const
{
    if (m_fIsDirect) str.Copy(m_Direct);
    else {
        MHUnion result;
        MHRoot *pBase = engine->FindObject(m_Indirect);
        pBase->GetVariableValue(result, engine);
        // From my reading of the MHEG documents implicit conversion is only
        // performed when assigning variables.  Nevertheless the Channel 4
        // Teletext assumes that implicit conversion takes place here as well.
        if (result.m_Type == MHUnion::U_Int) {
            // Implicit conversion of int to string.
            char buff[30]; // 30 chars is more than enough.
#ifdef WIN32
            _snprintf(buff, sizeof(buff), "%0d", result.m_nIntVal);
#else
            snprintf(buff, sizeof(buff), "%0d", result.m_nIntVal);
#endif
            str.Copy(buff);
        }
        else {
            result.CheckType(MHUnion::U_String);
            str.Copy(result.m_StrVal);
        }
    }
}

// Return an integer value.  May throw an exception if it isn't the correct type.
static int GetInt(MHParameter *parm, MHEngine *engine)
{
    MHUnion un;
    un.GetValueFrom(*parm, engine);
    un.CheckType(MHUnion::U_Int);
    return un.m_nIntVal;
}

// Return the value, looking up any indirect ref.
int MHGenericInteger::GetValue(MHEngine *engine) const
{
    if (m_fIsDirect) return m_nDirect;
    else {
        MHUnion result;
        MHRoot *pBase = engine->FindObject(m_Indirect);
        pBase->GetVariableValue(result, engine);
        // From my reading of the MHEG documents implicit conversion is only
        // performed when assigning variables.  Nevertheless the Channel 4
        // Teletext assumes that implicit conversion takes place here as well.
        if (result.m_Type == MHUnion::U_String) {
            // Implicit conversion of string to integer.
            int v = 0;
            int p = 0;
            bool fNegative = false;
            if (result.m_StrVal.Size() > 0 && result.m_StrVal.GetAt(0) == '-') { p++; fNegative = true; }
            for ( ; p < result.m_StrVal.Size(); p++) {
                unsigned char ch =  result.m_StrVal.GetAt(p);
                if (ch < '0' || ch > '9') break;
                v = v * 10 + ch - '0';
            }
            if (fNegative) return -v; else return v;
        }
        else {
            result.CheckType(MHUnion::U_Int);
            return result.m_nIntVal;
        }
    }
}

void MHSetVariable::Perform(MHEngine *engine)
{
    MHObjectRef target;
    m_Target.GetValue(target, engine); // Get the target
    MHUnion newValue;
    newValue.GetValueFrom(m_NewValue, engine); // Get the actual value to set.
    engine->FindObject(target)->SetVariableValue(newValue); // Set the value.
}

void MHSendEvent::Perform(MHEngine *engine)
{
    // The target is always the current scene so we ignore it here.
    MHObjectRef target, source;
    m_Target.GetValue(target, engine); // TODO: Check this is the scene?
    m_EventSource.GetValue(source, engine);
    // Generate the event.
    if (m_EventData.m_Type == MHParameter::P_Null)
        engine->EventTriggered(engine->FindObject(source), m_EventType);
    else {
        MHUnion data;
        data.GetValueFrom(m_EventData, engine);
        engine->EventTriggered(engine->FindObject(source), m_EventType, data);
    }
}

// Implement the TestVariable action.  Triggers a TestEvent event on the result.
void MHOctetStrVar::TestVariable(int nOp, const MHUnion &parm, MHEngine *engine)
{
    parm.CheckType(MHUnion::U_String);
    int nRes = m_Value.Compare(parm.m_StrVal);
    bool fRes = false;

    switch (nOp)
    {
        case TC_Equal:
            fRes = nRes == 0;
            break;
        case TC_NotEqual:
            fRes = nRes != 0;
            break;
            /*  case TC_Less: fRes = nRes < 0; break;
                case TC_LessOrEqual: fRes = nRes <= 0; break;
                case TC_Greater: fRes = nRes > 0; break;
                case TC_GreaterOrEqual: fRes = nRes >= 0; break;*/
        default:
            MHERROR("Invalid comparison for string"); // Shouldn't ever happen
    }

    MHOctetString sample1(m_Value, 0, 10);
    MHOctetString sample2(parm.m_StrVal, 0, 10);
    MHLOG(MHLogDetail, QString("Comparison %1 %2 and %3 => %4").arg(TestToText(nOp))
          .arg(sample1.Printable()).arg(sample2.Printable()).arg(fRes ? "true" : "false"));
    engine->EventTriggered(this, EventTestEvent, fRes);
}

// Return the value, looking up any indirect ref.
void MHGenericObjectRef::GetValue(MHObjectRef &ref, MHEngine *engine) const
{
    if (m_fIsDirect)
    {
        ref.Copy(m_ObjRef);
    }
    else
    {
        // LVR - Hmm I don't think this is right. Should be: ref.Copy(m_Indirect);
        // But it's used in several places so workaround in Stream::MHActionGenericObjectRefFix
        MHUnion result;
        MHRoot *pBase = engine->FindObject(m_Indirect);
        pBase->GetVariableValue(result, engine);
        result.CheckType(MHUnion::U_ObjRef);
        ref.Copy(result.m_ObjRefVal);
    }
}

// Implement the TestVariable action.  Triggers a TestEvent event on the result.
void MHContentRefVar::TestVariable(int nOp, const MHUnion &parm, MHEngine *engine)
{
    parm.CheckType(MHUnion::U_ContentRef);
    bool fRes = false;
    switch (nOp) {
    case TC_Equal: fRes = m_Value.Equal(parm.m_ContentRefVal, engine); break;
    case TC_NotEqual: fRes = !m_Value.Equal(parm.m_ContentRefVal, engine); break;
    default: MHERROR("Invalid comparison for content ref");
    }
    engine->EventTriggered(this, EventTestEvent, fRes);
}

// Implement the SetVariable action.
void MHOctetStrVar::SetVariableValue(const MHUnion &value)
{
    if (value.m_Type == MHUnion::U_Int) {
        // Implicit conversion of int to string.
        char buff[30]; // 30 chars is more than enough.
        snprintf(buff, sizeof(buff), "%0d", value.m_nIntVal);
        m_Value.Copy(buff);
    }
    else {
        value.CheckType(MHUnion::U_String);
        m_Value.Copy(value.m_StrVal);
    }
    // Debug
    MHOctetString sample(m_Value, 0, 10);
    MHLOG(MHLogDetail, QString("Update %1 := %2").arg(m_ObjectReference.Printable())
        .arg(sample.Printable()));
}

// Implement the SetVariable action.  Also used as part of Add, Subtract etc
void MHIntegerVar::SetVariableValue(const MHUnion &value)
{
    if (value.m_Type == MHUnion::U_String)
    {
        // Implicit conversion of string to integer.
        int v = 0;
        int p = 0;
        bool fNegative = false;

        if (value.m_StrVal.Size() > 0 && value.m_StrVal.GetAt(0) == '-')
        {
            p++;
            fNegative = true;
        }

        for (; p < value.m_StrVal.Size(); p++)
        {
            unsigned char ch =  value.m_StrVal.GetAt(p);

            if (ch < '0' || ch > '9')
            {
                break;
            }

            v = v * 10 + ch - '0';
        }

        if (fNegative)
        {
            m_nValue = -v;
        }
        else
        {
            m_nValue = v;
        }
    }
    else
    {
        value.CheckType(MHUnion::U_Int);
        m_nValue = value.m_nIntVal;
    }

    MHLOG(MHLogDetail, QString("Update %1 := %2").arg(m_ObjectReference.Printable()).arg(m_nValue));
}

//.........这里部分代码省略.........
                int netId, origNetId, transportId, serviceId;
                // Look the information up in the database.
                bool res = engine->GetContext()->GetServiceInfo(channelId, netId, origNetId,
                                                                transportId, serviceId);

                if (res)
                {
                    engine->FindObject(*(args.GetAt(1)->GetReference()))->SetVariableValue(netId);
                    engine->FindObject(*(args.GetAt(2)->GetReference()))->SetVariableValue(origNetId);
                    engine->FindObject(*(args.GetAt(3)->GetReference()))->SetVariableValue(transportId);
                    engine->FindObject(*(args.GetAt(4)->GetReference()))->SetVariableValue(serviceId);
                }

                SetSuccessFlag(success, res, engine);
            }
            else
            {
                SetSuccessFlag(success, false, engine);
            }
        }
        else if (m_Name.Equal("GBI"))   // GetBootInfo
        {
            // Gets the NB_info field.
            MHERROR("GetBootInfo ResidentProgram is not implemented");
        }
        else if (m_Name.Equal("CCR"))   // CheckContentRef
        {
            // Sees if an item with a particular content reference is available
            // in the carousel.  This looks like it should block until the file
            // is available.  The profile recommends that this should be forked
            // rather than called.
            if (args.Size() == 3)
            {
                MHUnion un;
                un.GetValueFrom(*(args.GetAt(0)), engine);
                un.CheckType(MHUnion::U_ContentRef);
                MHContentRef fileName;
                fileName.Copy(un.m_ContentRefVal);
                QString csPath = engine->GetPathName(fileName.m_ContentRef);
                bool result = false;
                QByteArray text;

                // Try to load the object.
                if (! csPath.isEmpty())
                {
                    result = engine->GetContext()->GetCarouselData(csPath, text);
                }

                // Set the result variable.
                MHParameter *pResFlag = args.GetAt(1);
                engine->FindObject(*(pResFlag->GetReference()))->SetVariableValue(result);
                MHParameter *pResCR = args.GetAt(2);
                // Copy the file name to the resulting content ref.
                engine->FindObject(*(pResCR->GetReference()))->SetVariableValue(fileName);
                SetSuccessFlag(success, true, engine);
            }
            else
            {
                SetSuccessFlag(success, false, engine);
            }
        }
        else if (m_Name.Equal("CGR"))   // CheckGroupIDRef
        {
            // Sees if an application or scene with a particular group id
            // is available in the carousel.
            MHERROR("CheckGroupIDRef ResidentProgram is not implemented");