Inside Macintosh: QuickDraw GX Objects /

Chapter 6 - Transform Objects / Transform Objects Reference

Functions / Getting and Setting the View Port List

GXGetTransformViewPorts

You can use the GXGetTransformViewPorts function to retrieve the view port list of a transform object.

long GXGetTransformViewPorts(gxTransform source, 
                              gxViewPort list[]);

source

A reference to the transform object whose view port list you want to examine.

list

An array of view port references. On return, the array contains the view port list of the source transform.

function result

The number of view ports in the source transform's view port list.

DESCRIPTION

The GXGetTransformViewPorts function copies the list of view port references in the source transform into the array referenced by the list parameter, and returns as the function result the total number of view port references in the list.

If you pass nil for the list parameter, the function returns the number of view ports as the function result, but does not return the references to the view ports. Thus you normally call this function twice: once to determine the size of view port array to allocate, and once to retrieve the array itself.

SPECIAL CONSIDERATIONS

This function returns all view port references in the source transform's view port list, including any invalid ones (for view ports that have been disposed of).

ERRORS, WARNINGS, AND NOTICES

Errors
out_of_memory
transform_is_nil
Notices (debugging version)
transform_references_disposed_viewPort

SEE ALSO

For an example of the use of this function, see Listing 6-6 on page 6-29.

To assign a view port list to a transform object, use the GXSetTransformViewPorts function, described next.

To retrieve the view port list of the transform object associated with a specified shape, use the GXGetShapeViewPorts function, described on page 6-75.