term: add minimal mouse support

Only detects mouse clicks. Though, "9" mode seems broken, or unsupported
or something? Probably need to upgrade to "1000" mode or higher, but
that also reports scrolling events and such, which don't want to steal
from the context we're running in just yet.

pkg/arvo/lib/hood/drum.hoon

@@ -699,6 +699,7 @@
       [%bac *]  ta-bac
       [%ctl *]  (ta-ctl p.bet)
       [%del *]  ta-del
+      [%hit *]  (ta-hit +.bet)
       [%met *]  (ta-met p.bet)
       [%ret *]  ta-ret
       [%txt *]  (ta-txt p.bet)
@@ -779,6 +780,15 @@
       ta-bel
     (ta-hom %del pos.inp)
   ::
+  ++  ta-hit                                          ::  hear click
+    |=  [r=@ud c=@ud]
+    ^+  +>
+    ?.  =(0 r)  +>
+    =/  pol=@ud
+      (lent-char:klr (make:klr cad.pom))
+    ?:  (lth c pol)  +>.$
+    +>.$(pos.inp (min (sub c pol) (lent buf.say.inp)))
+  ::
   ++  ta-erl                                          ::  hear local error
     |=  pos=@ud
     ta-bel(pos.inp (min pos (lent buf.say.inp)))

pkg/arvo/mar/belt.hoon

@@ -15,6 +15,7 @@
         bac+ul
         ctl+(cu taft so)
         del+ul
+        hit+(ot 'r'^ni 'c'^ni ~)
         met+(cu taft so)
         ret+ul
         txt+(ar (cu taft so))

pkg/arvo/sys/lull.hoon

@@ -1050,6 +1050,7 @@
         [%bac ~]                                        ::  true backspace
         [%ctl p=@c]                                     ::  control-key
         [%del ~]                                        ::  true delete
+        [%hit r=@ud c=@ud]                              ::  mouse click
         [%met p=@c]                                     ::  meta-key
         [%ret ~]                                        ::  return
         [%txt p=(list @c)]                              ::  utf32 text

pkg/urbit/include/vere/vere.h

@@ -154,6 +154,9 @@
         struct {                            //  escape code control
           c3_o    ape;                      //  escape received
           c3_o    bra;                      //  bracket or O received
+          c3_o    mou;                      //  M (for mouse event) received
+          c3_y    ton_y;                    //  mouse button
+          c3_y    col_y;                    //  column coordinate
         } esc;
 
         struct {

pkg/urbit/vere/io/term.c

@@ -224,6 +224,9 @@ u3_term_log_init(void)
 
       uty_u->tat_u.esc.ape = c3n;
       uty_u->tat_u.esc.bra = c3n;
+      uty_u->tat_u.esc.mou = c3n;
+      uty_u->tat_u.esc.ton_y = 0;
+      uty_u->tat_u.esc.col_y = 0;
 
       uty_u->tat_u.fut.len_w = 0;
       uty_u->tat_u.fut.wid_w = 0;
@@ -723,6 +726,8 @@ _term_io_suck_char(u3_utty* uty_u, c3_y cay_y)
 {
   u3_utat* tat_u = &uty_u->tat_u;
 
+  //  escape sequences
+  //
   if ( c3y == tat_u->esc.ape ) {
     if ( c3y == tat_u->esc.bra ) {
       switch ( cay_y ) {
@@ -734,6 +739,8 @@ _term_io_suck_char(u3_utty* uty_u, c3_y cay_y)
         case 'B': _term_io_belt(uty_u, u3nc(c3__aro, 'd')); break;
         case 'C': _term_io_belt(uty_u, u3nc(c3__aro, 'r')); break;
         case 'D': _term_io_belt(uty_u, u3nc(c3__aro, 'l')); break;
+      //
+        case 'M': tat_u->esc.mou = c3y; break;
       }
       tat_u->esc.ape = tat_u->esc.bra = c3n;
     }
@@ -760,6 +767,27 @@ _term_io_suck_char(u3_utty* uty_u, c3_y cay_y)
       }
     }
   }
+  //  mouse input
+  //
+  else if ( c3y == tat_u->esc.mou ) {
+    if ( 0 == tat_u->esc.ton_y ) {
+      tat_u->esc.ton_y = cay_y - 31;
+    }
+    else if ( 0 == tat_u->esc.col_y ) {
+      tat_u->esc.col_y = cay_y - 32;
+    }
+    else {
+      c3_y row_y = cay_y - 32;
+      //  only acknowledge button 1 presses within our window
+      if ( 1 != tat_u->esc.ton_y && row_y <= tat_u->siz.row_l ) {
+        _term_io_belt(uty_u, u3nt(c3__hit, tat_u->siz.row_l - row_y, tat_u->esc.col_y - 1));
+      }
+      tat_u->esc.mou = c3n;
+      tat_u->esc.ton_y = tat_u->esc.col_y = 0;
+    }
+  }
+  //  unicode inputs
+  //
   else if ( 0 != tat_u->fut.wid_w ) {
     tat_u->fut.syb_y[tat_u->fut.len_w++] = cay_y;
 
@@ -775,6 +803,8 @@ _term_io_suck_char(u3_utty* uty_u, c3_y cay_y)
       _term_io_belt(uty_u, u3nt(c3__txt, wug, u3_nul));
     }
   }
+  //  individual characters
+  //
   else {
     if ( (cay_y >= 32) && (cay_y < 127) ) {
       _term_io_belt(uty_u, u3nt(c3__txt, cay_y, u3_nul));
@@ -1615,6 +1645,11 @@ _term_io_talk(u3_auto* car_u)
   if ( c3n == u3_Host.ops_u.tem ) {
     u3_utty* uty_u = _term_main();
 
+    //  start mouse handling
+    //
+    uv_buf_t mon_u = TERM_LIT_BUF("\033[?9h");
+    _term_it_dump_buf(uty_u, &mon_u);
+
     uv_read_start((uv_stream_t*)&(uty_u->pop_u),
                   _term_alloc,
                   _term_read_cb);
@@ -1781,6 +1816,11 @@ _term_io_exit(u3_auto* car_u)
   uv_read_stop((uv_stream_t*)&(uty_u->pop_u));
 
   if ( c3n == u3_Host.ops_u.tem ) {
+    //  stop mouse handling
+    //
+    uv_buf_t mof_u = TERM_LIT_BUF("\033[?9l");
+    _term_it_dump_buf(uty_u, &mof_u);
+
     uv_timer_t* han_u = &(uty_u->tat_u.sun_u.tim_u);
     han_u->data       = car_u;