Rudimentary key rebinding in game options

Currently shown only in the full options list, as it's not
quite complete. (For example, it doesn't handle movement commands,
or the getpos keys)

src/cmd.c

@@ -161,6 +161,7 @@ static char *parse(void);
 static void show_direction_keys(winid, char, boolean);
 static boolean help_dir(char, uchar, const char *);
 
+static void handler_rebind_keys_add(boolean);
 static boolean bind_key_fn(uchar, int (*)(void));
 static void commands_init(void);
 static boolean keylist_func_has_key(const struct ext_func_tab *, boolean *);
@@ -2826,6 +2827,187 @@ extcmds_getentry(int i)
     return &extcmdlist[i];
 }
 
+/* return number of extended commands bound to a non-default key */
+int
+count_bind_keys(void)
+{
+    int nbinds = 0;
+    int i;
+
+    for (i = 0; i < extcmdlist_length; i++)
+        if (extcmdlist[i].key && g.Cmd.commands[extcmdlist[i].key] != &extcmdlist[i])
+            nbinds++;
+    return nbinds;
+}
+
+static void
+display_changed_key_binds(void)
+{
+    winid win;
+    int i;
+    char buf[BUFSZ];
+    char buf2[QBUFSZ];
+
+    win = create_nhwindow(NHW_TEXT);
+    for (i = 0; i < extcmdlist_length; i++) {
+        struct ext_func_tab *ec = &extcmdlist[i];
+
+        if (ec->key && g.Cmd.commands[ec->key]
+            && g.Cmd.commands[ec->key] != ec) {
+            Sprintf(buf, "BIND=%s:%s", key2txt(ec->key, buf2),
+                    g.Cmd.commands[ec->key]->ef_txt);
+            putstr(win, 0, buf);
+        }
+    }
+    display_nhwindow(win, TRUE);
+    destroy_nhwindow(win);
+}
+
+/* interactive key binding */
+static void
+handler_rebind_keys_add(boolean keyfirst)
+{
+    struct ext_func_tab *ec;
+    winid win;
+    anything any;
+    int i, npick;
+    menu_item *picks = (menu_item *) 0;
+    char buf[BUFSZ];
+    char buf2[QBUFSZ];
+    uchar key = '\0';
+
+    if (keyfirst) {
+        pline("Bind which key? ");
+        key = pgetchar();
+
+        if (!key || key == '\027')
+            return;
+    }
+
+    win = create_nhwindow(NHW_MENU);
+    start_menu(win, MENU_BEHAVE_STANDARD);
+    any = cg.zeroany;
+
+    if (key) {
+        if (g.Cmd.commands[key]) {
+            Sprintf(buf, "Key '%s' is currently bound to \"%s\".",
+                    key2txt(key, buf2), g.Cmd.commands[key]->ef_txt);
+        } else {
+            Sprintf(buf, "Key '%s' is not bound to anything.",
+                    key2txt(key, buf2));
+        }
+        add_menu(win, &nul_glyphinfo, &any, '\0', 0, ATR_NONE, 0, buf,
+                 MENU_ITEMFLAGS_NONE);
+        add_menu(win, &nul_glyphinfo, &any, '\0', 0, ATR_NONE, 0, "",
+                 MENU_ITEMFLAGS_NONE);
+    }
+
+    any.a_int = -1;
+    add_menu(win, &nul_glyphinfo, &any, '\0', 0, ATR_NONE, 0, "nothing: unbind the key",
+             MENU_ITEMFLAGS_NONE);
+
+    any.a_int = 0;
+    add_menu(win, &nul_glyphinfo, &any, '\0', 0, ATR_NONE, 0, "",
+             MENU_ITEMFLAGS_NONE);
+
+    for (i = 0; i < extcmdlist_length; i++) {
+        ec = &extcmdlist[i];
+
+        if ((ec->flags & (MOVEMENTCMD|INTERNALCMD|CMD_NOT_AVAILABLE)) != 0)
+            continue;
+
+        any.a_int = (i + 1);
+        Sprintf(buf, "%s: %s", ec->ef_txt, ec->ef_desc);
+        add_menu(win, &nul_glyphinfo, &any, '\0', 0, ATR_NONE, 0, buf,
+             MENU_ITEMFLAGS_NONE);
+    }
+    if (key)
+        Sprintf(buf, "Bind '%s' to what command?", key2txt(key, buf2));
+    else
+        Sprintf(buf, "Bind what command?");
+    end_menu(win, buf);
+    npick = select_menu(win, PICK_ONE, &picks);
+    destroy_nhwindow(win);
+    if (npick > 0) {
+        const struct ext_func_tab *prevec;
+        const char *cmdstr;
+
+        i = picks->item.a_int;
+        free((genericptr_t) picks);
+
+        if (i == -1) {
+            ec = NULL;
+            cmdstr = "nothing";
+            goto bindit;
+        } else {
+            ec = &extcmdlist[i-1];
+            cmdstr = ec->ef_txt;
+        }
+bindit:
+        if (!key) {
+            pline("Bind which key? ");
+            key = pgetchar();
+
+            if (!key || key == '\027')
+                return;
+        }
+
+        prevec = g.Cmd.commands[key];
+
+        if (bind_key(key, cmdstr)) {
+            if (prevec && prevec != ec) {
+                pline("Changed key '%s' from \"%s\" to \"%s\".",
+                      key2txt(key, buf2), prevec->ef_txt, cmdstr);
+            } else if (!prevec) {
+                pline("Bound key '%s' to \"%s\".", key2txt(key, buf2), cmdstr);
+            }
+        } else {
+            pline("Key binding failed?!");
+        }
+    }
+}
+
+void
+handler_rebind_keys(void)
+{
+    winid win;
+    anything any;
+    int i, npick;
+    menu_item *picks = (menu_item *) 0;
+
+redo_rebind:
+
+    win = create_nhwindow(NHW_MENU);
+    start_menu(win, MENU_BEHAVE_STANDARD);
+    any = cg.zeroany;
+
+    any.a_int = 1;
+    add_menu(win, &nul_glyphinfo, &any, '\0', 0, ATR_NONE, 0, "bind key to a command",
+             MENU_ITEMFLAGS_NONE);
+    any.a_int = 2;
+    add_menu(win, &nul_glyphinfo, &any, '\0', 0, ATR_NONE, 0, "bind command to a key",
+             MENU_ITEMFLAGS_NONE);
+    if (count_bind_keys()) {
+        any.a_int = 3;
+        add_menu(win, &nul_glyphinfo, &any, '\0', 0, ATR_NONE, 0, "view changed key binds",
+                 MENU_ITEMFLAGS_NONE);
+    }
+    end_menu(win, "Do what?");
+    npick = select_menu(win, PICK_ONE, &picks);
+    destroy_nhwindow(win);
+    if (npick > 0) {
+        i = picks->item.a_int;
+        free((genericptr_t) picks);
+
+        if (i == 1 || i == 2) {
+            handler_rebind_keys_add((i == 1));
+        } else if (i == 3) {
+            display_changed_key_binds();
+        }
+        goto redo_rebind;
+    }
+}
+
 /* find extended command entries matching findstr.
    if findstr is NULL, returns all available entries.
    returns: number of matching extended commands,