int SLscroll_pageup (SLscroll_Window_Type *win)
{
SLscroll_Type *l, *top;
unsigned int nrows, hidden_mask;
unsigned int n;
if (win == NULL)
return -1;
(void) SLscroll_find_top (win);
nrows = win->nrows;
if ((NULL != (top = win->top_window_line))
&& (nrows > 2))
{
n = 0;
hidden_mask = win->hidden_mask;
l = win->current_line;
while ((l != NULL) && (l != top))
{
l = l->prev;
if ((hidden_mask == 0)
|| ((l != NULL) && (0 == (l->flags & hidden_mask))))
n++;
}
if (l != NULL)
{
unsigned int save_line_num;
int ret = 0;
win->current_line = l;
win->line_num -= n;
/* Compute a new top/bottom header */
save_line_num = win->line_num;
if ((0 == SLscroll_prev_n (win, nrows - 1))
&& (n == 0))
ret = -1;
win->top_window_line = win->current_line;
win->current_line = l;
win->line_num = save_line_num;
find_window_bottom (win);
return ret;
}
}
if (nrows < 2) nrows++;
if (0 == SLscroll_prev_n (win, nrows - 1))
return -1;
return 0;
}
int SLscroll_pagedown (SLscroll_Window_Type *win)
{
SLscroll_Type *l, *bot;
unsigned int nrows, hidden_mask;
unsigned int n;
if (win == NULL)
return -1;
(void) SLscroll_find_top (win);
nrows = win->nrows;
if ((NULL != (bot = win->bot_window_line))
&& (nrows > 2))
{
n = 0;
hidden_mask = win->hidden_mask;
l = win->current_line;
while ((l != NULL) && (l != bot))
{
l = l->next;
if ((hidden_mask == 0)
|| ((l != NULL) && (0 == (l->flags & hidden_mask))))
n++;
}
if (l != NULL)
{
win->current_line = l;
win->top_window_line = l;
win->line_num += n;
find_window_bottom (win);
if (n || (bot != win->bot_window_line))
return 0;
return -1;
}
}
if (nrows < 2) nrows++;
if (0 == SLscroll_next_n (win, nrows - 1))
return -1;
return 0;
}
static void update_display (void)
{
unsigned int row, nrows;
File_Line_Type *line;
/* All well behaved applications should block signals that may affect
* the display while performing screen update.
*/
SLsig_block_signals ();
Line_Window.nrows = nrows = SLtt_Screen_Rows - 1;
/* Always make the current line equal to the top window line. */
if (Line_Window.top_window_line != NULL)
Line_Window.current_line = Line_Window.top_window_line;
SLscroll_find_top (&Line_Window);
row = 0;
line = (File_Line_Type *) Line_Window.top_window_line;
SLsmg_normal_video ();
while (row < Line_Window.nrows)
{
SLsmg_gotorc (row, 0);
if (line != NULL)
{
SLsmg_write_string (line->data);
line = line->next;
}
SLsmg_erase_eol ();
row++;
}
SLsmg_gotorc (row, 0);
SLsmg_reverse_video ();
SLsmg_printf ("%s | UTF-8 = %d",
(File_Name == NULL) ? "<stdin>" : File_Name,
SLutf8_is_utf8_mode ());
SLsmg_erase_eol ();
SLsmg_refresh ();
SLsig_unblock_signals ();
}
