add ncdirect_clear() #343

README.md

@@ -375,6 +375,7 @@ int ncdirect_dim_y(const struct ncdirect* nc);
 int ncdirect_styles_set(struct ncdirect* n, unsigned stylebits);
 int ncdirect_styles_on(struct ncdirect* n, unsigned stylebits);
 int ncdirect_styles_off(struct ncdirect* n, unsigned stylebits);
+int ncdirect_clear(struct ncdirect* nc); // clear the screen
 ```
 
 ### Alignment

doc/man/man3/notcurses_directmode.3.md

@@ -34,6 +34,8 @@ notcurses_directmode - minimal notcurses instances for styling text
 
 **int ncdirect_styles_off(struct ncdirect* n, unsigned stylebits);**
 
+**int ncdirect_clear(struct ncdirect* nc)**
+
 **int ncdirect_stop(struct ncdirect* nc);**
 
 # DESCRIPTION
@@ -55,6 +57,9 @@ display capabilities, and/or display errors. notcurses natively targets
 **ncdirect_dim_x** returns the current number of columns, and **ncdirect_dim_y**
 the current number of rows.
 
+**ncdirect_clear** clears the screen using a control code if one exists in
+terminfo. Otherwise, it prints successive newlines to scroll everything off.
+
 # RETURN VALUES
 
 **notcurses_directmode** returns **NULL** on failure. Otherwise, the return

include/notcurses.h

@@ -73,6 +73,9 @@ API int ncdirect_styles_set(struct ncdirect* n, unsigned stylebits);
 API int ncdirect_styles_on(struct ncdirect* n, unsigned stylebits);
 API int ncdirect_styles_off(struct ncdirect* n, unsigned stylebits);
 
+// Clear the screen.
+API int ncdirect_clear(struct ncdirect* nc);
+
 // Release 'nc' and any associated resources. 0 on success, non-0 on failure.
 API int ncdirect_stop(struct ncdirect* nc);
 

python/src/notcurses/build_notcurses.py

@@ -233,14 +233,15 @@ int palette256_get_rgb(const palette256* p, int idx, unsigned* r, unsigned* g, u
 void palette256_free(palette256* p);
 bool notcurses_canchangecolor(const struct notcurses* nc);
 struct ncdirect* notcurses_directmode(const char* termtype, FILE* fp);
-int ncdirect_bg_rgb8(struct ncdirect* nc, unsigned r, unsigned g, unsigned b);
-int ncdirect_fg_rgb8(struct ncdirect* nc, unsigned r, unsigned g, unsigned b);
-int ncdirect_fg(struct ncdirect* nc, unsigned rgb);
-int ncdirect_bg(struct ncdirect* nc, unsigned rgb);
+int ncdirect_bg_rgb8(struct ncdirect* n, unsigned r, unsigned g, unsigned b);
+int ncdirect_fg_rgb8(struct ncdirect* n, unsigned r, unsigned g, unsigned b);
+int ncdirect_fg(struct ncdirect* n, unsigned rgb);
+int ncdirect_bg(struct ncdirect* n, unsigned rgb);
 int ncdirect_styles_set(struct ncdirect* n, unsigned stylebits);
 int ncdirect_styles_on(struct ncdirect* n, unsigned stylebits);
 int ncdirect_styles_off(struct ncdirect* n, unsigned stylebits);
-int ncdirect_stop(struct ncdirect* nc);
+int ncdirect_clear(struct ncdirect* n);
+int ncdirect_stop(struct ncdirect* n);
 struct ncvisual* ncplane_visual_open(struct ncplane* nc, const char* file, int* averr);
 typedef enum {
   NCSCALE_NONE,

src/lib/internal.h

@@ -198,6 +198,7 @@ typedef struct ncdirect {
   char* italoff;  // CELL_STYLE_ITALIC (disable)
   char* initc;    // set a palette entry's RGB value
   char* oc;       // restore original colors
+  char* clear;    // clear the screen
   bool RGBflag;   // terminfo-reported "RGB" flag for 24bpc directcolor
   bool CCCflag;   // terminfo-reported "CCC" flag for palette set capability
   FILE* ttyfp;    // FILE* for controlling tty, from opts->ttyfp

src/lib/notcurses.c

@@ -803,6 +803,7 @@ ncdirect* notcurses_directmode(const char* termtype, FILE* outfp){
   term_verify_seq(&ret->oc, "oc");
   term_verify_seq(&ret->setaf, "setaf");
   term_verify_seq(&ret->setab, "setab");
+  term_verify_seq(&ret->clear, "clear");
   ret->RGBflag = query_rgb();
   if((ret->colors = tigetnum("colors")) <= 0){
     ret->colors = 1;
@@ -971,6 +972,13 @@ err:
   return NULL;
 }
 
+int ncdirect_clear(ncdirect* nc){
+  if(!nc->clear){
+    // FIXME scroll output off the screen
+  }
+  return term_emit("clear", nc->clear, nc->ttyfp, true);
+}
+
 int ncdirect_stop(ncdirect* nc){
   int ret = 0;
   if(nc){

src/poc/visual.cpp

@@ -31,7 +31,6 @@ int main(int argc, char** argv){
   if(notcurses_render(nc)){
     goto err;
   }
-  sleep(1);
   return notcurses_stop(nc) ? EXIT_FAILURE : EXIT_SUCCESS;
 
 err: