Volume 6A: Motif Programming Manual

XmALIGNMENT_BASELINE_TOP

XmALIGNMENT_CONTENTS_BOTTOM

XmALIGNMENT_CENTER

XmALIGNMENT_CONTENTS_TOP

The resource only takes effect when the children of the RowColumn are arranged in rows, which means that the

XmNorientation is XmHORIZONTAL. The default value is XmALIGNMENT_CENTER, which causes the center of

all of the children in a row to be aligned.

12.1.6 Multi−line and Multi−font Labels

The fonts used within a Label are directly associated with the font list element tags used in the compound string

specified for the XmNlabelString resource. The XmNfontList resource for a Label specifies the mapping

between font list tags and font names that is used when displaying the text. Since a compound string may use multiple

character sets, a Label can display any number of fonts, as specified in the XmNlabelString for the Label. A

compound string may also contain embedded newlines. the source code shows the use of a Label to display a single

compound string that contains a monthly calendar. XtSetLanguageProc() is only available in X11R5; there is

no corresponding function in X11R4. XmFontListEntryCreate() is only available in Motif 1.2; there is no

corresponding function in Motif 1.1. XmFontListAppendEntry() is only available in Motif 1.2;

XmFontListCreate() and XmFontListAdd() are the corresponding functions in Motif 1.1.

XmFONTLIST_DEFAULT_TAG replaces XmSTRING_DEFAULT_CHARSET in Motif 1.2.

/* xcal.c −− display a monthly calendar. The month displayed is a

* single Label widget whose text is generated from the output of

* the "cal" program found on any UNIX machine. popen() is used

* to run the program and read its output. Although this is an

* inefficient method for getting the output of a separate program,

* it suffices for demonstration purposes. A List widget displays

* the months and the user can provide the year as argv[1].

*/

#include <stdio.h>

#include <X11/Xos.h>

#include <Xm/List.h>

#include <Xm/Frame.h>

#include <Xm/LabelG.h>

#include <Xm/RowColumn.h>

#include <Xm/SeparatoG.h>

int year;

XmStringTable ArgvToXmStringTable();

void FreeXmStringTable();

char *months[] = {

"January", "February", "March", "April", "May", "June",

"July", "August", "September", "October", "November", "December"

};

main(argc, argv)

int argc;

char *argv[];

{

Widget toplevel, frame, rowcol, label, w;

XtAppContext app;

Display *dpy;

extern void set_month();

XmFontList fontlist;

XmFontListEntry entry;

12 Labels and Buttons 12.1.6 Multi−line and Multi−font Labels

310

XFontStruct *font;

XmStringTable strs;

int month_no;

XtSetLanguageProc (NULL, NULL, NULL);

toplevel = XtVaAppInitialize (&app, "Demos", NULL, 0,

&argc, argv, NULL, NULL);

/* Create a fontlist based on the fonts we're using. These are the

* fonts that are going to be hardcoded in the Label and List widgets.

*/

dpy = XtDisplay (toplevel);

font = XLoadQueryFont (dpy, "−*−courier−bold−r−*−−18−*");

entry = XmFontListEntryCreate ("tag1", XmFONT_IS_FONT, font);

fontlist = XmFontListAppendEntry (NULL, entry);

font = XLoadQueryFont (dpy, "−*−courier−medium−r−*−−18−*");

entry = XmFontListEntryCreate ("tag2", XmFONT_IS_FONT, font);

fontlist = XmFontListAppendEntry (fontlist, entry);

XtFree (entry);

if (argc > 1) {

month_no = 1;

year = atoi (argv[1]);

}

else {

long time(), t = time(0);

struct tm *today = localtime (&t);

year = 1900 + today−>tm_year;

month_no = today−>tm_mon+1;

}

/* The RowColumn is the general layout manager for the application.

* It contains two children: a Label gadget that displays the calendar

* month, and a ScrolledList to allow the user to change the month.

*/

rowcol = XtVaCreateWidget ("rowcol",

xmRowColumnWidgetClass, toplevel,

XmNorientation, XmHORIZONTAL,

NULL);

/* enclose the month in a Frame for decoration. */

frame = XtVaCreateManagedWidget ("frame",

xmFrameWidgetClass, rowcol, NULL);

label = XtVaCreateManagedWidget ("month",

xmLabelGadgetClass, frame,

XmNalignment, XmALIGNMENT_BEGINNING,

XmNfontList, fontlist,

NULL);

/* create a list of month names */

strs = ArgvToXmStringTable (XtNumber (months), months);

w = XmCreateScrolledList (rowcol, "list", NULL, 0);

XtVaSetValues (w,

XmNitems, strs,

XmNitemCount, XtNumber(months),

XmNfontList, fontlist,

NULL);

FreeXmStringTable (strs);

XmFontListFree (fontlist);

XtAddCallback (w, XmNbrowseSelectionCallback, set_month, label);

12 Labels and Buttons 12.1.6 Multi−line and Multi−font Labels

311

XtManageChild (w);

XmListSelectPos (w, month_no, True); /* initialize month */

XtManageChild (rowcol);

XtRealizeWidget (toplevel);

XtAppMainLoop (app);

}

/* callback function for the List widget −− change the month */

void

set_month(w, client_data, call_data)

Widget w;

XtPointer client_data;

XtPointer call_data;

{

register FILE *pp;

extern FILE *popen();

char text[BUFSIZ];

register char *p = text;

XmString str;

Widget label = (Widget) client_data;

XmListCallbackStruct *list_cbs =

(XmListCallbackStruct *) call_data;

/* Ask UNIX to execute the "cal" command and read its output */

sprintf (text, "cal %d %d", list_cbs−>item_position, year);

if (!(pp = popen (text, "r"))) {

perror (text);

return;

}

*p = 0;

while (fgets (p, sizeof (text) − strlen (text), pp))

p += strlen (p);

pclose (pp);

/* display the month using the "tag1" font from the

* Label gadget's XmNfontList.

*/

str = XmStringCreateLtoR (text, "tag1");

XtVaSetValues (label, XmNlabelString, str, NULL);

XmStringFree (str);

}

/* Convert an array of string to an array of compound strings */

XmStringTable

ArgvToXmStringTable(argc, argv)

int argc;

char **argv;

{

XmStringTable new =

(XmStringTable) XtMalloc ((argc+1) * sizeof (XmString));

if (!new)

return (XmStringTable) NULL;

new[argc] = 0;

while (−−argc >= 0)

new[argc] = XmStringCreate (argv[argc], "tag2");

return new;

}

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312