The GWM Extension

A Graphics Window Manager (GWM) widget is a window that conventional (i.e. non-event driven) programs that use Starlink graphics packages (e.g., GKS, SGS, PGPLOT, NCAR, IDI etc.) can use to plot in on X windows displays. GWM is described in SUN/130. The gwm widget makes it possible to integrate GKS and IDI based graphics with user interfaces written in Tcl and Tk. It also has commands for dumping its contents in JPEG, PostScript or LJ250 inkjet format, changing the colour lookup table, clearing the window, scrolling the window and displaying a cross hair that covers full width and height of the window.

The GWM canvas item turns an area of a canvas widget into a GWM window; this provides similar functionality to the GWM widget but also allows other canvas items (lines, polygons, etc.) to be overlayed on the window and therefore graphics from external programs and element created and minipulated by Tk to be mixed.