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# $Id: dialog.py,v 1.3 2004/09/21 00:52:15 tom Exp $
# Module: dialog.py
# Copyright (c) 2000 Robb Shecter <robb@acm.org>
# All rights reserved.
# This source is covered by the GNU GPL.
#
# This module is a Python wrapper around the Linux "dialog" utility
# by Savio Lam and Stuart Herbert. My goals were to make dialog as
# easy to use from Python as possible. The demo code at the end of
# the module is a good example of how to use it. To run the demo,
# execute:
#
# python dialog.py
#
# This module has one class in it, "Dialog". An application typically
# creates an instance of it, and possibly sets the background title option.
# Then, methods can be called on it for interacting with the user.
#
# I wrote this because I want to use my 486-33 laptop as my main
# development computer (!), and I wanted a way to nicely interact with the
# user in console mode. There are apparently other modules out there
# with similar functionality, but they require the Python curses library.
# Writing this module from scratch was easier than figuring out how to
# recompile Python with curses enabled. :)
#
# One interesting feature is that the menu and selection windows allow
# *any* objects to be displayed and selected, not just strings.
#
# TO DO:
# Add code so that the input buffer is flushed before a dialog box is
# shown. This would make the UI more predictable for users. This
# feature could be turned on and off through an instance method.
# Drop using temporary files when interacting with 'dialog'
# (it's possible -- I've already tried :-).
# Try detecting the terminal window size in order to make reasonable
# height and width defaults. Hmmm - should also then check for
# terminal resizing...
# Put into a package name to make more reusable - reduce the possibility
# of name collisions.
#
# NOTES:
# there is a bug in (at least) Linux-Mandrake 7.0 Russian Edition
# running on AMD K6-2 3D that causes core dump when 'dialog'
# is running with --gauge option;
# in this case you'll have to recompile 'dialog' program.
#
# Modifications:
# Jul 2000, Sultanbek Tezadov (http://sultan.da.ru)
# Added:
# - 'gauge' widget *)
# - 'title' option to some widgets
# - 'checked' option to checklist dialog; clicking "Cancel" is now
# recognizable
# - 'selected' option to radiolist dialog; clicking "Cancel" is now
# recognizable
# - some other cosmetic changes and improvements
#
import os
from tempfile import mktemp
from string import split
from time import sleep
#
# Path of the dialog executable
#
DIALOG = os.getenv("DIALOG");
if DIALOG is None:
DIALOG="../dialog";
class Dialog:
def __init__(self):
self.__bgTitle = '' # Default is no background title
def setBackgroundTitle(self, text):
self.__bgTitle = '--backtitle "%s"' % text
def __perform(self, cmd):
"""Do the actual work of invoking dialog and getting the output."""
fName = mktemp()
rv = os.system('%s %s %s 2> %s' % (DIALOG, self.__bgTitle, cmd, fName))
f = open(fName)
output = f.readlines()
f.close()
os.unlink(fName)
return (rv, output)
def __perform_no_options(self, cmd):
"""Call dialog w/out passing any more options. Needed by --clear."""
return os.system(DIALOG + ' ' + cmd)
def __handleTitle(self, title):
if len(title) == 0:
return ''
else:
return '--title "%s" ' % title
def yesno(self, text, height=10, width=30, title=''):
"""
Put a Yes/No question to the user.
Uses the dialog --yesno option.
Returns a 1 or a 0.
"""
(code, output) = self.__perform(self.__handleTitle(title) +\
'--yesno "%s" %d %d' % (text, height, width))
return code == 0
def msgbox(self, text, height=10, width=30, title=''):
"""
Pop up a message to the user which has to be clicked
away with "ok".
"""
self.__perform(self.__handleTitle(title) +\
'--msgbox "%s" %d %d' % (text, height, width))
def infobox(self, text, height=10, width=30):
"""Make a message to the user, and return immediately."""
self.__perform('--infobox "%s" %d %d' % (text, height, width))
def inputbox(self, text, height=10, width=30, init='', title=''):
"""
Request a line of input from the user.
Returns the user's input or None if cancel was chosen.
"""
(c, o) = self.__perform(self.__handleTitle(title) +\
'--inputbox "%s" %d %d "%s"' % (text, height, width, init))
try:
return o[0]
except IndexError:
if c == 0: # empty string entered
return ''
else: # canceled
return None
def textbox(self, filename, height=20, width=60, title=None):
"""Display a file in a scrolling text box."""
if title is None:
title = filename
self.__perform(self.__handleTitle(title) +\
' --textbox "%s" %d %d' % (filename, height, width))
def menu(self, text, height=15, width=54, list=[]):
"""
Display a menu of options to the user. This method simplifies the
--menu option of dialog, which allows for complex arguments. This
method receives a simple list of objects, and each one is assigned
a choice number.
The selected object is returned, or None if the dialog was canceled.
"""
menuheight = height - 8
pairs = map(lambda i, item: (i + 1, item), range(len(list)), list)
choices = reduce(lambda res, pair: res + '%d "%s" ' % pair, pairs, '')
(code, output) = self.__perform('--menu "%s" %d %d %d %s' %\
(text, height, width, menuheight, choices))
try:
return list[int(output[0]) - 1]
except IndexError:
return None
def checklist(self, text, height=15, width=54, list=[], checked=None):
"""
Returns a list of the selected objects.
Returns an empty list if nothing was selected.
Returns None if the window was canceled.
checked -- a list of boolean (0/1) values; len(checked) must equal
len(list).
"""
if checked is None:
checked = [0]*len(list)
menuheight = height - 8
triples = map(
lambda i, item, onoff, fs=('off', 'on'): (i + 1, item, fs[onoff]),
range(len(list)), list, checked)
choices = reduce(lambda res, triple: res + '%d "%s" %s ' % triple,
triples, '')
(c, o) = self.__perform('--checklist "%s" %d %d %d %s' %\
(text, height, width, menuheight, choices))
try:
output = o[0]
indexList = map(lambda x: int(x[1:-1]), split(output))
objectList = filter(lambda item, list=list, indexList=indexList:
list.index(item) + 1 in indexList,
list)
return objectList
except IndexError:
if c == 0: # Nothing was selected
return []
return None # Was canceled
def radiolist(self, text, height=15, width=54, list=[], selected=0):
"""
Return the selected object.
Returns empty string if no choice was selected.
Returns None if window was canceled.
selected -- the selected item (must be between 1 and len(list)
or 0, meaning no selection).
"""
menuheight = height - 8
triples = map(lambda i, item: (i + 1, item, 'off'),
range(len(list)), list)
if selected:
i, item, tmp = triples[selected - 1]
triples[selected - 1] = (i, item, 'on')
choices = reduce(lambda res, triple: res + '%d "%s" %s ' % triple,
triples, '')
(c, o) = self.__perform('--radiolist "%s" %d %d %d %s' %\
(text, height, width, menuheight, choices))
try:
return list[int(o[0]) - 1]
except IndexError:
if c == 0:
return ''
return None
def clear(self):
"""
Clear the screen. Equivalent to the dialog --clear option.
"""
self.__perform_no_options('--clear')
def scrollbox(self, text, height=20, width=60, title=''):
"""
This is a bonus method. The dialog package only has a function to
display a file in a scrolling text field. This method allows any
string to be displayed by first saving it in a temp file, and calling
--textbox.
"""
fName = mktemp()
f = open(fName, 'w')
f.write(text)
f.close()
self.__perform(self.__handleTitle(title) +\
'--textbox "%s" %d %d' % (fName, height, width))
os.unlink(fName)
def gauge_start(self, perc=0, text='', height=8, width=54, title=''):
"""
Display gauge output window.
Gauge normal usage (assuming that there is an instace of 'Dialog'
class named 'd'):
d.gauge_start()
# do something
d.gauge_iterate(10) # passed throgh 10%
# ...
d.gauge_iterate(100, 'any text here') # work is done
d.stop_gauge() # clean-up actions
"""
cmd = self.__handleTitle(title) +\
'--gauge "%s" %d %d %d' % (text, height, width, perc)
cmd = '%s %s %s 2> /dev/null' % (DIALOG, self.__bgTitle, cmd)
self.pipe = os.popen(cmd, 'w')
#/gauge_start()
def gauge_iterate(self, perc, text=''):
"""
Update percentage point value.
See gauge_start() function above for the usage.
"""
if text:
text = 'XXX\n%d\n%s\nXXX\n' % (perc, text)
else:
text = '%d\n' % perc
self.pipe.write(text)
self.pipe.flush()
#/gauge_iterate()
def gauge_stop(self):
"""
Finish previously started gauge.
See gauge_start() function above for the usage.
"""
self.pipe.close()
#/gauge_stop()
#
# DEMO APPLICATION
#
if __name__ == '__main__':
"""
This demo tests all the features of the class.
"""
d = Dialog()
d.setBackgroundTitle('dialog.py demo')
d.infobox(
"One moment... Just wasting some time here to test the infobox...")
sleep(3)
if d.yesno("Do you like this demo?"):
d.msgbox("Excellent! Here's the source code:")
else:
d.msgbox("Send your complaints to /dev/null")
d.textbox("dialog.py")
name = d.inputbox("What's your name?", init="Snow White")
fday = d.menu("What's your favorite day of the week?",
list=["Monday", "Tuesday", "Wednesday", "Thursday",
"Friday (The best day of all)", "Saturday", "Sunday"])
food = d.checklist("What sandwich toppings do you like?",
list=["Catsup", "Mustard", "Pesto", "Mayonaise", "Horse radish",
"Sun-dried tomatoes"], checked=[0,0,0,1,1,1])
sand = d.radiolist("What's your favorite kind of sandwich?",
list=["Hamburger", "Hotdog", "Burrito", "Doener", "Falafel",
"Bagel", "Big Mac", "Whopper", "Quarter Pounder",
"Peanut Butter and Jelly", "Grilled cheese"], selected=4)
# Prepare the message for the final window
bigMessage = "Here are some vital statistics about you:\n\nName: " + name +\
"\nFavorite day of the week: " + fday +\
"\nFavorite sandwich toppings:\n"
for topping in food:
bigMessage = bigMessage + " " + topping + "\n"
bigMessage = bigMessage + "Favorite sandwich: " + str(sand)
d.scrollbox(bigMessage)
#<># Gauge Demo
d.gauge_start(0, 'percentage: 0', title='Gauge Demo')
for i in range(1, 101):
if i < 50:
msg = 'percentage: %d' % i
elif i == 50:
msg = 'Over 50%'
else:
msg = ''
d.gauge_iterate(i, msg)
sleep(0.1)
d.gauge_stop()
#<>#
d.clear()
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