#!/usr/bin/python
"""Yet another curses-based directory tree browser, in Python.
I thought I could use something like this for filename entry, kind of
like the old 4DOS 'select' command --- cd $(cursoutline.py). So you
navigate and hit Enter, and it exits and spits out the file you're on.
"""
# There are several general approaches to the drawing-an-outline
# problem. This program supports the following operations:
# - move cursor to previous item (in preorder traversal)
# - move cursor to next item (likewise)
# - hide descendants
# - reveal children
# And because it runs over the filesystem, it must be at least somewhat lazy
# about expanding children.
# And it doesn't really bother to worry about someone else changing the outline
# behind its back.
# So the strategy is to store our current linear position in the
# inorder traversal, and defer operations on the current node until the next
# time we're traversing.
import curses.wrapper, time, random, cgitb, os, sys
cgitb.enable(format="text")
ESC = 27
result = ''
start = '.'
def pad(data, width):
# XXX this won't work with UTF-8
return data + ' ' * (width - len(data))
class File:
def __init__(self, name):
self.name = name
def render(self, depth, width):
return pad('%s%s %s' % (' ' * 4 * depth, self.icon(),
os.path.basename(self.name)), width)
def icon(self): return ' '
def traverse(self): yield self, 0
def expand(self): pass
def collapse(self): pass
class Dir(File):
def __init__(self, name):
File.__init__(self, name)
try: self.kidnames = os.listdir(name)
except: self.kidnames = None # probably permission denied
self.kids = None
self.expanded = False
def children(self):
if self.kidnames is None: return []
if self.kids is None:
self.kids = [factory(os.path.join(self.name, kid))
for kid in self.kidnames]
return self.kids
def icon(self):
if self.expanded: return '[-]'
elif self.kidnames is None: return '[?]'
elif self.children(): return '[+]'
else: return '[ ]'
def expand(self): self.expanded = True
def collapse(self): self.expanded = False
def traverse(self):
yield self, 0
if not self.expanded: return
for child in self.children():
for kid, depth in child.traverse():
yield kid, depth + 1
def factory(name):
if os.path.isdir(name): return Dir(name)
else: return File(name)
def main(stdscr):
cargo_cult_routine(stdscr)
stdscr.nodelay(0)
mydir = factory(start)
mydir.expand()
curidx = 3
pending_action = None
pending_save = False
while 1:
stdscr.clear()
curses.init_pair(1, curses.COLOR_WHITE, curses.COLOR_BLUE)
line = 0
offset = max(0, curidx - curses.LINES + 3)
for data, depth in mydir.traverse():
if line == curidx:
stdscr.attrset(curses.color_pair(1) | curses.A_BOLD)
if pending_action:
getattr(data, pending_action)()
pending_action = None
elif pending_save:
global result
result = data.name
return
else:
stdscr.attrset(curses.color_pair(0))
if 0 <= line - offset < curses.LINES - 1:
stdscr.addstr(line - offset, 0,
data.render(depth, curses.COLS))
line += 1
stdscr.refresh()
ch = stdscr.getch()
if ch == curses.KEY_UP: curidx -= 1
elif ch == curses.KEY_DOWN: curidx += 1
elif ch == curses.KEY_PPAGE:
curidx -= curses.LINES
if curidx < 0: curidx = 0
elif ch == curses.KEY_NPAGE:
curidx += curses.LINES
if curidx >= line: curidx = line - 1
elif ch == curses.KEY_RIGHT: pending_action = 'expand'
elif ch == curses.KEY_LEFT: pending_action = 'collapse'
elif ch == ESC: return
elif ch == ord('\n'): pending_save = True
curidx %= line
def cargo_cult_routine(win):
win.clear()
win.refresh()
curses.nl()
curses.noecho()
win.timeout(0)
def open_tty():
saved_stdin = os.dup(0)
saved_stdout = os.dup(1)
os.close(0)
os.close(1)
stdin = os.open('/dev/tty', os.O_RDONLY)
stdout = os.open('/dev/tty', os.O_RDWR)
return saved_stdin, saved_stdout
def restore_stdio((saved_stdin, saved_stdout)):
os.close(0)
os.close(1)
os.dup(saved_stdin)
os.dup(saved_stdout)
if __name__ == '__main__':
global start
if len(sys.argv) > 1:
start = sys.argv[1]
saved_fds = open_tty()
try: curses.wrapper(main)
finally: restore_stdio(saved_fds)
print result
