AAX_CDecibelDisplayDelegateDecorator.h

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#ifndef AAX_CDECIBELDISPLAYDELEGATEDECORATOR_H
#define AAX_CDECIBELDISPLAYDELEGATEDECORATOR_H


#include "AAX_IDisplayDelegateDecorator.h"
#include <cmath>



template <typename T>
class AAX_CDecibelDisplayDelegateDecorator : public AAX_IDisplayDelegateDecorator<T>
{
public:
    AAX_CDecibelDisplayDelegateDecorator(const AAX_IDisplayDelegate<T>& displayDelegate);
    
    //Virtual Overrides
    AAX_CDecibelDisplayDelegateDecorator<T>*    Clone() const;
    bool        ValueToString(T value, AAX_CString* valueString) const;
    bool        ValueToString(T value, int32_t maxNumChars, AAX_CString* valueString) const ;
    bool        StringToValue(const AAX_CString& valueString, T* value) const;
};






template <typename T>
AAX_CDecibelDisplayDelegateDecorator<T>::AAX_CDecibelDisplayDelegateDecorator(const AAX_IDisplayDelegate<T>& displayDelegate)  :
    AAX_IDisplayDelegateDecorator<T>(displayDelegate)
{

}

template <typename T>
AAX_CDecibelDisplayDelegateDecorator<T>*    AAX_CDecibelDisplayDelegateDecorator<T>::Clone() const
{
    return new AAX_CDecibelDisplayDelegateDecorator(*this);
}

template <typename T>
bool    AAX_CDecibelDisplayDelegateDecorator<T>::ValueToString(T value, AAX_CString* valueString) const 
{
    bool succeeded = false;
    if (value <= 0)
    {
        //*valueString = AAX_CString("--- dB");
        *valueString = AAX_CString("-INF ");
        succeeded = true;
    }
    else 
    {
        value = (T)(20.0*log10(value));
        if ( value > -0.01f && value < 0.0f) //To prevent minus for 0.0 value in automation turned on
            value = 0.0f;
        
        succeeded = AAX_IDisplayDelegateDecorator<T>::ValueToString(value, valueString);        
    }
    
    *valueString += AAX_CString("dB");
    return succeeded;
}

template <typename T>
bool    AAX_CDecibelDisplayDelegateDecorator<T>::ValueToString(T value, int32_t maxNumChars, AAX_CString* valueString) const
{
    if (value <= 0)
    {
        *valueString = AAX_CString("-INF");
        if (maxNumChars >= 7)
            valueString->Append(" dB"); //<DMT> Add a space for longer strings and dB
        return true;
    }

    value = (T)(20.0*log10(value));
    if ( value > -0.01f && value < 0.0f) //To prevent minus for 0.0 value in automation turned on
        value = 0.0f;
    bool succeeded = AAX_IDisplayDelegateDecorator<T>::ValueToString(value, maxNumChars, valueString);
    
    
    //<DMT> Check current string length and see if there is room to add units.  I believe these units are usually less important than precision on control surfaces.
    uint32_t strlen = valueString->Length();
    const uint32_t maxNumCharsUnsigned = (0 <= maxNumChars) ? static_cast<uint32_t>(maxNumChars) : 0;
    if (maxNumCharsUnsigned >= (strlen + 2))    //length of string plus 2 for the "dB"
        *valueString += AAX_CString("dB");
    return succeeded;
}


template <typename T>
bool    AAX_CDecibelDisplayDelegateDecorator<T>::StringToValue(const AAX_CString& valueString, T* value) const
{       
    //Just call through if there is obviously no unit string.
    if (valueString.Length() <= 2)
    {
        bool success = AAX_IDisplayDelegateDecorator<T>::StringToValue(valueString, value);
        *value = (T)pow((T)10.0, (*value / (T)20.0));
        return success;
    }
        
    //Just call through if the end of this string does not match the unit string.   
    AAX_CString unitSubString;
    valueString.SubString(valueString.Length() - 2, 2, &unitSubString);
    if (unitSubString != AAX_CString("dB"))
    {
        bool success = AAX_IDisplayDelegateDecorator<T>::StringToValue(valueString, value);
        *value = (T)pow((T)10.0, *value / (T)20.0);
        return success;
    }
            
    //Call through with the stripped down value string.  
    AAX_CString valueSubString;
    valueString.SubString(0, valueString.Length() - 2, &valueSubString);
    bool success = AAX_IDisplayDelegateDecorator<T>::StringToValue(valueSubString, value);
    *value = (T)pow((T)10.0, *value / (T)20.0);
    return success;
}




#endif //AAX_CDECIBELDISPLAYDELEGATEDECORATOR_H