Test a basic CGM-to-PNG link, from a Application Structure with 'linkuri' APS Attribute within the CGM, to a whole PNG file, with no behaviors or fragments associated with the link.

At the start of the test, the right-hand frame should display a CGM containing a simple picture with a blue-filled square on the left and a green-filled circle on the right, both with thick black borders. The circle is contained within an Application Structure, with id value of "myObjId". The APS contains a single APS Attribute of type 'linkuri', whose first parameter points to a local PNG file, and whose 2nd and 3rd parameters are null.

To execute the hyperlink, move the mouse anywhere over the circle and click the left mouse button. Because there is no "picture behavior" on the link-bearing object in the CGM instance, correct viewer handling of the link will result in image of the target PNG file replacing the CGM picture in the right-hand frame. This is the default WebCGM picture behavior. You should be able to use the browser "Back" and "Forward" buttons to go back and forth between the target PNG image and the source CGM picture in the right-hand frame. Note, however, that this latter normal browser behavior is not part of the WebCGM standard, and it is not a pass/fail criterion for WebCGM viewers for this test.

Viewers are required to give visual feedback to the user that a successful pick has occurred, and an indication of the particular object which has been picked. The exact method of feedback is viewer dependent.

The initial view in the left-hand frame is a PNG reference image of the target PNG image which should appear in the right-hand frame upon activating the link in the WebCGM source instance. There should be no significant visual deviation between the reference image of the left frame and the view in the right frame after link activation.