Inside Macintosh: 3D Graphics Programming With QuickDraw 3D /

Chapter 10 - Group Objects / Group Objects Reference

Group Objects Routines / Getting Group Positions

Q3Group_GetPreviousPositionOfType

You can use the Q3Group_GetPreviousPositionOfType function to get the position of the previous object of a particular type in a group.

TQ3Status Q3Group_GetPreviousPositionOfType (
TQ3GroupObject group, 
TQ3ObjectType isType, 
TQ3GroupPosition *position);

group

A group.

isType

An object type.

position

On entry, a pointer to a valid group position. On exit, a pointer to the position in the specified group of the next object that follows the object in that position and that has the specified type.

DESCRIPTION

The Q3Group_GetPreviousPositionOfType function returns, in the position parameter, the position in the group specified by the group parameter of the previous object that precedes the object having the position specified on entry in the position parameter and that has the type specified by the isType parameter. If the object specified on entry is the first object of that type in the group, Q3Group_GetNextPositionOfType returns the value NULL in the position parameter. Note that the type of the object in the position specified by the position parameter on entry to Q3Group_GetPreviousPositionOfType does not have to be the same as the type specified by the isType parameter.

ERRORS

kQ3ErrorInvalidObject
kQ3ErrorInvalidPositionForGroup
kQ3ErrorNULLParameter