Support resize

termemu.cpp

@@ -15,6 +15,8 @@
 #include <typeinfo>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <sys/signalfd.h>
+#include <termios.h>
 
 #include "parser.hpp"
 #include "terminal.hpp"
@@ -117,9 +119,31 @@ int main( int argc,
 
 void emulate_terminal( int fd, int debug_fd )
 {
+  /* establish WINCH fd and start listening for signal */
+  sigset_t signal_mask;
+  assert( sigemptyset( &signal_mask ) == 0 );
+  assert( sigaddset( &signal_mask, SIGWINCH ) == 0 );
+
+  /* stop "ignoring" WINCH signal */
+  assert( sigprocmask( SIG_BLOCK, &signal_mask, NULL ) == 0 );
+
+  int winch_fd = signalfd( -1, &signal_mask, 0 );
+  if ( winch_fd < 0 ) {
+    perror( "signalfd" );
+    return;
+  }
+
+  /* get current window size */
+  struct winsize window_size;
+  if ( ioctl( STDIN_FILENO, TIOCGWINSZ, &window_size ) < 0 ) {
+    perror( "ioctl TIOCGWINSZ" );
+    return;
+  }
+
+  /* open parser and terminal */
   Parser::UTF8Parser parser;
-  Terminal::Emulator terminal( 80, 24 );
-  struct pollfd pollfds[ 2 ];
+  Terminal::Emulator terminal( window_size.ws_col, window_size.ws_row );
+  struct pollfd pollfds[ 3 ];
 
   pollfds[ 0 ].fd = STDIN_FILENO;
   pollfds[ 0 ].events = POLLIN;
@@ -127,10 +151,13 @@ void emulate_terminal( int fd, int debug_fd )
   pollfds[ 1 ].fd = fd;
   pollfds[ 1 ].events = POLLIN;
 
+  pollfds[ 2 ].fd = winch_fd;
+  pollfds[ 2 ].events = POLLIN;
+
   swrite( STDOUT_FILENO, terminal.open().c_str() );
 
   while ( 1 ) {
-    int active_fds = poll( pollfds, 2, -1 );
+    int active_fds = poll( pollfds, 3, -1 );
     if ( active_fds <= 0 ) {
       perror( "poll" );
       break;
@@ -144,6 +171,26 @@ void emulate_terminal( int fd, int debug_fd )
       if ( termemu( fd, fd, false, debug_fd, &parser, &terminal ) < 0 ) {
 	break;
       }
+    } else if ( pollfds[ 2 ].revents & POLLIN ) {
+      /* resize */
+      struct signalfd_siginfo info;
+      assert( read( winch_fd, &info, sizeof( info ) ) == sizeof( info ) );
+      assert( info.ssi_signo == SIGWINCH );
+
+      /* get new size */
+      if ( ioctl( STDIN_FILENO, TIOCGWINSZ, &window_size ) < 0 ) {
+	perror( "ioctl TIOCGWINSZ" );
+	return;
+      }
+
+      /* tell emulator */
+      terminal.resize( window_size.ws_col, window_size.ws_row );
+
+      /* tell child process */
+      if ( ioctl( fd, TIOCSWINSZ, &window_size ) < 0 ) {
+	perror( "ioctl TIOCSWINSZ" );
+	return;
+      }
     } else if ( (pollfds[ 0 ].revents | pollfds[ 1 ].revents)
 		& (POLLERR | POLLHUP | POLLNVAL) ) {
       break;

terminal.cpp

@@ -34,7 +34,7 @@ void Emulator::print( Parser::Print *act )
 
   Cell *this_cell = fb.get_cell();
 
-  Cell *combining_cell = fb.get_combining_cell();
+  Cell *combining_cell = fb.get_combining_cell(); /* can be null if we were resized */
 
   switch ( chwidth ) {
   case 1: /* normal character */
@@ -68,6 +68,11 @@ void Emulator::print( Parser::Print *act )
     act->handled = true;
     break;
   case 0: /* combining character */
+    if ( combining_cell == NULL ) { /* character is now offscreen */
+      act->handled = true;
+      break;
+    }
+
     if ( combining_cell->contents.size() == 0 ) {
       /* cell starts with combining character */
       assert( this_cell == combining_cell );
@@ -195,3 +200,8 @@ std::string Emulator::close( void )
   char ansimode[ 6 ] = { 0x1b, '[', '?', '1', 'l', 0 };
   return std::string( ansimode );
 }
+
+void Emulator::resize( size_t s_width, size_t s_height )
+{
+  fb.resize( s_width, s_height );
+}

terminal.hpp

@@ -46,6 +46,9 @@ namespace Terminal {
 
     std::string open( void ); /* put user cursor keys in application mode */
     std::string close( void ); /* restore user cursor keys */
+
+    void resize( size_t s_width, size_t s_height );
+
   };
 }
 

terminalframebuffer.cpp

@@ -56,7 +56,10 @@ DrawState::DrawState( int s_width, int s_height )
 
 Framebuffer::Framebuffer( int s_width, int s_height )
   : rows( s_height, Row( s_width ) ), window_title(), ds( s_width, s_height )
-{}
+{
+  assert( s_height > 0 );
+  assert( s_width > 0 );
+}
 
 void Framebuffer::scroll( int N )
 {
@@ -183,6 +186,11 @@ Cell *Framebuffer::get_cell( int row, int col )
 
 Cell *Framebuffer::get_combining_cell( void )
 {
+  if ( (ds.get_combining_char_row() >= ds.get_width())
+       || (ds.get_combining_char_col() >= ds.get_height()) ) {
+    return NULL;
+  } /* can happen if a resize came in between */
+
   return &rows[ ds.get_combining_char_row() ].cells[ ds.get_combining_char_col() ];
 }
 
@@ -280,7 +288,7 @@ void DrawState::restore_cursor( void )
   auto_wrap_mode = save.auto_wrap_mode;
   origin_mode = save.origin_mode;
 
-  snap_cursor_to_border();
+  snap_cursor_to_border(); /* we could have resized in between */
   new_grapheme();
 }
 
@@ -352,3 +360,40 @@ void Framebuffer::soft_reset( void )
   ds.clear_renditions();
   ds.clear_saved_cursor();
 }
+
+void Framebuffer::resize( int s_width, int s_height )
+{
+  assert( s_width > 0 );
+  assert( s_height > 0 );
+
+  rows.resize( s_height, Row( ds.get_width() ) );
+
+  for ( std::deque<Row>::iterator i = rows.begin();
+	i != rows.end();
+	i++ ) {
+    (*i).cells.resize( s_width, Cell() );
+  }
+
+  ds.resize( s_width, s_height );
+}
+
+void DrawState::resize( int s_width, int s_height )
+{
+  width = s_width;
+  height = s_height;
+
+  snap_cursor_to_border();
+
+  if ( scrolling_region_top_row >= height ) {
+    scrolling_region_top_row = 0;
+  }
+
+  if ( scrolling_region_bottom_row >= height ) {
+    scrolling_region_bottom_row = height - 1;
+  }
+
+  tabs.resize( width );
+
+  /* saved cursor will be snapped to border on restore */
+  /* combining char cell can now be offscreen */
+}

terminalframebuffer.hpp

@@ -106,6 +106,8 @@ namespace Terminal {
     void restore_cursor( void );
     void clear_saved_cursor( void ) { save = SavedCursor(); }
 
+    void resize( int s_width, int s_height );
+
     DrawState( int s_width, int s_height );
   };
 
@@ -139,6 +141,8 @@ namespace Terminal {
 
     void set_window_title( std::vector<wchar_t> s ) { window_title = s; }
     std::vector<wchar_t> get_window_title( void ) { return window_title; }
+
+    void resize( int s_width, int s_height );
   };
 }