demo: handle menu navigation

src/demo/demo.h

@@ -156,6 +156,9 @@ int hud_completion_notify(const demoresult* result);
 const demoresult* demoresult_lookup(int idx);
 /*----------------------------------HUD----------------------------------*/
 
+// returns true if the input was handled by the menu/HUD
+bool menu_or_hud_key(const struct ncinput *ni);
+
 static inline int
 pulser(struct notcurses* nc, struct ncplane* ncp __attribute__ ((unused)), void* curry){
   struct timespec* start = curry;

src/demo/hud.c

@@ -26,6 +26,9 @@ typedef struct elem {
   struct elem* next;
 } elem;
 
+static bool menu_unrolled;
+static struct ncmenu* menu;
+
 static struct elem* elems;
 static struct elem* running;
 // which line we're writing the next entry to. once this becomes -1, we stop decrementing
@@ -57,6 +60,44 @@ hud_grabbed_bg(struct ncplane* n){
   return 0;
 }
 
+// returns true if the input was handled by the menu/HUD
+bool menu_or_hud_key(const struct ncinput *ni){
+  if(!menu){
+    return false;
+  }
+  if((ni->id == 'o' || ni->id == 'O') && ni->alt && !ni->ctrl){
+    if(ncmenu_unroll(menu, 0) == 0){
+      menu_unrolled = true;
+    }
+    return true;
+  }else if(ni->id == NCKEY_UP){
+    if(!menu_unrolled){
+      return false;
+    }
+    ncmenu_previtem(menu);
+    return true;
+  }else if(ni->id == NCKEY_DOWN){
+    if(!menu_unrolled){
+      return false;
+    }
+    ncmenu_nextitem(menu);
+    return true;
+  }else if(ni->id == NCKEY_LEFT){
+    if(!menu_unrolled){
+      return false;
+    }
+    ncmenu_prevsection(menu);
+    return true;
+  }else if(ni->id == NCKEY_RIGHT){
+    if(!menu_unrolled){
+      return false;
+    }
+    ncmenu_nextsection(menu);
+    return true;
+  }
+  return false;
+}
+
 struct ncmenu* menu_create(struct notcurses* nc){
   struct ncmenu_item demo_items[] = {
     { .desc = "Toggle HUD", .shortcut = { .id = 'H', .ctrl = true, }, },
@@ -89,7 +130,8 @@ struct ncmenu* menu_create(struct notcurses* nc){
     .headerchannels = headerchannels,
     .sectionchannels = sectionchannels,
   };
-  return ncmenu_create(nc, &mopts);
+  menu = ncmenu_create(nc, &mopts);
+  return menu;
 }
 
 struct ncplane* hud_create(struct notcurses* nc){

src/demo/input.c

@@ -95,13 +95,7 @@ ultramegaok_demo(void* vnc){
       handle_mouse(&ni);
     }else{
       // if this was about the menu or HUD, pass to them, and continue
-      if(ni.id == NCKEY_UP){
-        continue;
-      }else if(ni.id == NCKEY_DOWN){
-        continue;
-      }else if(ni.id == NCKEY_LEFT){
-        continue;
-      }else if(ni.id == NCKEY_RIGHT){
+      if(menu_or_hud_key(&ni)){
         continue;
       }
       if(ni.id == 'q'){

src/demo/witherworm.c

@@ -461,14 +461,14 @@ int witherworm_demo(struct notcurses* nc){
       int y, x, maxy, maxx;
       ncplane_dim_yx(n, &maxy, &maxx);
       int rgb = start;
-      if(ncplane_cursor_move_yx(n, 0, 0)){
-        return -1;
-      }
       int bytes_out = 0;
       int egcs_out = 0;
       int cols_out = 0;
-      y = 0;
+      y = 1;
       x = 0;
+      if(ncplane_cursor_move_yx(n, y, x)){
+        return -1;
+      }
       ncplane_set_bg_rgb(n, 20, 20, 20);
       do{ // we fill up the screen, however large, bouncing around our strtable
         s = strs + random() % ((sizeof(strs) / sizeof(*strs)) - 1);