blob: 139b949f7f2dad487477ec18a635de9865d29d69 [file] [log] [blame]
import re
from functools import lru_cache
from typing import Callable, List
from ._cell_widths import CELL_WIDTHS
# Regex to match sequence of the most common character ranges
_is_single_cell_widths = re.compile("^[\u0020-\u006f\u00a0\u02ff\u0370-\u0482]*$").match
@lru_cache(4096)
def cached_cell_len(text: str) -> int:
"""Get the number of cells required to display text.
This method always caches, which may use up a lot of memory. It is recommended to use
`cell_len` over this method.
Args:
text (str): Text to display.
Returns:
int: Get the number of cells required to display text.
"""
_get_size = get_character_cell_size
total_size = sum(_get_size(character) for character in text)
return total_size
def cell_len(text: str, _cell_len: Callable[[str], int] = cached_cell_len) -> int:
"""Get the number of cells required to display text.
Args:
text (str): Text to display.
Returns:
int: Get the number of cells required to display text.
"""
if len(text) < 512:
return _cell_len(text)
_get_size = get_character_cell_size
total_size = sum(_get_size(character) for character in text)
return total_size
@lru_cache(maxsize=4096)
def get_character_cell_size(character: str) -> int:
"""Get the cell size of a character.
Args:
character (str): A single character.
Returns:
int: Number of cells (0, 1 or 2) occupied by that character.
"""
return _get_codepoint_cell_size(ord(character))
@lru_cache(maxsize=4096)
def _get_codepoint_cell_size(codepoint: int) -> int:
"""Get the cell size of a character.
Args:
character (str): A single character.
Returns:
int: Number of cells (0, 1 or 2) occupied by that character.
"""
_table = CELL_WIDTHS
lower_bound = 0
upper_bound = len(_table) - 1
index = (lower_bound + upper_bound) // 2
while True:
start, end, width = _table[index]
if codepoint < start:
upper_bound = index - 1
elif codepoint > end:
lower_bound = index + 1
else:
return 0 if width == -1 else width
if upper_bound < lower_bound:
break
index = (lower_bound + upper_bound) // 2
return 1
def set_cell_size(text: str, total: int) -> str:
"""Set the length of a string to fit within given number of cells."""
if _is_single_cell_widths(text):
size = len(text)
if size < total:
return text + " " * (total - size)
return text[:total]
if total <= 0:
return ""
cell_size = cell_len(text)
if cell_size == total:
return text
if cell_size < total:
return text + " " * (total - cell_size)
start = 0
end = len(text)
# Binary search until we find the right size
while True:
pos = (start + end) // 2
before = text[: pos + 1]
before_len = cell_len(before)
if before_len == total + 1 and cell_len(before[-1]) == 2:
return before[:-1] + " "
if before_len == total:
return before
if before_len > total:
end = pos
else:
start = pos
# TODO: This is inefficient
# TODO: This might not work with CWJ type characters
def chop_cells(text: str, max_size: int, position: int = 0) -> List[str]:
"""Break text in to equal (cell) length strings, returning the characters in reverse
order"""
_get_character_cell_size = get_character_cell_size
characters = [
(character, _get_character_cell_size(character)) for character in text
]
total_size = position
lines: List[List[str]] = [[]]
append = lines[-1].append
for character, size in reversed(characters):
if total_size + size > max_size:
lines.append([character])
append = lines[-1].append
total_size = size
else:
total_size += size
append(character)
return ["".join(line) for line in lines]
if __name__ == "__main__": # pragma: no cover
print(get_character_cell_size("😽"))
for line in chop_cells("""这是对亚洲语言支持的测试。面对模棱两可的想法,拒绝猜测的诱惑。""", 8):
print(line)
for n in range(80, 1, -1):
print(set_cell_size("""这是对亚洲语言支持的测试。面对模棱两可的想法,拒绝猜测的诱惑。""", n) + "|")
print("x" * n)