Abstract cursor movement

terminal.cpp

@@ -45,24 +45,18 @@ void Emulator::execute( Parser::Execute *act )
 
   switch ( act->ch ) {
   case 0x0a: /* LF */
-    fb.cursor_row++;
-    fb.autoscroll();
-    fb.newgrapheme();
+    fb.move_rows_autoscroll( 1 );
     act->handled = true;
     break;
 
   case 0x0d: /* CR */
-    fb.cursor_col = 0;
-    fb.newgrapheme();
+    fb.ds.move_col( 0 );
     act->handled = true;
     break;
     
   case 0x08: /* BS */
-    if ( fb.cursor_col > 0 ) {
-      fb.cursor_col--;
-      fb.newgrapheme(); /* this is not xterm's behavior */
-      act->handled = true;
-    }
+    fb.ds.move_col( -1, true );
+    act->handled = true;
     break;
   }
 }
@@ -71,56 +65,47 @@ void Emulator::print( Parser::Print *act )
 {
   assert( act->char_present );
 
-  if ( (fb.width == 0) || (fb.height == 0) ) {
+  int chwidth = act->ch == L'\0' ? -1 : wcwidth( act->ch );
+
+  Cell *this_cell = fb.get_cell();
+
+  if ( !this_cell ) { /* zero-size framebuffer */
     return;
   }
 
-  assert( fb.cursor_row < fb.height ); /* must be on screen */
-  assert( fb.cursor_col <= fb.width + 1 ); /* two off is ok */
-  assert( fb.combining_char_row < fb.height );
-  assert( fb.combining_char_col < fb.width );
-
-  int chwidth = act->ch == L'\0' ? -1 : wcwidth( act->ch );
-
-  Cell *this_cell;
+  Cell *combining_cell = fb.get_combining_cell();
 
   switch ( chwidth ) {
   case 1: /* normal character */
   case 2: /* wide character */
-    if ( fb.cursor_col >= fb.width ) { /* wrap */
-      fb.cursor_col = 0;
-      fb.cursor_row++;
+    if ( fb.ds.next_print_will_wrap ) {
+      fb.ds.move_col( 0 );
+      fb.move_rows_autoscroll( 1 );
     }
 
-    fb.autoscroll();
-    fb.newgrapheme();
+    this_cell = fb.get_cell();
 
-    this_cell = &fb.rows[ fb.cursor_row ].cells[ fb.cursor_col ];
     this_cell->reset();
     this_cell->contents.push_back( act->ch );
+    this_cell->width = chwidth;
 
-    if ( (fb.cursor_col < fb.width - 1) && (chwidth == 2) ) {
-      Cell *next_cell = &fb.rows[ fb.cursor_row ].cells[ fb.cursor_col + 1 ];
-      this_cell->overlapped_cells.push_back( next_cell );
-      next_cell->overlapping_cell = this_cell;
-    }
+    fb.claim_overlap( fb.ds.get_cursor_row(), fb.ds.get_cursor_col() );
+
+    fb.ds.move_col( chwidth, true, true );
 
-    fb.cursor_col += chwidth;
     act->handled = true;
     break;
   case 0: /* combining character */
-    if ( fb.rows[ fb.combining_char_row ].cells[ fb.combining_char_col ].contents.size() == 0 ) {
+    if ( combining_cell->contents.size() == 0 ) {
       /* cell starts with combining character */
-      fb.rows[ fb.combining_char_row ].cells[ fb.combining_char_col ].fallback = true;
-      assert( fb.cursor_col == fb.combining_char_col );
-      assert( fb.cursor_row == fb.combining_char_row );
-      assert( fb.cursor_col < fb.width );
-      fb.cursor_col++;
-      /* a combining character should never be able to wrap us */
+      assert( this_cell == combining_cell );
+      assert( combining_cell->width == 1 );
+      combining_cell->fallback = true;
+      fb.ds.move_col( 1, true, true );
     }
 
-    if ( fb.rows[ fb.combining_char_row ].cells[ fb.combining_char_col ].contents.size() < 16 ) { /* seems like a reasonable limit on combining character */
-      fb.rows[ fb.combining_char_row ].cells[ fb.combining_char_col ].contents.push_back( act->ch );
+    if ( combining_cell->contents.size() < 16 ) { /* seems like a reasonable limit on combining characters */
+      combining_cell->contents.push_back( act->ch );
     }
     act->handled = true;
     break;
@@ -131,42 +116,6 @@ void Emulator::print( Parser::Print *act )
   }
 }
 
-void Emulator::debug_printout( int fd )
-{
-  std::string screen;
-  screen.append( "\033[H\033[2J" );
-
-  for ( int y = 0; y < fb.height; y++ ) {
-    for ( int x = 0; x < fb.width; x++ ) {
-      char curmove[ 32 ];
-      snprintf( curmove, 32, "\033[%d;%dH", y + 1, x + 1 );
-      screen.append( curmove );
-      Cell *cell = &fb.rows[ y ].cells[ x ];
-      if ( cell->overlapping_cell ) continue;
-
-      if ( cell->fallback ) {
-	char utf8[ 8 ];
-	snprintf( utf8, 8, "%lc", 0xA0 );
-	screen.append( utf8 );
-      }
-
-      for ( std::vector<wchar_t>::iterator i = cell->contents.begin();
-	    i != cell->contents.end();
-	    i++ ) {
-	char utf8[ 8 ];
-	snprintf( utf8, 8, "%lc", *i );
-	screen.append( utf8 );
-      }
-    }
-  }
-
-  char curmove[ 32 ];
-  snprintf( curmove, 32, "\033[%d;%dH", fb.cursor_row + 1, fb.cursor_col + 1 );
-  screen.append( curmove );
-
-  swrite( fd, screen.c_str() );
-}
-
 void Emulator::CSI_dispatch( Parser::CSI_Dispatch *act )
 {
   /* add final char to dispatch key */
@@ -212,3 +161,43 @@ void Emulator::Esc_dispatch( Parser::Esc_Dispatch *act )
     act->handled = true;
   }
 }
+
+void Emulator::debug_printout( int fd )
+{
+  std::string screen;
+  screen.append( "\033[H\033[2J" );
+
+  for ( int y = 0; y < fb.ds.get_height(); y++ ) {
+    for ( int x = 0; x < fb.ds.get_width(); x++ ) {
+      char curmove[ 32 ];
+      snprintf( curmove, 32, "\033[%d;%dH", y + 1, x + 1 );
+      screen.append( curmove );
+      Cell *cell = fb.get_cell( y, x );
+      if ( cell->overlapping_cell ) continue;
+
+      assert( (cell->overlapped_cells.size() + 1 == (size_t)cell->width)
+	      || (x == fb.ds.get_width() - 1) );
+
+      if ( cell->fallback ) {
+	char utf8[ 8 ];
+	snprintf( utf8, 8, "%lc", 0xA0 );
+	screen.append( utf8 );
+      }
+
+      for ( std::vector<wchar_t>::iterator i = cell->contents.begin();
+	    i != cell->contents.end();
+	    i++ ) {
+	char utf8[ 8 ];
+	snprintf( utf8, 8, "%lc", *i );
+	screen.append( utf8 );
+      }
+    }
+  }
+
+  char curmove[ 32 ];
+  snprintf( curmove, 32, "\033[%d;%dH", fb.ds.get_cursor_row() + 1,
+	    fb.ds.get_cursor_col() + 1 );
+  screen.append( curmove );
+
+  swrite( fd, screen.c_str() );
+}

terminalcsi.cpp

@@ -4,49 +4,42 @@
 
 using namespace Terminal;
 
+static void clearline( Framebuffer *fb, int row, int start, int end )
+{
+  for ( int col = start; col <= end; col++ ) {
+    fb->get_cell( row, col )->reset();
+  }
+}
+
 void Emulator::CSI_EL( void )
 {
+  /* default: active position to end of line, inclusive */
+  int start = fb.ds.get_cursor_col(), end = fb.ds.get_width() - 1;
+
   if ( as.params == "1" ) { /* start of screen to active position, inclusive */
-    for ( int x = 0; x <= fb.cursor_col; x++ ) {
-      if ( x < fb.width ) {
-	fb.rows[ fb.cursor_row ].cells[ x ].reset();
-      }
-    }
+    start = 0;
+    end = fb.ds.get_cursor_col();
   } else if ( as.params == "2" ) { /* all of line */
-    fb.rows[ fb.cursor_row ] = Row( fb.width );
-  } else { /* active position to end of line, inclusive */
-    for ( int x = fb.cursor_col; x < fb.width; x++ ) {
-      fb.rows[ fb.cursor_row ].cells[ x ].reset();
-    }
+    start = 0;
   }
+
+  clearline( &fb, -1, start, end );
 }
 
 void Emulator::CSI_ED( void ) {
   if ( as.params == "1" ) { /* start of screen to active position, inclusive */
-    for ( int y = 0; y < fb.cursor_row; y++ ) {
-      for ( int x = 0; x < fb.width; x++ ) {
-	fb.rows[ y ].cells[ x ].reset();
-      }
-    }
-    for ( int x = 0; x <= fb.cursor_col; x++ ) {
-      if ( x < fb.width ) {
-	fb.rows[ fb.cursor_row ].cells[ x ].reset();
-      }
+    for ( int y = 0; y < fb.ds.get_cursor_row(); y++ ) {
+      clearline( &fb, y, 0, fb.ds.get_width() - 1 );
     }
+    clearline( &fb, -1, 0, fb.ds.get_cursor_col() );
   } else if ( as.params == "2" ) { /* entire screen */
-    for ( int y = 0; y < fb.height; y++ ) {
-      for ( int x = 0; x < fb.width; x++ ) {
-	fb.rows[ y ].cells[ x ].reset();
-      }
+    for ( int y = 0; y < fb.ds.get_height(); y++ ) {
+      clearline( &fb, y, 0, fb.ds.get_width() - 1 );
     }
   } else { /* active position to end of screen, inclusive */
-    for ( int x = fb.cursor_col; x < fb.width; x++ ) {
-      fb.rows[ fb.cursor_row ].cells[ x ].reset();
-    }
-    for ( int y = fb.cursor_row + 1; y < fb.height; y++ ) {
-      for ( int x = 0; x < fb.width; x++ ) {
-	fb.rows[ y ].cells[ x ].reset();
-      }
+    clearline( &fb, -1, fb.ds.get_cursor_col(), fb.ds.get_width() - 1 );
+    for ( int y = fb.ds.get_cursor_row() + 1; y < fb.ds.get_height(); y++ ) {
+      clearline( &fb, y, 0, fb.ds.get_width() - 1 );
     }
   }
 }
@@ -57,31 +50,24 @@ void Emulator::CSI_cursormove( void )
 
   switch ( as.dispatch_chars[ 0 ] ) {
   case 'A':
-    fb.cursor_row -= num;
+    fb.ds.move_row( -num, true );
     break;
   case 'B':
-    fb.cursor_row += num;
+    fb.ds.move_row( num, true );
     break;
   case 'C':
-    fb.cursor_col += num;
+    fb.ds.move_col( num, true );
     break;
   case 'D':
-    fb.cursor_col -= num;
+    fb.ds.move_col( -num, true );
     break;
   case 'H':
   case 'f':
     int x = as.getparam( 0, 1 );
     int y = as.getparam( 1, 1 );
-    fb.cursor_row = x - 1;
-    fb.cursor_col = y - 1;
+    fb.ds.move_row( x - 1 );
+    fb.ds.move_col( y - 1 );
   }
-
-  if ( fb.cursor_row < 0 ) fb.cursor_row = 0;
-  if ( fb.cursor_row >= fb.height ) fb.cursor_row = fb.height - 1;
-  if ( fb.cursor_col < 0 ) fb.cursor_col = 0;
-  if ( fb.cursor_col >= fb.width ) fb.cursor_col = fb.width - 1;
-
-  fb.newgrapheme();
 }
 
 void Emulator::CSI_DA( void )
@@ -91,10 +77,10 @@ void Emulator::CSI_DA( void )
 
 void Emulator::Esc_DECALN( void )
 {
-  for ( int y = 0; y < fb.height; y++ ) {
-    for ( int x = 0; x < fb.width; x++ ) {
-      fb.rows[ y ].cells[ x ].reset();
-      fb.rows[ y ].cells[ x ].contents.push_back( L'E' );
+  for ( int y = 0; y < fb.ds.get_height(); y++ ) {
+    for ( int x = 0; x < fb.ds.get_width(); x++ ) {
+      fb.get_cell( y, x )->reset();
+      fb.get_cell( y, x )->contents.push_back( L'E' );
     }
   }
 }

terminalframebuffer.cpp

@@ -8,14 +8,16 @@ Cell::Cell()
   : overlapping_cell( NULL ),
     contents(),
     overlapped_cells(),
-    fallback( false )
+    fallback( false ),
+    width( 1 )
 {}
 
 Cell::Cell( const Cell &x )
   : overlapping_cell( x.overlapping_cell ),
     contents( x.contents ),
     overlapped_cells( x.overlapped_cells ),
-    fallback( x.fallback )
+    fallback( x.fallback ),
+    width( 1 )
 {}
 
 Cell & Cell::operator=( const Cell &x )
@@ -36,6 +38,7 @@ void Cell::reset( void )
 {
   contents.clear();
   fallback = false;
+  width = 1;
 
   if ( overlapping_cell ) {
     assert( overlapped_cells.size() == 0 );
@@ -50,11 +53,15 @@ void Cell::reset( void )
   }
 }
 
-Framebuffer::Framebuffer( int s_width, int s_height )
+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 ),
-    rows( height, Row( width ) )
+    next_print_will_wrap( false )
+{}
+
+Framebuffer::Framebuffer( int s_width, int s_height )
+  : rows( s_height, Row( s_width ) ), ds( s_width, s_height )
 {}
 
 void Framebuffer::scroll( int N )
@@ -63,22 +70,102 @@ void Framebuffer::scroll( int N )
 
   for ( int i = 0; i < N; i++ ) {
     rows.pop_front();
-    rows.push_back( Row( width ) );
-    cursor_row--;
-    combining_char_row--;
+    rows.push_back( Row( ds.get_width() ) );
+    ds.move_row( -1, true );
   }
 }
 
-void Framebuffer::newgrapheme( void )
+void DrawState::new_grapheme( void )
 {
   combining_char_col = cursor_col;
   combining_char_row = cursor_row;  
 }
 
-void Framebuffer::autoscroll( void )
+void DrawState::snap_cursor_to_border( void )
 {
-  if ( cursor_row >= height ) { /* scroll */
-    scroll( cursor_row - height + 1 );
+  if ( cursor_row < 0 ) cursor_row = 0;
+  if ( cursor_row >= height ) cursor_row = height - 1;
+  if ( cursor_col < 0 ) cursor_col = 0;
+  if ( cursor_col >= width ) cursor_col = width - 1;
+}
+
+void DrawState::move_row( int N, bool relative )
+{
+  if ( relative ) {
+    cursor_row += N;
+  } else {
+    cursor_row = N;
+  }
+
+  snap_cursor_to_border();
+  new_grapheme();
+  next_print_will_wrap = false;
+}
+
+void DrawState::move_col( int N, bool relative, bool implicit )
+{
+  if ( implicit ) {
+    new_grapheme();
+  }
+
+  if ( relative ) {
+    cursor_col += N;
+  } else {
+    cursor_col = N;
+  }
+
+  if ( implicit && (cursor_col >= width) ) {
+    next_print_will_wrap = true;
+  }
+
+  snap_cursor_to_border();
+  if ( !implicit ) {
+    new_grapheme();
+    next_print_will_wrap = false;
   }
 }
 
+void Framebuffer::move_rows_autoscroll( int rows )
+{
+  if ( ds.get_cursor_row() + rows >= ds.get_height() ) {
+    scroll( ds.get_height() - ds.get_cursor_row() - rows + 1 );
+  }
+
+  ds.move_row( rows, true );
+}
+
+Cell *Framebuffer::get_cell( void )
+{
+  if ( (ds.get_width() == 0) || (ds.get_height() == 0) ) {
+    return NULL;
+  }
+
+  return &rows[ ds.get_cursor_row() ].cells[ ds.get_cursor_col() ];
+}
+
+Cell *Framebuffer::get_cell( int row, int col )
+{
+  if ( row == -1 ) row = ds.get_cursor_row();
+  if ( col == -1 ) col = ds.get_cursor_col();
+
+  return &rows[ row ].cells[ col ];
+}
+
+Cell *Framebuffer::get_combining_cell( void )
+{
+  return &rows[ ds.get_combining_char_row() ].cells[ ds.get_combining_char_col() ];
+}
+
+void Framebuffer::claim_overlap( int row, int col )
+{
+  Cell *the_cell = &rows[ row ].cells[ col ];
+
+  for ( int i = col + 1; i < col + the_cell->width; i++ ) {
+    if ( i < ds.get_width() ) {
+      Cell *next_cell = get_cell( row, i );
+      next_cell->reset();
+      the_cell->overlapped_cells.push_back( next_cell );
+      next_cell->overlapping_cell = the_cell;
+    }
+  }
+}

terminalframebuffer.hpp

@@ -13,6 +13,7 @@ namespace Terminal {
     std::vector<wchar_t> contents;
     std::vector<Cell *> overlapped_cells;
     char fallback; /* first character is combining character */
+    int width;
 
     Cell();
   
@@ -29,19 +30,51 @@ namespace Terminal {
     Row( size_t s_width );
   };
 
-  class Framebuffer {
-  public:
+  class DrawState {
+  private:
     int width, height;
+
+    void new_grapheme( void );
+    void snap_cursor_to_border( void );
+
     int cursor_col, cursor_row;
     int combining_char_col, combining_char_row;
 
+  public:
+    bool next_print_will_wrap;
+
+    /* bold, etc. */
+
+    void move_row( int N, bool relative = false );
+    void move_col( int N, bool relative = false, bool implicit = false );
+
+    int get_cursor_col( void ) { return cursor_col; }
+    int get_cursor_row( void ) { return cursor_row; }
+    int get_combining_char_col( void ) { return combining_char_col; }
+    int get_combining_char_row( void ) { return combining_char_row; }
+    int get_width( void ) { return width; }
+    int get_height( void ) { return height; }
+
+    DrawState( int s_width, int s_height );
+  };
+
+  class Framebuffer {
+  private:
     std::deque<Row> rows;
 
     void scroll( int N );
-    void autoscroll( void );
-    void newgrapheme( void );
 
+  public:
     Framebuffer( int s_width, int s_height );
+    DrawState ds;
+
+    void move_rows_autoscroll( int rows );
+
+    Cell *get_cell( void );
+    Cell *get_cell( int row, int col );
+    Cell *get_combining_cell( void );
+
+    void claim_overlap( int row, int col );
   };
 }