fold_quoted_replies.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.
#
# adapted from example1.py and example3.collapse.py from the urwidtrees examples

from urwidtrees.tree import SimpleTree
from urwidtrees.decoration import CollapseIconMixin, DecoratedTree
from urwidtrees.widgets import TreeBox
import urwid
import re

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', ''),
]


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

    @property
    def text(self):
        return self._wrapped_widget._original_widget.text


mail = [
    "No problem. 6pm it is then. --Jim",
    "",
    "At 10.01am Wednesday, Danny wrote:",
    "> Whoa! I need to email a report at 5:30.",
    "> Could you push it back an hour? --Danny",
    ">",
    "> At 9.40am Wednesday, Jim wrote:",
    ">",
    ">> I'm going to suspend the mail service for approx. thirty",
    ">> minutes tonight, starting at 5pm. --Jim",
    ">>",
    ">",
    "> On the 16th, Alice wrote:",
    ">> Hello,",
    ">> how are you?",
    ">> I'm good.",
    ">> Bye",
    ">",
    "",
    "-- ",
    "Jim Doe",
    "Chief of Nothing",
    "Nothing Inc.",
    "",
    "",
    "",
    "------------------------------------------------------",
    "something mailing list",
    "list@mail.list",
    "http://mail.list.org",
]


# (?: ) is a non-capturing group
reg = re.compile(r'^((?:> ?)+)?(.*)')


def get_reply_levels(lines):
    for num, line in enumerate(lines):
        groups = reg.match(line).groups()
        indendation = groups[0] or ''
        content = groups[1] or ''
        level = indendation.count('>')
        yield level


def build_tree():
    levels = list(get_reply_levels(mail))
    oldlevel = last = 0
    subtrees = []
    for num, level in enumerate(levels):
        while level > oldlevel:
            new = FocusableText('\n'.join(mail[last:num]))
            subtrees.append(new)
            last = num
            oldlevel += 1
    new = FocusableText('\n'.join(mail[last:num]))
    subtrees.append(new)

    last = None
    for subtree in subtrees[::-1]:
        new = [(subtree, last)]
        last = new
    return SimpleTree(last)


class CollapsibleIconTree(CollapseIconMixin, DecoratedTree):
    """
    Indent collapsible tree nodes according to their depth in the tree and
    display icons indicating collapse-status in the gaps.
    """
    def __init__(self, walker, icon_offset=1, **kwargs):
        """
        :param walker: tree of widgets to be displayed
        :type walker: Tree
        :param indent: indentation width
        :type indent: int
        :param icon_offset: distance from icon to the eginning of the tree
                            node.
        :type icon_offset: int
        """
        self._icon_offset = icon_offset
        DecoratedTree.__init__(self, walker)
        CollapseIconMixin.__init__(self, **kwargs)

    def decorate(self, pos, widget, is_first=True):
        iwidth, icon = self._construct_collapse_icon(pos)
        cols = []
        void = urwid.SolidFill(' ')
        line = None
        # add icon only for non-leafs
        is_leaf = self._tree.is_leaf(pos)
        if not is_leaf:
            if icon is not None:
                # space to the left
                cols.append((1, urwid.SolidFill(' ')))
                # icon
                icon_pile = urwid.Pile([void, ('pack', icon)])
                cols.append((iwidth, icon_pile))
            cols.append((self._icon_offset, urwid.SolidFill(' ')))
        else:  # otherwise just add another spacer
            cols.append((3, urwid.SolidFill(' ')))

        cols.append(widget)  # original widget ]
        # construct a Columns, defining all spacer as Box widgets
        line = urwid.Columns(cols, box_columns=range(len(cols))[:-1])
        return line


def unhandled_input(key):
    if isinstance(key, str) and key.lower() == 'q':
        raise urwid.ExitMainLoop()


if __name__ == "__main__":
    tree = CollapsibleIconTree(
        build_tree(),
        is_collapsed=lambda _: True,
        icon_focussed_att='focus',
        icon_frame_left_char=None,
        icon_frame_right_char=None,
        icon_expanded_char='▼',
        icon_collapsed_char='▶',
    )

    treebox = TreeBox(tree)
    rootwidget = urwid.AttrMap(treebox, 'body')
    footer = urwid.AttrMap(urwid.Text('Q to quit'), 'focus')
    urwid.MainLoop(
        urwid.Frame(rootwidget, footer=footer),
        palette,
        unhandled_input=unhandled_input,
    ).run()