custom_filter.py

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from .base_filter import BaseFilter
from .message_filter import MessageFilter
from .node_filter import NodeFilter
from .severity_filter import SeverityFilter
from .topic_filter import TopicFilter


class CustomFilter(BaseFilter):
    """
    Contains filter logic for the custom filter which allows message, severity,
    node and topic filtering simultaniously. All of these filters must match
    together (if they are used) or the custom filter does not match.
    """

    def __init__(self):
        super(CustomFilter, self).__init__()

        self._message = MessageFilter()
        self._severity = SeverityFilter()
        self._node = NodeFilter()
        self._topic = TopicFilter()

        self._all_filters = [self._message, self._severity, self._node, self._topic]
        for f in self._all_filters:
            f.filter_changed_signal.connect(self._relay_signal)

    def set_enabled(self, checked):
        """
        :signal: emits filter_changed_signal
        :param checked: enables the filters if checked is True''bool''
        """
        for f in self._all_filters:
            f.set_enabled(checked)
        super(CustomFilter, self).set_enabled(checked)

    def _relay_signal(self):
        """
        Passes any signals emitted by the child filters along
        """
        self.start_emit_timer(1)

    def has_filter(self):
        for f in self._all_filters:
            if f.has_filter():
                return True
        return False

    def test_message(self, message):
        """
        Tests if the message matches the filter.
        :param message: the message to be tested against the filters, ''Message''
        :returns: True if the message matches all child filters, ''bool''
        """
        if not self.is_enabled():
            return False
        # if non of the subfilters contains any input the custom filter does not match
        if not self.has_filter():
            return False
        # the custom filter matches when all subfilters which contain input match
        all_filters = [not f.has_filter() or f.test_message(message) for f in self._all_filters]
        return False not in all_filters