From 92d80accf9957f5b568d7eb9857d53c1a12a2ada Mon Sep 17 00:00:00 2001
From: Keith Winstein <keithw@mit.edu>
Date: Mon, 31 Jan 2011 06:10:02 -0500
Subject: [PATCH] Implement tabs

---
 templates.cpp           |  1 +
 terminal.cpp            |  2 +-
 terminalframebuffer.cpp | 24 ++++++++++++++++++++++--
 terminalframebuffer.hpp |  7 +++++++
 terminalfunctions.cpp   | 32 ++++++++++++++++++++++++++++++++
 5 files changed, 63 insertions(+), 3 deletions(-)

diff --git a/templates.cpp b/templates.cpp
index 78eeb82..4cf6b79 100644
--- a/templates.cpp
+++ b/templates.cpp
@@ -16,3 +16,4 @@ template class std::vector<Terminal::Cell *>;
 template class std::vector<wchar_t>;
 template class std::vector<int>;
 template class std::map<std::string, Terminal::Function>;
+template class std::vector<bool>;
diff --git a/terminal.cpp b/terminal.cpp
index 8953f9f..fb5d3b4 100644
--- a/terminal.cpp
+++ b/terminal.cpp
@@ -63,7 +63,7 @@ void Emulator::print( Parser::Print *act )
   switch ( chwidth ) {
   case 1: /* normal character */
   case 2: /* wide character */
-    if ( fb.ds.next_print_will_wrap ) {
+    if ( fb.ds.auto_wrap_mode && fb.ds.next_print_will_wrap ) {
       fb.ds.move_col( 0 );
       fb.move_rows_autoscroll( 1 );
     }
diff --git a/terminalframebuffer.cpp b/terminalframebuffer.cpp
index e9e7193..b6b74ad 100644
--- a/terminalframebuffer.cpp
+++ b/terminalframebuffer.cpp
@@ -56,8 +56,8 @@ void Cell::reset( void )
 DrawState::DrawState( int s_width, int s_height )
   : width( s_width ), height( s_height ),
     cursor_col( 0 ), cursor_row( 0 ),
-    combining_char_col( 0 ), combining_char_row( 0 ),
-    next_print_will_wrap( false )
+    combining_char_col( 0 ), combining_char_row( 0 ), tabs( s_width ),
+    next_print_will_wrap( false ), auto_wrap_mode( true )
 {}
 
 Framebuffer::Framebuffer( int s_width, int s_height )
@@ -179,3 +179,23 @@ void Framebuffer::claim_overlap( int row, int col )
     }
   }
 }
+
+void DrawState::set_tab( void )
+{
+  tabs[ cursor_col ] = true;
+}
+
+void DrawState::clear_tab( int col )
+{
+  tabs[ col ] = false;
+}
+
+int DrawState::get_next_tab( void )
+{
+  for ( int i = cursor_col + 1; i < width; i++ ) {
+    if ( tabs[ i ] ) {
+      return i;
+    }
+  }
+  return -1;
+}
diff --git a/terminalframebuffer.hpp b/terminalframebuffer.hpp
index d2ea01e..91b4ff6 100644
--- a/terminalframebuffer.hpp
+++ b/terminalframebuffer.hpp
@@ -40,8 +40,11 @@ namespace Terminal {
     int cursor_col, cursor_row;
     int combining_char_col, combining_char_row;
 
+    std::vector<bool> tabs;
+
   public:
     bool next_print_will_wrap;
+    bool auto_wrap_mode;
 
     /* bold, etc. */
 
@@ -55,6 +58,10 @@ namespace Terminal {
     int get_width( void ) { return width; }
     int get_height( void ) { return height; }
 
+    void set_tab( void );
+    void clear_tab( int col );
+    int get_next_tab( void );
+
     DrawState( int s_width, int s_height );
   };
 
diff --git a/terminalfunctions.cpp b/terminalfunctions.cpp
index 6e5b3a2..443aed5 100644
--- a/terminalfunctions.cpp
+++ b/terminalfunctions.cpp
@@ -141,3 +141,35 @@ void Ctrl_NEL( Framebuffer *fb, Dispatcher *dispatch __attribute((unused)) )
 }
 
 static Function func_Ctrl_NEL( CONTROL, "\x85", Ctrl_NEL );
+
+void Ctrl_HT( Framebuffer *fb, Dispatcher *dispatch __attribute((unused)) )
+{
+  int col = fb->ds.get_next_tab();
+  if ( col == -1 ) { /* no tabs, go to end of line */
+    fb->ds.move_col( fb->ds.get_width() - 1 );
+  } else {
+    fb->ds.move_col( col );
+  }
+}
+
+static Function func_Ctrl_HT( CONTROL, "\x09", Ctrl_HT );
+
+void Ctrl_HTS( Framebuffer *fb, Dispatcher *dispatch __attribute((unused)) )
+{
+  fb->ds.set_tab();
+}
+
+static Function func_Ctrl_HTS( CONTROL, "\x88", Ctrl_HT );
+
+void CSI_TBC( Framebuffer *fb, Dispatcher *dispatch )
+{
+  if ( dispatch->getparam( 0, 0 ) == 3 ) { /* clear all tab stops */
+    for ( int x = 0; x < fb->ds.get_width(); x++ ) {
+      fb->ds.clear_tab( x );
+    }
+  } else {
+    fb->ds.clear_tab( fb->ds.get_cursor_col() );
+  }
+}
+
+static Function func_CSI_TBC( CSI, "g", CSI_TBC );