Event Bus

The event bus is the easiest way to attach behavior to CampAPI hooks.

Use `ModuleScope` for automatic cleanup

ModuleScope groups listeners together. When the scope goes away, its listeners are removed automatically.

cpp

CampAPI::ModuleScope scope;

Add a listener

cpp

scope.AddListener<BeforeRenderScreenEvent>([](BeforeRenderScreenEvent& event) {
    event.Cancel();
});

Listener order

Listeners run in the order they were registered. If you need the opposite order, ReverseInvoke() is available on the bus.

What this is useful for

blocking a render hook
consuming input so another handler does not use it
observing client lifecycle events
wiring up startup and shutdown behavior for a mod

Example: stop a screen from rendering

cpp

CampAPI::ModuleScope scope;

scope.AddListener<BeforeRenderScreenEvent>([](BeforeRenderScreenEvent& event) {
    if (event.isDebugOrToastScreen) {
        return;
    }

    event.Cancel();
});

Example: handle a key press

cpp

CampAPI::ModuleScope scope;

scope.AddListener<OnKeyEvent>([](OnKeyEvent& event) {
    if (event.isKeyDown && event.keyCode == 66) {
        event.Consume();
    }
});

When to use cancellable events

Use cancellable events when your code should be able to stop the default action.

cpp

scope.AddListener<CancelableClientInstanceEvent>([](CancelableClientInstanceEvent& event) {
    event.Cancel();
});

Event Bus ​

Use ModuleScope for automatic cleanup ​

Add a listener ​

Listener order ​

What this is useful for ​

Example: stop a screen from rendering ​

Example: handle a key press ​

When to use cancellable events ​