Path: utzoo!attcan!uunet!lll-winken!ames!mailrus!cornell!rochester!udel!burdvax!coltoff
From: coltoff@PRC.Unisys.COM (Joel Coltoff)
Newsgroups: comp.windows.x
Subject: Help needed with GC's
Keywords: I'm stuck again
Message-ID: <8937@burdvax.PRC.Unisys.COM>
Date: 13 Jan 89 21:55:22 GMT
Distribution: na
Organization: Unisys/Paoli Research Center, Paoli, PA 19301
Lines: 35

First let me apologize if you get two copies of this. I cancelled the
first one but in looking at news queues it doesn't appear as though
it worked. Now to the matter at hand.

I stuck on a small problem with GC's and could use somebody's help.
My interface uses a text widget to supply information to and get responses
from a user. In some cases I need to the user to highlight multiple lines.
This means I need to manage the highlighting and slection mechanisms by
myself. The current code looks like this.

		*
		*
/*
 * Copy the selected line to itself but invert the area.
*/
	gc = DefaultGCOfScreen(XtScreen(w));
	XSetFunction(XtDisplay(w), gc, GXcopyInverted);
	XCopyArea(XtDisplay(w), XtWindow(w), XtWindow(w), gc,
		Xpos, Ypos, barWidth, barHeight, Xpos, Ypos );
	XSetFunction(XtDisplay(w), gc, GXcopy);
/*
 * Mark the current line as being selected.
*/
		*
		*

This works just great in monochrome but gives the wrong result in color.
What I want to know is what is quickest way to swap the foreground and
background pixels of a given rectangle that works on both monochrome and
color monitors? It is possible, but not convenient, to get the text on
the slected line and redraw it. Thanks in advance.
-- 
	- Joel
		{psuvax1,sdcrdcf}!burdvax!coltoff	(UUCP)
		coltoff@burdvax.prc.unisys.com		(ARPA)