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Autodocs
 Libraries:
 datatypes.library
  --background--
  --rexxhost--
  AddDTObject
  DisposeDTObject
  DoAsyncLayout
  DoDTMethodA
  DrawDTObjectA
  GetDTAttrsA
  GetDTMethods
  GetDTString
  GetDTTriggerMethods
  NewDTObjectA
  ObtainDTDrawInfoA
  ObtainDataTypeA
  PrintDTObjectA
  RefreshDTObjectA
  ReleaseDTDrawInfo
  ReleaseDataType
  RemoveDTObject
  SetDTAttrsA
Include
GuruMeditation
Docs » Autodocs » datatypes.library » NewDTObjectA

NAME

	NewDTObjectA - Create an data type object.              (V39)

SYNOPSIS

	o = NewDTObjectA (name, attrs);
d0 d0 a0
Object *NewDTObjectA (APTR, struct TagItem *);
o = NewDTObject (name, tag1, ...);
Object *NewDTObject (APTR, Tag tag1, ...);

FUNCTION

	This is the method for creating datatype objects from
'boopsi' classes. Boopsi' stands for "basic object-oriented
programming system for Intuition".)
You further specify initial "create-time" attributes for the
object via a TagItem list, and they are applied to the
resulting datatype object that is returned.

INPUTS

	name - Name of the data source.  Usually an existing file name.
attrs - Pointer to a taglist containing additional arguments.

TAGS

	DTA_SourceType - Specify the type of source data; such as coming
from a file or clipboard (defaults to DTST_FILE). If
source type is clipboard, then the name field contains the
numeric clipboard unit. If source type is DTST_MEMORY,
the name field will be ignored (V44).
DTA_Handle - Can optionally be used instead of the name field.
Must be a valid FileHandle if DTA_SourceType is DTST_FILE.
Must be a valid IFFHandle if DTA_SourceType is DTST_CLIPBOARD.
Will be ignored if DTA_SourceType is DTST_MEMORY.
DTA_DataType - Specify the class of data. Data is a pointer to a
valid DataType. This is only used when attempting to create
a new object that doesn't have any source data.
DTA_GroupID - Specify that the object must be of this type, or
NewDTObject() will fail with IoErr() of
ERROR_OBJECT_WRONG_TYPE.
DTA_SourceAddress (APTR) -- For DTST_MEMORY source data, this
specifies the memory address at which the source data is
located. This must be non-NULL. This attribute is required
for DTST_MEMORY source data (V44).
DTA_SourceSize (ULONG) -- For DTST_MEMORY source data, this
specifies the size of the source data (in bytes). This must
be greater than 0. This attribute is required for DTST_MEMORY
source data (V44).
GA_Left, GA_RelRight, GA_Top, GA_RelBottom, GA_Width, GA_RelWidth,
GA_Height, GA_RelHeight - Specify the placement of the object
within the destination window.
GA_ID - Specify the object ID.
GA_UserData - Specify the application specific data for the
object.

RESULT

	A boopsi object, which may be used in different contexts such
as a gadget or image, and may be manipulated by generic functions.
You eventually free the object using DisposeDTObject().
A NULL return indicates failure. Use IoErr() to get error value.
Following is a summary of the error number used and there meaning
as it relates to DataTypes.
ERROR_REQUIRED_ARG_MISSING - Indicates that a required attribute
wasn't passed in.
ERROR_BAD_NUMBER - An invalid group ID was passed in.
ERROR_OBJECT_WRONG_TYPE - Object data type doesn't match
DTA_GroupID.
ERROR_NO_FREE_STORE - Not enough memory.
DTERROR_UNKNOWN_DATATYPE - Unable to open the class library
associated with the data type.
DTERROR_COULDNT_OPEN - Unable to open the data object.
ERROR_NOT_IMPLEMENTED - Unknown handle type.

NOTES

	This function invokes the OM_NEW "method" for the class specified.
The DTST_MEMORY source type introduced in V44 makes in-memory
data available to subclasses as if the data were stored in a
file. Thus, subclasses will see the data as DTST_FILE. Since
the data does not correspond to an on-disk file, subclasses
and examine hook code must not assume that they will be able
to reopen the "file" whose data has been provided to them.

EXAMPLE

	STRPTR fileName = "s:startup-sequence"
Object *o;
/* Simplest use is to just open an existing file */
if (o = NewDTObject ((APTR)fileName, NULL))
{
/* Free the object when we are done with it */
DisposeDTObject (o);
}

SEE ALSO

AddDTObject(), DisposeDTObject(), RemoveDTObject(), intuition.library/NewObjectA

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$VER: d0.se 1.14 Copyright © 2011-2019 Tobias Geijersson support at d0 dot se