add ncdirect_supported_styles(), move SGR/SGR0/OC into escblock #1525

NEWS.md

@@ -7,6 +7,7 @@ rearrangements of Notcurses.
   * `ncinput_nomod_p()` has been added. This function returns `true` if and
     only if its `ncinput` argument has no modifiers active.
   * Added `notcurses_cursor_yx()` to get the current location of the cursor.
+  * Added `ncdirect_supported_styles()`.
 
 * 2.3.1 (2021-05-18)
   * Sprixels no longer interact with their associated plane's framebuffer. This

doc/man/man3/notcurses_direct.3.md

@@ -40,6 +40,8 @@ notcurses_direct - minimal notcurses instances for styling text
 
 **int ncdirect_dim_y(const struct ncdirect* ***nc***);**
 
+**unsigned ncdirect_supported_styles(const struct ncdirect* ***nc***);**
+
 **int ncdirect_styles_set(struct ncdirect* ***n***, unsigned ***stylebits***);**
 
 **int ncdirect_styles_on(struct ncdirect* ***n***, unsigned ***stylebits***);**

include/notcurses/direct.h

@@ -177,6 +177,12 @@ API int ncdirect_dim_x(const struct ncdirect* nc)
 API int ncdirect_dim_y(const struct ncdirect* nc)
   __attribute__ ((nonnull (1)));
 
+// Returns a 16-bit bitmask of supported curses-style attributes
+// (NCSTYLE_UNDERLINE, NCSTYLE_BOLD, etc.) The attribute is only
+// indicated as supported if the terminal can support it together with color.
+// For more information, see the "ncv" capability in terminfo(5).
+API unsigned ncdirect_supported_styles(const struct ncdirect* nc);
+
 // ncplane_styles_*() analogues
 API int ncdirect_set_styles(struct ncdirect* n, unsigned stylebits)
   __attribute__ ((nonnull (1)));

src/lib/debug.c

@@ -19,7 +19,8 @@ tinfo_debug_caps(const tinfo* ti, FILE* debugfp, int rows, int cols,
           capyn(get_escape(ti, ESCAPE_SETAF)),
           capyn(get_escape(ti, ESCAPE_SETAB)));
   fprintf(debugfp, "%ssgr: %c sgr0: %c\n",
-          indent, capyn(ti->sgr), capyn(ti->sgr0));
+          indent, capyn(get_escape(ti, ESCAPE_SGR)),
+                  capyn(get_escape(ti, ESCAPE_SGR0)));
   fprintf(debugfp, "%sop: %c fgop: %c bgop: %c\n",
           indent, capyn(get_escape(ti, ESCAPE_OP)),
                   capyn(get_escape(ti, ESCAPE_FGOP)),

src/lib/direct.c

@@ -812,10 +812,11 @@ char* ncdirect_readline(ncdirect* n, const char* prompt){
 static inline int
 ncdirect_style_emit(ncdirect* n, unsigned stylebits, FILE* out){
   int r = -1;
-  if(stylebits == 0 && n->tcache.sgr0){
-    r = term_emit(n->tcache.sgr0, n->ttyfp, false);
-  }else if(n->tcache.sgr){
-    r = term_emit(tiparm(n->tcache.sgr, stylebits & NCSTYLE_STANDOUT,
+  const char* esc;
+  if(stylebits == 0 && (esc = get_escape(&n->tcache, ESCAPE_SGR0))){
+    r = term_emit(esc, n->ttyfp, false);
+  }else if( (esc = get_escape(&n->tcache, ESCAPE_SGR)) ){
+    r = term_emit(tiparm(esc, stylebits & NCSTYLE_STANDOUT,
                          stylebits & NCSTYLE_UNDERLINE,
                          stylebits & NCSTYLE_REVERSE,
                          stylebits & NCSTYLE_BLINK,
@@ -1291,3 +1292,7 @@ int ncdirectf_geom(ncdirect* n, ncdirectf* frame,
   }
   return r;
 }
+
+unsigned ncdirect_supported_styles(const ncdirect* nc){
+  return term_supported_styles(&nc->tcache);
+}

src/lib/notcurses.c

@@ -42,10 +42,10 @@ int reset_term_attributes(const tinfo* ti, FILE* fp){
   if((esc = get_escape(ti, ESCAPE_OP)) && term_emit(esc, fp, true)){
     ret = -1;
   }
-  if(ti->sgr0 && term_emit(ti->sgr0, fp, true)){
+  if((esc = get_escape(ti, ESCAPE_SGR0)) && term_emit(esc, fp, true)){
     ret = -1;
   }
-  if(ti->oc && term_emit(ti->oc, fp, true)){
+  if((esc = get_escape(ti, ESCAPE_OC)) && term_emit(esc, fp, true)){
     ret = -1;
   }
   return ret;
@@ -812,9 +812,10 @@ init_banner_warnings(const notcurses* nc, FILE* out){
   if(!get_escape(&nc->tcache, ESCAPE_HPA)){
     fprintf(out, "\n Warning! No absolute horizontal placement.\n");
   }
-  if(nc->tcache.sgr0){
+  const char* sgr0;
+  if( (sgr0 = get_escape(&nc->tcache, ESCAPE_SGR0)) ){
     if(tty){
-      term_emit(nc->tcache.sgr0, out, true);
+      term_emit(sgr0, out, true);
     }
   }
 }

src/lib/render.c

@@ -610,14 +610,16 @@ term_setstyles(FILE* out, notcurses* nc, const nccell* c){
   // target ought have all 0s in the lower 8 bits if only italics changed.
   if((cellattr ^ nc->rstate.curattr) & 0xfful){
     // if everything's 0, emit the shorter sgr0
-    if(nc->tcache.sgr0 && ((cellattr & NCSTYLE_MASK) == 0)){
-      if(term_emit(nc->tcache.sgr0, out, false) < 0){
+    const char* sgr0 = get_escape(&nc->tcache, ESCAPE_SGR0);
+    const char* sgr = get_escape(&nc->tcache, ESCAPE_SGR);
+    if(sgr0 && ((cellattr & NCSTYLE_MASK) == 0)){
+      if(term_emit(sgr0, out, false) < 0){
         ret = -1;
       }else{
         normalized = true;
       }
-    }else if(nc->tcache.sgr){
-      if(term_emit(tiparm(nc->tcache.sgr,
+    }else if(sgr){
+      if(term_emit(tiparm(sgr,
                           cellattr & NCSTYLE_STANDOUT,
                           cellattr & NCSTYLE_UNDERLINE,
                           cellattr & NCSTYLE_REVERSE,

src/lib/termdesc.h

@@ -36,6 +36,7 @@ typedef enum {
   ESCAPE_SGR0,     // "sgr0" turn off all styles
   ESCAPE_CIVIS,    // "civis" make the cursor invisiable
   ESCAPE_CNORM,    // "cnorm" restore the cursor to normal
+  ESCAPE_OC,       // "oc" restore original colors
   ESCAPE_MAX
 } escape_e;
 
@@ -47,8 +48,6 @@ typedef enum {
 typedef struct tinfo {
   uint16_t escindices[ESCAPE_MAX]; // table of 1-biased indices into esctable
   char* esctable;                  // packed table of escape sequences
-  char* sgr;      // set many graphics properties at once
-  char* sgr0;     // restore default presentation properties
   unsigned colors;// number of colors terminfo reported usable for this screen
   char* cuu;      // move N cells up
   char* cub;      // move N cells left
@@ -66,7 +65,6 @@ typedef struct tinfo {
   char* struck;   // NCSTYLE_STRUCK
   char* struckoff;// NCSTYLE_STRUCK (disable)
   char* initc;    // set a palette entry's RGB value
-  char* oc;       // restore original colors
   char* clearscr; // erase screen and home cursor
   char* sc;       // push the cursor location onto the stack
   char* rc;       // pop the cursor location off the stack

src/lib/terminfo.c

@@ -204,6 +204,8 @@ int interrogate_terminfo(tinfo* ti, int fd, const char* termname,
     { ESCAPE_OP, "op", },
     { ESCAPE_CNORM, "cnorm", },
     { ESCAPE_CIVIS, "civis", },
+    { ESCAPE_SGR, "sgr", },
+    { ESCAPE_SGR0, "sgr0", },
     { ESCAPE_MAX, NULL, },
   };
   size_t tablelen = 0;
@@ -256,9 +258,6 @@ int interrogate_terminfo(tinfo* ti, int fd, const char* termname,
   }
   terminfostr(&ti->italics, "sitm");  // begin italic mode
   terminfostr(&ti->italoff, "ritm");  // end italic mode
-  terminfostr(&ti->sgr, "sgr");       // define video attributes
-  terminfostr(&ti->sgr0, "sgr0");     // turn off all video attributes
-  terminfostr(&ti->oc, "oc");         // restore defaults to all colors
   terminfostr(&ti->home, "home");     // home the cursor
   terminfostr(&ti->clearscr, "clear");// clear screen, home cursor
   terminfostr(&ti->cuu, "cuu"); // move N up

src/tests/direct.cpp

@@ -8,14 +8,15 @@ TEST_CASE("DirectMode") {
   }
 
   SUBCASE("SetItalic") {
-    if(nc_->tcache.sgr){
+    unsigned styles = ncdirect_supported_styles(nc_);
+    if(styles & NCSTYLE_ITALIC){
       CHECK(0 == ncdirect_set_styles(nc_, NCSTYLE_ITALIC));
     }else{
       CHECK(0 != ncdirect_set_styles(nc_, NCSTYLE_ITALIC));
     }
     printf("DirectMode *italic*!\n");
     fflush(stdout);
-    if(nc_->tcache.sgr0){
+    if(styles & NCSTYLE_ITALIC){
       CHECK(0 == ncdirect_off_styles(nc_, NCSTYLE_ITALIC));
     }else{
       CHECK(0 != ncdirect_off_styles(nc_, NCSTYLE_ITALIC));
@@ -23,7 +24,8 @@ TEST_CASE("DirectMode") {
   }
 
   SUBCASE("SetBold") {
-    if(nc_->tcache.sgr){
+    unsigned styles = ncdirect_supported_styles(nc_);
+    if(styles & NCSTYLE_BOLD){
       CHECK(0 == ncdirect_set_styles(nc_, NCSTYLE_BOLD));
       printf("DirectMode *bold*!\n");
       fflush(stdout);
@@ -32,7 +34,8 @@ TEST_CASE("DirectMode") {
   }
 
   SUBCASE("SetUnderline") {
-    if(nc_->tcache.sgr){
+    unsigned styles = ncdirect_supported_styles(nc_);
+    if(styles & NCSTYLE_UNDERLINE){
       CHECK(0 == ncdirect_set_styles(nc_, NCSTYLE_UNDERLINE));
       printf("DirectMode *underline*!\n");
       fflush(stdout);
@@ -41,7 +44,8 @@ TEST_CASE("DirectMode") {
   }
 
   SUBCASE("SetStruck") {
-    if(nc_->tcache.sgr){
+    unsigned styles = ncdirect_supported_styles(nc_);
+    if(styles & NCSTYLE_STRUCK){
       CHECK(0 == ncdirect_set_styles(nc_, NCSTYLE_STRUCK));
       printf("DirectMode *struck*!\n");
       fflush(stdout);