Correctly copy in shrink + SIGWINCH (#80) (#93)

* notcurses_resize(): properly set new lenx/leny #80
* ppoll() for SIGWINCH #80
* widecolor-demo: keystroke-driven

src/demo/widecolor.c

@@ -256,7 +256,13 @@ int widecolor_demo(struct notcurses* nc){
     // ncplane_erase(n);
     const int start = starts[i];
     const int step = steps[i];
-    //do{
+    ncspecial_key special;
+    cell c;
+    do{
+      int dimy, dimx;
+      notcurses_resize(nc, &dimy, &dimx);
+      cell_init(&c);
+      special = NCKEY_INVALID;
       int y, x, maxy, maxx;
       ncplane_dim_yx(n, &maxy, &maxx);
       int rgb = start;
@@ -309,12 +315,13 @@ int widecolor_demo(struct notcurses* nc){
       /*if(i){ FIXME
         fadein(w, count, palette, FADE_MILLISECONDS);
       }
-      do{
-        key = wgetch(w);
-      }while(key == ERR);
       */
-      nanosleep(&demodelay, NULL);
+      int key;
-    //}while(key == KEY_RESIZE);
+      do{
+        key = notcurses_getc_blocking(nc, &c, &special);
+      }while(key < 0);
+      // nanosleep(&demodelay, NULL);
+    }while(c.gcluster == 0 && special == NCKEY_RESIZE);
   }
   return 0;
 }

src/lib/notcurses.c

@@ -353,9 +353,11 @@ int notcurses_resize(notcurses* n, int* rows, int* cols){
   }
   int y, idx;
   idx = 0;
+  p->lenx = *cols;
+  p->leny = *rows;
   for(y = 0 ; y < p->leny ; ++y){
     idx = y * p->lenx;
-    if(y > oldrows){
+    if(y >= oldrows){
       memset(&p->fb[idx], 0, sizeof(*p->fb) * p->lenx);
       continue;
     }
@@ -366,7 +368,7 @@ int notcurses_resize(notcurses* n, int* rows, int* cols){
       }
       memcpy(&p->fb[idx], &preserved[y * oldcols], oldcopy * sizeof(*p->fb));
     }
-    if(p->lenx - oldcopy){
+    if(p->lenx > oldcopy){
       memset(&p->fb[idx + oldcopy], 0, sizeof(*p->fb) * (p->lenx - oldcopy));
     }
   }
@@ -1470,6 +1472,10 @@ void ncplane_erase(ncplane* n){
 static int
 handle_getc(const notcurses* nc __attribute__ ((unused)), cell* c, int kpress,
             ncspecial_key* special){
+fprintf(stderr, "KEYPRESS: %d\n", kpress);
+  if(kpress < 0){
+    return -1;
+  }
   *special = 0;
   if(kpress == 0x04){ // ctrl-d
     return -1;
@@ -1505,22 +1511,26 @@ int notcurses_getc_blocking(const notcurses* nc, cell* c, ncspecial_key* special
     .events = POLLIN | POLLRDHUP,
     .revents = 0,
   };
-  int pret;
+  int pret, r;
-  while((pret = poll(&pfd, 1, -1)) >= 0){
+  sigset_t smask;
+  sigfillset(&smask);
+  sigdelset(&smask, SIGWINCH);
+  while((pret = ppoll(&pfd, 1, NULL, &smask)) >= 0){
     if(pret == 0){
       continue;
     }
-    int r = getc(nc->ttyinfp);
+    r = getc(nc->ttyinfp);
     if(r < 0){
-      if(errno == EINTR){
+      break; // want EINTR handling below
-        if(resize_seen){
+    }
-          resize_seen = 0;
+    return handle_getc(nc, c, r, special);
-          c->gcluster = 0;
+  }
-          *special = NCKEY_RESIZE;
+  if(errno == EINTR){
-          return 1;
+    if(resize_seen){
-        }
+      resize_seen = 0;
-      }
+      c->gcluster = 0;
-      return handle_getc(nc, c, r, special);
+      *special = NCKEY_RESIZE;
+      return 1;
     }
   }
   return -1;