ncreader: horizontal scrolling mostly works #839

NEWS.md

@@ -17,6 +17,7 @@ rearrangements of Notcurses.
     * `int ncreader_move_up(struct ncreader* n);`
     * `int ncreader_move_down(struct ncreader* n);`
     * `int ncreader_write_egc(struct ncreader* n, const char* egc);`
+  * Added `ncplane_above()` and `notcurses_bottom()`.
 
 * 1.6.17 (2020-08-22)
   * `ncdirect_flush()` now takes a `const struct ncdirect*`.

USAGE.md

@@ -214,6 +214,9 @@ Utility functions operating on the toplevel `notcurses` object include:
 // Return the topmost ncplane, of which there is always at least one.
 struct ncplane* notcurses_top(struct notcurses* n);
 
+// Return the bottommost ncplane, of which there is always at least one.
+struct ncplane* notcurses_bottom(struct notcurses* n);
+
 // Return our current idea of the terminal dimensions in rows and cols.
 static inline void
 notcurses_term_dim_yx(const struct notcurses* n, int* restrict rows,
@@ -826,6 +829,9 @@ int ncplane_move_above(struct ncplane* restrict n, struct ncplane* restrict abov
 
 // Return the ncplane below this one, or NULL if this is at the stack's bottom.
 struct ncplane* ncplane_below(struct ncplane* n);
+
+// Return the ncplane above this one, or NULL if this is at the stack's top.
+struct ncplane* ncplane_above(struct ncplane* n);
 ```
 
 Each plane holds a user pointer which can be retrieved and set (or ignored). In

doc/man/man3/notcurses_plane.3.md

@@ -10,6 +10,10 @@ notcurses_plane - operations on ncplanes
 
 **#include <notcurses/notcurses.h>**
 
+**struct ncplane* notcurses_top(struct notcurses* n);**
+
+**struct ncplane* notcurses_bottom(struct notcurses* n);**
+
 **struct ncplane* ncplane_new(struct notcurses* nc, int rows, int cols, int yoff, int xoff, void* opaque);**
 
 **struct ncplane* ncplane_new_named(struct notcurses* nc, int rows, int cols, int yoff, int xoff, void* opaque, const char* name);**
@@ -52,6 +56,8 @@ notcurses_plane - operations on ncplanes
 
 **struct ncplane* ncplane_below(struct ncplane* n);**
 
+**struct ncplane* ncplane_above(struct ncplane* n);**
+
 **char* ncplane_at_cursor(struct ncplane* n, uint16_t* stylemask, uint64_t* channels);**
 
 **int ncplane_at_cursor_cell(struct ncplane* n, cell* c);**

include/notcurses/notcurses.h

@@ -858,6 +858,9 @@ API int notcurses_render_to_file(struct notcurses* nc, FILE* fp);
 // Return the topmost ncplane, of which there is always at least one.
 API struct ncplane* notcurses_top(struct notcurses* n);
 
+// Return the bottommost ncplane, of which there is always at least one.
+API struct ncplane* notcurses_bottom(struct notcurses* n);
+
 // Destroy all ncplanes other than the stdplane.
 API void notcurses_drop_planes(struct notcurses* nc);
 
@@ -1197,6 +1200,7 @@ API int ncplane_move_below(struct ncplane* RESTRICT n,
 
 // Return the plane below this one, or NULL if this is at the bottom.
 API struct ncplane* ncplane_below(struct ncplane* n);
+API struct ncplane* ncplane_above(struct ncplane* n);
 
 // Rotate the plane π/2 radians clockwise or counterclockwise. This cannot
 // be performed on arbitrary planes, because glyphs cannot be arbitrarily

python/src/notcurses/build_notcurses.py

@@ -62,6 +62,7 @@ int ncplane_set_base_cell(struct ncplane* ncp, const cell* c);
 int ncplane_set_base(struct ncplane* ncp, const char* egc, uint32_t styles, uint64_t channels);
 int ncplane_base(struct ncplane* ncp, cell* c);
 struct ncplane* notcurses_top(struct notcurses* n);
+struct ncplane* notcurses_bottom(struct notcurses* n);
 void notcurses_drop_planes(struct notcurses* nc);
 int notcurses_refresh(struct notcurses* n, int* restrict y, int* restrict x);
 struct ncplane* ncplane_reparent(struct ncplane* n, struct ncplane* newparent);
@@ -102,6 +103,7 @@ void ncplane_move_bottom(struct ncplane* n);
 int ncplane_move_below(struct ncplane* restrict n, struct ncplane* restrict below);
 int ncplane_move_above(struct ncplane* restrict n, struct ncplane* restrict above);
 struct ncplane* ncplane_below(struct ncplane* n);
+struct ncplane* ncplane_above(struct ncplane* n);
 char* notcurses_at_yx(struct notcurses* nc, int yoff, int xoff, uint16_t* stylemask, uint64_t* channels);
 char* ncplane_at_cursor(struct ncplane* n, uint16_t* stylemask, uint64_t* channels);
 char* ncplane_at_yx(const struct ncplane* n, int y, int x, uint16_t* stylemask, uint64_t* channels);

src/lib/notcurses.c

@@ -1888,10 +1888,18 @@ ncplane* notcurses_top(notcurses* n){
   return n->top;
 }
 
+ncplane* notcurses_bottom(notcurses* n){
+  return n->bottom;
+}
+
 ncplane* ncplane_below(ncplane* n){
   return n->below;
 }
 
+ncplane* ncplane_above(ncplane* n){
+  return n->above;
+}
+
 #define SET_BTN_EVENT_MOUSE   "1002"
 #define SET_FOCUS_EVENT_MOUSE "1004"
 #define SET_SGR_MODE_MOUSE    "1006"

src/lib/reader.c

@@ -181,10 +181,15 @@ int ncreader_write_egc(ncreader* n, const char* egc){
     logerror(n->ncp->nc, "Fed illegal UTF-8 [%s]\n", egc);
     return -1;
   }
-  if(n->textarea->x >= n->textarea->lenx - (cols + 1)){
+  if(n->textarea->x >= n->textarea->lenx - cols){
     if(n->horscroll){
-      // FIXME resize
+      if(ncplane_resize_simple(n->textarea, n->textarea->leny, n->textarea->lenx + cols)){
+        return -1;
+      }
+      ++n->xproject;
     }
+  }else if(n->ncp->x >= n->ncp->lenx){
+    ++n->xproject;
   }
   // use ncplane_putegc on both planes because it'll get cursor movement right
   if(ncplane_putegc(n->textarea, egc, NULL) < 0){
@@ -193,7 +198,6 @@ int ncreader_write_egc(ncreader* n, const char* egc){
   if(ncplane_putegc(n->ncp, egc, NULL) < 0){
     return -1;
   }
-  // FIXME pan right if necessary
   return 0;
 }
 
@@ -225,6 +229,7 @@ bool ncreader_offer_input(ncreader* n, const ncinput* ni){
     }
     ncplane_putegc_yx(n->textarea, y, x, "", NULL);
     ncplane_cursor_move_yx(n->textarea, y, x);
+    ncplane_cursor_move_yx(n->ncp, n->ncp->y, n->ncp->x - 1);
     ncreader_redraw(n);
     return true;
   }

src/poc/reader.cpp

@@ -56,13 +56,16 @@ auto main(int argc, const char** argv) -> int {
     int y, x;
     struct ncplane* ncp = ncreader_plane(nr);
     ncplane_cursor_yx(ncp, &y, &x);
-    nc.cursor_enable(y + 2, x + 2);
+    nc.cursor_enable(y + 2, 2 + (x >= ncplane_dim_x(ncp) ? ncplane_dim_x(ncp) - 1 : x));
     int ncpy, ncpx;
     ncplane_cursor_yx(ncp, &ncpy, &ncpx);
+    struct ncplane* tplane = ncplane_above(ncp);
     int tgeomy, tgeomx, vgeomy, vgeomx;
-    (*n)->get_dim(&tgeomy, &tgeomx);
+    ncplane_dim_yx(tplane, &tgeomy, &tgeomx);
     ncplane_dim_yx(ncp, &vgeomy, &vgeomx);
-    (*n)->printf(0, 0, "Cursor: %d/%d Viewgeom: %d/%d Textgeom: %d/%d", ncpy, ncpx, vgeomy, vgeomx, tgeomy, tgeomx);
+    (*n)->printf(0, 0, "Scroll: %lc Cursor: %d/%d Viewgeom: %d/%d Textgeom: %d/%d",
+                 horscroll ? L'✔' : L'🗴',
+                 ncpy, ncpx, vgeomy, vgeomx, tgeomy, tgeomx);
     nc.render();
   }
   nc.render();