TEXT HELP: Multiline per-entry help messages in the simple menu system.syslinux-3.40-pre10

5 files changed, 84 insertions, 4 deletions

diff --git a/NEWS b/NEWS
index 3b17d5b4..abff5966 100644
--- a/NEWS
+++ b/NEWS
@@ -10,6 +10,8 @@ Changes in 3.40:
 	* Fix API call 0x0019 (Read Disk.)
 	* MENU AUTOBOOT, MENU TABMSG, MENU PASSPROMPT allows
 	  internationalization of menu messages.
+	* A new feature, TEXT HELP, allows the administrator to set
+	  a multi-line help message for individual selections.
 
 Changes in 3.36:
 	* MEMDISK: Disable EDD by default on floppy disks.  EDD can be
diff --git a/README.menu b/README.menu
index 4eccf068..98526299 100644
--- a/README.menu
+++ b/README.menu
@@ -33,7 +33,7 @@ PROMPT 0
 
 
 There are a few menu additions to the command line, all starting with
-the keyword MENU; like the rest of the SYSLINUX config file
+the keywords MENU or TEXT; like the rest of the SYSLINUX config file
 language, it is case insensitive:
 
 MENU TITLE title
@@ -70,6 +70,7 @@ MENU LABEL label
 	Keep in mind that the LABELs, not MENU LABELs, must be unique,
 	or odd things will happen to the command-line.
 
+
 MENU HIDE
 
 	(Only valid after a LABEL statement.)
@@ -83,6 +84,16 @@ MENU DEFAULT
 	default is specified, use the first one.
 
 
+TEXT HELP
+Help text ...
+... which can span multiple lines
+ENDTEXT
+
+	(Only valid after a LABEL statement.)
+	Specifies a help text that should be displayed when a particular
+	selection is highlighted.
+
+
 MENU PASSWD passwd
 
 	(Only valid after a LABEL statement.)
@@ -164,6 +175,7 @@ MENU COLOR element ansi foreground background shadow
 	pwdentry        Password box contents
 	timeout_msg     Timeout message
 	timeout         Timeout counter
+	help		Help text
 
 
 	"ansi" is a sequence of semicolon-separated ECMA-48 Set
@@ -238,6 +250,7 @@ MENU COLOR element ansi foreground background shadow
 	menu color pwdentry	30;47      #80ffffff #20ffffff std
 	menu color timeout_msg	37;40      #80ffffff #00000000 std
 	menu color timeout	1;37;40    #c0ffffff #00000000 std
+	menu color help		37;40      #c0ffffff #00000000 std
 
 
 MENU WIDTH 80
@@ -249,6 +262,7 @@ MENU CMDLINEROW 18
 MENU ENDROW 24
 MENU PASSWORDROW 11
 MENU TIMEOUTROW 20
+MENU HELPMSGROW 22
 
 	These options control the layout of the menu on the screen.
 	The values above are the defaults.
diff --git a/com32/modules/menu.h b/com32/modules/menu.h
index c15b84d5..5c15b396 100644
--- a/com32/modules/menu.h
+++ b/com32/modules/menu.h
@@ -34,6 +34,7 @@ struct menu_entry {
   char *label;
   char *cmdline;
   char *passwd;
+  char *helptext;
   unsigned char hotkey;
 };
 
diff --git a/com32/modules/menumain.c b/com32/modules/menumain.c
index d661dbf6..e44207d1 100644
--- a/com32/modules/menumain.c
+++ b/com32/modules/menumain.c
@@ -76,6 +76,7 @@ static const struct color_table default_color_table[] = {
   { "pwdentry",    "30;47",     0x80ffffff, 0x20ffffff, SHADOW_NORMAL },
   { "timeout_msg", "37;40",     0x80ffffff, 0x00000000, SHADOW_NORMAL },
   { "timeout",     "1;37;40",   0xc0ffffff, 0x00000000, SHADOW_NORMAL },
+  { "help",        "37;40",     0xc0ffffff, 0x00000000, SHADOW_NORMAL },
 };
 
 #define NCOLORS (sizeof default_color_table/sizeof(struct color_table))
@@ -90,6 +91,7 @@ struct menu_parameter mparm[] = {
   { "endrow", -1 },
   { "passwordrow", 11 },
   { "timeoutrow", 20 },
+  { "helpmsgrow", 22 },
   { NULL, 0 }
 };
 
@@ -102,6 +104,7 @@ struct menu_parameter mparm[] = {
 #define END_ROW		mparm[6].value
 #define PASSWD_ROW	mparm[7].value
 #define TIMEOUT_ROW	mparm[8].value
+#define HELPMSG_ROW	mparm[9].value
 
 static void
 install_default_color_table(void)
@@ -397,7 +400,6 @@ draw_menu(int sel, int top, int edit_line)
     tabmsg = messages[MSG_NOTAB].msg;
     
   printf("\1#08\033[%d;1H%s", TABMSG_ROW, pad_line(tabmsg, 1, WIDTH));
-
   printf("\1#00\033[%d;1H", END_ROW);
 }
 
@@ -407,6 +409,41 @@ clear_screen(void)
   fputs("\033e\033%@\033)0\033(B\1#00\033[?25l\033[2J", stdout);
 }
 
+static void
+display_help(const char *text)
+{
+  int row;
+  const char *p;
+
+  if (!text) {
+    text = "";
+    printf("\1#00\033[%d;1H", HELPMSG_ROW);
+  } else {
+    printf("\1#16\033[%d;1H", HELPMSG_ROW);
+  }
+
+  for (p = text, row = HELPMSG_ROW; *p && row < END_ROW; p++) {
+    switch (*p) {
+    case '\r':
+    case '\f':
+    case '\v':
+    case '\033':
+      break;
+    case '\n':
+      printf("\033[K\033[%d;1H", ++row);
+      break;
+    default:
+      putchar(*p);
+    }
+  }
+
+  fputs("\033[K", stdout);
+
+  while (row < END_ROW) {
+    printf("\033[K\033[%d;1H", ++row);
+  }
+}
+
 static const char *
 edit_cmdline(char *input, int top)
 {
@@ -620,9 +657,11 @@ run_menu(void)
 
     if ( top != prev_top ) {
       draw_menu(entry, top, 1);
+      display_help(menu_entries[entry].helptext);
     } else if ( entry != prev_entry ) {
       draw_row(prev_entry-top+4, entry, top, 0, 0);
       draw_row(entry-top+4, entry, top, 0, 0);
+      display_help(menu_entries[entry].helptext);
     }
 
     prev_entry = entry;  prev_top = top;
@@ -767,8 +806,9 @@ run_menu(void)
 	  clear_screen();
 	  draw_menu(-1, top, 0);
 	} else {
-	  /* Erase [Tab] message */
+	  /* Erase [Tab] message and help text*/
 	  printf("\033[%d;1H\1#00\033[K", TABMSG_ROW);
+	  display_help(NULL);
 	}
 
 	if ( ok ) {
diff --git a/com32/modules/readconfig.c b/com32/modules/readconfig.c
index 0fa5a6aa..cf180bd9 100644
--- a/com32/modules/readconfig.c
+++ b/com32/modules/readconfig.c
@@ -154,6 +154,7 @@ struct labeldata {
   char *append;
   char *menulabel;
   char *passwd;
+  char *helptext;
   unsigned int ipappend;
   unsigned int menuhide;
   unsigned int menudefault;
@@ -171,6 +172,7 @@ record(struct labeldata *ld, char *append)
     me->displayname = ld->menulabel ? ld->menulabel : ld->label;
     me->label       = ld->label;
     me->passwd      = ld->passwd;
+    me->helptext    = ld->helptext;
     me->hotkey = 0;
 
     if ( ld->menulabel ) {
@@ -545,14 +547,34 @@ static void parse_config_file(FILE *f)
 	}
       }
     } else if ( looking_at(p, "text") ) {
+      enum text_cmd {
+	TEXT_UNKNOWN,
+	TEXT_HELP
+      } cmd = TEXT_UNKNOWN;
+      int len = ld.helptext ? strlen(ld.helptext) : 0;
+      int xlen;
+
       p = skipspace(p+4);
       
-      /* p points to the TEXT command */
+      if (looking_at(p, "help"))
+	cmd = TEXT_HELP;
       
       while ( fgets(line, sizeof line, f) ) {
 	p = skipspace(line);
 	if (looking_at(p, "endtext"))
 	  break;
+
+	xlen = strlen(line);
+
+	switch (cmd) {
+	case TEXT_UNKNOWN:
+	  break;
+	case TEXT_HELP:
+	  ld.helptext = realloc(ld.helptext, len+xlen+1);
+	  memcpy(ld.helptext+len, line, xlen+1);
+	  len += xlen;
+	  break;
+	}
       }
     } else if ( looking_at(p, "append") ) {
       char *a = strdup(skipspace(p+6));
@@ -569,6 +591,7 @@ static void parse_config_file(FILE *f)
       ld.passwd    = NULL;
       ld.append    = NULL;
       ld.menulabel = NULL;
+      ld.helptext  = NULL;
       ld.ipappend  = ipappend;
       ld.menudefault = ld.menuhide = 0;
     } else if ( (ep = is_kernel_type(p, &type)) ) {