Serious Python/Curses Wierdness

[Matthew Alton]

The appended program freaks python 2.2 & 2.3 completely out. To
reproduce the wierdness: i) copy the source to a file called
consarn.py ii) $ python consarn.py; iii) the program is now doing a
getch(); iv) hit a key; v) the program locks up, the interptreter is
now munching on the CPU; vi) kill the interpreter from another shell;
vii) scratch head and wonder why neither of the mutually exclusive
clauses in the _io() member function have written any output via dbg()
calls to the consarn.debug file.

This has simply got to be a major problem with the interpreter and/or
the curses module(s).

__rcsid__ = "$Id: consarn.py,v 1.10 2004/09/17 22:43:30 mqa Exp
zma0472 $"

import string, curses, curses.ascii, time

(_Y, _X) = (24, 80)

def dbg(str):
f = open("consarn.debug", 'a')
f.write(time.ctime() + " : " + str + '\n')
f.close()

class Menu:
def __init__(self, title="Consarn Menu"):
self.title = string.center(string.strip(title), _X)
self.items = []; self.label_width = 0; self.linked = False

def link(self):
y = 1; idx = 0; screen = 0
x = range(2, _X-self.label_width+1, self.label_width+2)
up = left = ppage = top = self.items[0]
for i in self.items:
i["up"] = up; i["down"] = i; i["up"]["down"] = i; up = i
i["right"] = i["left"] = i["npage"] = i
if idx > 0: i["left"] = left
i["left"]["right"] = i; i["ppage"] = ppage
i["screen"] = screen; i["y"] = y; i["x"] = x[idx]
if _Y-1 == y:
y = 1; left = top
if len(x)-1 == idx:
idx = 0; ppage = i; screen += 1
else:
idx += 1
else:
if 1 == y: top = i
y += 1; left = left["down"]
self.linked = True

f = open("link.out", 'w')
for i in self.items:
f.write("%s:\n" % i["label"])
f.write(" up = " + i["up"]["label"] + '\n')
f.write(" down = " + i["down"]["label"] + '\n')
f.write(" right = " + i["right"]["label"] + '\n')
f.write(" left = " + i["left"]["label"] + '\n')
f.write(" npage = " + i["npage"]["label"] + '\n')
f.write(" ppage = " + i["ppage"]["label"] + '\n')
f.write(" x = " + str(i["x"]) + '\n')
f.write(" y = " + str(i["y"]) + '\n')
f.write(" screen = " + str(i["screen"]) + '\n')
f.close()

def _io(self, scr):
if not self.linked: self.link(); scr.keypad(1); #
curses.curs_set(0);
item = self.items[0]; item["attributes"] = curses.A_STANDOUT
while True:
scr.clear()
scr.addnstr(0, 0, self.title, _X, curses.A_STANDOUT)
for i in [j for j in self.items if j["screen"] ==
item["screen"]]:
scr.addnstr(i["y"], i["x"], i["label"], _X,
i["attributes"])
scr.refresh()
while True:
m = { curses.KEY_DOWN : item["down"],
curses.KEY_UP : item["up"],
curses.KEY_RIGHT : item["right"],
curses.KEY_LEFT : item["left"],
curses.KEY_PPAGE : item["ppage"] }
c = scr.getch(); dbg("c = scr.getch()")
if c in m.keys():
if c in m.keys():
dbg("if c in m.keys():")
if m[c] != item:
dbg(" if m[c] != item:")
item["attributes"] = curses.A_NORMAL
m[c]["attributes"] = curses.A_STANDOUT
scr.addnstr(item["y"], item["x"],
item["label"], _X,

item["attributes"])
scr.addnstr(m[c]["y"], m[c]["x"],
m[c]["label"], _X,

m[c]["attributes"])
if item["screen"] == m[c]["screen"]:
item = m[c]; scr.refresh()
else:
item = m[c]; break
else:
dbg("Inside else")
elif curses.ascii.ESC == c:
return

def add_item(self, item_label):
self.items.append({"label" : item_label, "up" : None, "down" :
None,
"left" : None, "right" : None, "ppage" :
None,
"npage" : None, "x" : None, "y" : None,
"screen" : None, "attributes" :
curses.A_NORMAL})
self.label_width = max(len(item_label), self.label_width)
self.linked = False

def delete_item(self, item):
if item in self.items:
self.items.remove(item); self.linked = False

def IO(self):
curses.wrapper(self._io)

def test():
import string
import random

print "Initializing the Consarn Demo..."
random.seed()
population = string.ascii_letters+string.digits+string.punctuat ion
# max_width = random.randint(1, _X-1)
for max_width in range(1, _X-1):
m = Menu(title="ROWS=%d COLS=%d R=%d" % (_Y, _X, max_width))
for x in range(0, 400):
width = random.randint(1, max_width)
s = random.sample(population, width)
label = ""
for c in s: label += c
m.add_item(label)
m.IO()
del(m)

def test1():
print "Initializing Debug Test..."
m = Menu(title="ROWS=%d COLS=%d" % (_Y, _X))
f = open("debug", 'w')
f.write("Create start = " + time.ctime() + '\n')
for x in range(0, 40):
m.add_item(str(x))
f.write("Create end = " + time.ctime() + '\n')
f.close()
m.IO()
del(m)

if "__main__" == __name__:
curses.wrapper(test1())