[comp.sys.mac.programmer] Finding screensize from within an xWindow in Hypercard

jcocon@hubcap.clemson.edu (james c oconnor) (03/28/91)

Is there a good reason not to use the global screenBits.bounds to find
out the screen size?  I am trying to, and it isn't stable for me.  Does
anyone know if that is normal, or have I got something randomly changing
memory and am just lucky that it hits that and not any of the other
running apps?

Jim

christer@cs.umu.se (Christer Ericson) (03/29/91)

In article <1991Mar27.200633.17639@hubcap.clemson.edu> jcocon@hubcap.clemson.edu (james c oconnor) writes:
>Is there a good reason not to use the global screenBits.bounds to find
>out the screen size?  I am trying to, and it isn't stable for me.  Does
>anyone know if that is normal, or have I got something randomly changing
>memory and am just lucky that it hits that and not any of the other
>running apps?

A good reason not to use screenBits.bounds is that there are multiple
screen machines around. For example, if you use screenBits.bounds when
calling DragWindow your window will be locked to one of the screens. The
right thing to do is to call GetGrayRgn and use the bounding box of that
region. This is explained on pages 121 and 205 in IM V.

>Jim


| Christer Ericson                            Internet: christer@cs.umu.se |
| Department of Computer Science, University of Umea, S-90187 UMEA, Sweden |