Public Types | Public Member Functions | Static Public Member Functions

TQT_DBusDataConverter Class Reference

Template based converter for getting complex data into or from TQT_DBusData objects. More...

#include <tqdbusdataconverter.h>

List of all members.

Public Types

enum  Result { Success, InvalidSignature, InvalidArgument }

Public Member Functions

template<>
TQT_DBusDataConverter::Result convertFromTQT_DBusData (const TQT_DBusData &dbusData, TQRect &typeData)
template<>
TQT_DBusDataConverter::Result convertToTQT_DBusData (const TQRect &typeData, TQT_DBusData &dbusData)
template<>
TQT_DBusDataConverter::Result convertFromTQT_DBusData (const TQT_DBusData &dbusData, TQPoint &typeData)
template<>
TQT_DBusDataConverter::Result convertToTQT_DBusData (const TQPoint &typeData, TQT_DBusData &dbusData)
template<>
TQT_DBusDataConverter::Result convertFromTQT_DBusData (const TQT_DBusData &dbusData, TQSize &typeData)
template<>
TQT_DBusDataConverter::Result convertToTQT_DBusData (const TQSize &typeData, TQT_DBusData &dbusData)

Static Public Member Functions

template<class T >
static Result convertFromTQT_DBusData (const TQT_DBusData &dbusData, T &typeData)
template<class T >
static Result convertToTQT_DBusData (const T &typeData, TQT_DBusData &dbusData)

Detailed Description

Template based converter for getting complex data into or from TQT_DBusData objects.

Any data to transport over D-Bus, i.e. method/signal paramaters or properties, need to be converted into a TQT_DBusData instance.

For complex types, e.g. structures or nested containers, this can be quite some code, and will likely be needed for more than one call. Therefore it is more convenient to implement the conversions once per complex type.

Example: sending and recieving a TQRect over D-Bus. In D-Bus terminology a TQRect is a struct of four 32-bit signed integers. The code to do this manually looks like this:

 TQRect rect(0, 0, 100, 100);
 
 TQValueList<TQT_DBusData> structMembers;
 structMembers << TQT_DBusData::fromInt32(rect.x());
 structMembers << TQT_DBusData::fromInt32(rect.y());
 structMembers << TQT_DBusData::fromInt32(rect.wdth());
 structMembers << TQT_DBusData::fromInt32(rect.height());

 TQT_DBusData rectStruct = TQT_DBusData::fromStruct(structMembers);

and reverse (without the error checking)

 TQT_DBusData dbusData; // assume we got this from a D-Bus call
 
 TQValueList<TQT_DBusData> structMembers = dbudData.toStruct();
 
 int x = structMembers[0].toInt32();
 int y = structMembers[1].toInt32();
 int w = structMembers[2].toInt32();
 int h = structMembers[3].toInt32();

 TQRect rect(x, y, w, h);

Rather than implementing it in the method which performs the D-Bus call, basically the same code can be used as a spezialisation of the TQT_DBusDataConverter methods and then used like this:

 TQRect rect(0, 0, 100, 100);
 TQT_DBusData rectStruct;

 TQT_DBusDataConverter::convertToTQT_DBusData<TQRect>(rect, rectStruct);

and

 TQRect rect;
 TQT_DBusData dbusData; // assume we got this from a D-Bus call

 TQT_DBusDataConverter::convertFromTQT_DBusData<TQRect>(dbusData, rect);
Note:
The bindings library contains the spezialisations for TQRect, TQPoint and TQSize.

Definition at line 87 of file tqdbusdataconverter.h.


Member Enumeration Documentation

Conversion result values.

Enumerator:
Success 

Conversion successfull

InvalidSignature 

Conversion failed because the passed TQT_DBusData instance does not contain data of the needed signature, e.g. too few to too many members for a struct or wrong types.

See also:
TQT_DBusError::stdInvalidSignature()
InvalidArgument 

Conversion failed because the passed TQT_DBusData contained values which are not allowed, e.g. out of range for a numerical type used a an enum or flags.

See also:
TQT_DBusError::stdInvalidArgs()

Definition at line 93 of file tqdbusdataconverter.h.

    {
        Success,
        
        InvalidSignature,
        
        InvalidArgument
    };


Member Function Documentation

template<class T >
static Result TQT_DBusDataConverter::convertFromTQT_DBusData ( const TQT_DBusData dbusData,
T &  typeData 
) [static]

Conversion from a filled TQT_DBusData instance to a native type.

For example the implementation for TQPoint looks like this:

 template <>
 TQT_DBusDataConverter::Result
 TQT_DBusDataConverter::convertFromTQT_DBusData<TQPoint>(const TQT_DBusData& dbusData, TQPoint& typeData)
 {
     if (dbusData.type() != TQT_DBusData::Struct) return InvalidSignature;
     
     TQValueList<TQT_DBusData> members = dbusData.toStruct();
     if (members.count() != 2) return InvalidSignature;

     bool ok = false;
     int x = members[0].toInt32(&ok);
     if (!ok) return InvalidSignature;

     int y = members[1].toInt32(&ok);
     if (!ok) return InvalidSignature;

     typeData = TQPoint(x, y);

     return Success;
 }

And then can be used like this:

 TQT_DBusMessage reply; // assume we got this as a D-Bus call reply
 TQPoint point;

 if (TQT_DBusDataConverter::convertFromTQT_DBusData(reply[0], point) != TQT_DBusDataConverter::Success)
 {
     // error handling
 }
Parameters:
dbusData the binding's data instance to get the content from
typeData the native type instance to put the content into
Returns:
the conversion result value
template<>
TQT_DBusDataConverter::Result TQT_DBusDataConverter::convertFromTQT_DBusData ( const TQT_DBusData dbusData,
TQPoint &  typeData 
)
template<>
TQT_DBusDataConverter::Result TQT_DBusDataConverter::convertFromTQT_DBusData ( const TQT_DBusData dbusData,
TQSize &  typeData 
)
template<>
TQT_DBusDataConverter::Result TQT_DBusDataConverter::convertFromTQT_DBusData ( const TQT_DBusData dbusData,
TQRect &  typeData 
)
template<class T >
static Result TQT_DBusDataConverter::convertToTQT_DBusData ( const T &  typeData,
TQT_DBusData dbusData 
) [static]

Conversion from a native type to a TQT_DBusData instance.

For example the implementation for TQPoint looks like this:

 template <>
 TQT_DBusDataConversion::Result
 TQT_DBusDataConversion::convertToTQT_DBusData<TQPoint>(const TQPoint& typeData, TQT_DBusData& dbusData)
 {
     TQValueList<TQT_DBusData> members;
     members << TQT_DBusData::fromInt32(typeData.x());
     members << TQT_DBusData::fromInt32(typeData.y());

     dbusData = TQT_DBusData::fromStruct(members);

     return Success;
 }

And then can be used like this:

 TQPoint point(-10, 100);
 TQT_DBusMessage methodCall; // assume created by TQBusMessage::methodCall()

 TQT_DBusData dbusData;
 if (TQT_DBusDataConverter::convertToTQT_DBusData<TQPoint>(point, dbusData) != TQT_DBusDataConverter::Success)
 {
     // error handling
 }
 else
 {
     methodCall << dbusData;
 }
Parameters:
typeData the native type instance to get the content from
dbusData the binding's data instance to put the content into
Returns:
the conversion result value
template<>
TQT_DBusDataConverter::Result TQT_DBusDataConverter::convertToTQT_DBusData ( const TQRect &  typeData,
TQT_DBusData dbusData 
)
template<>
TQT_DBusDataConverter::Result TQT_DBusDataConverter::convertToTQT_DBusData ( const TQPoint &  typeData,
TQT_DBusData dbusData 
)
template<>
TQT_DBusDataConverter::Result TQT_DBusDataConverter::convertToTQT_DBusData ( const TQSize &  typeData,
TQT_DBusData dbusData 
)

The documentation for this class was generated from the following files: