fold_quoted_replies_2.py

#!/usr/bin/python
# coding: utf-8
# 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.nested import NestedTree
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 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,
                                   is_collapsed=lambda _: False,
                                   icon_focussed_att='focus',
                                   icon_frame_left_char=None,
                                   icon_frame_right_char=None,
                                   icon_expanded_char='▼',
                                   icon_collapsed_char='▶',
                                   icon_offset=0,
                                   )

    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((4, 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


class FocusableText(urwid.WidgetWrap):
    """Selectable Text used for nodes in our example"""
    def __init__(self, txt, att, att_focus):
        t = urwid.Text(txt)
        w = urwid.AttrMap(t, att, att_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


class TextlinesList(SimpleTree):
    def __init__(self, content, attr=None, attr_focus=None):
        """
        :class:`SimpleTree` that contains a list of all-level-0 Text widgets
        for each line in content.
        """
        structure = []

        # depending on this config setting, we either add individual lines
        # or the complete context as focusable objects.
        for line in content.splitlines():
            structure.append((FocusableText(line, attr, attr_focus), None))
        SimpleTree.__init__(self, structure)

    def selectable(self):
        return True


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 ''
        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 = TextlinesList('\n'.join(mail[last:num]), 'body', 'focus')
            #new = FocusableText('\n'.join(mail[last:num]), 'body', 'focus')
            subtrees.append(new)
            last = num
            oldlevel += 1
    new = TextlinesList('\n'.join(mail[last:num]), 'body', 'focus')
    subtrees.append(new)

    last_tree = None
    for subtree in subtrees[::-1]:
        last_tree = [(subtree, last_tree)]
    return CollapsibleIconTree(last_tree)


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


if __name__ == "__main__":
    tree = CollapsibleIconTree(build_tree())

    treebox = TreeBox(NestedTree(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()