Share logic between prepare_term and fullscreen_alt.

* basta.sh (basta.ensure_bottom_margin): New function,
factored off from basta.prepare_term.
(basta.prepare_term): Code for ensuring that screen contents
move out of status-sized bottom area now moved into
basta.ensure_bottom_margin.
(basta.fullscreen_alt): Complex logic involving knowing
the current line, moving the cursor to the bottom,
and scrolling a certain nummber of lines removed.
Replaced with call to basta.ensure_bottom_margin.

1 files changed, 15 insertions, 22 deletions

diff --git a/basta.sh b/basta.sh
index 5707e0e..4f6c032 100644
--- a/basta.sh
+++ b/basta.sh
@@ -36,6 +36,18 @@ basta.query_termios_lines_cols()
   colsvar=$2
 }
 
+basta.ensure_bottom_margin()
+{
+  local i
+  local realrows=$1
+
+  printf $'\e7\e[1;%sr\e8' $realrows
+  for (( i = 0; i <= basta_prev_reserved_rows; i++ )); do
+    printf $'\n'
+  done
+  printf $'\e[%sA' $i
+}
+
 basta.prepare_term()
 {
   local realrows
@@ -47,11 +59,7 @@ basta.prepare_term()
 
   if [ -z "$basta_prev_reserved_rows" ] ; then
     basta_prev_reserved_rows=${#LC_basta_status[@]}
-    printf $'\e7\e[1;%sr\e8' $realrows
-    for (( i = 0; i <= basta_prev_reserved_rows; i++ )); do
-      printf $'\n'
-    done
-    printf $'\e[%sA' $i
+    basta.ensure_bottom_margin $realrows
   fi
 
   LINES=$((realrows - $basta_prev_reserved_rows - 1))
@@ -359,23 +367,8 @@ basta.fullscreen_alt() {
   basta_deferred_intr=WINCH
   LINES=$realrows command "$@" || exit=$?
 
-  local scrolls_needed=$((basta_prev_reserved_rows + 1))
-
-  if basta.query_terminal_lines realrows >&$ttyfd <&$ttyfd &&
-     basta.get_cur_line curline >&$ttyfd <&$ttyfd
-  then
-    : $(( scrolls_needed -= realrows - curline ))
-  fi
-
-  if [ $scrolls_needed -gt 0 ] ; then
-    printf $'\e[%s;1H' $realrows >&$ttyfd
-
-    for (( i = 0 ; i < scrolls_needed; i++ )) ; do
-      printf $'\n' >&$ttyfd
-    done
-
-    printf $'\e[%sA' $(( basta_prev_reserved_rows + 1 )) >&$ttyfd
-  fi
+  basta.query_terminal_lines realrows >&$ttyfd <&$ttyfd &&
+    basta.ensure_bottom_margin $realrows >&$ttyfd
 
   exec {ttyfd}>&-