Events

Myriad posts events for everything that happens: ticks, packets, input, rendering, the world, the UI. Handle one by annotating a method with @Subscribe. A module’s handlers run only while it’s on.


@Subscribe(inGame = true)                             // skipped unless there's a world and a player
private void onTick(TickEvent.Pre e) { ... }
 
@Subscribe(priority = Priority.HIGH)                  // higher runs first; any int works
private void onChat(ChatReceiveEvent e) {
    if (e.message().getString().contains("spam")) e.cancel();
}
 
@Subscribe(packets = ClientboundSetTimePacket.class)  // only for these packets: far cheaper than instanceof
private void onTime(PacketEvent.Receive e) { ... }

`@Subscribe` option
`priority`	order among handlers (`Priority.HIGHEST` 200 … `LOWEST` -200; `BEFORE_ACTIONS` runs before services act)
`inGame`	skip the handler unless a world and player exist
`packets`	on a `PacketEvent` handler: only these packet classes
`receiveCancelled`	still receive the event after another handler cancelled it

A handler for a supertype receives its subtypes too. A handler that keeps throwing is logged against its addon and then turned off, so one broken addon can’t break the game.

Outside modules


// Any object's @Subscribe methods, until you unsubscribe it:
ctx.events().subscribe(sessionStats);
 
// One handler, as a lambda; keep the Subscription to drop it:
Subscription sub = Myriad.events().listen(WorldEvent.Join.class, e -> joinedAt = System.currentTimeMillis());
sub.unsubscribe();

Timing

Act (click, place, break, attack, switch slots) in TickEvent.Pre, before the player moves, as vanilla does. Grim flags actions sent after the tick’s movement packet; Myriad holds any that come later until the start of the next tick, so they’re safe but a tick late. The services act at the right time on their own.

Core events

Event
`TickEvent.Pre`, `TickEvent.Post`	every client tick (20 a second), before and after the player
`Render2DEvent`	the HUD frame; `canvas()` draws in GUI pixels
`Render3DEvent`	the world frame; `shapes()` draws boxes and lines (see Drawing)
`PacketEvent.Send`, `PacketEvent.Receive`	every packet, bundles split; cancel or `setPacket` to replace
`MovementPacketsEvent`	the movement packet about to go out: rewrite position, rotation, on-ground
`PlayerMoveEvent`	this tick’s movement: change speed, fly
`InputEvent`	the movement keys for this tick: press or release them
`MouseLookEvent`	turning the camera: scale or cancel it
`CollisionShapeEvent`	what a block collides as: walk on water, avoid cactus
`TeleportEvent`	the server set your position (a teleport, a rubberband)
`HealthEvent`	your health and food from the server, with the damage taken
`AttackEvent`	before an attack goes out (cancellable)
`InteractEvent.Block`, `.Item`, `.EntityTarget`	right-clicks (cancellable)
`ItemUseEvent.Finished`, `.Stopped`	eating, drinking, drawing a bow
`BlockBreakEvent.Start`, `.Progress`, `BlockBrokenEvent`	mining
`BlockUpdateEvent`	the server changed a block (old and new state)
`ChunkEvent.Loaded`, `.Unloaded`	chunks
`EntityEvent.Added`, `.Removed`, `.TotemPopped`, `.Died`	entities
`ContainerEvent.Opened`, `.Loaded`, `.SlotUpdated`, `.Closed`	containers (chests, your inventory)
`ContainerScreenEvent.SlotDrawn`, `.Tooltip`, `.Click`	icons on slots, previews, taking over clicks
`ItemTooltipEvent`	add tooltip lines
`ChatReceiveEvent`, `ChatSendEvent`	chat in and out (cancel, change); `parsed()` says who and whether it’s a whisper
`BlockRenderEvent`	leave a block out of the chunk mesh (X-ray)
`EntityRenderEvent.Visible`, `.Nametag`, `.Model`	hide an entity, replace its name tag, draw its model again
`HighlightEvent.Entity`, `.Shapes`	shader outlines and glows (see Highlights)
`GlideEvent`	an elytra glide’s movement this tick
`CameraEvent`, `PlaySoundEvent`	the camera; cancel any sound
`KeyEvent`, `MouseButtonEvent`, `MouseScrollEvent`, `CharEvent`	input
`ScreenOpenEvent`	a screen about to open: replace or cancel it
`WorldEvent.Join`, `.Leave`, `DisconnectEvent`	joining and leaving
`ModuleToggleEvent`	any module turned on or off
`WindowResizeEvent`, `GameReadyEvent`, `ShutdownEvent`	the game window and lifecycle

Event objects are made by Myriad (their constructors are @ApiStatus.Internal). Some are reused for every call (HighlightEvent.Entity is): don’t keep one past your handler.