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#!/usr/bin/python
#
# Urwid example fibonacci sequence viewer / unbounded data demo
# 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: http://excess.org/urwid/
"""
Urwid example fibonacci sequence viewer / unbounded data demo
Features:
- custom list walker class for browsing infinite set
- custom wrap mode "numeric" for wrapping numbers to right and bottom
"""
import urwid
class FibonacciWalker(urwid.ListWalker):
"""ListWalker-compatible class for browsing fibonacci set.
positions returned are (value at position-1, value at poistion) tuples.
"""
def __init__(self):
self.focus = (0L,1L)
self.numeric_layout = NumericLayout()
def _get_at_pos(self, pos):
"""Return a widget and the position passed."""
return urwid.Text("%d"%pos[1], layout=self.numeric_layout), pos
def get_focus(self):
return self._get_at_pos(self.focus)
def set_focus(self, focus):
self.focus = focus
self._modified()
def get_next(self, start_from):
a, b = start_from
focus = b, a+b
return self._get_at_pos(focus)
def get_prev(self, start_from):
a, b = start_from
focus = b-a, a
return self._get_at_pos(focus)
def main():
palette = [
('body','black','dark cyan', 'standout'),
('foot','light gray', 'black'),
('key','light cyan', 'black', 'underline'),
('title', 'white', 'black',),
]
footer_text = [
('title', "Fibonacci Set Viewer"), " ",
('key', "UP"), ", ", ('key', "DOWN"), ", ",
('key', "PAGE UP"), " and ", ('key', "PAGE DOWN"),
" move view ",
('key', "Q"), " exits",
]
def exit_on_q(input):
if input in ('q', 'Q'):
raise urwid.ExitMainLoop()
listbox = urwid.ListBox(FibonacciWalker())
footer = urwid.AttrMap(urwid.Text(footer_text), 'foot')
view = urwid.Frame(urwid.AttrWrap(listbox, 'body'), footer=footer)
loop = urwid.MainLoop(view, palette, unhandled_input=exit_on_q)
loop.run()
class NumericLayout(urwid.TextLayout):
"""
TextLayout class for bottom-right aligned numbers
"""
def layout( self, text, width, align, wrap ):
"""
Return layout structure for right justified numbers.
"""
lt = len(text)
r = lt % width # remaining segment not full width wide
if r:
linestarts = range( r, lt, width )
return [
# right-align the remaining segment on 1st line
[(width-r,None),(r, 0, r)]
# fill the rest of the lines
] + [[(width, x, x+width)] for x in linestarts]
else:
linestarts = range( 0, lt, width )
return [[(width, x, x+width)] for x in linestarts]
if __name__=="__main__":
main()
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