ages/agame/display/display.py

import abc
from typing import Optional, Sequence, Tuple, TYPE_CHECKING
from agame.action import Action
from agame.dialog import DialogOption

if TYPE_CHECKING:
    from agame.game import Game


class Display(metaclass=abc.ABCMeta):
    """
    Displays are an abstraction over printing things to the screen.

    Use a specific implementation based on the kind of display you want to use.
    """

    @abc.abstractmethod
    def line(self, line: str = ""):
        "Print a single line to the display."

    @abc.abstractmethod
    def input(self, prompt: Optional[str] = None) -> str:
        "Get player input."

    @abc.abstractmethod
    def wait_for_ack(self, prompt: Optional[str] = None):
        """
        Wait for the user to press a key.

        The behavior is up to the implementor. This could be something like
        "press any key to continue", "press enter to continue", or "click OK to
        continue". This method should block until input is acknowleged by the
        user.
        """

    def dialog_options(self, options: Sequence[DialogOption]) -> DialogOption:
        """
        Displays, and gets, an answer from a list of dialog options.

        Returns the selected DialogOption.next value and actions.
        """
        valid_opts = range(1, len(options) + 1)

        def print_opts():
            for i, opt in enumerate(options):
                self.line(f"{i}. {opt.text}")

        print_opts()
        while True:
            got = self.input("? ")
            try:
                choice = int(got)
            except ValueError:
                print_opts()
                continue
            if choice in valid_opts:
                break
        index = choice - 1
        selection = options[index]
        return selection

    def finish(self):
        "Final cleanup code for this display."