Method prevent

src/textual/message_pump.py:199–217

A context manager to *temporarily* prevent the given message types from being posted. Example: ```python input = self.query_one(Input) with self.prevent(Input.Changed): input.value = "foo" ```

(self, *message_types: type[Message])

    @contextmanager
    def prevent(self, *message_types: type[Message]) -> Generator[None, None, None]:
        """A context manager to *temporarily* prevent the given message types from being posted.

        Example:
            ```python
            input = self.query_one(Input)
            with self.prevent(Input.Changed):
                input.value = "foo"
            ```
        """
        if message_types:
            prevent_stack = self._prevent_message_types_stack
            prevent_stack.append(prevent_stack[-1].union(message_types))
            try:
                yield
            finally:
                prevent_stack.pop()
        else:
            yield

    @property
    def task(self) -> Task: