GetCollectionItemInfo

GetCollectionItemInfo
Header:	Collections.h		Carbon status:	Supported

Obtains information about a specific collection item given the item’s collection tag and collection ID.

OSErr GetCollectionItemInfo (
    Collection c, 
    CollectionTag tag, 
    SInt32 id, 
    SInt32 *index, 
    SInt32 *itemSize, 
    SInt32 *attributes
);

c: A reference to the collection object containing the item you want to obtain information about. The behavior of this function is undefined if you do not provide a reference to a valid collection object.
tag: The collection tag associated with the item you want to obtain information about.
id: The collection ID associated with the item you want to obtain information about.
index: On return, this value represents the collection index of the specified item. You may specify the constant dontWantIndex for this parameter if you do not want to determine the specified item’s collection index.
itemSize: On return, this value indicates the size in bytes of the variable-length data associated with the specified item. You may specify the constant dontWantSize for this parameter to indicate that you do not want to determine the size of this data.
attributes: On return, this value contains a copy of the attributes associated with the specified item. You may specify the constant dontWantAttributes for this parameter if you do not want a copy of the item’s attributes.

function result: A result code.

DISCUSSION

This function returns information in the index, itemSize, and attributes parameters:

If you provide a pointer in the index parameter, the function uses this parameter to return the collection index of the specified item. Once you have determined an item’s collection index, you can use it to specify the item when calling Collection Manager functions, rather than using the item’s collection tag and collection ID. Specifying collection items using their collection index, rather than using the item’s collection tag and collection ID, generally results in improved performance.
If you provide a pointer in the itemSize parameter, the function uses this parameter to return the size in bytes of the variable-length data associated with the specified collection item.
If you provide a pointer in the attributes parameter, the function uses this parameter to return a copy of the attributes associated with the specified collection item.

To obtain information about a collection item using the collection index to specify the item, use the GetIndexedCollectionItemInfo function.

To obtain information about a collection item using the tag and whichItem parameters to specify the item, use the GetTaggedCollectionItemInfo function.

AVAILABILITY

Supported in Carbon. Available in Mac OS 8.1 and later when Carbon 1.0.2 or later is present.