MMTPType Class Reference
Defines the generic MTP data type interface. All non-opaque MTP data comprises either a single atomic value of a simple type, or a set of atomic simple type values organised according to some dataset structure. Structured datasets may take one of the following general forms:
1. Flat - a contiguous collection of values. 2. Complex - a contiguous array or string of values. 3. Compound - a mixed sequence of simple, flat, and complex types.
Any time data is passed as a parameter to an MTP operation, response or event; or any time data is passed in the data phase of a fully described operation, that data must be of a type that implements the generic MTP data type interface.
Member Functions Documentation
CommitChunkL(TPtr8 &)
Commits the specified write data chunk. This method should only be invoked if the type indicates that committing data is required (
CommitRequired). Generally this would only be required by types which are performing intermediate buffering, e.g. a file data object.
- leave
- KErrNotSupported, if the type does not support data commit.
- leave
- KMTPDataTypeInvalid, if the data type is structurally invalid.
- leave
- One of the system wide error codes, if a general processing error occurs.
CommitRequired Parameters
| TPtr8 & aChunk | The data chunk to be commited. |
CommitRequired()
| IMPORT_C TBool | CommitRequired | ( | ) | const [virtual] |
Indicates if the data type requires that data be committed during data write sequences. Generally this would only be required by types which perform intermediate buffering (e.g. a file data object), or by data types whose final structure is determined by the value of meta data elements within the data stream itself (e.g an MTP ObjectPropDesc dataset). CommitChunkL ChunkWritePtr
CopyL(const MMTPType &, MMTPType &)
Copies the data from one MTP data type object to another. This is accomplished by attaching read and write data streams from the source object to the sink object. The source and sink objects are not required to be of the same type and no type compatibility checking is performed.
- leave
- One of the system wide error codes, if a general processing error occurs.
Parameters
| const MMTPType & aFrom | The MTP source data type object. |
| MMTPType & aTo | The MTP source data type object. |
FirstReadChunk(TPtrC8 &)
|
TInt
| FirstReadChunk | ( | TPtrC8 & | aChunk | ) | const [pure virtual] |
Initiates a data read sequence on the type by providing a const pointer to the first in the sequence of data chunks that make up the type's data stream. Subsequent chunks in the sequence can be sequentially retrieved using NextReadChunk. NextReadChunk.
Parameters
| TPtrC8 & aChunk | The const pointer to be set to point to the start of the first data chunk. This pointer's length is set to zero if no data chunk exists or a processing error occurs. |
FirstWriteChunk(TPtr8 &)
|
TInt
| FirstWriteChunk | ( | TPtr8 & | aChunk | ) | [pure virtual] |
Initiates a data write sequence on the type by providing a non-const pointer to the first in the sequence of data chunks that make up the type's data stream. Subsequent chunks in the sequence can be sequentially retrieved using NextWriteChunk. NextWriteChunk.
Parameters
| TPtr8 & aChunk | The non-const pointer to be set to point to the start of the first data chunk. If successful, the pointer's Length is set to zero, and MaxLength is set to the available capacity of the data chunk. If not successful, the pointer's MaxLength is set to zero. |
FirstWriteChunk(TPtr8 &, TUint)
| IMPORT_C TInt | FirstWriteChunk | ( | TPtr8 & | aChunk, |
| | TUint | aDataLength |
| | ) | [virtual] |
GetExtendedInterface(TUid)
| IMPORT_C TAny * | GetExtendedInterface | ( | TUid | aInterfaceUid | ) | [virtual] |
Provides an MTP data type extension interface implementation for the specified interface Uid.
Parameters
| TUid aInterfaceUid | The unique identifier for the extension interface being requested. |
NextReadChunk(TPtrC8 &)
|
TInt
| NextReadChunk | ( | TPtrC8 & | aChunk | ) | const [pure virtual] |
Continues a data read sequence on the type by providing a const pointer to the next in the sequence of data chunks that make up the type's data stream. This data read sequence should have been previously initiated by invoking FirstReadChunk. FirstReadChunk.
Parameters
| TPtrC8 & aChunk | The const pointer to be set to point to the start of the next data chunk. This pointer's length is set to zero if no data chunk exists or a processing error occurs. |
NextWriteChunk(TPtr8 &)
|
TInt
| NextWriteChunk | ( | TPtr8 & | aChunk | ) | [pure virtual] |
Continues a data write sequence on the type by providing a non-const pointer to the next in the sequence of data chunks that make up the type's data stream. This data write sequence should have been previously initiated by invoking FirstWriteChunk. FirstReadChunk.
Parameters
| TPtr8 & aChunk | The non-const pointer to be set to point to the start of the next data chunk. If successful, the pointer's Length is set to zero, and MaxLength is set to the available capacity of the data chunk. If not successful, the pointer's MaxLength is set to zero.. |
NextWriteChunk(TPtr8 &, TUint)
| IMPORT_C TInt | NextWriteChunk | ( | TPtr8 & | aChunk, |
| | TUint | aDataLength |
| | ) | [virtual] |
ReserveTransportHeader(TUint, TPtr8 &)
| IMPORT_C TBool | ReserveTransportHeader | ( | TUint | aHeaderLength, |
| | TPtr8 & | aHeader |
| | ) | [virtual] |
Size()
Provides the size in bytes of the MTP data type.
Type()
|
TUint
| Type | ( | ) | const [pure virtual] |
Provides the MTP data type identification datacode.
Validate()
| IMPORT_C TInt | Validate | ( | ) | const [virtual] |
Validates the structural integrity of the data type. This method can be invoked on completion of a data write sequence to validate that the received data represents a structurally valid instance of the data type.
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