If the container field were in it's own window, you could size the window and the container field's auto-size anchors could size it to that of the window. you'd have to modify the calculated dimensions of the window to be the container size plus the added borders around the window, but this seems possible to do.
But sizing a container field inside a layout to different sizes isn't really possible except for using sliding fields to shrink a large container down to a smaller size--and then only when printing, previewing or saving as PDF.
To set a container field to resize in this second context, you must:
- Use the Inspector's data tab to set the container fields alignment to Top, left, rather than the default center, center alignment.
- Use the position tab to set the container field to slide up and to resize the enclosing part.
- Set all layout objects in the same layout part to also slide up and resize.
Thanks. I was trying to do it in a layout mainly for aesthetic purposes & to give people an idea of what this or that print will look when framed and matted. It appears like what I'm trying to do may not be possible, in this layout anyway, since I would need the container to slide left when it's a vertical image and up when it's a horizontal image. It would require a complete overhaul of the layout so, probably, not going to work in this layout.
I does sound like I may be able to accomplish what I want by opening the image-container in it's own window? If so, that may be the best approach. I'll give that a try.