Struct design_pattern_examples_rust::handlerchain::handlerchain_handlerchain::HandlerChain

pub struct HandlerChain {
    message_handlers: Vec<Box<RefCell<dyn IMessageHandler>>>,
}

Represents a list of handlers that all implement the IMessageHandler trait. This list can be dynamically updated and each element in the list is passed messages for processing.

Fields

message_handlers: Vec<Box<RefCell<dyn IMessageHandler>>>

The list of message handlers.

Implementations

impl HandlerChain

pub fn new() -> HandlerChain

Constructor.

Returns

Returns a new instance of the HandlerChain struct.

pub fn add_handler(&mut self, handler: impl IMessageHandler + 'static)

Add the given instance of the IMessageHandler interface to end of the list of handlers.

Normally this would guard against adding the same window twice, but this HandlerChain takes ownership of the window and therefore the same window can never be added twice to this HandlerChain.

pub fn remove_handler(&mut self, handler_id: i32)

Remove an instance of the IMessageHandler interface from the list.

If the message handler is not in the list, the request to remove is ignored.

pub fn send_message(&mut self, message: &Message)

Send a message to each of the handlers in the list.

Parameters

• message

  The Message object to send to each handler.

Trait Implementations

impl Display for HandlerChain

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Convert this HandlerChain to a string that is returned.