layer23/mobile: Added generic user interface

The user interface instance is currently accessed via telnet. It supports
different views to display or enter something.

It is still not complete.

9 files changed, 1207 insertions, 2 deletions

diff --git a/src/host/layer23/configure.ac b/src/host/layer23/configure.ac
index 102d2344..a9068668 100644
--- a/src/host/layer23/configure.ac
+++ b/src/host/layer23/configure.ac
@@ -30,11 +30,13 @@ AC_OUTPUT(
     src/Makefile
     src/common/Makefile
     src/misc/Makefile
+    src/ui/Makefile
     src/mobile/Makefile
     include/Makefile
     include/osmocom/Makefile
     include/osmocom/bb/Makefile
     include/osmocom/bb/common/Makefile
     include/osmocom/bb/misc/Makefile
+    include/osmocom/bb/ui/Makefile
     include/osmocom/bb/mobile/Makefile
     Makefile)
diff --git a/src/host/layer23/include/osmocom/bb/Makefile.am b/src/host/layer23/include/osmocom/bb/Makefile.am
index 58a5f7fb..a8791fe4 100644
--- a/src/host/layer23/include/osmocom/bb/Makefile.am
+++ b/src/host/layer23/include/osmocom/bb/Makefile.am
@@ -1 +1 @@
-SUBDIRS = common misc mobile
+SUBDIRS = common misc ui mobile
diff --git a/src/host/layer23/include/osmocom/bb/ui/Makefile.am b/src/host/layer23/include/osmocom/bb/ui/Makefile.am
new file mode 100644
index 00000000..b010e53c
--- /dev/null
+++ b/src/host/layer23/include/osmocom/bb/ui/Makefile.am
@@ -0,0 +1,2 @@
+noinst_HEADERS = ui.h telnet_interface.h
+
diff --git a/src/host/layer23/include/osmocom/bb/ui/telnet_interface.h b/src/host/layer23/include/osmocom/bb/ui/telnet_interface.h
new file mode 100644
index 00000000..b35b47f9
--- /dev/null
+++ b/src/host/layer23/include/osmocom/bb/ui/telnet_interface.h
@@ -0,0 +1,17 @@
+#ifndef _LIBUI_TELNET_IF_H
+#define _LIBUI_TELNET_IF_H
+
+struct ui_telnet_connection {
+	struct llist_head entry;
+	void *priv;
+	struct osmo_fd fd;
+	struct ui_inst *ui;
+	struct buffer *obuf;
+	int iac, sb, esc;
+};
+
+int ui_telnet_init(struct ui_inst *ui, void *tall_ctx, int port);
+int ui_telnet_puts(struct ui_inst *ui, const char *text);
+void ui_telnet_exit(struct ui_inst *ui);
+
+#endif /* _LIBUI_TELNET_IF_H */
diff --git a/src/host/layer23/include/osmocom/bb/ui/ui.h b/src/host/layer23/include/osmocom/bb/ui/ui.h
new file mode 100644
index 00000000..75e2fad7
--- /dev/null
+++ b/src/host/layer23/include/osmocom/bb/ui/ui.h
@@ -0,0 +1,96 @@
+#ifndef _libui_h
+#define _libui_h
+
+#define UI_ROWS		8
+#define UI_COLS		12
+#define UI_TARGET	0
+
+enum ui_key {
+	UI_KEY_0 = '0',
+	UI_KEY_1 = '1',
+	UI_KEY_2 = '2',
+	UI_KEY_3 = '3',
+	UI_KEY_4 = '4',
+	UI_KEY_5 = '5',
+	UI_KEY_6 = '6',
+	UI_KEY_7 = '7',
+	UI_KEY_8 = '8',
+	UI_KEY_9 = '9',
+	UI_KEY_STAR = '*',
+	UI_KEY_HASH = '#',
+	UI_KEY_F1 = 1,
+	UI_KEY_F2 = 2,
+	UI_KEY_PICKUP = 26,
+	UI_KEY_HANGUP = 27,
+	UI_KEY_UP = 28,
+	UI_KEY_DOWN = 29,
+	UI_KEY_LEFT = 30,
+	UI_KEY_RIGHT = 31,
+};
+
+union ui_view_data {
+	struct {
+		int lines;
+		const char **text;
+		int vpos;
+	} listview;
+	struct {
+		int lines;
+		const char **text;
+		int vpos;
+		int cursor;
+	} selectview;
+	struct {
+		char *number;
+		int num_len;
+		int pos;
+		int options;
+		int options_pos;
+	} stringview;
+	struct {
+		unsigned int value;
+		int sign;
+		int min, max;
+	} intview;
+};
+
+struct ui_inst;
+
+struct ui_view {
+	const char *name;
+	int (*init)(struct ui_view *uv, union ui_view_data *ud);
+	int (*keypad)(struct ui_inst *ui, struct ui_view *uv,
+		union ui_view_data *ud, enum ui_key kp);
+	int (*display)(struct ui_inst *ui, union ui_view_data *ud);
+};
+
+struct ui_inst {
+	struct ui_view *uv;
+	const char *title;
+	const char *bottom_line;
+	union ui_view_data ud;
+	int (*key_cb)(struct ui_inst *ui, enum ui_key kp);
+	int (*beep_cb)(struct ui_inst *ui);
+	/* display */
+	char buffer[(UI_COLS + 1) * UI_ROWS];
+	int cursor_on, cursor_x, cursor_y;
+	/* telnet */
+	void *tall_telnet_ctx;
+	struct osmo_fd server_socket;
+	struct llist_head active_connections;
+	int (*telnet_cb)(struct ui_inst *ui);
+};
+
+extern struct ui_view ui_listview;
+extern struct ui_view ui_selectview;
+extern struct ui_view ui_stringview;
+extern struct ui_view ui_intview;
+
+int ui_inst_init(struct ui_inst *ui, struct ui_view *uv,
+	int (*key_cb)(struct ui_inst *ui, enum ui_key kp),
+	int (*beep_cb)(struct ui_inst *ui),
+	int (*telnet_cb)(struct ui_inst *ui));
+int ui_inst_keypad(struct ui_inst *ui, enum ui_key kp);
+int ui_inst_refresh(struct ui_inst *ui);
+
+#endif /* _libui_h */
diff --git a/src/host/layer23/src/Makefile.am b/src/host/layer23/src/Makefile.am
index 58a5f7fb..a8791fe4 100644
--- a/src/host/layer23/src/Makefile.am
+++ b/src/host/layer23/src/Makefile.am
@@ -1 +1 @@
-SUBDIRS = common misc mobile
+SUBDIRS = common misc ui mobile
diff --git a/src/host/layer23/src/ui/Makefile.am b/src/host/layer23/src/ui/Makefile.am
new file mode 100644
index 00000000..62357cc3
--- /dev/null
+++ b/src/host/layer23/src/ui/Makefile.am
@@ -0,0 +1,7 @@
+INCLUDES = $(all_includes) -I$(top_srcdir)/include
+AM_CFLAGS = -Wall $(LIBOSMOCORE_CFLAGS)
+
+noinst_LIBRARIES = libui.a
+libui_a_SOURCES = ui.c telnet_interface.c
+
+
diff --git a/src/host/layer23/src/ui/telnet_interface.c b/src/host/layer23/src/ui/telnet_interface.c
new file mode 100644
index 00000000..d7e9bfb0
--- /dev/null
+++ b/src/host/layer23/src/ui/telnet_interface.c
@@ -0,0 +1,353 @@
+/* minimalistic telnet/network interface it might turn into a wire interface */
+/* (C) 2009 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2011 by Andreas Eversberg <jolly@eversberg.eu>
+ * All Rights Reserved
+ *
+ * This program 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 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/telnet.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/select.h>
+#include <osmocom/vty/buffer.h>
+
+#include <osmocom/bb/ui/ui.h>
+#include <osmocom/bb/ui/telnet_interface.h>
+
+/* Send WILL TELOPT_ECHO to remote server. */
+static void vty_will_echo(struct ui_inst *ui)
+{
+	unsigned char cmd[] = { IAC, WILL, TELOPT_ECHO, '\0' };
+	ui_telnet_puts(ui, (char *)cmd);
+}
+
+/* Make suppress Go-Ahead telnet option. */
+static void vty_will_suppress_go_ahead(struct ui_inst *ui)
+{
+	unsigned char cmd[] = { IAC, WILL, TELOPT_SGA, '\0' };
+	ui_telnet_puts(ui, (char *)cmd);
+}
+
+/* Make don't use linemode over telnet. */
+static void vty_dont_linemode(struct ui_inst *ui)
+{
+	unsigned char cmd[] = { IAC, DONT, TELOPT_LINEMODE, '\0' };
+	ui_telnet_puts(ui, (char *)cmd);
+}
+
+/* Use window size. */
+static void vty_do_window_size(struct ui_inst *ui)
+{
+	unsigned char cmd[] = { IAC, DO, TELOPT_NAWS, '\0' };
+	ui_telnet_puts(ui, (char *)cmd);
+}
+
+static int telnet_new_connection(struct osmo_fd *fd, unsigned int what);
+
+int ui_telnet_init(struct ui_inst *ui, void *tall_ctx, int port)
+{
+	struct sockaddr_in sock_addr;
+	int fd, rc, on = 1;
+
+	ui->tall_telnet_ctx = talloc_named_const(tall_ctx, 1,
+					     "ui_telnet_connection");
+
+	INIT_LLIST_HEAD(&ui->active_connections);
+
+	/* FIXME: use new socket.c code of libosmocore */
+	fd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+
+	if (fd < 0) {
+		LOGP(0, LOGL_ERROR, "Telnet interface socket creation "
+			"failed\n");
+		talloc_free(ui->tall_telnet_ctx);
+		return fd;
+	}
+
+	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+
+	memset(&sock_addr, 0, sizeof(sock_addr));
+	sock_addr.sin_family = AF_INET;
+	sock_addr.sin_port = htons(port);
+	sock_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+	rc = bind(fd, (struct sockaddr*)&sock_addr, sizeof(sock_addr));
+	if (rc < 0) {
+		LOGP(0, LOGL_ERROR, "Telnet interface failed to bind\n");
+		close(fd);
+		talloc_free(ui->tall_telnet_ctx);
+		return rc;
+	}
+
+	rc = listen(fd, 0);
+	if (rc < 0) {
+		LOGP(0, LOGL_ERROR, "Telnet interface failed to listen\n");
+		close(fd);
+		talloc_free(ui->tall_telnet_ctx);
+		return rc;
+	}
+
+	ui->server_socket.when = BSC_FD_READ;
+	ui->server_socket.cb = telnet_new_connection;
+	ui->server_socket.priv_nr = 0;
+	ui->server_socket.data = ui;
+	ui->server_socket.fd = fd;
+	osmo_fd_register(&ui->server_socket);
+
+	return 0;
+}
+
+int ui_telnet_puts(struct ui_inst *ui, const char *text)
+{
+	struct ui_telnet_connection *conn;
+
+	llist_for_each_entry(conn, &ui->active_connections, entry) {
+		buffer_put(conn->obuf, text, strlen(text));
+		conn->fd.when |= BSC_FD_WRITE;
+	}
+
+	return 0;
+}
+
+static int telnet_close_client(struct osmo_fd *fd)
+{
+	struct ui_telnet_connection *conn =
+		(struct ui_telnet_connection*)fd->data;
+	struct ui_inst *ui = conn->ui;
+
+	close(fd->fd);
+	osmo_fd_unregister(fd);
+
+	buffer_free(conn->obuf);
+
+	llist_del(&conn->entry);
+	talloc_free(conn);
+
+	/* notify about connection */
+	ui->telnet_cb(ui);
+
+	return 0;
+}
+
+//#define DEBUG_SEQEUENCES
+static int telnet_getc(struct ui_telnet_connection *conn, unsigned char p)
+{
+#ifdef DEBUG_SEQEUENCES
+	printf("k: %d\n", p);
+#endif
+	
+	if (conn->sb) {
+		if (p == SE) {
+#ifdef DEBUG_SEQEUENCES
+			puts("se");
+#endif
+			conn->sb = 0;
+			conn->iac = 0;
+		}
+		return 0;
+	}
+	if (conn->iac) {
+		if (conn->iac == 1) {
+			if (p == SB) {
+				conn->sb = 1;
+#ifdef DEBUG_SEQEUENCES
+				puts("sb");
+#endif
+				return 0;
+			}
+			if (p == IAC) {
+				conn->iac = 0;
+#ifdef DEBUG_SEQEUENCES
+				puts("iac iac (ende)");
+#endif
+				return 0;
+			}
+			conn->iac = 2;
+			return 0;
+		}
+		conn->iac = 0;
+#ifdef DEBUG_SEQEUENCES
+		puts("iac ende");
+#endif
+		return 0;
+	}
+	if (p == IAC) {
+		conn->iac = 1;
+#ifdef DEBUG_SEQEUENCES
+		puts("iac");
+#endif
+		return 0;
+	}
+
+	if (conn->esc) {
+		if (conn->esc == 1) {
+			if (p == 91) {
+				conn->esc = 2;
+				return 0;
+			}
+			if (p == 79) {
+				conn->esc = 3;
+				return 0;
+			}
+			conn->esc = 0;
+#ifdef DEBUG_SEQEUENCES
+			puts("esc abort");
+#endif
+			return 0;
+		}
+		if (conn->esc == 2) {
+			if (p == 65)
+				ui_inst_keypad(conn->ui, UI_KEY_UP);
+			if (p == 66)
+				ui_inst_keypad(conn->ui, UI_KEY_DOWN);
+			if (p == 67)
+				ui_inst_keypad(conn->ui, UI_KEY_RIGHT);
+			if (p == 68)
+				ui_inst_keypad(conn->ui, UI_KEY_LEFT);
+			if (p == 72)
+				ui_inst_keypad(conn->ui, UI_KEY_PICKUP);
+			if (p == 70)
+				ui_inst_keypad(conn->ui, UI_KEY_HANGUP);
+		}
+		if (conn->esc == 3) {
+			if (p == 80)
+				ui_inst_keypad(conn->ui, UI_KEY_F1);
+			if (p == 81)
+				ui_inst_keypad(conn->ui, UI_KEY_F2);
+		}
+		conn->esc = 0;
+#ifdef DEBUG_SEQEUENCES
+		puts("esc ende");
+#endif
+		return 0;
+	}
+	if (p == 27) {
+		conn->esc = 1;
+#ifdef DEBUG_SEQEUENCES
+		puts("esc");
+#endif
+		return 0;
+	}
+
+	if (p == 3 || p == 4)
+		return -1;
+
+	/* refresh */
+	if (p == 12) {
+		ui_inst_refresh(conn->ui);
+		return 0;
+	}
+
+	ui_inst_keypad(conn->ui, p);
+
+	return 0;
+}
+
+static int client_data(struct osmo_fd *fd, unsigned int what)
+{
+	struct ui_telnet_connection *conn = fd->data;
+	int rc = 0;
+
+	if (what & BSC_FD_READ) {
+		char buffer[16], *p = buffer;
+		int nbytes;
+		nbytes = read(fd->fd, buffer, sizeof(buffer));
+		if (nbytes == 0) {
+			conn->ui = NULL;
+			telnet_close_client(fd);
+			return rc;
+		}
+		if (nbytes > 0) {
+			while (nbytes--) {
+				rc = telnet_getc(conn, *p++);
+				if (rc < 0) {
+					telnet_close_client(&conn->fd);
+					/* telnet conn is gone, must exit! */
+					return 0;
+				}
+			}
+		}
+	}
+
+	if (what & BSC_FD_WRITE) {
+		rc = buffer_flush_all(conn->obuf, fd->fd);
+		if (rc == BUFFER_EMPTY)
+			conn->fd.when &= ~BSC_FD_WRITE;
+	}
+
+	return rc;
+}
+
+static int telnet_new_connection(struct osmo_fd *fd, unsigned int what)
+{
+	struct ui_telnet_connection *conn;
+	struct sockaddr_in sockaddr;
+	socklen_t len = sizeof(sockaddr);
+	int new_connection = accept(fd->fd, (struct sockaddr*)&sockaddr, &len);
+	struct ui_inst *ui = (struct ui_inst *) fd->data;
+
+	if (new_connection < 0) {
+		LOGP(0, LOGL_ERROR, "telnet accept failed\n");
+		return new_connection;
+	}
+
+	conn = talloc_zero(ui->tall_telnet_ctx, struct ui_telnet_connection);
+	conn->ui = ui;
+	conn->fd.data = conn;
+	conn->fd.fd = new_connection;
+	conn->fd.when = BSC_FD_READ;
+	conn->fd.cb = client_data;
+	osmo_fd_register(&conn->fd);
+	llist_add_tail(&conn->entry, &ui->active_connections);
+
+	conn->obuf = buffer_new(ui->tall_telnet_ctx, 0);
+
+	vty_will_echo(ui);
+	vty_will_suppress_go_ahead(ui);
+	vty_dont_linemode(ui);
+	vty_do_window_size(ui);
+
+	/* notify about connection */
+	ui->telnet_cb(ui);
+
+	return 0;
+}
+
+void ui_telnet_exit(struct ui_inst *ui) 
+{
+	struct ui_telnet_connection *tc, *tc2;
+
+	if (ui->server_socket.fd <= 0)
+		return;
+
+	llist_for_each_entry_safe(tc, tc2, &ui->active_connections, entry)
+		telnet_close_client(&tc->fd);
+
+	osmo_fd_unregister(&ui->server_socket);
+	close(ui->server_socket.fd);
+	ui->server_socket.fd = -1;
+	talloc_free(ui->tall_telnet_ctx);
+}
+
diff --git a/src/host/layer23/src/ui/ui.c b/src/host/layer23/src/ui/ui.c
new file mode 100644
index 00000000..5545a5e7
--- /dev/null
+++ b/src/host/layer23/src/ui/ui.c
@@ -0,0 +1,728 @@
+/* (C) 2011 by Andreas Eversberg <jolly@eversberg.eu>
+ *
+ * All Rights Reserved
+ *
+ * This program 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 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+
+#include <osmocom/core/select.h>
+#include <osmocom/bb/ui/ui.h>
+#include <osmocom/bb/ui/telnet_interface.h>
+
+static char *ui_center(const char *text)
+{
+	static char line[UI_COLS + 1];
+	int len, shift;
+
+	strncpy(line, text, UI_COLS);
+	line[UI_COLS] = '\0';
+	len = strlen(line);
+	if (len + 1 < UI_COLS) {
+		shift = (UI_COLS - len) / 2;
+		memcpy(line + shift, line, len + 1);
+		memset(line, ' ', shift);
+	}
+
+	return line;
+}
+
+/*
+ * io functions
+ */
+
+int ui_clearhome(struct ui_inst *ui)
+{
+	int i;
+
+	/* initialize with spaces */
+	memset(ui->buffer, ' ', sizeof(ui->buffer));
+	/* terminate with EOL */
+	for (i = 0; i < UI_ROWS; i++)
+		ui->buffer[(UI_COLS + 1) * (i + 1) - 1] = '\0';
+
+	ui->cursor_x = ui->cursor_y = 0;
+	ui->cursor_on = 0;
+
+	return 0;
+}
+
+int ui_puts(struct ui_inst *ui, int ln, const char *text)
+{
+	int len = strlen(text);
+
+	/* out of range */
+	if (ln < 0 || ln >= UI_ROWS)
+		return -EINVAL;
+
+	/* clip */
+	if (len > UI_COLS)
+		len = UI_COLS;
+
+	/* copy */
+	if (len)
+		memcpy(ui->buffer + (UI_COLS + 1) * ln, text, len);
+
+	return 0;
+}
+
+int ui_flush(struct ui_inst *ui)
+{
+	int i;
+	char frame[UI_COLS + 5];
+	char line[UI_COLS + 5];
+	char cursor[16];
+
+	/* clear */
+	ui_telnet_puts(ui, "\033c");
+
+	/* display */
+	memset(frame + 1, '-', UI_COLS);
+	frame[0] = frame[UI_COLS + 1] = '+';
+	frame[UI_COLS + 2] = '\r';
+	frame[UI_COLS + 3] = '\n';
+	frame[UI_COLS + 4] = '\0';
+	ui_telnet_puts(ui, frame);
+	for (i = 0; i < UI_ROWS; i++) {
+		sprintf(line, "|%s|\r\n", ui->buffer + (UI_COLS + 1) * i);
+		ui_telnet_puts(ui, line);
+	}
+	ui_telnet_puts(ui, frame);
+
+	ui_telnet_puts(ui, "\r\n"
+		"1 2 3 4 5 6 7 8 9 * 0 # = digits\r\n"
+		"Pos1 = pickup, End = hangup\r\n"
+		"F1 = left button, F2 = right button\r\n"
+		"arrow keys = navigation buttons\r\n"); 
+
+	/* set cursor */
+	if (ui->cursor_on) {
+		sprintf(cursor, "\033[%d;%dH", ui->cursor_y + 2,
+			ui->cursor_x + 2);
+		ui_telnet_puts(ui, cursor);
+	}
+
+	return 0;
+}
+
+static int bottom_puts(struct ui_inst *ui, const char *text)
+{
+	char bottom_line[UI_COLS + 1], *p;
+	int space;
+
+	strncpy(bottom_line, text, UI_COLS);
+	bottom_line[UI_COLS] = '\0';
+	if ((p = strchr(bottom_line, ' '))
+	 && (space = UI_COLS - strlen(bottom_line))) {
+	 	p++;
+	 	memcpy(p + space, p, strlen(p));
+		memset(p, ' ', space);
+	}
+
+	return ui_puts(ui, UI_ROWS - 1, bottom_line);
+}
+
+/*
+ * listview
+ */
+
+static int init_listview(struct ui_view *uv, union ui_view_data *ud)
+{
+	ud->listview.vpos = 0;
+	ud->listview.lines = 0;
+
+	return 0;
+}
+
+static int keypad_listview(struct ui_inst *ui, struct ui_view *uv,
+	union ui_view_data *ud, enum ui_key kp)
+{
+	int rows = UI_ROWS;
+
+	if (ui->title)
+		rows--;
+	if (ui->bottom_line)
+		rows--;
+
+	switch (kp) {
+	case UI_KEY_UP:
+		if (ud->listview.vpos == 0)
+			return -1;
+		ud->listview.vpos--;
+		break;
+	case UI_KEY_DOWN:
+		if (rows + ud->listview.vpos >= ud->listview.lines)
+			return -1;
+		ud->listview.vpos++;
+		break;
+	default:
+		return 0;
+	}
+	/* refresh display */
+	uv->display(ui, ud);
+
+	return 0;
+}
+
+static int display_listview(struct ui_inst *ui, union ui_view_data *ud)
+{
+	const char **text = ud->listview.text;
+	int lines = ud->listview.lines;
+	int i, j = 0;
+	int rows = UI_ROWS;
+	
+	if (ui->bottom_line)
+		rows--;
+
+	/* vpos will skip lines */
+	for (i = 0; i < ud->listview.vpos; i++) {
+		/* if we reached end of test, we leave the pointer there */
+		if (*text == NULL)
+			break;
+		text++;
+		j++;
+	}
+
+	ui_clearhome(ui);
+	/* title */
+	i = 0;
+	if (ui->title)
+		ui_puts(ui, i++, ui_center(ui->title));
+	for (; i < rows; i++) {
+		if (*text && j < lines) {
+			ui_puts(ui, i, *text);
+			text++;
+			j++;
+		} else
+			break;
+//			ui_puts(ui, i, "~");
+	}
+	if (ui->bottom_line)
+		bottom_puts(ui, ui->bottom_line);
+	ui_flush(ui);
+
+	return 0;
+}
+
+/*
+ * selectview
+ */
+
+static int init_selectview(struct ui_view *uv, union ui_view_data *ud)
+{
+	ud->selectview.vpos = 0;
+	ud->selectview.cursor = 0;
+	ud->selectview.lines = 0;
+
+	return 0;
+}
+
+static int keypad_selectview(struct ui_inst *ui, struct ui_view *uv,
+	union ui_view_data *ud, enum ui_key kp)
+{
+	int rows = UI_ROWS;
+	
+	if (ui->title)
+		rows--;
+	if (ui->bottom_line)
+		rows--;
+
+	switch (kp) {
+	case UI_KEY_UP:
+		if (ud->selectview.cursor == 0)
+			return -1;
+		ud->selectview.cursor--;
+		/* follow cursor */
+		if (ud->selectview.cursor < ud->selectview.vpos)
+			ud->selectview.vpos = ud->selectview.cursor;
+		break;
+	case UI_KEY_DOWN:
+		if (ud->selectview.cursor >= ud->selectview.lines - 1)
+			return -1;
+		ud->selectview.cursor++;
+		/* follow cursor */
+		if (ud->selectview.cursor > ud->selectview.vpos + rows - 1)
+			ud->selectview.vpos = ud->selectview.cursor -
+								(rows - 1);
+		break;
+	default:
+		return 0;
+	}
+	/* refresh display */
+	uv->display(ui, ud);
+
+	return 0;
+}
+
+static int display_selectview(struct ui_inst *ui, union ui_view_data *ud)
+{
+	const char **text = ud->selectview.text;
+	int lines = ud->selectview.lines;
+	int i, j = 0, y = 0;
+	int rows = UI_ROWS;
+	char line[UI_COLS + 1];
+	
+	if (ui->bottom_line)
+		rows--;
+
+	/* vpos will skip lines */
+	for (i = 0; i < ud->selectview.vpos; i++) {
+		/* if we reached end of test, we leave the pointer there */
+		if (*text == NULL)
+			break;
+		text++;
+		j++;
+	}
+
+	ui_clearhome(ui);
+	/* title */
+	i = 0;
+	if (ui->title)
+		ui_puts(ui, i++, ui_center(ui->title));
+	for (; i < rows; i++) {
+		if (*text && j < lines) {
+			if (ud->selectview.cursor == j)
+				y = i;
+			strncpy(line, *text, UI_COLS);
+			line[UI_COLS] = '\0';
+			ui_puts(ui, i, line);
+			text++;
+			j++;
+		} else
+			break;
+//			ui_puts(ui, i, "~");
+	}
+	if (ui->bottom_line)
+		bottom_puts(ui, ui->bottom_line);
+	ui->cursor_on = 1;
+	ui->cursor_x = 0;
+	ui->cursor_y = y;
+	ui_flush(ui);
+
+	return 0;
+}
+
+/*
+ * stringview
+ */
+
+static int init_stringview(struct ui_view *uv, union ui_view_data *ud)
+{
+	ud->stringview.options = 0;
+	ud->stringview.pos = 0;
+
+	return 0;
+}
+
+static int keypad_stringview(struct ui_inst *ui, struct ui_view *uv,
+	union ui_view_data *ud, enum ui_key kp);
+
+static int keypad_stringview_options(struct ui_inst *ui, struct ui_view *uv,
+	union ui_view_data *ud, enum ui_key kp)
+{
+	switch (kp) {
+	case UI_KEY_F1: /* back */
+		ud->stringview.options = 0;
+		break;
+	case UI_KEY_1:
+		ud->stringview.options = 0;
+		return keypad_stringview(ui, uv, ud, 'a');
+	case UI_KEY_2:
+		ud->stringview.options = 0;
+		return keypad_stringview(ui, uv, ud, 'b');
+	case UI_KEY_3:
+		ud->stringview.options = 0;
+		return keypad_stringview(ui, uv, ud, 'c');
+	case UI_KEY_0:
+		ud->stringview.options = 0;
+		return keypad_stringview(ui, uv, ud, '+');
+	default:
+		return 0;
+	}
+	/* refresh display */
+	uv->display(ui, ud);
+
+	return 0;
+}
+
+static int keypad_stringview(struct ui_inst *ui, struct ui_view *uv,
+	union ui_view_data *ud, enum ui_key kp)
+{
+	if (ud->stringview.options)
+		return keypad_stringview_options(ui, uv, ud, kp);
+
+	switch (kp) {
+	case UI_KEY_STAR:
+	case UI_KEY_HASH:
+	case UI_KEY_1:
+	case UI_KEY_2:
+	case UI_KEY_3:
+	case UI_KEY_4:
+	case UI_KEY_5:
+	case UI_KEY_6:
+	case UI_KEY_7:
+	case UI_KEY_8:
+	case UI_KEY_9:
+	case UI_KEY_0:
+	case 'a':
+	case 'b':
+	case 'c':
+	case '+':
+		/* check if number is full */
+		if (strlen(ud->stringview.number) + 1 == ud->stringview.num_len)
+			return -1;
+		/* add digit */
+		if (ud->stringview.number[ud->stringview.pos] == '\0') {
+			/* add to the end */
+			ud->stringview.number[ud->stringview.pos] = kp;
+			ud->stringview.pos++;
+			ud->stringview.number[ud->stringview.pos] = '\0';
+		} else {
+			/* insert digit */
+			memcpy(ud->stringview.number + ud->stringview.pos + 1,
+				ud->stringview.number + ud->stringview.pos,
+				strlen(ud->stringview.number +
+							ud->stringview.pos)
+					+ 1);
+			ud->stringview.number[ud->stringview.pos] = kp;
+			ud->stringview.pos++;
+		}
+		break;
+	case UI_KEY_LEFT:
+		if (ud->stringview.pos == 0)
+			return -1;
+		ud->stringview.pos--;
+		break;
+	case UI_KEY_RIGHT:
+		if (ud->stringview.pos == strlen(ud->stringview.number))
+			return -1;
+		ud->stringview.pos++;
+		break;
+	case UI_KEY_UP: /* select options */
+		ud->stringview.options = 1;
+		ud->stringview.options_pos = 0;
+		break;
+	case UI_KEY_F1: /* clear */
+		ud->stringview.pos = 0;
+		ud->stringview.number[0] = '\0';
+		break;
+	case UI_KEY_F2: /* delete */
+		if (ud->stringview.pos == 0)
+			return -1;
+		/* del digit */
+		if (ud->stringview.number[ud->stringview.pos] == '\0') {
+			/* del digit from the end */
+			ud->stringview.pos--;
+			ud->stringview.number[ud->stringview.pos] = '\0';
+		} else {
+			/* remove digit */
+			memcpy(ud->stringview.number + ud->stringview.pos - 1,
+				ud->stringview.number + ud->stringview.pos,
+				strlen(ud->stringview.number +
+							ud->stringview.pos)
+					+ 1);
+			ud->stringview.pos--;
+		}
+		break;
+	default:
+		return 0;
+	}
+	/* refresh display */
+	uv->display(ui, ud);
+
+	return 0;
+}
+
+static int display_stringview(struct ui_inst *ui, union ui_view_data *ud)
+{
+	char line[UI_COLS + 1];
+	char *p = ud->stringview.number;
+	int len = strlen(p);
+	int i = 1, y;
+
+	/* options screen */
+	if (ud->stringview.options) {
+		ui_clearhome(ui);
+		ui_puts(ui, 0, ui_center("Extra Keys"));
+		ui_puts(ui, 2, "1:a 2:b 3:c");
+		ui_puts(ui, 3, "4:  5:  6: ");
+		ui_puts(ui, 4, "7:  8:  9: ");
+		ui_puts(ui, 5, "*:  0:+ #: ");
+		bottom_puts(ui, "back ");
+		ui_flush(ui);
+		return 0;
+	}
+
+	/* if number shrunk */
+	if (ud->stringview.pos > len)
+		ud->stringview.pos = len;
+
+	ui_clearhome(ui);
+	/* title */
+	if (ui->title) {
+		ui_puts(ui, i++, ui_center(ui->title));
+		i++;
+	}
+	y = i;
+	/* if line exceeds display width */
+	while (len > UI_COLS) {
+		memcpy(line, p, UI_COLS);
+		line[UI_COLS] = '\0';
+		ui_puts(ui, i++, line);
+		p += UI_COLS;
+		len -= UI_COLS;
+	}
+	/* last line */
+	if (len)
+		ui_puts(ui, i, p);
+	/* cursor */
+	ui->cursor_on = 1;
+	ui->cursor_x = ud->stringview.pos % UI_COLS;
+	ui->cursor_y = y + (ud->stringview.pos / UI_COLS);
+	/* F-keys info */
+	bottom_puts(ui, "clear del");
+	ui_flush(ui);
+
+	return 0;
+}
+
+/*
+ * integer view
+ */
+
+static int init_intview(struct ui_view *uv, union ui_view_data *ud)
+{
+	ud->intview.min = -128;
+	ud->intview.max = 127;
+	ud->intview.value = 0;
+
+	return 0;
+}
+
+static int keypad_intview(struct ui_inst *ui, struct ui_view *uv,
+	union ui_view_data *ud, enum ui_key kp)
+{
+	int value;
+
+	switch (kp) {
+	case UI_KEY_1:
+	case UI_KEY_2:
+	case UI_KEY_3:
+	case UI_KEY_4:
+	case UI_KEY_5:
+	case UI_KEY_6:
+	case UI_KEY_7:
+	case UI_KEY_8:
+	case UI_KEY_9:
+	case UI_KEY_0:
+		value = ud->intview.value;
+		value = value * 10 + kp - UI_KEY_0;
+		/* if additional digit would cause overflow (or no change) */
+		if (value <= ud->intview.value)
+			return - 1;
+		if (value > 0x7fffffff)
+			return - 1;
+		ud->intview.value = value;
+		break;
+	case UI_KEY_STAR:
+		ud->intview.sign = 1 - ud->intview.sign;
+		break;
+	case UI_KEY_UP:
+	case UI_KEY_DOWN:
+		if (ud->intview.sign)
+			value = 0 - ud->intview.value;
+		else
+			value = ud->intview.value;
+		/* check if limit is already reached */
+		if (kp == UI_KEY_UP && value == ud->intview.max)
+			return -1;
+		if (kp == UI_KEY_DOWN && value == ud->intview.min)
+			return -1;
+		/* if value out of range, put it in range */
+		if (value > ud->intview.max) {
+			value = ud->intview.max;
+			goto store_value;
+		}
+		if (value < ud->intview.min) {
+			value = ud->intview.min;
+			goto store_value;
+		}
+		if (kp == UI_KEY_UP)
+			value++;
+		else
+			value--;
+		goto store_value;
+	case UI_KEY_LEFT: /* delete */
+		/* already 0 */
+		if (ud->intview.value == 0)
+			return -1;
+		ud->intview.value /= 10;
+		break;
+	default:
+		/* if other key is pressed, make value fit in range */
+		if (ud->intview.sign)
+			value = 0 - ud->intview.value;
+		else
+			value = ud->intview.value;
+		if (value < ud->intview.min) {
+			value = ud->intview.min;
+			goto store_value;
+		}
+		if (value > ud->intview.max) {
+			value = ud->intview.max;
+			goto store_value;
+		}
+		return 0;
+	}
+	/* refresh display */
+	uv->display(ui, ud);
+
+	return 0;
+
+store_value:
+	/* store new value */
+	if (value < 0) {
+		ud->intview.value = 0 - value;
+		ud->intview.sign = 1;
+	} else {
+		ud->intview.value = value;
+		ud->intview.sign = 0;
+	}
+	/* refresh display */
+	uv->display(ui, ud);
+
+	return 0;
+}
+
+static int display_intview(struct ui_inst *ui, union ui_view_data *ud)
+{
+	char line[UI_COLS + 2];
+	int i = 1, y, x = 1;
+	int value;
+
+	ui_clearhome(ui);
+	/* title */
+	if (ui->title) {
+		ui_puts(ui, i++, ui_center(ui->title));
+		i++;
+	}
+	y = i;
+	/* value */
+	if (ud->intview.sign)
+		line[0] = '-';
+	else
+		line[0] = ' ';
+	sprintf(line + 1, "%d", ud->intview.value);
+	ui_puts(ui, i++, line);
+	/* range */
+	i++;
+	snprintf(line, UI_COLS + 1, "(%d..%d)", ud->intview.min,
+		ud->intview.max);
+	line[UI_COLS] = '\0';
+	ui_puts(ui, i++, line);
+	/* cursor */
+	value = ud->intview.value;
+	while (value) {
+		x++;
+		value /= 10;
+	}
+	ui->cursor_on = 1;
+	ui->cursor_x = x;
+	ui->cursor_y = y;
+	/* F-keys info */
+	if (ui->bottom_line)
+		bottom_puts(ui, ui->bottom_line);
+	ui_flush(ui);
+
+	return 0;
+}
+
+/*
+ * structure of all views
+ */
+
+struct ui_view ui_listview = {
+	.init = init_listview,
+	.keypad = keypad_listview,
+	.display = display_listview,
+};
+
+struct ui_view ui_selectview = {
+	.init = init_selectview,
+	.keypad = keypad_selectview,
+	.display = display_selectview,
+};
+
+struct ui_view ui_stringview = {
+	.init = init_stringview,
+	.keypad = keypad_stringview,
+	.display = display_stringview,
+};
+
+struct ui_view ui_intview = {
+	.init = init_intview,
+	.keypad = keypad_intview,
+	.display = display_intview,
+};
+
+/*
+ * instance handling
+ */
+
+int ui_inst_init(struct ui_inst *ui, struct ui_view *uv,
+	int (*key_cb)(struct ui_inst *ui, enum ui_key kp),
+	int (*beep_cb)(struct ui_inst *ui),
+	int (*telnet_cb)(struct ui_inst *ui))
+{
+	ui->uv = uv;
+	ui->key_cb = key_cb;
+	ui->beep_cb = beep_cb;
+	ui->telnet_cb = telnet_cb;
+
+	ui_clearhome(ui);
+
+	/* initialize view */
+	uv->init(uv, &ui->ud);
+
+	return 0;
+}
+
+int ui_inst_refresh(struct ui_inst *ui)
+{
+	/* refresh display */
+	return ui->uv->display(ui, &ui->ud);
+}
+
+/* process keypress at user interface */
+int ui_inst_keypad(struct ui_inst *ui, enum ui_key kp)
+{
+	int rc;
+
+	/* first check if key is handled by callback */
+	rc = ui->key_cb(ui, kp);
+	if (rc)
+		return rc; /* must exit, since key_cb() may reconfigure UI */
+
+	rc = ui->uv->keypad(ui, ui->uv, &ui->ud, kp);
+	if (rc < 0)
+		ui->beep_cb(ui);
+
+	return rc;
+}
+