ebcli/bundled/asciimatics/exceptions.py

# Copyright 2016 Peter Brittain
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
This module defines the exceptions used by asciimatics.
"""


class ResizeScreenError(Exception):
    """
    Asciimatics raises this Exception if the terminal is resized while playing
    a Scene (and the Screen has been told not to ignore a resizing event).
    """

    def __init__(self, message, scene=None):
        """
        :param message: Error message for this exception.
        :param scene: Scene that was active at time of resize.
        """
        super(ResizeScreenError, self).__init__()
        self._scene = scene
        self._message = message

    def __str__(self):
        """
        Printable form of the exception.
        """
        return self._message

    @property
    def scene(self):
        """
        The Scene that was running when the Screen resized.
        """
        return self._scene


class StopApplication(Exception):
    """
    Any component can raise this exception to tell Asciimatics to stop running.
    If playing a Scene (i.e. inside `Screen.play()`) the Screen will return
    to the calling function.  When used at any other time, the exception will
    need to be caught by the application using Asciimatics.
    """

    def __init__(self, message):
        """
        :param message: Error message for this exception.
        """
        super(StopApplication, self).__init__()
        self._message = message

    def __str__(self):
        """
        Printable form of the exception.
        """
        return self._message


class NextScene(Exception):
    """
    Any component can raise this exception to tell Asciimatics to move to the
    next Scene being played.  Only effective inside `Screen.play()`.
    """

    def __init__(self, name=None):
        """
        :param name: Next Scene to invoke.  Defaults to next in the list.
        """
        super(NextScene, self).__init__()
        self._name = name

    @property
    def name(self):
        """
        The name of the next Scene to invoke.
        """
        return self._name


class InvalidFields(Exception):
    """
    When saving data from a Frame, you can ask the Frame to validate the data
    before saving.  This is the exception that gets thrwn if any invalid datd
    is found.
    """

    def __init__(self, fields):
        """
        :param fields: The list of the fields that are invalid.
        """
        super(InvalidFields, self).__init__()
        self._fields = fields

    @property
    def fields(self):
        """
        The list of fields that are invalid.
        """
        return self._fields


class Highlander(Exception):
    """
    There can be only one Layout or Widget with certain options set (designed
    to fill the rest of the screen).  If you hit this exception you have
    a bug in your application.

    If you don't get the name, take a look at `this link
    <https://en.wikipedia.org/wiki/Highlander_(film)>`__.
    """