MArrayDataHandle Class Reference
[OpenMaya - API module for common classes]

#include <MArrayDataHandle.h>

List of all members.

Detailed Description

Data block handle for array data.

An MArrayDataHandle is a smart pointer into a data block (MDataBlock) that handles access to array data. MArrayDataHandle supports attributes that can have an array of data.

The array indices do not have to be continuous. The array can be sparse. Thus, an array could have four elements with the indicies 1, 6, 8, and 10.

MArrayDataHandle methods cannot be assumed to be threadsafe. The jumpToElement() method sets an internal pointer so definitely cannot be called by multiple threads simultaneously.

Examples:

anisotropicShader.cpp, apiMeshShape.cpp, apiMeshShape.h, backfillShader.cpp, dynExprField.cpp, fullLoftNode.cpp, geometrySurfaceConstraint.cpp, lambertShader.cpp, multiCurveNode.cpp, ownerEmitter.cpp, ownerEmitter.h, phongShader.cpp, shadowMatteShader.cpp, simpleEmitter.cpp, simpleEmitter.h, stringFormatNode.cpp, sweptEmitter.cpp, sweptEmitter.h, testNucleusNode.cpp, torusField.cpp, and weightListNode.cpp.


Public Member Functions
  MArrayDataHandle (const MDataHandle &in, MStatus *ReturnStatus=NULL)
MDataHandle  inputValue (MStatus *ReturnStatus=NULL)
MDataHandle  outputValue (MStatus *ReturnStatus=NULL)
MArrayDataHandle  inputArrayValue (MStatus *ReturnStatus=NULL)
MArrayDataHandle  outputArrayValue (MStatus *ReturnStatus=NULL)
MStatus  next ()
unsigned int  elementCount (MStatus *ReturnStatus=NULL)
unsigned int  elementIndex (MStatus *ReturnStatus=NULL)
MStatus  jumpToElement (unsigned int index)
MStatus  jumpToArrayElement (unsigned int position)
MStatus  setClean ()
MStatus  setAllClean ()
MArrayDataBuilder  builder (MStatus *ReturnStatus=NULL)
MStatus  set (MArrayDataBuilder &builder)
MArrayDataHandle &  operator= (const MArrayDataHandle &other)

Friends
class  MDataBlock
class  MArrayDataBuilder

Constructor & Destructor Documentation

MArrayDataHandle::MArrayDataHandle ( const MDataHandle &  in,
MStatus *  ReturnStatus = NULL  
)

Copy constructor. Creates an new array data handle from the specified data handle.

This method can be used to access an array attribute that is a child of a compound array. Example: weightList[].weights[]

This method will only work for data handles to attributes that are arrays.

Parameters:
[in]  in  Handle to the child array attribute.
[out]  ReturnStatus  return status
Status Codes:
  • kSuccess operation successful
  • kInvalidParameter source handle is null or is not an array

Member Function Documentation

MDataHandle MArrayDataHandle::inputValue ( MStatus *  ReturnStatus = NULL  ) 

Gets a handle into this data block for the current array element. The data represented by the handle will be valid. If the data is from an dirty connection, then the connection will be evaluated.

It is important to note that you can not call inputValue on an element that is greater than the elementCount in this arrayDataHandle. That is, calls to inputValue must be protected by a call to elementCount to ensure the element exists. If this is not done, the call to inputValue will fail with an invalidParameter error.

Parameters:
[out]  ReturnStatus  return status
Returns:
Data handle for the current element's data
Status Codes:
  • kSuccess operation successful
  • kInvalidParameter the requested element is out of range
  • kFailure an object error has occurred
Examples:
anisotropicShader.cpp, backfillShader.cpp, dynExprField.cpp, fullLoftNode.cpp, geometrySurfaceConstraint.cpp, lambertShader.cpp, ownerEmitter.h, phongShader.cpp, shadowMatteShader.cpp, simpleEmitter.h, stringFormatNode.cpp, sweptEmitter.h, testNucleusNode.cpp, torusField.cpp, and weightListNode.cpp.

MDataHandle MArrayDataHandle::outputValue ( MStatus *  ReturnStatus = NULL  ) 

Gets a handle into this data block for the current array element. The data is not guaranteed to be valid. Therefore, this handle should only be used for writing over the data.

Parameters:
[out]  ReturnStatus  return status
Returns:
Data handle for the current element's data
Status Codes:
  • kSuccess operation successful
  • kFailure an object error has occurred
Examples:
apiMeshShape.cpp.

MArrayDataHandle MArrayDataHandle::inputArrayValue ( MStatus *  ReturnStatus = NULL  ) 

Gets a handle into this data block for the current array element. This method should be used when the array elements are also arrays. The data represented by the handle will be valid. If the data is from an dirty connection, then the connection will be evailuated.

It is important to note that you can not call inputArrayValue on an element that is greater than the elementCount in this arrayDataHandle. That is, calls to inputValue must be protected by a call to elementCount to ensure the element exists. If this is not done, the the call to inputArrayValue will fail with an invalidParameter error.

Parameters:
[out]  ReturnStatus  return status
Returns:
Data handle for the current element's data
Status Codes:
  • kSuccess operation successful
  • kInvalidParameter the current item is not an array or the requested element is out of range.
  • kFailure an object error has occurred
Examples:
apiMeshShape.cpp.

MArrayDataHandle MArrayDataHandle::outputArrayValue ( MStatus *  ReturnStatus = NULL  ) 

Gets a handle into this data block for the current array element. This method should be used when the array elements are also arrays. The data is not guaranteed to be valid. Therefore, this handle should only be used for writing over the data.

Parameters:
[out]  ReturnStatus  return status
Returns:
Data handle for the current element's data
Status Codes:
  • kSuccess operation successful
  • kInvalidParameter the current item is not an array
  • kFailure an object error has occurred

MStatus MArrayDataHandle::next (  ) 

Advance to the next element in the array. These may be sparse arrays so the next consecutive element may not necessarily have a consecutive index.

Returns:
Examples:
anisotropicShader.cpp, apiMeshShape.cpp, backfillShader.cpp, fullLoftNode.cpp, geometrySurfaceConstraint.cpp, lambertShader.cpp, phongShader.cpp, and shadowMatteShader.cpp.

unsigned int MArrayDataHandle::elementCount ( MStatus *  ReturnStatus = NULL  ) 

Returns the number of elements in the array.

Parameters:
[out]  ReturnStatus  return status
Returns:
The number of elements
Status Codes:
  • kSuccess operation successful
  • kFailure an object error has occurred
Examples:
anisotropicShader.cpp, backfillShader.cpp, fullLoftNode.cpp, geometrySurfaceConstraint.cpp, lambertShader.cpp, phongShader.cpp, shadowMatteShader.cpp, and weightListNode.cpp.

unsigned int MArrayDataHandle::elementIndex ( MStatus *  ReturnStatus = NULL  ) 

Returns the index that we are currently at in the array. It is possible for the index to be invalid, in which case the return status will report an error. These may be sparse arrays so the element index returned will be a logical index.

Parameters:
[out]  ReturnStatus  return status
Returns:
The current element's logical index
Status Codes:
  • kSuccess operation successful
  • kFailure current element has an invalid index, or this function set has an invalid object
Examples:
apiMeshShape.cpp.

MStatus MArrayDataHandle::jumpToElement ( unsigned int  index  ) 

Jump to a specific element in the array. The array is sparse, so the indices may not be consecutive.

NOTE: The index is the logical element index, which may be sparse. Jumping to an element is done through a binary search.

Parameters:
[in]  index  the logical index to jump to
Returns:
Status code
Status Codes:
Examples:
dynExprField.cpp, fullLoftNode.cpp, ownerEmitter.h, simpleEmitter.h, stringFormatNode.cpp, sweptEmitter.h, testNucleusNode.cpp, torusField.cpp, and weightListNode.cpp.

MStatus MArrayDataHandle::jumpToArrayElement ( unsigned int  position  ) 

Jump to a specific array element in the array. This method can be used to iterate over the entire array.

NOTE: Jumping to an array element does not require a search, since the array indices are non-sparse. The MArrayDataHandle::elementIndex() method can be used to determine the logical index related to the current array index.

Parameters:
[in]  position  the array position to jump to
Returns:
Status code
Status Codes:
Examples:
weightListNode.cpp.

MStatus MArrayDataHandle::setClean (  ) 

Marks the data that is represented by this handle as being clean. This should be done after recalculating the data from the inputs.

Returns:
Return status
Status Codes:
  • kSuccess operation successful
  • kFailure an object error has occurred

MStatus MArrayDataHandle::setAllClean (  ) 

Marks every element of the array attribute represented by the handle as clean. This method should be used if a compute function is asked to compute a single element of a multi, but instead calculates all the elements. Calling setAllClean in this situation will prevent further calls to the node's compute method for the other elements of the multi.

Returns:
Return status
Status Codes:
  • kSuccess operation successful
  • kFailure an object error has occurred
Examples:
apiMeshShape.cpp, and multiCurveNode.cpp.

MArrayDataBuilder MArrayDataHandle::builder ( MStatus *  ReturnStatus = NULL  ) 

Returns a builder for this handle's array so that it can be expanded.

This method will fail if the current array does not support array data builders. This can be changed in a node's initialize routine using the setUsesArrayDataBuilder method in MFnAttribute.

Parameters:
[out]  ReturnStatus  return status
Returns:
The builder object
Status Codes:
  • kSuccess operation successful
  • kInvalidParameter This item does not support array data builders
  • kFailure an object error has occurred
Examples:
apiMeshShape.cpp, ownerEmitter.cpp, simpleEmitter.cpp, sweptEmitter.cpp, and torusField.cpp.

MStatus MArrayDataHandle::set ( MArrayDataBuilder &  builder  ) 

Sets the data for this array from the data in the builder object

Parameters:
[in]  builder  the builder object
Returns:
Return status
Status Codes:
  • kSuccess operation successful
  • kInvalidParameter the builder passed is invalid
  • kFailure an object error has occurred
Examples:
apiMeshShape.cpp, and multiCurveNode.cpp.

MArrayDataHandle & MArrayDataHandle::operator= ( const MArrayDataHandle &  other  )  [inline]

/fn MArrayDataHandle::MArrayDataHandle( const MArrayDataHandle &other )

Copy constructor.

Assignment operator.

Parameters:
[in]  other  the source object to copy from.
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