MovementController

xin.bbtt.movement.MovementController is the scheduler that runs Movements one at a time off a queue. Access the shared instance via MovementSync.INSTANCE.getMovementController().

The Movement lifecycle

Every action is a subclass of the abstract xin.bbtt.movement.Movement:

public abstract class Movement {
    protected boolean finished = false;

    public abstract void init();      // called once before the first tick
    public abstract void onTick();    // called every 50 ms while active
    public abstract long getTime();   // time limit in ms; negative = use isFinished()
    public abstract void onStop();    // cleanup when stopped/finished

    public void onPause()  {}         // optional
    public void onResume() {}         // optional
}

The controller wraps the current movement in a MovementTask scheduled at 20 TPS (every 50 ms). A movement ends when either:

• its getTime() limit elapses, or
• it sets finished = true (checked via the inherited isFinished()).

When a movement finishes the controller pulls the next one off the queue.

Built-in Movements

WalkMovement, JumpMovement, LookAtMovement, DigBlockMovement, PlaceBlockMovement, InteractEntityMovement, ActionMovement and PathMovement (the path follower) all live in xin.bbtt.movements.

Queue API

MovementController mc = MovementSync.INSTANCE.getMovementController();

mc.addMovement(movement);     // append to the back of the queue
mc.insertMovement(movement);  // interrupt now; resume the old one afterwards
mc.finishCurrentMovement();   // stop the current one, advance to the next
mc.cancelAll();               // clear the queue and stop the current movement

Method	Behaviour
addMovement(Movement)	Adds to the tail. Starts execution if idle.
insertMovement(Movement)	Cancels the running task immediately, pushes the interrupted movement back to the head so it resumes afterward, then runs the inserted one first.
finishCurrentMovement()	Stops the current movement and advances.
removeMovement(int index)	Removes a queued movement by index.
cancelAll()	Clears everything and stops.
getCurrentMovement()	The movement currently executing (or null).
getMovements()	A snapshot List of queued movements.

add vs. insert

addMovement is cooperative — it waits for the queue. insertMovement is pre-emptive — it cancels the running task's thread now (Future.cancel(true)) and runs your movement before resuming what was interrupted. PILLAR, for example, inserts a PlaceBlockMovement ahead of a JumpMovement this way.

Pause / Resume

mc.pause();   // calls onPause() on the current movement; halts dispatch
mc.resume();  // calls onResume(); resumes dispatch
boolean paused = mc.isPaused();

Pausing stops new movements from being dispatched and notifies the current movement, without discarding the queue. This backs the movement pause|resume|cancel command.

Threading notes

• State transitions are guarded by an internal stateLock; isExecuting and isPaused are AtomicBooleans for lock-free fast paths.
• Movements run on a dedicated single-thread ScheduledExecutorService (MovementSync.INSTANCE.movementService), separate from the physics loop.
• Because insertMovement cancels with interruption, long-running onTick work should be interrupt-aware.