Inside Macintosh: QuickDraw GX Objects /

Chapter 7 - View-Related Objects / View-Related Objects Reference

View Port Functions / Creating and Manipulating View Port Objects

GXEqualViewPort

You can use the GXEqualViewPort function to determine whether two view port objects are equal.

boolean GXEqualViewPort(gxViewPort one, gxViewPort two);

one

A reference to a view port to test for equality.

two

A reference to another view port to test for equality.

function result

true if the view port specified by the one parameter is equal to the view port specified by the two parameter; false otherwise.

DESCRIPTION

The GXEqualViewPort function returns as its function result a Boolean value indicating whether the view port object specified by the one parameter is equal to the view port object specified by the two parameter.

For two view port objects to be equal, they must have identical mappings, clips, dithers, halftones, and attributes. They also must have the same parent view port, if any, and (therefore) be in the same view group. If one view port is attached to a window, the other view port must be attached to the same window. The tag lists or child view ports of the view ports need not be identical.

ERRORS, WARNINGS, AND NOTICES

Errors
invalid_viewPort_reference

SEE ALSO

To make a copy of a view port object that is equal by the criteria of this function, use the GXCopyToViewPort function, described in the previous section.