codekingpro/portable-devtools

1"""2Code related to text extraction.3 4Some parts are still in _page.py. In doubt, they will stay there.5"""6 7import math8from typing import Any, Callable, Optional, Union9 10from .._font import Font11from ..generic import DictionaryObject, TextStringObject, encode_pdfdocencoding12 13CUSTOM_RTL_MIN: int = -114CUSTOM_RTL_MAX: int = -115CUSTOM_RTL_SPECIAL_CHARS: list[int] = []16LAYOUT_NEW_BT_GROUP_SPACE_WIDTHS: int = 517 18 19class OrientationNotFoundError(Exception):20    pass21 22 23def set_custom_rtl(24    _min: Union[str, int, None] = None,25    _max: Union[str, int, None] = None,26    specials: Union[str, list[int], None] = None,27) -> tuple[int, int, list[int]]:28    """29    Change the Right-To-Left and special characters custom parameters.30 31    Args:32        _min: The new minimum value for the range of custom characters that33            will be written right to left.34            If set to ``None``, the value will not be changed.35            If set to an integer or string, it will be converted to its ASCII code.36            The default value is -1, which sets no additional range to be converted.37        _max: The new maximum value for the range of custom characters that will38            be written right to left.39            If set to ``None``, the value will not be changed.40            If set to an integer or string, it will be converted to its ASCII code.41            The default value is -1, which sets no additional range to be converted.42        specials: The new list of special characters to be inserted in the43            current insertion order.44            If set to ``None``, the current value will not be changed.45            If set to a string, it will be converted to a list of ASCII codes.46            The default value is an empty list.47 48    Returns:49        A tuple containing the new values for ``CUSTOM_RTL_MIN``,50        ``CUSTOM_RTL_MAX``, and ``CUSTOM_RTL_SPECIAL_CHARS``.51 52    """53    global CUSTOM_RTL_MIN, CUSTOM_RTL_MAX, CUSTOM_RTL_SPECIAL_CHARS54    if isinstance(_min, int):55        CUSTOM_RTL_MIN = _min56    elif isinstance(_min, str):57        CUSTOM_RTL_MIN = ord(_min)58    if isinstance(_max, int):59        CUSTOM_RTL_MAX = _max60    elif isinstance(_max, str):61        CUSTOM_RTL_MAX = ord(_max)62    if isinstance(specials, str):63        CUSTOM_RTL_SPECIAL_CHARS = [ord(x) for x in specials]64    elif isinstance(specials, list):65        CUSTOM_RTL_SPECIAL_CHARS = specials66    return CUSTOM_RTL_MIN, CUSTOM_RTL_MAX, CUSTOM_RTL_SPECIAL_CHARS67 68 69def mult(m: list[float], n: list[float]) -> list[float]:70    return [71        m[0] * n[0] + m[1] * n[2],72        m[0] * n[1] + m[1] * n[3],73        m[2] * n[0] + m[3] * n[2],74        m[2] * n[1] + m[3] * n[3],75        m[4] * n[0] + m[5] * n[2] + n[4],76        m[4] * n[1] + m[5] * n[3] + n[5],77    ]78 79 80def orient(m: list[float]) -> int:81    if m[3] > 1e-6:82        return 083    if m[3] < -1e-6:84        return 18085    if m[1] > 0:86        return 9087    return 27088 89 90def crlf_space_check(91    text: str,92    cmtm_prev: tuple[list[float], list[float]],93    cmtm_matrix: tuple[list[float], list[float]],94    memo_cmtm: tuple[list[float], list[float]],95    font_resource: Optional[DictionaryObject],96    orientations: tuple[int, ...],97    output: str,98    font_size: float,99    visitor_text: Optional[Callable[[Any, Any, Any, Any, Any], None]],100    str_widths: float,101    spacewidth: float,102    str_height: float,103) -> tuple[str, str, list[float], list[float]]:104    cm_prev = cmtm_prev[0]105    tm_prev = cmtm_prev[1]106    cm_matrix = cmtm_matrix[0]107    tm_matrix = cmtm_matrix[1]108    memo_cm = memo_cmtm[0]109    memo_tm = memo_cmtm[1]110 111    m_prev = mult(tm_prev, cm_prev)112    m = mult(tm_matrix, cm_matrix)113    orientation = orient(m)114    delta_x = m[4] - m_prev[4]115    delta_y = m[5] - m_prev[5]116    # Table 108 of the 1.7 reference ("Text positioning operators")117    scale_prev_x = math.sqrt(tm_prev[0]**2 + tm_prev[1]**2)118    scale_prev_y = math.sqrt(tm_prev[2]**2 + tm_prev[3]**2)119    scale_y = math.sqrt(tm_matrix[2]**2 + tm_matrix[3]**2)120    cm_prev = m121 122    if orientation not in orientations:123        raise OrientationNotFoundError124    if orientation in (0, 180):125        moved_height: float = delta_y126        moved_width: float = delta_x127    elif orientation in (90, 270):128        moved_height = delta_x129        moved_width = delta_y130    try:131        if abs(moved_height) > 0.8 * min(str_height * scale_prev_y, font_size * scale_y):132            if (output + text)[-1] != "\n":133                output += text + "\n"134                if visitor_text is not None:135                    visitor_text(136                        text + "\n",137                        memo_cm,138                        memo_tm,139                        font_resource,140                        font_size,141                    )142                text = ""143        elif (144            (moved_width >= (spacewidth + str_widths) * scale_prev_x)145            and (output + text)[-1] != " "146        ):147            text += " "148    except Exception:149        pass150    tm_prev = tm_matrix.copy()151    cm_prev = cm_matrix.copy()152    return text, output, cm_prev, tm_prev153 154 155def get_text_operands(156    operands: list[Union[str, TextStringObject]],157    cm_matrix: list[float],158    tm_matrix: list[float],159    font: Font,160    orientations: tuple[int, ...]161) -> tuple[str, bool]:162    t: str = ""163    is_str_operands = False164    m = mult(tm_matrix, cm_matrix)165    orientation = orient(m)166    if orientation in orientations and len(operands) > 0:167        if isinstance(operands[0], str):168            t = operands[0]169            is_str_operands = True170        else:171            t = ""172            tt: bytes = (173                encode_pdfdocencoding(operands[0])174                if isinstance(operands[0], str)175                else operands[0]176            )177            if isinstance(font.encoding, str):178                try:179                    t = tt.decode(font.encoding, "surrogatepass")  # apply str encoding180                except Exception:181                    # the data does not match the expectation,182                    # we use the alternative ;183                    # text extraction may not be good184                    t = tt.decode(185                        "utf-16-be" if font.encoding == "charmap" else "charmap",186                        "surrogatepass",187                    )  # apply str encoding188            else:  # apply dict encoding189                t = "".join(190                    [font.encoding[x] if x in font.encoding else bytes((x,)).decode() for x in tt]191                )192    return (t, is_str_operands)193 194 195def get_display_str(196    text: str,197    cm_matrix: list[float],198    tm_matrix: list[float],199    font_resource: Optional[DictionaryObject],200    font: Font,201    text_operands: str,202    font_size: float,203    rtl_dir: bool,204    visitor_text: Optional[Callable[[Any, Any, Any, Any, Any], None]]205) -> tuple[str, bool, float]:206    # "\u0590 - \u08FF \uFB50 - \uFDFF"207    widths: float = 0.0208    for x in [font.character_map.get(x, x) for x in text_operands]:209        # x can be a sequence of bytes ; ex: habibi.pdf210        if len(x) == 1:211            xx = ord(x)212        else:213            xx = 1214        # fmt: off215        if (216            # cases where the current inserting order is kept217            (xx <= 0x2F)                        # punctuations but...218            or 0x3A <= xx <= 0x40               # numbers (x30-39)219            or 0x2000 <= xx <= 0x206F           # upper punctuations..220            or 0x20A0 <= xx <= 0x21FF           # but (numbers) indices/exponents221            or xx in CUSTOM_RTL_SPECIAL_CHARS   # customized....222        ):223            text = x + text if rtl_dir else text + x224        elif (  # right-to-left characters set225            0x0590 <= xx <= 0x08FF226            or 0xFB1D <= xx <= 0xFDFF227            or 0xFE70 <= xx <= 0xFEFF228            or CUSTOM_RTL_MIN <= xx <= CUSTOM_RTL_MAX229        ):230            if not rtl_dir:231                rtl_dir = True232                if visitor_text is not None:233                    visitor_text(text, cm_matrix, tm_matrix, font_resource, font_size)234                text = ""235            text = x + text236        else:  # left-to-right237            if rtl_dir:238                rtl_dir = False239                if visitor_text is not None:240                    visitor_text(text, cm_matrix, tm_matrix, font_resource, font_size)241                text = ""242            text = text + x243        widths += font.space_width if x == " " else font.text_width(x)244        # fmt: on245    return text, rtl_dir, widths246