notcurses-ncreel: handle +/- for tablets

include/notcurses/notcurses.h

@@ -50,12 +50,12 @@ struct ncfadectx; // context for a palette fade operation
 typedef enum {
   NCBLIT_DEFAULT, // let the ncvisual pick
   NCBLIT_1x1,     // full block                █
-  NCBLIT_2x1,     // full/(upper|left) blocks  ▄█
+  NCBLIT_2x1,     // upper half + 1x1          ▀█
   NCBLIT_1x1x4,   // shaded full blocks        ▓▒░█
-  NCBLIT_2x2,     // quadrants                 ▗▐ ▖▄▟▌▙█
-  NCBLIT_4x1,     // four vert/horz levels     █▆▄▂ / ▎▌▊█
+  NCBLIT_2x2,     // quadrants + 2x1           ▗▐ ▖▀▟▌▙█
+  NCBLIT_4x1,     // four vertical levels      █▆▄▂
   NCBLIT_BRAILLE, // 4 rows, 2 cols (braille)  ⡀⡄⡆⡇⢀⣀⣄⣆⣇⢠⣠⣤⣦⣧⢰⣰⣴⣶⣷⢸⣸⣼⣾⣿
-  NCBLIT_8x1,     // eight vert/horz levels    █▇▆▅▄▃▂▁ / ▏▎▍▌▋▊▉█
+  NCBLIT_8x1,     // eight vertical levels     █▇▆▅▄▃▂▁
   NCBLIT_SIXEL,   // 6 rows, 1 col (RGB), spotty support among terminals
 } ncblitter_e;
 

src/lib/reel.c

@@ -832,6 +832,8 @@ bool ncreel_offer_input(ncreel* n, const ncinput* nc){
     ncreel_next(n);
     return true;
   }
-  // FIXME there are a few more
+  // FIXME there are a few more:
+  //  page up/page down
+  //  end/home (when not using infinite scrolling)
   return false;
 }

src/ncreel/main.cpp

@@ -19,6 +19,14 @@ class TabletCtx {
     int getLines() const {
       return lines;
     }
+    void addLine() {
+      ++lines;
+    }
+    void subLine() {
+      if(lines){
+        --lines;
+      }
+    }
     int getIdx() const {
       return idx;
     }
@@ -122,7 +130,21 @@ int runreels(struct notcurses* nc, struct ncplane* n, ncreel_options* nopts){
       case 'd':
         ncreel_del(nr, ncreel_focused(nr));
         break;
-      case '*':
+      case '+':{
+        auto t = ncreel_focused(nr);
+        if(t){
+          auto tctx = static_cast<TabletCtx*>(nctablet_userptr(t));
+          tctx->addLine();
+        }
+        break;
+      }case '-':{
+        auto t = ncreel_focused(nr);
+        if(t){
+          auto tctx = static_cast<TabletCtx*>(nctablet_userptr(t));
+          tctx->subLine();
+        }
+        break;
+      }case '*':
         notcurses_debug(nc, stderr);
         break;
       case NCKEY_LEFT:
@@ -170,7 +192,7 @@ int main(int argc, char** argv){
   }
   int dimy, dimx;
   auto nstd = notcurses_stddim_yx(nc, &dimy, &dimx);
-  if(ncplane_putstr_aligned(nstd, 0, NCALIGN_CENTER, "(a)dd (d)el (q)uit") <= 0){
+  if(ncplane_putstr_aligned(nstd, 0, NCALIGN_CENTER, "(a)dd (d)el (+/-) change lines (q)uit") <= 0){
     return -1;
   }
   auto n = ncplane_new(nc, dimy - 1 - (margin_t + margin_b),