Shofel2_T124_python/venv/lib/python3.10/site-packages/urwid/web_display.py

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2024-05-25 16:45:07 +00:00
#!/usr/bin/python
#
# Urwid web (CGI/Asynchronous Javascript) display module
# Copyright (C) 2004-2007 Ian Ward
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# Urwid web site: https://urwid.org/
"""
Urwid web application display module
"""
from __future__ import annotations
import glob
import os
import random
import select
import signal
import socket
import sys
import typing
from urwid import util
if typing.TYPE_CHECKING:
from typing_extensions import Literal
_js_code = r"""
// Urwid web (CGI/Asynchronous Javascript) display module
// Copyright (C) 2004-2005 Ian Ward
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
// Urwid web site: https://urwid.org/
colours = new Object();
colours = {
'0': "black",
'1': "#c00000",
'2': "green",
'3': "#804000",
'4': "#0000c0",
'5': "#c000c0",
'6': "teal",
'7': "silver",
'8': "gray",
'9': "#ff6060",
'A': "lime",
'B': "yellow",
'C': "#8080ff",
'D': "#ff40ff",
'E': "aqua",
'F': "white"
};
keycodes = new Object();
keycodes = {
8: "backspace", 9: "tab", 13: "enter", 27: "esc",
33: "page up", 34: "page down", 35: "end", 36: "home",
37: "left", 38: "up", 39: "right", 40: "down",
45: "insert", 46: "delete",
112: "f1", 113: "f2", 114: "f3", 115: "f4",
116: "f5", 117: "f6", 118: "f7", 119: "f8",
120: "f9", 121: "f10", 122: "f11", 123: "f12"
};
var conn = null;
var char_width = null;
var char_height = null;
var screen_x = null;
var screen_y = null;
var urwid_id = null;
var send_conn = null;
var send_queue_max = 32;
var send_queue = new Array(send_queue_max);
var send_queue_in = 0;
var send_queue_out = 0;
var check_font_delay = 1000;
var send_more_delay = 100;
var poll_again_delay = 500;
var document_location = null;
var update_method = "multipart";
var sending = false;
var lastkeydown = null;
function setup_connection() {
if (window.XMLHttpRequest) {
conn = new XMLHttpRequest();
} else if (window.ActiveXObject) {
conn = new ActiveXObject("Microsoft.XMLHTTP");
}
if (conn == null) {
set_status("Connection Failed");
alert( "Can't figure out how to send request." );
return;
}
try{
conn.multipart = true;
}catch(e){
update_method = "polling";
}
conn.onreadystatechange = handle_recv;
conn.open("POST", document_location, true);
conn.setRequestHeader("X-Urwid-Method",update_method);
conn.setRequestHeader("Content-type","text/plain");
conn.send("window resize " +screen_x+" "+screen_y+"\n");
}
function do_poll() {
if (urwid_id == null){
alert("that's unpossible!");
return;
}
if (window.XMLHttpRequest) {
conn = new XMLHttpRequest();
} else if (window.ActiveXObject) {
conn = new ActiveXObject("Microsoft.XMLHTTP");
}
conn.onreadystatechange = handle_recv;
conn.open("POST", document_location, true);
conn.setRequestHeader("X-Urwid-Method","polling");
conn.setRequestHeader("X-Urwid-ID",urwid_id);
conn.setRequestHeader("Content-type","text/plain");
conn.send("eh?");
}
function handle_recv() {
if( ! conn ){ return;}
if( conn.readyState != 4) {
return;
}
if( conn.status == 404 && urwid_id != null) {
set_status("Connection Closed");
return;
}
if( conn.status == 403 && update_method == "polling" ) {
set_status("Server Refused Connection");
alert("This server does not allow polling clients.\n\n" +
"Please use a web browser with multipart support " +
"such as Mozilla Firefox");
return;
}
if( conn.status == 503 ) {
set_status("Connection Failed");
alert("The server has reached its maximum number of "+
"connections.\n\nPlease try again later.");
return;
}
if( conn.status != 200) {
set_status("Connection Failed");
alert("Error from server: "+conn.statusText);
return;
}
if( urwid_id == null ){
urwid_id = conn.getResponseHeader("X-Urwid-ID");
if( send_queue_in != send_queue_out ){
// keys waiting
do_send();
}
if(update_method=="polling"){
set_status("Polling");
}else if(update_method=="multipart"){
set_status("Connected");
}
}
if( conn.responseText == "" ){
if(update_method=="polling"){
poll_again();
}
return; // keepalive
}
if( conn.responseText == "Z" ){
set_status("Connection Closed");
update_method = null;
return;
}
var text = document.getElementById('text');
var last_screen = Array(text.childNodes.length);
for( var i=0; i<text.childNodes.length; i++ ){
last_screen[i] = text.childNodes[i];
}
var frags = conn.responseText.split("\n");
var ln = document.createElement('span');
var k = 0;
for( var i=0; i<frags.length; i++ ){
var f = frags[i];
if( f == "" ){
var br = document.getElementById('br').cloneNode(true);
ln.appendChild( br );
if( text.childNodes.length > k ){
text.replaceChild(ln, text.childNodes[k]);
}else{
text.appendChild(ln);
}
k = k+1;
ln = document.createElement('span');
}else if( f.charAt(0) == "<" ){
line_number = parseInt(f.substr(1));
if( line_number == k ){
k = k +1;
continue;
}
var clone = last_screen[line_number].cloneNode(true);
if( text.childNodes.length > k ){
text.replaceChild(clone, text.childNodes[k]);
}else{
text.appendChild(clone);
}
k = k+1;
}else{
var span=make_span(f.substr(2),f.charAt(0),f.charAt(1));
ln.appendChild( span );
}
}
for( var i=k; i < text.childNodes.length; i++ ){
text.removeChild(last_screen[i]);
}
if(update_method=="polling"){
poll_again();
}
}
function poll_again(){
if(conn.status == 200){
setTimeout("do_poll();",poll_again_delay);
}
}
function load_web_display(){
if( document.documentURI ){
document_location = document.documentURI;
}else{
document_location = document.location;
}
document.onkeypress = body_keypress;
document.onkeydown = body_keydown;
document.onresize = body_resize;
body_resize();
send_queue_out = send_queue_in; // don't queue the first resize
set_status("Connecting");
setup_connection();
setTimeout("check_fontsize();",check_font_delay);
}
function set_status( status ){
var s = document.getElementById('status');
var t = document.createTextNode(status);
s.replaceChild(t, s.firstChild);
}
function make_span(s, fg, bg){
d = document.createElement('span');
d.style.backgroundColor = colours[bg];
d.style.color = colours[fg];
d.appendChild(document.createTextNode(s));
return d;
}
function body_keydown(e){
if (conn == null){
return;
}
if (!e) var e = window.event;
if (e.keyCode) code = e.keyCode;
else if (e.which) code = e.which;
var mod = "";
var key;
if( e.ctrlKey ){ mod = "ctrl " + mod; }
if( e.altKey || e.metaKey ){ mod = "meta " + mod; }
if( e.shiftKey && e.charCode == 0 ){ mod = "shift " + mod; }
key = keycodes[code];
if( key != undefined ){
lastkeydown = key;
send_key( mod + key );
stop_key_event(e);
return false;
}
}
function body_keypress(e){
if (conn == null){
return;
}
if (!e) var e = window.event;
if (e.keyCode) code = e.keyCode;
else if (e.which) code = e.which;
var mod = "";
var key;
if( e.ctrlKey ){ mod = "ctrl " + mod; }
if( e.altKey || e.metaKey ){ mod = "meta " + mod; }
if( e.shiftKey && e.charCode == 0 ){ mod = "shift " + mod; }
if( e.charCode != null && e.charCode != 0 ){
key = String.fromCharCode(e.charCode);
}else if( e.charCode == null ){
key = String.fromCharCode(code);
}else{
key = keycodes[code];
if( key == undefined || lastkeydown == key ){
lastkeydown = null;
stop_key_event(e);
return false;
}
}
send_key( mod + key );
stop_key_event(e);
return false;
}
function stop_key_event(e){
e.cancelBubble = true;
if( e.stopPropagation ){
e.stopPropagation();
}
if( e.preventDefault ){
e.preventDefault();
}
}
function send_key( key ){
if( (send_queue_in+1)%send_queue_max == send_queue_out ){
// buffer overrun
return;
}
send_queue[send_queue_in] = key;
send_queue_in = (send_queue_in+1)%send_queue_max;
if( urwid_id != null ){
if (send_conn == undefined || send_conn.ready_state != 4 ){
send_more();
return;
}
do_send();
}
}
function do_send() {
if( ! urwid_id ){ return; }
if( ! update_method ){ return; } // connection closed
if( send_queue_in == send_queue_out ){ return; }
if( sending ){
//var queue_delta = send_queue_in - send_queue_out;
//if( queue_delta < 0 ){ queue_delta += send_queue_max; }
//set_status("Sending (queued "+queue_delta+")");
return;
}
try{
sending = true;
//set_status("starting send");
if( send_conn == null ){
if (window.XMLHttpRequest) {
send_conn = new XMLHttpRequest();
} else if (window.ActiveXObject) {
send_conn = new ActiveXObject("Microsoft.XMLHTTP");
}
}else if( send_conn.status != 200) {
alert("Error from server: "+send_conn.statusText);
return;
}else if(send_conn.readyState != 4 ){
alert("not ready on send connection");
return;
}
} catch(e) {
alert(e);
sending = false;
return;
}
send_conn.open("POST", document_location, true);
send_conn.onreadystatechange = send_handle_recv;
send_conn.setRequestHeader("Content-type","text/plain");
send_conn.setRequestHeader("X-Urwid-ID",urwid_id);
var tmp_send_queue_in = send_queue_in;
var out = null;
if( send_queue_out > tmp_send_queue_in ){
out = send_queue.slice(send_queue_out).join("\n")
if( tmp_send_queue_in > 0 ){
out += "\n" + send_queue.slice(0,tmp_send_queue_in).join("\n");
}
}else{
out = send_queue.slice(send_queue_out,
tmp_send_queue_in).join("\n");
}
send_queue_out = tmp_send_queue_in;
//set_status("Sending");
send_conn.send( out +"\n" );
}
function send_handle_recv() {
if( send_conn.readyState != 4) {
return;
}
if( send_conn.status == 404) {
set_status("Connection Closed");
update_method = null;
return;
}
if( send_conn.status != 200) {
alert("Error from server: "+send_conn.statusText);
return;
}
sending = false;
if( send_queue_out != send_queue_in ){
send_more();
}
}
function send_more(){
setTimeout("do_send();",send_more_delay);
}
function check_fontsize(){
body_resize()
setTimeout("check_fontsize();",check_font_delay);
}
function body_resize(){
var t = document.getElementById('testchar');
var t2 = document.getElementById('testchar2');
var text = document.getElementById('text');
var window_width;
var window_height;
if (window.innerHeight) {
window_width = window.innerWidth;
window_height = window.innerHeight;
}else{
window_width = document.documentElement.clientWidth;
window_height = document.documentElement.clientHeight;
//var z = "CI:"; for(var i in bod){z = z + " " + i;} alert(z);
}
char_width = t.offsetLeft / 44;
var avail_width = window_width-18;
var avail_width_mod = avail_width % char_width;
var x_size = (avail_width - avail_width_mod)/char_width;
char_height = t2.offsetTop - t.offsetTop;
var avail_height = window_height-text.offsetTop-10;
var avail_height_mod = avail_height % char_height;
var y_size = (avail_height - avail_height_mod)/char_height;
text.style.width = x_size*char_width+"px";
text.style.height = y_size*char_height+"px";
if( screen_x != x_size || screen_y != y_size ){
send_key("window resize "+x_size+" "+y_size);
}
screen_x = x_size;
screen_y = y_size;
}
"""
ALARM_DELAY = 60
POLL_CONNECT = 3
MAX_COLS = 200
MAX_ROWS = 100
MAX_READ = 4096
BUF_SZ = 16384
_code_colours = {
'black': "0",
'dark red': "1",
'dark green': "2",
'brown': "3",
'dark blue': "4",
'dark magenta': "5",
'dark cyan': "6",
'light gray': "7",
'dark gray': "8",
'light red': "9",
'light green': "A",
'yellow': "B",
'light blue': "C",
'light magenta': "D",
'light cyan': "E",
'white': "F",
}
# replace control characters with ?'s
_trans_table = "?" * 32 + "".join([chr(x) for x in range(32, 256)])
_css_style = """
body { margin: 8px 8px 8px 8px; border: 0;
color: black; background-color: silver;
font-family: fixed; overflow: hidden; }
form { margin: 0 0 8px 0; }
#text { position: relative;
background-color: silver;
width: 100%; height: 100%;
margin: 3px 0 0 0; border: 1px solid #999; }
#page { position: relative; width: 100%;height: 100%;}
"""
# HTML Initial Page
_html_page = [
"""<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Urwid Web Display - ""","""</title>
<style type="text/css">
""" + _css_style + r"""
</style>
</head>
<body id="body" onload="load_web_display()">
<div style="position:absolute; visibility:hidden;">
<br id="br"\>
<pre>The quick brown fox jumps over the lazy dog.<span id="testchar">X</span>
<span id="testchar2">Y</span></pre>
</div>
Urwid Web Display - <b>""","""</b> -
Status: <span id="status">Set up</span>
<script type="text/javascript">
//<![CDATA[
""" + _js_code +"""
//]]>
</script>
<pre id="text"></pre>
</body>
</html>
"""]
class Screen:
def __init__(self):
self.palette = {}
self.has_color = True
self._started = False
@property
def started(self):
return self._started
def register_palette( self, l ):
"""Register a list of palette entries.
l -- list of (name, foreground, background) or
(name, same_as_other_name) palette entries.
calls self.register_palette_entry for each item in l
"""
for item in l:
if len(item) in (3,4):
self.register_palette_entry( *item )
continue
assert len(item) == 2, "Invalid register_palette usage"
name, like_name = item
if like_name not in self.palette:
raise Exception(f"palette entry '{like_name}' doesn't exist")
self.palette[name] = self.palette[like_name]
def register_palette_entry( self, name, foreground, background,
mono=None):
"""Register a single palette entry.
name -- new entry/attribute name
foreground -- foreground colour
background -- background colour
mono -- monochrome terminal attribute
See curses_display.register_palette_entry for more info.
"""
if foreground == "default":
foreground = "black"
if background == "default":
background = "light gray"
self.palette[name] = (foreground, background, mono)
def set_mouse_tracking(self, enable=True):
"""Not yet implemented"""
pass
def tty_signal_keys(self, *args, **vargs):
"""Do nothing."""
pass
def start(self):
"""
This function reads the initial screen size, generates a
unique id and handles cleanup when fn exits.
web_display.set_preferences(..) must be called before calling
this function for the preferences to take effect
"""
global _prefs
if self._started:
return util.StoppingContext(self)
client_init = sys.stdin.read(50)
assert client_init.startswith("window resize "),client_init
ignore1,ignore2,x,y = client_init.split(" ",3)
x = int(x)
y = int(y)
self._set_screen_size( x, y )
self.last_screen = {}
self.last_screen_width = 0
self.update_method = os.environ["HTTP_X_URWID_METHOD"]
assert self.update_method in ("multipart","polling")
if self.update_method == "polling" and not _prefs.allow_polling:
sys.stdout.write("Status: 403 Forbidden\r\n\r\n")
sys.exit(0)
clients = glob.glob(os.path.join(_prefs.pipe_dir,"urwid*.in"))
if len(clients) >= _prefs.max_clients:
sys.stdout.write("Status: 503 Sever Busy\r\n\r\n")
sys.exit(0)
urwid_id = "%09d%09d"%(random.randrange(10**9),
random.randrange(10**9))
self.pipe_name = os.path.join(_prefs.pipe_dir,f"urwid{urwid_id}")
os.mkfifo(f"{self.pipe_name}.in",0o600)
signal.signal(signal.SIGTERM,self._cleanup_pipe)
self.input_fd = os.open(f"{self.pipe_name}.in",
os.O_NONBLOCK | os.O_RDONLY)
self.input_tail = ""
self.content_head = ("Content-type: "
"multipart/x-mixed-replace;boundary=ZZ\r\n"
"X-Urwid-ID: "+urwid_id+"\r\n"
"\r\n\r\n"
"--ZZ\r\n")
if self.update_method=="polling":
self.content_head = (
f'Content-type: text/plain\r\nX-Urwid-ID: {urwid_id}\r\n\r\n\r\n')
signal.signal(signal.SIGALRM,self._handle_alarm)
signal.alarm( ALARM_DELAY )
self._started = True
return util.StoppingContext(self)
def stop(self):
"""
Restore settings and clean up.
"""
if not self._started:
return
# XXX which exceptions does this actually raise? EnvironmentError?
try:
self._close_connection()
except Exception:
pass
signal.signal(signal.SIGTERM,signal.SIG_DFL)
self._cleanup_pipe()
self._started = False
def set_input_timeouts(self, *args):
pass
def run_wrapper(self,fn):
"""
Run the application main loop, calling start() first
and stop() on exit.
"""
try:
self.start()
return fn()
finally:
self.stop()
def _close_connection(self):
if self.update_method == "polling child":
self.server_socket.settimeout(0)
sock, addr = self.server_socket.accept()
sock.sendall("Z")
sock.close()
if self.update_method == "multipart":
sys.stdout.write("\r\nZ"
"\r\n--ZZ--\r\n")
sys.stdout.flush()
def _cleanup_pipe(self, *args):
if not self.pipe_name: return
# XXX which exceptions does this actually raise? EnvironmentError?
try:
os.remove(f"{self.pipe_name}.in")
os.remove(f"{self.pipe_name}.update")
except Exception:
pass
def _set_screen_size(self, cols, rows ):
"""Set the screen size (within max size)."""
if cols > MAX_COLS:
cols = MAX_COLS
if rows > MAX_ROWS:
rows = MAX_ROWS
self.screen_size = cols, rows
def draw_screen(self, size, r ):
"""Send a screen update to the client."""
(cols, rows) = size
if cols != self.last_screen_width:
self.last_screen = {}
sendq = [self.content_head]
if self.update_method == "polling":
send = sendq.append
elif self.update_method == "polling child":
signal.alarm( 0 )
try:
s, addr = self.server_socket.accept()
except socket.timeout:
sys.exit(0)
send = s.sendall
else:
signal.alarm( 0 )
send = sendq.append
send("\r\n")
self.content_head = ""
assert r.rows() == rows
if r.cursor is not None:
cx, cy = r.cursor
else:
cx = cy = None
new_screen = {}
y = -1
for row in r.content():
y += 1
row = list(row)
l = []
sig = tuple(row)
if y == cy: sig = sig + (cx,)
new_screen[sig] = new_screen.get(sig,[]) + [y]
old_line_numbers = self.last_screen.get(sig, None)
if old_line_numbers is not None:
if y in old_line_numbers:
old_line = y
else:
old_line = old_line_numbers[0]
send( "<%d\n"%old_line )
continue
col = 0
for (a, cs, run) in row:
run = run.translate(_trans_table)
if a is None:
fg,bg,mono = "black", "light gray", None
else:
fg,bg,mono = self.palette[a]
if y == cy and col <= cx:
run_width = util.calc_width(run, 0,
len(run))
if col+run_width > cx:
l.append(code_span(run, fg, bg,
cx-col))
else:
l.append(code_span(run, fg, bg))
col += run_width
else:
l.append(code_span(run, fg, bg))
send(f"{''.join(l)}\n")
self.last_screen = new_screen
self.last_screen_width = cols
if self.update_method == "polling":
sys.stdout.write("".join(sendq))
sys.stdout.flush()
sys.stdout.close()
self._fork_child()
elif self.update_method == "polling child":
s.close()
else: # update_method == "multipart"
send("\r\n--ZZ\r\n")
sys.stdout.write("".join(sendq))
sys.stdout.flush()
signal.alarm( ALARM_DELAY )
def clear(self):
"""
Force the screen to be completely repainted on the next
call to draw_screen().
(does nothing for web_display)
"""
pass
def _fork_child(self):
"""
Fork a child to run CGI disconnected for polling update method.
Force parent process to exit.
"""
daemonize( f"{self.pipe_name}.err" )
self.input_fd = os.open(f"{self.pipe_name}.in",
os.O_NONBLOCK | os.O_RDONLY)
self.update_method = "polling child"
s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
s.bind( f"{self.pipe_name}.update" )
s.listen(1)
s.settimeout(POLL_CONNECT)
self.server_socket = s
def _handle_alarm(self, sig, frame):
assert self.update_method in ("multipart","polling child")
if self.update_method == "polling child":
# send empty update
try:
s, addr = self.server_socket.accept()
s.close()
except socket.timeout:
sys.exit(0)
else:
# send empty update
sys.stdout.write("\r\n\r\n--ZZ\r\n")
sys.stdout.flush()
signal.alarm( ALARM_DELAY )
def get_cols_rows(self):
"""Return the screen size."""
return self.screen_size
@typing.overload
def get_input(self, raw_keys: Literal[False]) -> list[str]:
...
@typing.overload
def get_input(self, raw_keys: Literal[True]) -> tuple[list[str], list[int]]:
...
def get_input(self, raw_keys: bool = False) -> list[str] | tuple[list[str], list[int]]:
"""Return pending input as a list."""
l = []
resized = False
try:
iready, oready, eready = select.select([self.input_fd],[],[],0.5)
except OSError as e:
# return on interruptions
if e.args[0] == 4:
if raw_keys:
return [], []
return []
raise
if not iready:
if raw_keys:
return [], []
return []
keydata = os.read(self.input_fd, MAX_READ)
os.close(self.input_fd)
self.input_fd = os.open(f"{self.pipe_name}.in", os.O_NONBLOCK | os.O_RDONLY)
#sys.stderr.write( repr((keydata,self.input_tail))+"\n" )
keys = keydata.split("\n")
keys[0] = self.input_tail + keys[0]
self.input_tail = keys[-1]
for k in keys[:-1]:
if k.startswith("window resize "):
ign1, ign2, x, y = k.split(" ", 3)
x = int(x)
y = int(y)
self._set_screen_size(x, y)
resized = True
else:
l.append(k)
if resized:
l.append("window resize")
if raw_keys:
return l, []
return l
def code_span( s, fg, bg, cursor = -1):
code_fg = _code_colours[ fg ]
code_bg = _code_colours[ bg ]
if cursor >= 0:
c_off, _ign = util.calc_text_pos(s, 0, len(s), cursor)
c2_off = util.move_next_char(s, c_off, len(s))
return ( code_fg + code_bg + s[:c_off] + "\n" +
code_bg + code_fg + s[c_off:c2_off] + "\n" +
code_fg + code_bg + s[c2_off:] + "\n")
else:
return f"{code_fg + code_bg + s}\n"
def html_escape(text):
"""Escape text so that it will be displayed safely within HTML"""
text = text.replace('&','&amp;')
text = text.replace('<','&lt;')
text = text.replace('>','&gt;')
return text
def is_web_request():
"""
Return True if this is a CGI web request.
"""
return 'REQUEST_METHOD' in os.environ
def handle_short_request():
"""
Handle short requests such as passing keystrokes to the application
or sending the initial html page. If returns True, then this
function recognised and handled a short request, and the calling
script should immediately exit.
web_display.set_preferences(..) should be called before calling this
function for the preferences to take effect
"""
global _prefs
if not is_web_request():
return False
if os.environ['REQUEST_METHOD'] == "GET":
# Initial request, send the HTML and javascript.
sys.stdout.write("Content-type: text/html\r\n\r\n" +
html_escape(_prefs.app_name).join(_html_page))
return True
if os.environ['REQUEST_METHOD'] != "POST":
# Don't know what to do with head requests etc.
return False
if 'HTTP_X_URWID_ID' not in os.environ:
# If no urwid id, then the application should be started.
return False
urwid_id = os.environ['HTTP_X_URWID_ID']
if len(urwid_id)>20:
#invalid. handle by ignoring
#assert 0, "urwid id too long!"
sys.stdout.write("Status: 414 URI Too Long\r\n\r\n")
return True
for c in urwid_id:
if c not in "0123456789":
# invald. handle by ignoring
#assert 0, "invalid chars in id!"
sys.stdout.write("Status: 403 Forbidden\r\n\r\n")
return True
if os.environ.get('HTTP_X_URWID_METHOD',None) == "polling":
# this is a screen update request
s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
try:
s.connect( os.path.join(_prefs.pipe_dir,
f"urwid{urwid_id}.update") )
data = f'Content-type: text/plain\r\n\r\n{s.recv(BUF_SZ)}'
while data:
sys.stdout.write(data)
data = s.recv(BUF_SZ)
return True
except OSError:
sys.stdout.write("Status: 404 Not Found\r\n\r\n")
return True
# this is a keyboard input request
try:
fd = os.open((os.path.join(_prefs.pipe_dir,
f"urwid{urwid_id}.in")), os.O_WRONLY)
except OSError:
sys.stdout.write("Status: 404 Not Found\r\n\r\n")
return True
# FIXME: use the correct encoding based on the request
keydata = sys.stdin.read(MAX_READ)
os.write(fd,keydata.encode('ascii'))
os.close(fd)
sys.stdout.write("Content-type: text/plain\r\n\r\n")
return True
class _Preferences:
app_name = "Unnamed Application"
pipe_dir = "/tmp"
allow_polling = True
max_clients = 20
_prefs = _Preferences()
def set_preferences( app_name, pipe_dir="/tmp", allow_polling=True,
max_clients=20 ):
"""
Set web_display preferences.
app_name -- application name to appear in html interface
pipe_dir -- directory for input pipes, daemon update sockets
and daemon error logs
allow_polling -- allow creation of daemon processes for
browsers without multipart support
max_clients -- maximum concurrent client connections. This
pool is shared by all urwid applications
using the same pipe_dir
"""
global _prefs
_prefs.app_name = app_name
_prefs.pipe_dir = pipe_dir
_prefs.allow_polling = allow_polling
_prefs.max_clients = max_clients
class ErrorLog:
def __init__(self, errfile ):
self.errfile = errfile
def write(self, err):
open(self.errfile,"a").write(err)
def daemonize( errfile ):
"""
Detach process and become a daemon.
"""
pid = os.fork()
if pid:
os._exit(0)
os.setsid()
signal.signal(signal.SIGHUP, signal.SIG_IGN)
os.umask(0)
pid = os.fork()
if pid:
os._exit(0)
os.chdir("/")
for fd in range(0,20):
try:
os.close(fd)
except OSError:
pass
sys.stdin = open("/dev/null")
sys.stdout = open("/dev/null","w")
sys.stderr = ErrorLog( errfile )