This function provides an interface to setting or retrieving many of the individual
attributes of a widget's underlying image. For example, IWidget_SetImageParm() could be
used to establish the position of an image within its enclosing border, or used to
retrieved the AEERasterOp
identifying how the pixel data of the image will behave.
Image attributes are managed through a parameter block interface, with the parameter
block identifying the attribute to be accessed, as well as the values associated with
that attribute. Again, to illustrate, the attribute of image size is identified by
the constant IPARM_SIZE, as well as a pair of values that specify the horizontal
width and vertical height of the image. These items are collected in the ImageParm
data structure, with this structure then passed to IWidget_SetImageParm() to set (or get)
a given attribute.