movement.c

一个开源著名的TDE编辑器源代码

 * Passed:  window:  pointer to current window
 */
int  goto_bottom( TDE_WIN *window )
{
register TDE_WIN *win;   /* put window pointer in a register */
int  diff;
long line;
int  empty;
long length;

   if (g_status.command_count == 0) {
      win   = window;
      diff  = win->bottom_line - win->cline;
      line  = win->rline;
      empty = ((length = win->file_info->length) == 0);
      if ((diff && (line != length || empty)) || (line == length+1 && !empty)) {
         if (un_copy_line( win->ll, win, TRUE, TRUE ) == ERROR)
            return( ERROR );

         undo_move( win, 0 );

         if (line == length+1) {
            dec_line( win, TRUE );
            if (win->cline == win->top_line)
               win->file_info->dirty = LOCAL;
            else {
               --win->cline;    /* we aren't at top of screen - so move up */
               show_curl_line( win );
            }
         } else {
            update_line( win );
            if (line + diff > length)
               diff = (int)(length - line);
            line += diff;
            win->cline += diff;
            move_to_line( win, line, TRUE );
            show_curl_line( win );
         }
      }
      cursor_sync( win );
   }
   return( OK );
}


/*
 * Name:    page_up
 * Purpose: To move the cursor one (half) page up the window
 * Date:    June 5, 1991
 * Passed:  window:  pointer to current window
 * Notes:   The cursor line is moved back the required number of lines
 *           towards the start of the file.
 *          If the start of the file is reached, then movement stops.
 *
 * jmh 020906: added the half-page function.
 */
int  page_up( TDE_WIN *window )
{
int  i;                 /* count of lines scanned */
int  rc = OK;           /* default return code */
register TDE_WIN *win;  /* put window pointer in a register */
long number;

   win = window;
   i   = win->cline - win->top_line;
   if (win->rline != i) {
      if (un_copy_line( win->ll, win, TRUE, TRUE ) == ERROR)
         return( ERROR );

      number = win->rline - ((g_status.command == ScreenUp) ? win->page
                             : ((win->page + g_status.overlap) / 2));
      if (number < i) {
         number = i;
         undo_move( win, 0 );
      } else
         undo_move( win, (g_status.command == ScreenUp) ? ScreenDown
                                                        : HalfScreenDown );

      move_to_line( win, number, TRUE );
      win->file_info->dirty = LOCAL;
   } else
      rc = ERROR;
   cursor_sync( win );
   return( rc );
}


/*
 * Name:    page_down
 * Purpose: To move the cursor one (half) page down the window
 * Date:    June 5, 1991
 * Passed:  window:  pointer to current window
 * Notes:   The cursor line is moved forwards the required number of lines
 *           towards the end of the file.
 *          If the end of the file is reached, then movement stops.
 *
 * jmh 020906: added the half-page function.
 */
int  page_down( TDE_WIN *window )
{
int  rc = OK;
long line;
long last;
register TDE_WIN *win;  /* put window pointer in a register */

   win  = window;
   line = win->rline;
   last = win->file_info->length + 1;
   if (line - (win->cline - win->top_line) <
       last - (win->bottom_line - win->top_line)) {
      if (un_copy_line( win->ll, win, TRUE, TRUE ) == ERROR)
         return( ERROR );

      line += (g_status.command == ScreenDown) ? win->page
              : ((win->page + g_status.overlap) / 2);
      if (line > last) {
         win->cline -= (int)(line - last);
         line = last;
         undo_move( win, 0 );
      } else
         undo_move( win, (g_status.command == ScreenDown) ? ScreenUp
                                                          : HalfScreenUp );

      move_to_line( win, line, TRUE );
      win->file_info->dirty = LOCAL;
   } else
      rc = ERROR;
   cursor_sync( win );
   return( rc );
}


/*
 * Name:    scroll_up
 * Purpose: To scroll the window up one line
 * Date:    June 5, 1991
 * Passed:  window:  pointer to current window
 * Notes:   If this is the first page, then update screen here.  Else, make
 *           the window LOCAL dirty because we have to redraw screen.
 */
int  scroll_up( TDE_WIN *window )
{
int  rc = OK;
register TDE_WIN *win;   /* put window pointer in a register */

   win = window;
   if (win->rline > 0) {
      if (un_copy_line( win->ll, win, TRUE, TRUE ) == ERROR)
         return( ERROR );

      if (win->rline == (win->cline - win->top_line)) {
         undo_move( win, LineDown );
         update_line( win );
         dec_line( win, TRUE );
         --win->cline;
         show_curl_line( win );
      } else {
         if (win->cline == win->bottom_line) {
            undo_move( win, LineDown );
            dec_line( win, TRUE );
         } else
            ++win->cline;
         win->file_info->dirty = LOCAL;
      }
   } else
     rc = ERROR;
   cursor_sync( win );
   return( rc );
}


/*
 * Name:    scroll_down
 * Purpose: scroll window down one line
 * Date:    June 5, 1991
 * Passed:  window:  pointer to current window
 * Notes:   If there is a line to scroll_down, make the window LOCAL dirty.
 *          We have to redraw the screen anyway, so don't update here.
 */
int  scroll_down( TDE_WIN *window )
{
int  rc = OK;
register TDE_WIN *win;   /* put window pointer in a register */

   win = window;
   if (win->cline == win->top_line) {
      if (un_copy_line( win->ll, win, TRUE, TRUE ) == ERROR)
         return( ERROR );
      if (inc_line( win, TRUE )) {
         undo_move( win, LineUp );
         win->file_info->dirty = LOCAL;
      } else
         rc = ERROR;
   } else {
      --win->cline;
      win->file_info->dirty = LOCAL;
   }
   cursor_sync( win );
   return( rc );
}


/*
 * Name:    pan_up
 * Purpose: To leave cursor on same logical line and scroll text up
 * Date:    September 1, 1991
 * Passed:  window:  pointer to current window
 * Notes:   If cursor is on first page then do not scroll.
 */
int  pan_up( TDE_WIN *window )
{
int  rc = OK;
register TDE_WIN *win;   /* put window pointer in a register */

   win = window;

   /*
    * see if cursor is on the first page. if it's not then pan_up.
    */
   if (win->rline != (win->cline - win->top_line)) {
      if (un_copy_line( win->ll, win, TRUE, TRUE ) == ERROR)
         return( ERROR );
      undo_move( win, PanDn );
      dec_line( win, TRUE );
      win->file_info->dirty = LOCAL;
   } else
      rc = ERROR;
   cursor_sync( win );
   return( rc );
}


/*
 * Name:    pan_down
 * Purpose: To leave cursor on same logical line and scroll text down
 * Date:    September 1, 1991
 * Passed:  window:  pointer to current window
 * Notes:   If cursor is on last line in file then do not scroll.
 */
int  pan_down( TDE_WIN *window )
{
int  rc = OK;
register TDE_WIN *win;   /* put window pointer in a register */

   win = window;
   if (win->ll->next != NULL) {
      if (un_copy_line( win->ll, win, TRUE, TRUE ) == ERROR)
         return( ERROR );
      undo_move( win, PanUp );
      inc_line( win, TRUE );
      win->file_info->dirty = LOCAL;
   } else
      rc = ERROR;
   cursor_sync( win );
   return( rc );
}


/*
 * Name:    move_up
 * Purpose: To move the cursor up one line
 * Date:    June 5, 1991
 * Passed:  window:  pointer to current window
 * Notes:   If the cursor is at the top of the window, then the file must
 *           be scrolled down.
 *
 * jmh 991018: added drawing mode.
 */
int  move_up( TDE_WIN *window )
{
int  rc = OK;
register TDE_WIN *win;  /* put window pointer in a register */

   win = window;

   if (mode.draw && win->ll->len != EOF)
      set_vert_g_char( win, G_UP );

   rc = prepare_move_up( win );

   if (mode.draw && rc == OK) {
      if (win->rline == 0) {
         g_status.command = AddLine;
         rc = insert_newline( win );
         prepare_move_down( win );
      } else
         set_vert_g_char( win, ~G_DN );
   }

   cursor_sync( win );
   return( rc );
}


/*
 * Name:    move_down
 * Purpose: To move the cursor down one line
 * Date:    June 5, 1991
 * Passed:  window:  pointer to current window
 * Notes:   If the cursor is at the bottom of the window, then the file must
 *           be scrolled up.   If the cursor is at the bottom of the file,
 *           then scroll line up until it is at top of screen.
 *
 * jmh 991018: added drawing mode.
 */
int  move_down( TDE_WIN *window )
{
int  rc;
register TDE_WIN *win;   /* put window pointer in a register */

   win = window;

   if (mode.draw) {
      if (win->ll->len != EOF)
         set_vert_g_char( win, G_DN );
      if (win->rline == win->file_info->length) {
         g_status.command = AddLine;
         insert_newline( win );
      }
   }

   rc = prepare_move_down( win );

   if (mode.draw && win->ll->len != EOF)
      set_vert_g_char( win, ~G_UP );

   cursor_sync( win );
   return( rc );
}


/*
 * Name:    beg_next_line
 * Purpose: To move the cursor to the beginning of the next line.
 * Date:    October 4, 1991
 * Passed:  window:  pointer to current window
 */
int  beg_next_line( TDE_WIN *window )
{
int  rc;

   rc = prepare_move_down( window );
   show_ruler_char( window );
   check_virtual_col( window, 0, window->start_col );
   cursor_sync( window );
   return( rc );
}


/*
 * Name:    next_line
 * Purpose: To move the cursor to the first character of the next line.
 * Date:    October 4, 1991
 * Passed:  window:  pointer to current window
 *
 * jmh 990504: match indentation/margin if the next line is blank.
 * jmh 031114: indent mode overrides fixed wrap mode.
 */
int  next_line( TDE_WIN *window )
{
register int rcol;
register TDE_WIN *win;   /* put window pointer in a register */
line_list_ptr ll;
int  tabs;
int  tab_size;
int  rc;

   win = window;
   tabs = win->file_info->inflate_tabs;
   tab_size = win->file_info->ptab_size;

   rc = prepare_move_down( win );
   ll = win->ll;
   rcol =  (mode.indent || mode.word_wrap == DYNAMIC_WRAP) ?
          find_left_margin( ll, DYNAMIC_WRAP, tabs, tab_size ) :
          first_non_blank( ll->line, ll->len, tabs, tab_size );
   show_ruler_char( win );
   check_virtual_col( win, rcol, win->ccol );
   cursor_sync( win );
   return( rc );
}


/*
 * Name:    move_left
 * Purpose: To move the cursor left one character
 * Date:    June 5, 1991
 * Passed:  window:  pointer to current window
 * Notes:   If the cursor is already at the left of the screen, then
 *           scroll horizontally if we're not at beginning of line.
 * jmh 980724: update cursor cross
 * jmh 991018: added drawing mode.
 * jmh 991123: return ERROR if already at BOL;
 *             skip ccol == start_col test;
 *             don't bother showing the ruler after the sync.
 * jmh 030302: recognise the stream version.
 * jmh 031114: for the stream version treat beyond EOL as EOL.
 */
int  move_left( TDE_WIN *window )
{
register TDE_WIN *win;
text_ptr p;
int  len;
int  rc = OK;

   win = window;
   if (win->rcol > 0) {
      if (mode.cursor_cross)
         win->file_info->dirty = LOCAL;

      if (mode.draw && win->ll->len != EOF)
         set_horz_g_char( win, G_LF );

      undo_move( win, CharRight );

      if (g_status.command == StreamCharLeft  &&  !mode.draw) {
         if (g_status.copied && win->file_info == g_status.current_file) {
            p   = g_status.line_buff;
            len = g_status.line_buff_len;
         } else {
            p   = win->ll->line;
            len = win->ll->len;
         }
         len = find_end( p, len, win->file_info->inflate_tabs,
                                 win->file_info->ptab_size );
         if (len == 0)
            goto prev_line;
         if (win->rcol >= len)
            rc = goto_eol( win );
      }

      if (win->ccol > win->start_col) {
         show_ruler_char( win );
         --win->ccol;
      } else { /* (win->ccol == win->start_col) */
         --win->bcol;
         win->file_info->dirty = LOCAL | RULER;
      }
      --win->rcol;
   } else if (g_status.command == StreamCharLeft  &&  !mode.draw) {
prev_line:
      rc = prepare_move_up( win );
      if (rc == OK)
         rc = goto_eol( win );
   } else
      rc = ERROR;
   cursor_sync( win );
   return( rc );
}


/*
 * Name:    move_right
 * Purpose: To move the cursor right one character
 * Date:    June 5, 1991
 * Passed:  window:  pointer to current window
 * Notes:   If the cursor is already at the right of the screen (logical
 *          column 80) then scroll horizontally right.
 * jmh 980724: update cursor cross
 * jmh 991018: added drawing mode.