bowl/cheuph/render/tree_display.py

136 lines
4 KiB
Python

import collections
from typing import Any, List, Optional, Set
from .element import Element, ElementSupply, Id, RenderedElement
from .tree_list import TreeList
__all__ = ["TreeDisplay"]
class TreeDisplay:
def __init__(self,
supply: ElementSupply,
width: int,
height: int,
) -> None:
self._width = width
self._height = height
self._root_id: Optional[Id] = None
self._anchor_id: Optional[Id] = None
self._cursor_id: Optional[Id] = None
self._anchor_offset: int = 0
self._horizontal_offset: int = 0
# Object references
self._supply = supply
self._rendered: Optional[TreeList] = None
self._folded: Set[Id] = set()
def resize(self, width: int, height: int) -> None:
# TODO maybe empty _rendered/invalidate caches etc.?
self._width = width
self._height = height
def render(self) -> None:
# Steps:
#
# 1. Find and render anchor's branch to TreeList
# 2. Render above and below the branch until the screen is full (with
# the specified anchor offset)
# 2.1. Keep the TreeList for later things like scrolling
# 3. Cut out the visible lines and messages
# 4. Cut out the visible parts horizontally (self._horizontal_offset)
# 4.1. Keep the result for later reference (mouse clicks)
# 5. Convert the result to plain text and draw it in the curses window
#
# Not happy with these steps yet. Scrolling, checking if the cursor is
# in view, switching anchors etc. still feel weird.
#
# TODO Add the above into the TreeDisplay model.
if self._anchor_id is None:
return # TODO draw empty screen
if self._root_id is None:
ancestor_id = self._supply.get_furthest_ancestor_id(
self._anchor_id)
else:
ancestor_id = self._root_id
ancestor_tree = self._render_tree(self._supply.get_tree(ancestor_id))
self._rendered = TreeList(ancestor_tree, self._anchor_id)
self._rendered.offset_by(self._anchor_offset)
if self._root_id is None:
self._fill_screen_upwards()
self._fill_screen_downwards()
def _render_tree(self,
tree: Element,
depth: int = 0
) -> List[RenderedElement]:
elements: List[RenderedElement] = []
highlighted = tree.id == self._cursor_id
folded = tree.id in self._folded
elements.append(tree.render(depth=depth, highlighted=highlighted,
folded=folded))
if not folded:
for child in tree.children:
elements.extend(self._render_tree(child, depth=depth+1))
return elements
def _fill_screen_upwards(self) -> None:
if self._rendered is None:
return # TODO
while True:
if self._rendered.upper_offset <= 0:
break
above_tree_id = self._supply.get_previous_id(
self._rendered.upper_tree_id)
if above_tree_id is None:
break
above_tree = self._supply.get_tree(above_tree_id)
self._rendered.add_above(self._render_tree(above_tree))
def _fill_screen_downwards(self) -> None:
"""
Eerily similar to _fill_screen_upwards()...
"""
if self._rendered is None:
return # TODO
while True:
if self._rendered.lower_offset >= self._height - 1:
break
below_tree_id = self._supply.get_next_id(
self._rendered.lower_tree_id)
if below_tree_id is None:
break
below_tree = self._supply.get_tree(below_tree_id)
self._rendered.add_below(self._render_tree(below_tree))
def draw_to(self, window: Any) -> None:
pass
# Terminology:
#
# root
# ancestor
# parent
# sibling
# child