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: codepoint (int): Codepoint of a 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)