Source code for pystrich.qrcode

#!/usr/bin/env python

"""QR Code encoder

All needed by the user is done via the QRCodeEncoder class:

>>> encoder = QRCodeEncoder("HuDoRa")
>>> # encoder.save( "test.png" )
>>> print encoder.get_ascii()

"""

from __future__ import annotations

from typing import Literal

from pystrich.matrix_encoder import Matrix2DEncoder

from .renderer import QRCodeRenderer
from .textencoder import TextEncoder

QRErrorCorrectionLevel = Literal["L", "M", "Q", "H"]




class QRCodeEncoder(Matrix2DEncoder[int]):
    """Encode a string as a QR Code 2D barcode.

    Typical use::

        encoder = QRCodeEncoder("https://d-nb.info/gnd/135514053")
        encoder.save("qr.png")

    :ivar matrix: 2D list describing the symbol prior to rendering.
    :ivar width: Pixel width of the most recently rendered image.
    :ivar height: Pixel height of the most recently rendered image.
    """

    def __init__(self, text: str, ecl: QRErrorCorrectionLevel | None = None) -> None:
        """Encode ``text`` and build the QR matrix.

        :param text: The data to encode.
        :param ecl: Error correction level. ``None`` (the default) selects
            ``"M"``; pass one of ``"L"``, ``"M"``, ``"Q"`` or ``"H"`` to
            override.
        """

        enc = TextEncoder()
        self.matrix = enc.encode(text, ecl)
        self.height = 0
        self.width = 0



    def init_renderer(self) -> QRCodeRenderer:
        """Construct a :class:`QRCodeRenderer` for the encoded matrix.

        Updates :attr:`width` and :attr:`height` with the renderer's
        dimensions and returns the renderer.
        """
        qrc = QRCodeRenderer(self.matrix)
        self.width = qrc.width
        self.height = qrc.height
        return qrc