display.c

gcc-2.95.3 Linux下最常用的C编译器

          if (rep_carried_over)
            for (; rep[pl_index]; pl_index++)
              printed_line[pl_index] = rep[pl_index];

          /* If this window has chosen not to wrap lines, skip to the end
             of the physical line in the buffer, and start a new line here. */
          if (pl_index && (win->flags & W_NoWrap))
            {
              char *begin;

              pl_index = 0;
              printed_line[0] = '\0';

              begin = nodetext;
              
              while ((nodetext < last_node_char) && (*nodetext != '\n'))
                nodetext++;
            }
        }
    }

 done_with_node_display:
  /* We have reached the end of the node or the end of the window.  If it
     is the end of the node, then clear the lines of the window from here
     to the end of the window. */
  for (; line_index < win->height; line_index++)
    {
      DISPLAY_LINE *entry = display[line_index + win->first_row];

      /* If this line has text on it then make it go away. */
      if (entry && entry->textlen)
        {
          entry->textlen = 0;
          entry->text[0] = '\0';

          terminal_goto_xy (0, line_index + win->first_row);
          terminal_clear_to_eol ();
        }
    }

  /* Finally, if this window has a modeline it might need to be redisplayed.
     Check the window's modeline against the one in the display, and update
     if necessary. */
  if ((win->flags & W_InhibitMode) == 0)
    {
      window_make_modeline (win);
      line_index = win->first_row + win->height;

      /* This display line must both be in inverse, and have the same
         contents. */
      if ((!display[line_index]->inverse) ||
          (strcmp (display[line_index]->text, win->modeline) != 0))
        {
          terminal_goto_xy (0, line_index);
          terminal_begin_inverse ();
          terminal_put_text (win->modeline);
          terminal_end_inverse ();
          strcpy (display[line_index]->text, win->modeline);
          display[line_index]->inverse = 1;
          display[line_index]->textlen = strlen (win->modeline);
          fflush (stdout);
        }
    }

  /* Okay, this window doesn't need updating anymore. */
  win->flags &= ~W_UpdateWindow;
  free (printed_line);
  fflush (stdout);
}

/* Scroll the region of the_display starting at START, ending at END, and
   moving the lines AMOUNT lines.  If AMOUNT is less than zero, the lines
   are moved up in the screen, otherwise down.  Actually, it is possible
   for no scrolling to take place in the case that the terminal doesn't
   support it.  This doesn't matter to us. */
void
display_scroll_display (start, end, amount)
     int start, end, amount;
{
  register int i, last;
  DISPLAY_LINE *temp;

  /* If this terminal cannot do scrolling, give up now. */
  if (!terminal_can_scroll)
    return;

  /* If there isn't anything displayed on the screen because it is too
     small, quit now. */
  if (!the_display[0])
    return;

  /* If there is typeahead pending, then don't actually do any scrolling. */
  if (info_any_buffered_input_p ())
    return;

  /* Do it on the screen. */
  terminal_scroll_terminal (start, end, amount);

  /* Now do it in the display buffer so our contents match the screen. */
  if (amount > 0)
    {
      last = end + amount;

      /* Shift the lines to scroll right into place. */
      for (i = 0; i < (end - start); i++)
        {
          temp = the_display[last - i];
          the_display[last - i] = the_display[end - i];
          the_display[end - i] = temp;
        }

      /* The lines have been shifted down in the buffer.  Clear all of the
         lines that were vacated. */
      for (i = start; i != (start + amount); i++)
        {
          the_display[i]->text[0] = '\0';
          the_display[i]->textlen = 0;
          the_display[i]->inverse = 0;
        }
    }

  if (amount < 0)
    {
      last = start + amount;
      for (i = 0; i < (end - start); i++)
        {
          temp = the_display[last + i];
          the_display[last + i] = the_display[start + i];
          the_display[start + i] = temp;
        }

      /* The lines have been shifted up in the buffer.  Clear all of the
         lines that are left over. */
      for (i = end + amount; i != end; i++)
        {
          the_display[i]->text[0] = '\0';
          the_display[i]->textlen = 0;
          the_display[i]->inverse = 0;
        }
    }
}

/* Try to scroll lines in WINDOW.  OLD_PAGETOP is the pagetop of WINDOW before
   having had its line starts recalculated.  OLD_STARTS is the list of line
   starts that used to appear in this window.  OLD_COUNT is the number of lines
   that appear in the OLD_STARTS array. */
void
display_scroll_line_starts (window, old_pagetop, old_starts, old_count)
     WINDOW *window;
     int old_pagetop, old_count;
     char **old_starts;
{
  register int i, old, new;     /* Indices into the line starts arrays. */
  int last_new, last_old;       /* Index of the last visible line. */
  int old_first, new_first;     /* Index of the first changed line. */
  int unchanged_at_top = 0;
  int already_scrolled = 0;

  /* Locate the first line which was displayed on the old window. */
  old_first = old_pagetop;
  new_first = window->pagetop;

  /* Find the last line currently visible in this window. */
  last_new = window->pagetop + (window->height - 1);
  if (last_new > window->line_count)
    last_new = window->line_count - 1;

  /* Find the last line which used to be currently visible in this window. */
  last_old = old_pagetop + (window->height - 1);
  if (last_old > old_count)
    last_old = old_count - 1;

  for (old = old_first, new = new_first;
       old < last_old && new < last_new;
       old++, new++)
    if (old_starts[old] != window->line_starts[new])
      break;
    else
      unchanged_at_top++;

  /* Loop through the old lines looking for a match in the new lines. */
  for (old = old_first + unchanged_at_top; old < last_old; old++)
    {
      for (new = new_first; new < last_new; new++)
        if (old_starts[old] == window->line_starts[new])
          {
            /* Find the extent of the matching lines. */
            for (i = 0; (old + i) < last_old; i++)
              if (old_starts[old + i] != window->line_starts[new + i])
                break;

            /* Scroll these lines if there are enough of them. */
            {
              int start, end, amount;

              start = (window->first_row
                       + ((old + already_scrolled) - old_pagetop));
              amount = new - (old + already_scrolled);
              end = window->first_row + window->height;

              /* If we are shifting the block of lines down, then the last
                 AMOUNT lines will become invisible.  Thus, don't bother
                 scrolling them. */
              if (amount > 0)
                end -= amount;

              if ((end - start) > 0)
                {
                  display_scroll_display (start, end, amount);

                  /* Some lines have been scrolled.  Simulate the scrolling
                     by offsetting the value of the old index. */
                  old += i;
                  already_scrolled += amount;
                }
            }
          }
    }
}

/* Move the screen cursor to directly over the current character in WINDOW. */
void
display_cursor_at_point (window)
     WINDOW *window;
{
  int vpos, hpos;

  vpos = window_line_of_point (window) - window->pagetop + window->first_row;
  hpos = window_get_cursor_column (window);
  terminal_goto_xy (hpos, vpos);
  fflush (stdout);
}

/* **************************************************************** */
/*                                                                  */
/*                   Functions Static to this File                  */
/*                                                                  */
/* **************************************************************** */

/* Make a DISPLAY_LINE ** with width and height. */
static DISPLAY_LINE **
make_display (width, height)
     int width, height;
{
  register int i;
  DISPLAY_LINE **display;

  display = (DISPLAY_LINE **)xmalloc ((1 + height) * sizeof (DISPLAY_LINE *));

  for (i = 0; i < height; i++)
    {
      display[i] = (DISPLAY_LINE *)xmalloc (sizeof (DISPLAY_LINE));
      display[i]->text = (char *)xmalloc (1 + width);
      display[i]->textlen = 0;
      display[i]->inverse = 0;
    }
  display[i] = (DISPLAY_LINE *)NULL;
  return (display);
}

/* Free the storage allocated to DISPLAY. */
static void
free_display (display)
     DISPLAY_LINE **display;
{
  register int i;
  register DISPLAY_LINE *display_line;

  if (!display)
    return;

  for (i = 0; (display_line = display[i]); i++)
    {
      free (display_line->text);
      free (display_line);
    }
  free (display);
}