sz@cci632.cci.com (Stephen Zehl) (05/25/91)
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I'm looking for a little help with scrolling lists under OpenWindows
(XView). I'm using DevGuide to generate C code stubs of scrolling lists,
I'm having trouble getting the information into the lists.
Volume Seven of the XView Programming Manual gives two examples of how
to hard code these choices into the code on pages 155 and 157. As shown
below:
xv_create(panel, PANEL_LIST,
PANEL_LIST_STRINGS, "One", "Two", "Three", NULL,
NULL);
This is fine if you know what you want in the list ahead of time, but
what if you want to read in a list of files from a directory? I figured I
could just substitute a pointer to an array of strings in place of the
strings themselves as shown below:
static char *mylist[3] = { "One", "Two", "Three" };
xv_create(panel, PANEL_LIST,
PANEL_LIST_STRINGS, *mylist, NULL,
NULL);
This will give me the first string in the list, but not the rest.
And if I tack the NULL onto the list itself and remove it from after *mylist,
I get a segmentation fault and a core in my lap.
If anyone out there has worked on this, Please, Please send me some
e-mail with an explaination of how you did this. I'd really appreciate it.
Thanks again,
Steve.
CCCC CCCC IIII Stephen Zehl Internet: sz@cci.com
CC CC II Computer Consoles. Inc. Usenet: uupsi!cci632!sz
CC CC II Rochester, New York. or : uunet!ccicpg!cci632!sz
CCCC CCCC IIII DISCLAIMER: I speak for myself, not for my employer.
brentb@montagne.Eng.Sun.COM (Brent Browning) (05/28/91)
In article <1991May24.211132.10282@cci632.cci.com> sz@cci632.cci.com (Stephen Zehl) writes: > This is fine if you know what you want in the list ahead of time, but >what if you want to read in a list of files from a directory? I figured I >could just substitute a pointer to an array of strings in place of the >strings themselves as shown below: > > static char *mylist[3] = { "One", "Two", "Three" }; PANEL_LIST_STRINGS must *really* have a NULL terminated list of strings, *not* a char ** pointing at a NULL terminated list of strings. I've included a sample program that does just what you need to do. Type in a filename, then hit the load button. It will load that file into the scrolling list. Hitting the save button saves it out to a file. This particular example was written for someone else. It also saves the contents of the scrolling list when the application is quit from the window menu. Brent Browning Internet: brentb@Eng.Sun.COM Sun Microsystems, Inc UUCP: ...!sun!brentb 2550 Garcia Ave. MTV 01-40 Phone: (415) 336-5573 Mountain View, CA 94043 --------8<--------8<---- Cut here ----8<--------8<-------- #include <stdio.h> #include <sys/param.h> #include <sys/types.h> #include <xview/xview.h> #include <xview/panel.h> void load_file(); void save_file(); void load_list_from_file(); void save_list_to_file(); Notify_value destroy_func(); Xv_opaque File_name; Xv_opaque File_list; main(argc, argv) int argc; char **argv; { Xv_opaque frame; Xv_opaque panel; xv_init(XV_INIT_ARGC_PTR_ARGV, &argc, argv, NULL); frame = xv_create(NULL, FRAME, NULL); notify_interpose_destroy_func(frame, destroy_func); panel = xv_create(frame, PANEL, PANEL_LAYOUT, PANEL_VERTICAL, NULL); File_name = xv_create(panel, PANEL_TEXT, PANEL_VALUE_DISPLAY_LENGTH, 30, PANEL_VALUE_STORED_LENGTH, 80, PANEL_LABEL_STRING, "File:", PANEL_VALUE, "TEST", NULL); File_list = xv_create(panel, PANEL_LIST, PANEL_LIST_WIDTH, 250, PANEL_LIST_DISPLAY_ROWS, 10, PANEL_CHOOSE_ONE, TRUE, PANEL_CHOOSE_NONE, FALSE, NULL); xv_set(panel, PANEL_LAYOUT, PANEL_HORIZONTAL, NULL); xv_create(panel, PANEL_BUTTON, PANEL_NEXT_ROW, -1, PANEL_LABEL_STRING, "Load From File", PANEL_NOTIFY_PROC, load_file, NULL); xv_create(panel, PANEL_BUTTON, PANEL_LABEL_STRING, "Save To File", PANEL_NOTIFY_PROC, save_file, NULL); window_fit(panel); window_fit(frame); xv_main_loop(frame); } void load_file(item, event) Panel_item item; Event *event; { load_list_from_file(); } void save_file(item, event) Panel_item item; Event *event; { save_list_to_file(); } Notify_value destroy_func(frame, status) Frame frame; Destroy_status status; { if (status == DESTROY_CLEANUP) save_list_to_file(); return notify_next_destroy_func(frame, status); } void load_list_from_file() { int i = 0; FILE *fp; char buf[MAXPATHLEN]; char *file = (char *)xv_get(File_name, PANEL_VALUE); if ((fp = fopen(file, "r")) == NULL) { perror(file); return; } for (i = 0; fgets(buf, MAXPATHLEN, fp); i++) { buf[strlen(buf)-1] = '\0'; xv_set(File_list, PANEL_LIST_INSERT, i, PANEL_LIST_STRING, i, buf, NULL); } fclose(fp); } void save_list_to_file() { int i; int n; FILE *fp; char *file = (char *)xv_get(File_name, PANEL_VALUE); if ((fp = fopen(file, "w")) == NULL) { perror(file); return; } n = xv_get(File_list, PANEL_LIST_NROWS); for (i = 0; i < n; i++) { fprintf(fp, "%s\n", (char *)xv_get(File_list, PANEL_LIST_STRING, i)); } fclose(fp); } -- Brent Browning Internet: brentb@Eng.Sun.COM Sun Microsystems, Inc UUCP: ...!sun!brentb 2550 Garcia Ave. MTV 01-40 Phone: (415) 336-5573 Mountain View, CA 94043