.. _py-flow/Printer:

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flow/Printer
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.. default-domain:: py

.. py:currentmodule:: mod
.. cpp:namespace:: mod

.. class:: FlowPrinter

    An object of this class holds information on how derivation graphs with flow are visualised.

    .. attribute:: dgPrinter

        (Read-only) Retrieve the :class:`DGPrinter` used when printing solutions.

        :type: DGPrinter
    .. attribute:: withFlowLabels

        Control whether or not a flow label is appended to each hyperedge label (see also :meth:`DGPrinter.pushEdgeLabel`).

        :type: bool
    .. method:: pushInEdgeLabel(f)

        Add another function for in-edge labelling.
        The result of this function is appended to each label using the edge label separator
        of the underlying :class:`DGPrinter`.

        :param f: the function to push for labelling in-edges.
        :type f: Callable[DGVertex], str] or str
    .. method:: popInEdgeLabel()

        Remove the last pushed in-edge labelling function.

        :raises: :class:`LogicError` if no callback is left to pop.
    .. method:: pushOutEdgeLabel(f)

        Add another function for out-edge labelling.
        The result of this function is appended to each label using the edge label separator
        of the underlying :class:`DGPrinter`.

        :param f: the function to push for labelling out-edges.
        :type f: Callable[DGVertex], str] or str
    .. method:: popOutEdgeLabel()

        Remove the last pushed out-edge labelling function.

        :raises: :class:`LogicError` if no callback is left to pop.
    .. attribute:: printUnfiltered

        Control whether or not the unfiltered version of a solution is printed.

        :type: bool
    .. attribute:: printFiltered

        Control whether or not the filtered version of a solution is printed.

        :type: bool
    .. attribute:: unfilteredFlowColour

        When printing the unfiltered version, use this colour on vertices and edges with non-zero flow.
        Use an empty string to not colour them.

        :type: str