Constify strings in selector/mselector_items

Use internal types to track items within the
selector/mselector widgets, rather than pressing the
user-provided item structs into double-duty. With this
change, we can constify the strings within those
user-provided items. Do so, also removing the internal-side
elements. Update documentation. Closes #2267.

doc/man/man3/notcurses_multiselector.3.md

@@ -16,9 +16,8 @@ struct notcurses;
 struct ncmultiselector;
 
 struct ncmselector_item {
-  char* option;
-  char* desc;
-  bool selected;
+  const char* option;
+  const char* desc;
 };
 
 typedef struct ncmultiselector_options {

doc/man/man3/notcurses_selector.3.md

@@ -16,8 +16,8 @@ struct notcurses;
 struct ncselector;
 
 struct ncselector_item {
-  char* option;
-  char* desc;
+  const char* option;
+  const char* desc;
 };
 
 typedef struct ncselector_options {

include/notcurses/notcurses.h

@@ -3325,10 +3325,8 @@ API void ncplane_greyscale(struct ncplane* n);
 //
 // At all times, exactly one item is selected.
 struct ncselector_item {
-  char* option;
-  char* desc;
-  size_t opcolumns;   // filled in by library
-  size_t desccolumns; // filled in by library
+  const char* option;
+  const char* desc;
 };
 
 typedef struct ncselector_options {
@@ -3384,8 +3382,8 @@ API bool ncselector_offer_input(struct ncselector* n, const ncinput* nc)
 API void ncselector_destroy(struct ncselector* n, char** item);
 
 struct ncmselector_item {
-  char* option;
-  char* desc;
+  const char* option;
+  const char* desc;
   bool selected;
 };
 

src/demo/zoo.c

@@ -27,7 +27,7 @@ draw_background(struct notcurses* nc){
 
 // we list all distributions on which notcurses is known to exist
 static struct ncselector_item select_items[] = {
-#define SITEM(short, long) { short, long, 0, 0, }
+#define SITEM(s, l) { s, l, }
   SITEM("fbsd", "FreeBSD"),
   SITEM("deb", "Debian Unstable Linux"),
   SITEM("rpm", "Fedora Rawhide Linux"),

src/lib/selector.c

@@ -1,5 +1,19 @@
 #include "internal.h"
 
+// internal ncselector item
+struct ncselector_int {
+  char* option;
+  char* desc;
+  size_t opcolumns;   // filled in by library
+  size_t desccolumns; // filled in by library
+};
+
+struct ncmselector_int {
+  char* option;
+  char* desc;
+  bool selected;
+};
+
 typedef struct ncselector {
   ncplane* ncp;                  // backing ncplane
   unsigned selected;             // index of selection
@@ -7,7 +21,7 @@ typedef struct ncselector {
   unsigned maxdisplay;           // max number of items to display, 0 -> no limit
   int longop;                    // columns occupied by longest option
   int longdesc;                  // columns occupied by longest description
-  struct ncselector_item* items; // list of items and descriptions, heap-copied
+  struct ncselector_int* items;  // list of items and descriptions, heap-copied
   unsigned itemcount;            // number of pairs in 'items'
   char* title;                   // can be NULL, in which case there's no riser
   int titlecols;                 // columns occupied by title
@@ -29,7 +43,7 @@ typedef struct ncmultiselector {
   unsigned startdisp;             // index of first option displayed
   unsigned maxdisplay;            // max number of items to display, 0 -> no limit
   int longitem;                   // columns occupied by longest item
-  struct ncmselector_item* items; // items, descriptions, and statuses, heap-copied
+  struct ncmselector_int* items;  // items, descriptions, and statuses, heap-copied
   unsigned itemcount;             // number of pairs in 'items'
   char* title;                    // can be NULL, in which case there's no riser
   int titlecols;                  // columns occupied by title
@@ -332,7 +346,7 @@ int ncselector_additem(ncselector* n, const struct ncselector_item* item){
   int origdimy, origdimx;
   ncselector_dim_yx(n, &origdimy, &origdimx);
   size_t newsize = sizeof(*n->items) * (n->itemcount + 1);
-  struct ncselector_item* items = realloc(n->items, newsize);
+  struct ncselector_int* items = realloc(n->items, newsize);
   if(!items){
     return -1;
   }

src/poc/selector.c

@@ -6,7 +6,7 @@
 #include "version.h"
 
 static struct ncselector_item items[] = {
-#define SITEM(short, long) { short, long, 0, 0, }
+#define SITEM(s, l) { s, l, }
   SITEM("Afrikaans", "Ek kan glas eet, dit maak my nie seer nie."),
   SITEM("AngloSax", "ᛁᚳ᛫ᛗᚨᚷ᛫ᚷᛚᚨᛋ᛫ᛖᚩᛏᚪᚾ᛫ᚩᚾᛞ᛫ᚻᛁᛏ᛫ᚾᛖ᛫ᚻᛖᚪᚱᛗᛁᚪᚧ᛫ᛗᛖ᛬"),
   SITEM("Japanese", "私はガラスを食べられます。それは私を傷つけません。"),

src/tests/selector.cpp

@@ -109,10 +109,10 @@ TEST_CASE("Selectors") {
 
   SUBCASE("PopulatedSelector") {
     ncselector_item items[] = {
-      { strdup("op1"), strdup("this is option 1"), 0, 0, },
-      { strdup("2ndop"), strdup("this is option #2"), 0, 0, },
-      { strdup("tres"), strdup("option the third"), 0, 0, },
-      { NULL, NULL, 0, 0, },
+      { strdup("op1"), strdup("this is option 1"), },
+      { strdup("2ndop"), strdup("this is option #2"), },
+      { strdup("tres"), strdup("option the third"), },
+      { NULL, NULL, },
     };
     struct ncselector_options opts{};
     opts.items = items;
@@ -164,10 +164,10 @@ TEST_CASE("Selectors") {
 
   SUBCASE("SelectorMovement") {
     ncselector_item items[] = {
-      { strdup("op1"), strdup("this is option 1"), 0, 0, },
-      { strdup("2ndop"), strdup("this is option #2"), 0, 0, },
-      { strdup("tres"), strdup("option the third"), 0, 0, },
-      { NULL, NULL, 0, 0, },
+      { strdup("op1"), strdup("this is option 1"), },
+      { strdup("2ndop"), strdup("this is option #2"), },
+      { strdup("tres"), strdup("option the third"), },
+      { NULL, NULL, },
     };
     struct ncselector_options opts{};
     opts.items = items;
@@ -210,10 +210,10 @@ TEST_CASE("Selectors") {
   // Provide three items, limited to 1 shown at a time
   SUBCASE("ScrollingSelectorOne") {
     ncselector_item items[] = {
-      { strdup("op1"), strdup("this is option 1"), 0, 0, },
-      { strdup("2ndop"), strdup("this is option #2"), 0, 0, },
-      { strdup("tres"), strdup("option the third"), 0, 0, },
-      { NULL, NULL, 0, 0, },
+      { strdup("op1"), strdup("this is option 1"), },
+      { strdup("2ndop"), strdup("this is option #2"), },
+      { strdup("tres"), strdup("option the third"), },
+      { NULL, NULL, },
     };
     struct ncselector_options opts{};
     opts.maxdisplay = 1;
@@ -262,10 +262,10 @@ TEST_CASE("Selectors") {
   // Provide three items, limited to 2 shown at a time
   SUBCASE("ScrollingSelectorTwo") {
     ncselector_item items[] = {
-      { strdup("op1"), strdup("this is option 1"), 0, 0, },
-      { strdup("2ndop"), strdup("this is option #2"), 0, 0, },
-      { strdup("tres"), strdup("option the third"), 0, 0, },
-      { NULL, NULL, 0, 0, },
+      { strdup("op1"), strdup("this is option 1"), },
+      { strdup("2ndop"), strdup("this is option #2"), },
+      { strdup("tres"), strdup("option the third"), },
+      { NULL, NULL, },
     };
     struct ncselector_options opts{};
     opts.maxdisplay = 2;