example1.py

#!/usr/bin/python
# Copyright (C) 2013  Patrick Totzke <patricktotzke@gmail.com>
# This file is released under the GNU GPL, version 3 or a later revision.

import urwid
from urwidtrees.tree import SimpleTree
from urwidtrees.widgets import TreeBox


# define some colours
palette = [
    ('body', 'black', 'light gray'),
    ('focus', 'light gray', 'dark blue', 'standout'),
    ('bars', 'dark blue', 'light gray', ''),
    ('arrowtip', 'light blue', 'light gray', ''),
    ('connectors', 'light red', 'light gray', ''),
]

# We use selectable Text widgets for our example..


class FocusableText(urwid.WidgetWrap):
    """Selectable Text used for nodes in our example"""
    def __init__(self, txt):
        t = urwid.Text(txt)
        w = urwid.AttrMap(t, 'body', 'focus')
        urwid.WidgetWrap.__init__(self, w)

    def selectable(self):
        return True

    def keypress(self, size, key):
        return key

# define a test tree in the format accepted by SimpleTree. Essentially, a
# tree is given as (nodewidget, [list, of, subtrees]). SimpleTree accepts
# lists of such trees.


def construct_example_simpletree_structure(selectable_nodes=True, children=3):

    Text = FocusableText if selectable_nodes else urwid.Text

    # define root node
    tree = (Text('ROOT'), [])

    # define some children
    c = g = gg = 0  # counter
    for i in range(children):
        subtree = (Text('Child {0:d}'.format(c)), [])
        # and grandchildren..
        for j in range(children):
            subsubtree = (Text('Grandchild {0:d}'.format(g)), [])
            for k in range(children):
                leaf = (Text('Grand Grandchild {0:d}'.format(gg)), None)
                subsubtree[1].append(leaf)
                gg += 1  # inc grand-grandchild counter
            subtree[1].append(subsubtree)
            g += 1  # inc grandchild counter
        tree[1].append(subtree)
        c += 1
    return tree


def construct_example_tree(selectable_nodes=True, children=2):
    # define a list of tree structures to be passed on to SimpleTree
    forrest = [construct_example_simpletree_structure(selectable_nodes,
                                                      children)]

    # stick out test tree into a SimpleTree and return
    return SimpleTree(forrest)

def unhandled_input(k):
    #exit on q
    if k in ['q', 'Q']: raise urwid.ExitMainLoop()

if __name__ == "__main__":
    # get example tree
    stree = construct_example_tree()

    # put the tree into a treebox
    treebox = TreeBox(stree)

    # add some decoration
    rootwidget = urwid.AttrMap(treebox, 'body')
    #add a text footer
    footer = urwid.AttrMap(urwid.Text('Q to quit'), 'focus')
    #enclose all in a frame
    urwid.MainLoop(urwid.Frame(rootwidget, footer=footer), palette, unhandled_input = unhandled_input).run()  # go