Inside Macintosh: QuickDraw GX Objects /

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

View Device Functions / Creating and Manipulating View Device Objects

GXEqualViewDevice

You can use the GXEqualViewDevice function to determine whether two view device objects are equal.

boolean GXEqualViewDevice(gxViewDevice one, gxViewDevice two);

one

A reference to one view device to test for equality.

two

A reference to another view device to test for equality.

function result

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

DESCRIPTION

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

For two view device objects to be equal, they must have identical clips, mappings, bitmap shapes, and attributes. They also must be in the same view group, represent the same Macintosh graphics device (same GDevice record), and point to the same pixel image, color set, and color profile. The view device objects are not equal if they point to different but equivalent pixel images, color sets, or color profiles. The tag lists of the view devices need not be identical.

ERRORS, WARNINGS, AND NOTICES

Errors
invalid_viewDevice_reference

SEE ALSO

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

Macintosh graphics devices and the GDevice record are described in Inside Macintosh: Imaging With QuickDraw. The relationship of view devices to GDevice records is discussed in the Macintosh environment chapter of Inside Macintosh: QuickDraw GX Environment and Utilities.