Support 256color (and assume 256color terminal). Closes #3 github issue.

src/terminal/terminalframebuffer.cc

@@ -369,6 +369,7 @@ Renditions::Renditions( int s_background )
     background_color( s_background )
 {}
 
+/* This routine cannot be used to set a color beyond the 8-color set. */
 void Renditions::set_rendition( int num )
 {
   if ( num == 0 ) {
@@ -377,10 +378,18 @@ void Renditions::set_rendition( int num )
     return;
   }
 
-  if ( (30 <= num) && (num <= 39) ) { /* foreground color */
+  if ( num == 39 ) {
+    foreground_color = 0;
+    return;
+  } else if ( num == 49 ) {
+    background_color = 0;
+    return;
+  }
+
+  if ( (30 <= num) && (num <= 37) ) { /* foreground color in 8-color set */
     foreground_color = num;
     return;
-  } else if ( (40 <= num) && (num <= 49) ) { /* background color */
+  } else if ( (40 <= num) && (num <= 47) ) { /* background color in 8-color set */
     background_color = num;
     return;
   }
@@ -394,6 +403,20 @@ void Renditions::set_rendition( int num )
   }
 }
 
+void Renditions::set_foreground_color( int num )
+{
+  if ( (0 <= num) && (num <= 255) ) {
+    foreground_color = 30 + num;
+  }
+}
+
+void Renditions::set_background_color( int num )
+{
+  if ( (0 <= num) && (num <= 255) ) {
+    background_color = 40 + num;
+  }
+}
+
 std::string Renditions::sgr( void ) const
 {
   std::string ret;
@@ -404,16 +427,27 @@ std::string Renditions::sgr( void ) const
   if ( blink ) ret.append( ";5" );
   if ( inverse ) ret.append( ";7" );
   if ( invisible ) ret.append( ";8" );
-  if ( foreground_color ) {
+
+  if ( foreground_color > 37 ) { /* use 256-color set */
+    char col[ 64 ];
+    snprintf( col, 64, "m\033[38;5;%d", foreground_color - 30 );
+    ret.append( col );
+  } else if ( foreground_color ) {
     char col[ 8 ];
     snprintf( col, 8, ";%d", foreground_color );
     ret.append( col );
   }
-  if ( background_color ) {
+
+  if ( background_color > 47 ) { /* use 256-color set */
+    char col[ 64 ];
+    snprintf( col, 64, "m\033[48;5;%d", background_color - 40 );
+    ret.append( col );
+  } else if ( background_color ) {
     char col[ 8 ];
     snprintf( col, 8, ";%d", background_color );
     ret.append( col );
   }
+
   ret.append( "m" );
 
   return ret;

src/terminal/terminalframebuffer.h

@@ -35,6 +35,8 @@ namespace Terminal {
     int background_color;
 
     Renditions( int s_background );
+    void set_foreground_color( int num );
+    void set_background_color( int num );
     void set_rendition( int num );
     std::string sgr( void ) const;
 
@@ -182,9 +184,11 @@ namespace Terminal {
     int limit_top( void );
     int limit_bottom( void );
 
+    void set_foreground_color( int x ) { renditions.set_foreground_color( x ); }
+    void set_background_color( int x ) { renditions.set_background_color( x ); }
     void add_rendition( int x ) { renditions.set_rendition( x ); }
     Renditions get_renditions( void ) const { return renditions; }
-    int get_background_rendition( void ) { return renditions.background_color; }
+    int get_background_rendition( void ) const { return renditions.background_color; }
 
     void save_cursor( void );
     void restore_cursor( void );

src/terminal/terminalfunctions.cc

@@ -332,9 +332,24 @@ static Function func_Ctrl_BEL( CONTROL, "\x07", Ctrl_BEL );
 /* select graphics rendition -- e.g., bold, blinking, etc. */
 void CSI_SGR( Framebuffer *fb, Dispatcher *dispatch )
 {
-  for ( int i = 0; i < dispatch->param_count(); i++ ) {
-    int rendition = dispatch->getparam( i, 0 );
-    fb->ds.add_rendition( rendition );
+  /* We need to special-case the handling of CSI [34]8 ; 5 ; Ps m,
+     because Ps of 0 in that case does not mean reset to default, even
+     though it means that otherwise (as usually renditions are applied
+     in order). */
+
+  if ( (dispatch->param_count() == 3)
+       && (dispatch->getparam( 0, -1 ) == 38)
+       && (dispatch->getparam( 1, -1 ) == 5) ) {
+    fb->ds.set_foreground_color( dispatch->getparam( 2, 0 ) );
+  } else if ( (dispatch->param_count() == 3)
+	      && (dispatch->getparam( 0, -1 ) == 48)
+	      && (dispatch->getparam( 1, -1 ) == 5) ) {
+    fb->ds.set_background_color( dispatch->getparam( 2, 0 ) );
+  } else {
+    for ( int i = 0; i < dispatch->param_count(); i++ ) {
+      int rendition = dispatch->getparam( i, 0 );
+      fb->ds.add_rendition( rendition );
+    }
   }
 }