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From: sundar@ai.mit.edu (Sundar Narasimhan)
Newsgroups: comp.windows.x
Subject: Re: Help - resizing Athena widgets
Keywords: resizing widget AthenaHello,
Message-ID: <12608@life.ai.mit.edu>
Date: 4 Jan 91 07:34:24 GMT
References: <1991Jan3.053442.6086@mel.dit.csiro.au>
Sender: news@ai.mit.edu
Reply-To: sundar@ai.mit.edu
Organization: MIT Artificial Intelligence Laboratory
Lines: 149

In article <1991Jan3.053442.6086@mel.dit.csiro.au>, kmy@mel.dit.csiro.au (Kid Mun Yap) writes:
|> 
|> I am currently writing a program using the Athena widget set
|> and have found that resizing one of the children of a certain
|> form widget does not cause it (the form widget) to resize itself,
|> hence causing the child to be clipped off at the right hand edge.
I have used something like the following to take care of this for
some time now and am posting it now since I've seen a couple of
posts refer to how difficult dealing with the Form widget's layout
code can be (especially after Resizes). The xt_equalize_geometry() 
function takes a list of widgets, and a direction (either XtNwidth
or XtNheight), finds out the widget with the maximum width or height 
and resizes every widget in the list to that size.

Of course, the idea can be generalized to do other things. (I've
found that with this function I can get around most of the resize
hackery in the Athena Form widget).

Good Luck!
------------------------------------------------------------------
struct _xt_widget_list {
    struct _xt_widget_list *next;
    Widget widget;
};

typedef struct _xt_widget_list *xt_widget_list;
xt_widget_list xt_create_list();

#define W_MAXARGS     20
#define W_STRSIZ      256

xt_equalize_geometry(direction, list)
char *direction;			/* XtNwidth/XtNheight */
xt_widget_list list;
{
    xt_widget_list l;
    Arg args[W_MAXARGS];
    int i = 0;
    Dimension width, height, borderwidth;
    int maxvalue = 0;
    int widflag = 0;

    xt_set_args(args, &i, W_MAXARGS, 
		XtNwidth, &width,
		XtNheight, &height,
		XtNborderWidth, &borderwidth,
		NULL);
    if(strcmp(direction, XtNwidth) == 0) 
      widflag = 1;

    for(l = list; l != NULL; l = l->next) {
	XtGetValues(l->widget, args, i);
	if(widflag) {
	    if (maxvalue < width) maxvalue = width;
	} else
	  if(maxvalue < height) maxvalue = height;
    }

    for(l = list; l != NULL; l = l->next) {
	XtGetValues(l->widget, args, i);
	XtResizeWidget(l->widget, (widflag == 1) ? maxvalue : width,
		       (widflag == 1) ? height : maxvalue,
		       borderwidth);
    }
    return(maxvalue);
}

/*VARARGS*/
xt_set_args(args, i, maxval, va_alist)
Arg args[];
int *i;
int maxval;
va_dcl
{
    va_list  var;
    int      argno;
    String argstr;
    XtArgVal argval;

    va_start(var);
    
    argstr = va_arg(var, char *);

    if(i != NULL) argno = *i;
    else argno = 0;

    while(argstr) {
	argval = va_arg(var, XtArgVal);
	if((argno + 1) > maxval) {
	    fprintf(stderr, "xt_set_args: Arg array overflowed!\n");
	    va_end(var);
	    return -1;
	}
	XtSetArg(args[argno], argstr, argval);
	if(i != NULL)
	  *i = ++argno;
	argstr = va_arg(var, char *);
    }
    va_end(var);
    return 0;
}

/*VARARGS*/
xt_widget_list
xt_create_list(list, va_alist)
xt_widget_list list;
va_dcl
{
    va_list var;
    Widget  w;
    xt_widget_list retval, l;

    va_start(var);
    
    if(list != NULL) retval = list;
    else retval = NULL;

    w = va_arg(var, Widget);
    while(w) {
	l = (xt_widget_list) calloc(sizeof(*retval), 1);
	if(l == NULL) {
	    fprintf(stderr, "create_list: calloc failure\n");
	    exit(0);
	}
	l->widget = w;
	l->next = NULL;

	if(retval == NULL) 
	  retval = l;
	else {
	    l->next = retval;
	    retval = l;
	}
	w = va_arg(var, Widget);
    }
    va_end(var);
    return(retval);
}

xt_free_list(l)
xt_widget_list l;
{
    xt_widget_list temp;
    while(l) {
	temp = l;
	l = l->next;
	free((char *)temp);
    }
}