ncmenu: print item shortcut aligned right #179

include/notcurses.h

@@ -2213,7 +2213,6 @@ 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/internal.h

@@ -124,10 +124,19 @@ typedef struct renderstate {
   bool defaultelidable;
 } renderstate;
 
+// ncmenu_item and ncmenu_section have internal and (minimal) external forms
+typedef struct ncmenu_int_item {
+  char* desc;           // utf-8 menu item, NULL for horizontal separator
+  ncinput shortcut;     // shortcut, all should be distinct
+  int shortcut_offset;  // column offset with desc of shortcut EGC
+  char* shortdesc;      // description of shortcut, can be NULL
+  int shortdesccols;    // columns occupied by shortcut description
+} ncmenu_int_item;
+
 typedef struct ncmenu_int_section {
   char* name;             // utf-8 c string
   int itemcount;
-  struct ncmenu_item* items;
+  ncmenu_int_item* items; // items, NULL iff itemcount == 0
   ncinput shortcut;       // shortcut, will be underlined if present in name
   int xoff;               // column offset from beginning of menu bar
   int bodycols;           // column width of longest item
@@ -137,13 +146,13 @@ typedef struct ncmenu_int_section {
 
 typedef struct ncmenu {
   ncplane* ncp;
-  ncmenu_int_section* sections;
-  bool bottom;              // are we on the bottom (vs top)?
   int sectioncount;         // must be positive
+  ncmenu_int_section* sections; // NULL iff sectioncount == 0
   int unrolledsection;      // currently unrolled section, -1 if none
   int headerwidth;          // minimum space necessary to display all sections
   uint64_t headerchannels;  // styling for header
   uint64_t sectionchannels; // styling for sections
+  bool bottom;              // are we on the bottom (vs top)?
 } ncmenu;
 
 typedef struct ncselector {

src/lib/menu.c

@@ -17,6 +17,50 @@ free_menu_sections(ncmenu* ncm){
   free(ncm->sections);
 }
 
+static int
+dup_menu_item(ncmenu_int_item* dst, const struct ncmenu_item* src){
+#define ALTMOD "Alt+"
+#define CTLMOD "Ctrl+"
+  if((dst->desc = strdup(src->desc)) == NULL){
+    return -1;
+  }
+  if(!src->shortcut.id){
+    dst->shortdesccols = 0;
+    dst->shortdesc = NULL;
+    return 0;
+  }
+  size_t bytes = 1; // NUL terminator
+  if(src->shortcut.alt){
+    bytes += strlen(ALTMOD);
+  }
+  if(src->shortcut.ctrl){
+    bytes += strlen(CTLMOD);
+  }
+  mbstate_t ps;
+  memset(&ps, 0, sizeof(ps));
+  size_t shortsize = wcrtomb(NULL, src->shortcut.id, &ps);
+  if(shortsize == (size_t)-1){
+    free(dst->desc);
+    return -1;
+  }
+  bytes += shortsize;
+  char* sdup = malloc(bytes);
+  int n = snprintf(sdup, bytes, "%s%s", src->shortcut.alt ? ALTMOD : "",
+                   src->shortcut.ctrl ? CTLMOD : "");
+  if(n < 0 || (size_t)n >= bytes){
+    free(sdup);
+    free(dst->desc);
+    return -1;
+  }
+  memset(&ps, 0, sizeof(ps));
+  wcrtomb(sdup + n, src->shortcut.id, &ps);
+  dst->shortdesc = sdup;
+  dst->shortdesccols = mbswidth(dst->shortdesc);
+  return 0;
+#undef CTLMOD
+#undef ALTMOD
+}
+
 static int
 dup_menu_section(ncmenu_int_section* dst, const struct ncmenu_section* src){
   // we must reject any empty section
@@ -35,7 +79,7 @@ dup_menu_section(ncmenu_int_section* dst, const struct ncmenu_section* src){
   }
   for(int i = 0 ; i < src->itemcount ; ++i){
     if(src->items[i].desc){
-      if((dst->items[i].desc = strdup(src->items[i].desc)) == NULL){
+      if(dup_menu_item(&dst->items[i], &src->items[i])){
         while(i--){
           free(&dst->items[i].desc);
         }
@@ -43,7 +87,10 @@ dup_menu_section(ncmenu_int_section* dst, const struct ncmenu_section* src){
         return -1;
       }
       gotitem = true;
-      const int cols = mbswidth(dst->items[i].desc);
+      int cols = mbswidth(dst->items[i].desc);
+      if(dst->items[i].shortdesc){
+        cols += 2 + dst->items[i].shortdesccols; // two spaces minimum
+      }
       if(cols > dst->bodycols){
         dst->bodycols = cols;
       }
@@ -55,6 +102,7 @@ dup_menu_section(ncmenu_int_section* dst, const struct ncmenu_section* src){
       }
     }else{
       dst->items[i].desc = NULL;
+      dst->items[i].shortdesc = NULL;
     }
   }
   if(!gotitem){
@@ -245,11 +293,24 @@ int ncmenu_unroll(ncmenu* n, int sectionidx){
       if(cols < 0){
         return -1;
       }
-      for(int j = cols + 1 ; j < width - 1 ; ++j){
+      // we need pad out the remaining columns of this line with spaces. if
+      // there's a shortcut description, we align it to the right, printing
+      // spaces only through the start of the aligned description.
+      int thiswidth = width;
+      if(sec->items[i].shortdesc){
+        thiswidth -= sec->items[i].shortdesccols;
+      }
+      // print any necessary padding spaces
+      for(int j = cols + 1 ; j < thiswidth - 1 ; ++j){
         if(ncplane_putsimple(n->ncp, ' ') < 0){
           return -1;
         }
       }
+      if(sec->items[i].shortdesc){
+        if(ncplane_putstr(n->ncp, sec->items[i].shortdesc) < 0){
+          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){

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 = {}, .shortcut_offset = -1, },
+      { .desc = nullptr, .shortcut = {}, },
     };
     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 = {}, .shortcut_offset = -1, },
+      { .desc = strdup("I would like a new file"), .shortcut = {}, },
     };
     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 = {}, .shortcut_offset = -1, },
+      { .desc = strdup("Generic menu entry"), .shortcut = {}, },
     };
     struct ncmenu_section sections[] = {
       { .name = strdup("antidisestablishmentarianism"), .itemcount = sizeof(items) / sizeof(*items), .items = items, .shortcut{}, },