libcons/

2002-09-09  Marcus Brinkmann  <marcus@gnu.org>

	* Makefile (SRCS): Add vcons-scrollback.c.
	* vcons-scrollback.c: New file.
	* cons.h (struct vcons): Add SCROLLING member.
	* file-changed.c: Include <assert.h>.
	(cons_S_file_changed): Be careful to take VCONS->scrolling into
	account when doing clipping and scrolling.

	* cons-switch.c: Roll back to earlier version with vcons ->
	vcons_entry adjustments.  The user is now expected to hold a
	reference to the VCONS.
	* cons.h: Fix prototype, too.

	* vcons-open.c (cons_vcons_open): Initialize VCONS->lock,
	VCONS->input and VCONS->display.

utils/
2002-09-09  Marcus Brinkmann  <marcus@gnu.org>

	* console-ncurses.c (console_switch): Keep a reference to the port
	instead refering to it by number.

1 files changed, 122 insertions, 0 deletions

diff --git a/libcons/vcons-scrollback.c b/libcons/vcons-scrollback.c
new file mode 100644
index 00000000..cfc94458
--- /dev/null
+++ b/libcons/vcons-scrollback.c
@@ -0,0 +1,122 @@
+/* vcons-scrollback.c - Move forward and backward in the scrollback buffer.
+   Copyright (C) 2002 Free Software Foundation, Inc.
+   Written by Marcus Brinkmann.
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+
+#include <stdint.h>
+
+#include <cthreads.h>
+
+#include "cons.h"
+
+/* Scroll back into the history of VCONS by DELTA lines.  */
+int
+cons_vcons_scrollback (vcons_t vcons, int delta)
+{
+  int scrolling;
+  uint32_t new_scr;
+
+  mutex_lock (&vcons->lock);
+  if (delta > 0 || vcons->scrolling > (uint32_t) (-delta))
+    {
+      new_scr = vcons->scrolling + delta;
+      if (new_scr > vcons->state.screen.scr_lines)
+	new_scr = vcons->state.screen.scr_lines;
+    }
+  else
+    new_scr = 0;
+
+  if (new_scr == vcons->scrolling)
+    {
+      mutex_unlock (&vcons->lock);
+      return 0;
+    }
+  
+  scrolling = vcons->scrolling - new_scr;
+  {
+    uint32_t new_cur_line;
+    off_t size = vcons->state.screen.width
+      * vcons->state.screen.lines;
+    off_t vis_start;
+    off_t start;
+    off_t end;
+
+    if (vcons->state.screen.cur_line >= new_scr)
+      new_cur_line = vcons->state.screen.cur_line - new_scr;
+    else
+      new_cur_line = (UINT32_MAX - (new_scr - vcons->state.screen.cur_line)) + 1;
+
+    if (scrolling > 0 && (uint32_t) scrolling > vcons->state.screen.height)
+      scrolling = vcons->state.screen.height;
+    else if (scrolling < 0
+	     && (uint32_t) (-scrolling) > vcons->state.screen.height)
+      scrolling = -vcons->state.screen.height;
+    if ((scrolling > 0 && scrolling < vcons->state.screen.height)
+	|| (scrolling < 0
+	    && (uint32_t) (-scrolling) < vcons->state.screen.height))
+      cons_vcons_scroll (vcons, scrolling);
+
+    vis_start = vcons->state.screen.width
+      * (new_cur_line % vcons->state.screen.lines);
+    if (scrolling > 0)
+      start = (((new_cur_line % vcons->state.screen.lines)
+		+ vcons->state.screen.height - scrolling)
+	       * vcons->state.screen.width) % size;
+    else
+      start = vis_start;
+    end = start + abs (scrolling) * vcons->state.screen.width - 1;
+
+    cons_vcons_write (vcons,
+		      vcons->state.screen.matrix + start,
+		      end < size
+		      ? end - start + 1 
+		      : size - start,
+		      0, (scrolling > 0)
+		      ? vcons->state.screen.height - scrolling : 0);
+    if (end >= size)
+      cons_vcons_write (vcons,
+			vcons->state.screen.matrix,
+			end - size + 1,
+			0, (size - vis_start)
+			/ vcons->state.screen.width);
+  }
+
+  /* Set the new cursor position.  */
+  {
+    uint32_t row = vcons->state.cursor.row;
+    uint32_t height = vcons->state.screen.height;
+
+    if (row + new_scr < height)
+      {
+	cons_vcons_set_cursor_pos (vcons, vcons->state.cursor.col,
+				   row + new_scr);
+	if (row + vcons->scrolling >= height)
+	  /* The cursor was invisible before.  */
+	  cons_vcons_set_cursor_status (vcons, vcons->state.cursor.status);
+      }
+    else if (row + vcons->scrolling < height)
+      /* The cursor was visible before.  */
+      cons_vcons_set_cursor_status (vcons, CONS_CURSOR_INVISIBLE);
+  }
+
+  cons_vcons_update (vcons);
+  vcons->scrolling -= scrolling;
+  mutex_unlock (&vcons->lock);
+
+  return -scrolling;
+}