Implement terminal bell

terminaldisplay.cpp

@@ -12,6 +12,11 @@ std::string Display::new_frame( bool initialized, const Framebuffer &last, const
 
   char tmp[ 64 ];
 
+  /* has bell been rung? */
+  if ( f.get_bell_count() != frame.last_frame.get_bell_count() ) {
+    frame.append( "\x07" );
+  }
+
   /* has window title changed? */
   if ( (!initialized)
        || (f.get_window_title() != frame.last_frame.get_window_title()) ) {

terminalframebuffer.cpp

@@ -28,7 +28,7 @@ DrawState::DrawState( int s_width, int s_height )
 }
 
 Framebuffer::Framebuffer( int s_width, int s_height )
-  : rows( s_height, Row( s_width, 0 ) ), window_title(), ds( s_width, s_height )
+  : rows( s_height, Row( s_width, 0 ) ), window_title(), bell_count( 0 ), ds( s_width, s_height )
 {
   assert( s_height > 0 );
   assert( s_width > 0 );
@@ -286,6 +286,7 @@ void Framebuffer::reset( void )
   ds = DrawState( width, height );
   rows = std::deque<Row>( height, newrow() );
   window_title.clear();
+  /* do not reset bell_count */
 }
 
 void Framebuffer::soft_reset( void )

terminalframebuffer.hpp

@@ -189,6 +189,7 @@ namespace Terminal {
   private:
     std::deque<Row> rows;
     std::deque<wchar_t> window_title;
+    unsigned int bell_count;
 
     Row newrow( void ) { return Row( ds.get_width(), ds.get_background_rendition() ); }
 
@@ -262,9 +263,12 @@ namespace Terminal {
     void reset_cell( Cell *c ) { c->reset( ds.get_background_rendition() ); }
     void reset_row( Row *r ) { r->reset( ds.get_background_rendition() ); }
 
+    void ring_bell( void ) { bell_count++; }
+    unsigned int get_bell_count( void ) const { return bell_count; }
+
     bool operator==( const Framebuffer &x ) const
     {
-      return ( rows == x.rows ) && ( window_title == x.window_title ) && ( ds == x.ds );
+      return ( rows == x.rows ) && ( window_title == x.window_title ) && ( bell_count == x.bell_count ) && ( ds == x.ds );
     }
   };
 }

terminalfunctions.cpp

@@ -303,9 +303,10 @@ void CSI_DECSTBM( Framebuffer *fb, Dispatcher *dispatch )
 
 static Function func_CSI_DECSTMB( CSI, "r", CSI_DECSTBM );
 
-/* terminal bell -- ignored for now */
-void Ctrl_BEL( Framebuffer *fb __attribute((unused)), Dispatcher *dispatch __attribute((unused)) )
-{}
+/* terminal bell */
+void Ctrl_BEL( Framebuffer *fb, Dispatcher *dispatch __attribute((unused)) ) {
+  fb->ring_bell();
+}
 
 static Function func_Ctrl_BEL( CONTROL, "\x07", Ctrl_BEL );