subiquity/subiquitycore/ui/container.py

232 lines
8.1 KiB
Python

# Portions Copyright 2017 Canonical, Ltd.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# This is adapted from
# https://github.com/pimutils/khal/commit/bd7c5f928a7670de9afae5657e66c6dc846688ac, which has this license:
#
# Copyright (c) 2013-2015 Christian Geier et al.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy of
# this software and associated documentation files (the "Software"), to deal in
# the Software without restriction, including without limitation the rights to
# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
# the Software, and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
# FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
# COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
# IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
import logging
import urwid
log = logging.getLogger('subiquitycore.ui.container')
def _maybe_call(w, methname):
if w is None:
return
m = getattr(w.base_widget, methname, None)
if m is not None:
m()
class TabCyclingMixin:
"""Tab-cycling implementation that works with Pile and Columns."""
def _select_first_selectable(self):
"""Select first selectable child (possibily recursively)."""
for i, (w, o) in enumerate(self.contents):
if w.selectable():
self.set_focus(i)
_maybe_call(w, "_select_first_selectable")
return
def _select_last_selectable(self):
"""Select last selectable child (possibily recursively)."""
for i, (w, o) in reversed(list(enumerate(self.contents))):
if w.selectable():
self.set_focus(i)
_maybe_call(w, "_select_last_selectable")
return
def keypress(self, size, key):
key = super(TabCyclingMixin, self).keypress(size, key)
if len(self.contents) == 0:
return key
if self._command_map[key] == 'next selectable':
next_fp = self.focus_position + 1
for i, (w, o) in enumerate(self._contents[next_fp:], next_fp):
if w.selectable():
self.set_focus(i)
_maybe_call(w, "_select_first_selectable")
return
self._select_first_selectable()
return key
elif self._command_map[key] == 'prev selectable':
for i, (w, o) in reversed(list(enumerate(self._contents[:self.focus_position]))):
if w.selectable():
self.set_focus(i)
_maybe_call(w, "_select_last_selectable")
return
self._select_last_selectable()
return key
else:
return key
class TabCyclingPile(TabCyclingMixin, urwid.Pile):
pass
class TabCyclingColumns(TabCyclingMixin, urwid.Columns):
pass
class TabCyclingListBox(urwid.ListBox):
# It feels like it ought to be possible to write TabCyclingMixin
# so it works for a ListBox as well, but it seems to be just
# awkward enough to make the repeated code the easier and clearer
# option.
def __init__(self, body):
# urwid.ListBox converts an arbitrary sequence argument to a
# PollingListWalker, which doesn't work with the below code.
if getattr(body, 'get_focus', None) is None:
body = urwid.SimpleFocusListWalker(body)
super().__init__(body)
def _set_focus_no_move(self, i):
# We call set_focus twice because otherwise the listbox
# attempts to do the minimal amount of scrolling required to
# get the new focus widget into view, which is not what we
# want, as if our first widget is a compound widget it results
# its last widget being focused -- in fact the opposite of
# what we want!
self.set_focus(i)
self.set_focus(i)
# I don't really understand why this is required but it seems it is.
self._invalidate()
def _select_first_selectable(self):
"""Select first selectable child (possibily recursively)."""
for i, w in enumerate(self.body):
if w.selectable():
self._set_focus_no_move(i)
_maybe_call(w, "_select_first_selectable")
return
def _select_last_selectable(self):
"""Select last selectable child (possibily recursively)."""
for i, w in reversed(list(enumerate(self.body))):
if w.selectable():
self._set_focus_no_move(i)
_maybe_call(w, "_select_last_selectable")
return
def keypress(self, size, key):
key = super(TabCyclingListBox, self).keypress(size, key)
if len(self.body) == 0:
return key
if self._command_map[key] == 'next selectable':
next_fp = self.focus_position + 1
for i, w in enumerate(self.body[next_fp:], next_fp):
if w.selectable():
self._set_focus_no_move(i)
_maybe_call(w, "_select_first_selectable")
return
self._select_first_selectable()
return key
elif self._command_map[key] == 'prev selectable':
for i, w in reversed(list(enumerate(self.body[:self.focus_position]))):
if w.selectable():
self._set_focus_no_move(i)
_maybe_call(w, "_select_last_selectable")
return
self._select_last_selectable()
return key
else:
return key
class FocusTrackingMixin:
def __init__(self, *args, **kw):
super().__init__(*args, **kw)
self._contents.set_focus_changed_callback(self._focus_changed)
def lost_focus(self):
try:
cur_focus = self.focus
except IndexError:
pass
else:
_maybe_call(cur_focus, 'lost_focus')
def gained_focus(self):
_maybe_call(self.focus, 'gained_focus')
def _focus_changed(self, new_focus):
#log.debug("_focus_changed %s", self)
try:
cur_focus = self.focus
except IndexError:
pass
else:
_maybe_call(cur_focus, 'lost_focus')
_maybe_call(self[new_focus], 'gained_focus')
self._invalidate()
class FocusTrackingColumns(FocusTrackingMixin, TabCyclingColumns):
pass
class FocusTrackingPile(FocusTrackingMixin, TabCyclingPile):
pass
class FocusTrackingListBox(TabCyclingListBox):
def __init__(self, *args, **kw):
super().__init__(*args, **kw)
self.body.set_focus_changed_callback(self._focus_changed)
def _focus_changed(self, new_focus):
log.debug("_focus_changed %s", self)
_maybe_call(self.focus, 'lost_focus')
_maybe_call(self.body[new_focus], 'gained_focus')
self._invalidate()
def lost_focus(self):
_maybe_call(self.focus, 'lost_focus')
def gained_focus(self):
_maybe_call(self.focus, 'gained_focus')
Columns = FocusTrackingColumns
Pile = FocusTrackingPile
ListBox = FocusTrackingListBox