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dot-files/qutebrowser/venv/lib/python3.11/site-packages/urwid/widget/treetools.py
2025-02-21 22:00:16 -05:00

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Python

# Generic TreeWidget/TreeWalker class
# Copyright (c) 2010 Rob Lanphier
# Copyright (C) 2004-2010 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: https://urwid.org/
"""
Urwid tree view
Features:
- custom selectable widgets for trees
- custom list walker for displaying widgets in a tree fashion
"""
from __future__ import annotations
import typing
from .columns import Columns
from .constants import WHSettings
from .listbox import ListBox, ListWalker
from .padding import Padding
from .text import Text
from .widget import WidgetWrap
from .wimp import SelectableIcon
if typing.TYPE_CHECKING:
from collections.abc import Hashable, Sequence
__all__ = ("ParentNode", "TreeListBox", "TreeNode", "TreeWalker", "TreeWidget", "TreeWidgetError")
class TreeWidgetError(RuntimeError):
pass
class TreeWidget(WidgetWrap[Padding[typing.Union[Text, Columns]]]):
"""A widget representing something in a nested tree display."""
indent_cols = 3
unexpanded_icon = SelectableIcon("+", 0)
expanded_icon = SelectableIcon("-", 0)
def __init__(self, node: TreeNode) -> None:
self._node = node
self._innerwidget: Text | None = None
self.is_leaf = not hasattr(node, "get_first_child")
self.expanded = True
widget = self.get_indented_widget()
super().__init__(widget)
def selectable(self) -> bool:
"""
Allow selection of non-leaf nodes so children may be (un)expanded
"""
return not self.is_leaf
def get_indented_widget(self) -> Padding[Text | Columns]:
widget = self.get_inner_widget()
if not self.is_leaf:
widget = Columns(
[(1, [self.unexpanded_icon, self.expanded_icon][self.expanded]), widget],
dividechars=1,
)
indent_cols = self.get_indent_cols()
return Padding(widget, width=(WHSettings.RELATIVE, 100), left=indent_cols)
def update_expanded_icon(self) -> None:
"""Update display widget text for parent widgets"""
# icon is first element in columns indented widget
icon = [self.unexpanded_icon, self.expanded_icon][self.expanded]
self._w.base_widget.contents[0] = (icon, (WHSettings.GIVEN, 1, False))
def get_indent_cols(self) -> int:
return self.indent_cols * self.get_node().get_depth()
def get_inner_widget(self) -> Text:
if self._innerwidget is None:
self._innerwidget = self.load_inner_widget()
return self._innerwidget
def load_inner_widget(self) -> Text:
return Text(self.get_display_text())
def get_node(self) -> TreeNode:
return self._node
def get_display_text(self) -> str | tuple[Hashable, str] | list[str | tuple[Hashable, str]]:
return f"{self.get_node().get_key()}: {self.get_node().get_value()!s}"
def next_inorder(self) -> TreeWidget | None:
"""Return the next TreeWidget depth first from this one."""
# first check if there's a child widget
first_child = self.first_child()
if first_child is not None:
return first_child
# now we need to hunt for the next sibling
this_node = self.get_node()
next_node = this_node.next_sibling()
depth = this_node.get_depth()
while next_node is None and depth > 0:
# keep going up the tree until we find an ancestor next sibling
this_node = this_node.get_parent()
next_node = this_node.next_sibling()
depth -= 1
if depth != this_node.get_depth():
raise ValueError(depth)
if next_node is None:
# we're at the end of the tree
return None
return next_node.get_widget()
def prev_inorder(self) -> TreeWidget | None:
"""Return the previous TreeWidget depth first from this one."""
this_node = self._node
prev_node = this_node.prev_sibling()
if prev_node is not None:
# we need to find the last child of the previous widget if its
# expanded
prev_widget = prev_node.get_widget()
last_child = prev_widget.last_child()
if last_child is None:
return prev_widget
return last_child
# need to hunt for the parent
depth = this_node.get_depth()
if prev_node is None and depth == 0:
return None
if prev_node is None:
prev_node = this_node.get_parent()
return prev_node.get_widget()
def keypress(
self,
size: tuple[int] | tuple[()],
key: str,
) -> str | None:
"""Handle expand & collapse requests (non-leaf nodes)"""
if self.is_leaf:
return key
if key in {"+", "right"}:
self.expanded = True
self.update_expanded_icon()
return None
if key == "-":
self.expanded = False
self.update_expanded_icon()
return None
if self._w.selectable():
return super().keypress(size, key)
return key
def mouse_event(
self,
size: tuple[int] | tuple[()],
event: str,
button: int,
col: int,
row: int,
focus: bool,
) -> bool:
if self.is_leaf or event != "mouse press" or button != 1:
return False
if row == 0 and col == self.get_indent_cols():
self.expanded = not self.expanded
self.update_expanded_icon()
return True
return False
def first_child(self) -> TreeWidget | None:
"""Return first child if expanded."""
if self.is_leaf or not self.expanded:
return None
if self._node.has_children():
first_node = self._node.get_first_child()
return first_node.get_widget()
return None
def last_child(self) -> TreeWidget | None:
"""Return last child if expanded."""
if self.is_leaf or not self.expanded:
return None
if self._node.has_children():
last_child = self._node.get_last_child().get_widget()
else:
return None
# recursively search down for the last descendant
last_descendant = last_child.last_child()
if last_descendant is None:
return last_child
return last_descendant
class TreeNode:
"""
Store tree contents and cache TreeWidget objects.
A TreeNode consists of the following elements:
* key: accessor token for parent nodes
* value: subclass-specific data
* parent: a TreeNode which contains a pointer back to this object
* widget: The widget used to render the object
"""
def __init__(
self,
value: typing.Any,
parent: ParentNode | None = None,
key: Hashable | None = None,
depth: int | None = None,
) -> None:
self._key = key
self._parent = parent
self._value = value
self._depth = depth
self._widget: TreeWidget | None = None
def get_widget(self, reload: bool = False) -> TreeWidget:
"""Return the widget for this node."""
if self._widget is None or reload:
self._widget = self.load_widget()
return self._widget
def load_widget(self) -> TreeWidget:
return TreeWidget(self)
def get_depth(self) -> int:
if self._depth is self._parent is None:
self._depth = 0
elif self._depth is None:
self._depth = self._parent.get_depth() + 1
return self._depth
def get_index(self) -> int | None:
if self.get_depth() == 0:
return None
return self.get_parent().get_child_index(self.get_key())
def get_key(self) -> Hashable | None:
return self._key
def set_key(self, key: Hashable | None) -> None:
self._key = key
def change_key(self, key: Hashable | None) -> None:
self.get_parent().change_child_key(self._key, key)
def get_parent(self) -> ParentNode:
if self._parent is None and self.get_depth() > 0:
self._parent = self.load_parent()
return self._parent
def load_parent(self):
"""Provide TreeNode with a parent for the current node. This function
is only required if the tree was instantiated from a child node
(virtual function)"""
raise TreeWidgetError("virtual function. Implement in subclass")
def get_value(self):
return self._value
def is_root(self) -> bool:
return self.get_depth() == 0
def next_sibling(self) -> TreeNode | None:
if self.get_depth() > 0:
return self.get_parent().next_child(self.get_key())
return None
def prev_sibling(self) -> TreeNode | None:
if self.get_depth() > 0:
return self.get_parent().prev_child(self.get_key())
return None
def get_root(self) -> ParentNode:
root = self
while root.get_parent() is not None:
root = root.get_parent()
return root
class ParentNode(TreeNode):
"""Maintain sort order for TreeNodes."""
def __init__(
self,
value: typing.Any,
parent: ParentNode | None = None,
key: Hashable = None,
depth: int | None = None,
) -> None:
super().__init__(value, parent=parent, key=key, depth=depth)
self._child_keys: Sequence[Hashable] | None = None
self._children: dict[Hashable, TreeNode] = {}
def get_child_keys(self, reload: bool = False) -> Sequence[Hashable]:
"""Return a possibly ordered list of child keys"""
if self._child_keys is None or reload:
self._child_keys = self.load_child_keys()
return self._child_keys
def load_child_keys(self) -> Sequence[Hashable]:
"""Provide ParentNode with an ordered list of child keys (virtual function)"""
raise TreeWidgetError("virtual function. Implement in subclass")
def get_child_widget(self, key) -> TreeWidget:
"""Return the widget for a given key. Create if necessary."""
return self.get_child_node(key).get_widget()
def get_child_node(self, key, reload: bool = False) -> TreeNode:
"""Return the child node for a given key. Create if necessary."""
if key not in self._children or reload:
self._children[key] = self.load_child_node(key)
return self._children[key]
def load_child_node(self, key: Hashable) -> TreeNode:
"""Load the child node for a given key (virtual function)"""
raise TreeWidgetError("virtual function. Implement in subclass")
def set_child_node(self, key: Hashable, node: TreeNode) -> None:
"""Set the child node for a given key.
Useful for bottom-up, lazy population of a tree.
"""
self._children[key] = node
def change_child_key(self, oldkey: Hashable, newkey: Hashable) -> None:
if newkey in self._children:
raise TreeWidgetError(f"{newkey} is already in use")
self._children[newkey] = self._children.pop(oldkey)
self._children[newkey].set_key(newkey)
def get_child_index(self, key: Hashable) -> int:
try:
return self.get_child_keys().index(key)
except ValueError as exc:
raise TreeWidgetError(
f"Can't find key {key} in ParentNode {self.get_key()}\nParentNode items: {self.get_child_keys()!s}"
).with_traceback(exc.__traceback__) from exc
def next_child(self, key: Hashable) -> TreeNode | None:
"""Return the next child node in index order from the given key."""
index = self.get_child_index(key)
# the given node may have just been deleted
if index is None:
return None
index += 1
child_keys = self.get_child_keys()
if index < len(child_keys):
# get the next item at same level
return self.get_child_node(child_keys[index])
return None
def prev_child(self, key: Hashable) -> TreeNode | None:
"""Return the previous child node in index order from the given key."""
index = self.get_child_index(key)
if index is None:
return None
child_keys = self.get_child_keys()
index -= 1
if index >= 0:
# get the previous item at same level
return self.get_child_node(child_keys[index])
return None
def get_first_child(self) -> TreeNode:
"""Return the first TreeNode in the directory."""
child_keys = self.get_child_keys()
return self.get_child_node(child_keys[0])
def get_last_child(self) -> TreeNode:
"""Return the last TreeNode in the directory."""
child_keys = self.get_child_keys()
return self.get_child_node(child_keys[-1])
def has_children(self) -> bool:
"""Does this node have any children?"""
return len(self.get_child_keys()) > 0
class TreeWalker(ListWalker):
"""ListWalker-compatible class for displaying TreeWidgets
positions are TreeNodes."""
def __init__(self, start_from) -> None:
"""start_from: TreeNode with the initial focus."""
self.focus = start_from
def get_focus(self):
widget = self.focus.get_widget()
return widget, self.focus
def set_focus(self, focus) -> None:
self.focus = focus
self._modified()
# pylint: disable=arguments-renamed # its bad, but we should not change API
def get_next(self, start_from) -> tuple[TreeWidget, TreeNode] | tuple[None, None]:
target = start_from.get_widget().next_inorder()
if target is None:
return None, None
return target, target.get_node()
def get_prev(self, start_from) -> tuple[TreeWidget, TreeNode] | tuple[None, None]:
target = start_from.get_widget().prev_inorder()
if target is None:
return None, None
return target, target.get_node()
# pylint: enable=arguments-renamed
class TreeListBox(ListBox):
"""A ListBox with special handling for navigation and
collapsing of TreeWidgets"""
def keypress(
self,
size: tuple[int, int], # type: ignore[override]
key: str,
) -> str | None:
key: str | None = super().keypress(size, key)
return self.unhandled_input(size, key)
def unhandled_input(self, size: tuple[int, int], data: str) -> str | None:
"""Handle macro-navigation keys"""
if data == "left":
self.move_focus_to_parent(size)
return None
if data == "-":
self.collapse_focus_parent(size)
return None
return data
def collapse_focus_parent(self, size: tuple[int, int]) -> None:
"""Collapse parent directory."""
_widget, pos = self.body.get_focus()
self.move_focus_to_parent(size)
_pwidget, ppos = self.body.get_focus()
if pos != ppos:
self.keypress(size, "-")
def move_focus_to_parent(self, size: tuple[int, int]) -> None:
"""Move focus to parent of widget in focus."""
_widget, pos = self.body.get_focus()
parentpos = pos.get_parent()
if parentpos is None:
return
middle, top, _bottom = self.calculate_visible(size)
row_offset, _focus_widget, _focus_pos, _focus_rows, _cursor = middle # pylint: disable=unpacking-non-sequence
_trim_top, fill_above = top # pylint: disable=unpacking-non-sequence
for _widget, pos, rows in fill_above:
row_offset -= rows
if pos == parentpos:
self.change_focus(size, pos, row_offset)
return
self.change_focus(size, pos.get_parent())
def _keypress_max_left(self, size: tuple[int, int]) -> None:
self.focus_home(size)
def _keypress_max_right(self, size: tuple[int, int]) -> None:
self.focus_end(size)
def focus_home(self, size: tuple[int, int]) -> None:
"""Move focus to very top."""
_widget, pos = self.body.get_focus()
rootnode = pos.get_root()
self.change_focus(size, rootnode)
def focus_end(self, size: tuple[int, int]) -> None:
"""Move focus to far bottom."""
maxrow, _maxcol = size
_widget, pos = self.body.get_focus()
lastwidget = pos.get_root().get_widget().last_child()
if lastwidget:
lastnode = lastwidget.get_node()
self.change_focus(size, lastnode, maxrow - 1)