ncmenu: highlight shortcut keys for menu items

include/notcurses.h

@@ -2213,6 +2213,7 @@ API void ncselector_destroy(struct ncselector* n, char** item);
 struct ncmenu_item {
   char* desc;           // utf-8 menu item, NULL for horizontal separator
   ncinput shortcut;     // shortcut, all should be distinct
+  int shortcut_offset;  // used only by library
 };
 
 struct ncmenu_section {

src/lib/menu.c

@@ -47,6 +47,12 @@ dup_menu_section(ncmenu_int_section* dst, const struct ncmenu_section* src){
       if(cols > dst->bodycols){
         dst->bodycols = cols;
       }
+      memcpy(&dst->items[i].shortcut, &src->items[i].shortcut, sizeof(dst->items[i].shortcut));
+      if(mbstr_find_codepoint(dst->items[i].desc,
+                              dst->items[i].shortcut.id,
+                              &dst->items[i].shortcut_offset) < 0){
+        dst->items[i].shortcut_offset = -1;
+      }
     }else{
       dst->items[i].desc = NULL;
     }
@@ -244,6 +250,17 @@ int ncmenu_unroll(ncmenu* n, int sectionidx){
           return -1;
         }
       }
+      if(sec->items[i].shortcut_offset >= 0){
+        cell cl = CELL_TRIVIAL_INITIALIZER;
+        if(ncplane_at_yx(n->ncp, ypos, xpos + 1 + sec->items[i].shortcut_offset, &cl) < 0){
+          return -1;
+        }
+        cell_styles_on(&cl, NCSTYLE_UNDERLINE|NCSTYLE_BOLD);
+        if(ncplane_putc_yx(n->ncp, ypos, xpos + 1 + sec->items[i].shortcut_offset, &cl) < 0){
+          return -1;
+        }
+        cell_release(n->ncp, &cl);
+      }
     }else{
       n->ncp->channels = n->headerchannels;
       ncplane_styles_set(n->ncp, 0);

src/poc/menu.c

@@ -64,14 +64,14 @@ int main(void){
     return EXIT_FAILURE;
   }
   struct ncmenu_item demo_items[] = {
-    { .desc = "Restart", },
+    { .desc = "Restart", .shortcut = { .id = 'r', .ctrl = true, }, },
   };
   struct ncmenu_item file_items[] = {
     { .desc = "New", .shortcut = { .id = 'n', .ctrl = true, }, },
-    { .desc = "Open", },
-    { .desc = "Close", },
+    { .desc = "Open", .shortcut = { .id = 'o', .ctrl = true, }, },
+    { .desc = "Close", .shortcut = { .id = 'c', .ctrl = true, }, },
     { .desc = NULL, },
-    { .desc = "Quit", },
+    { .desc = "Quit", .shortcut = { .id = 'q', .ctrl = true, }, },
   };
   struct ncmenu_section sections[] = {
     { .name = "Schwarzgerät", .items = demo_items, .shortcut = { .id = 0x00e4, .alt = true, }, },

tests/menu.cpp

@@ -52,7 +52,7 @@ TEST_CASE("MenuTest") {
   // a section with only separators ought be rejected
   SUBCASE("SeparatorSectionReject") {
     struct ncmenu_item empty_items[] = {
-      { .desc = nullptr, .shortcut = {}, },
+      { .desc = nullptr, .shortcut = {}, .shortcut_offset = -1, },
     };
     struct ncmenu_section sections[] = {
       { .name = strdup("Empty"), .itemcount = 1, .items = empty_items, .shortcut{}, },
@@ -68,7 +68,7 @@ TEST_CASE("MenuTest") {
 
   SUBCASE("MenuOneSection") {
     struct ncmenu_item file_items[] = {
-      { .desc = strdup("I would like a new file"), .shortcut = {}, },
+      { .desc = strdup("I would like a new file"), .shortcut = {}, .shortcut_offset = -1, },
     };
     struct ncmenu_section sections[] = {
       { .name = strdup("File"), .itemcount = sizeof(file_items) / sizeof(*file_items), .items = file_items, .shortcut{}, },
@@ -84,7 +84,7 @@ TEST_CASE("MenuTest") {
 
   SUBCASE("VeryLongMenu") {
     struct ncmenu_item items[] = {
-      { .desc = strdup("Generic menu entry"), .shortcut = {}, },
+      { .desc = strdup("Generic menu entry"), .shortcut = {}, .shortcut_offset = -1, },
     };
     struct ncmenu_section sections[] = {
       { .name = strdup("antidisestablishmentarianism"), .itemcount = sizeof(items) / sizeof(*items), .items = items, .shortcut{}, },