net.happybrackets.core.scheduling

Class Clock

java.lang.Object

net.happybrackets.core.scheduling.Clock

All Implemented Interfaces:

ScheduledEventListener

public class Clock
extends java.lang.Object
implements ScheduledEventListener

Clock Class that uses the HBScheduler class. If the HBScheduler has it's time adjusted, all Clock objects will follow the time of the HBScheduler .
A clock event is detected by adding a Clock.ClockTickListener to it through the addClockTickListener(ClockTickListener). More than one listener can be added to a clock
Clocks are created stopped and must be started outside the clock definition. For example:

     Clock testclock1 = new Clock(1000);

     testclock1.addClockTickListener((offset, clock) - > {
          long number_ticks = clock.getNumberTicks();
          System.out.println("Num Ticks: " + number_ticks);
       });

     testclock1.start();

 

The clock is stopped through stop() or when the sketch is reset
Utility functions BPM2Interval(double) and Interval2BPM(double) facilitate converting intervals to and from Beats per minute
It is possible to shift a clock forwards or backwards using shiftTime(double), change the interval through setInterval(double), synchronise to another Clock using synchronizeClock(Clock), or cause the clock to restart with a zero count using reset()
You can obtain status of clock through function getNumberTicks(), getClockInterval() and isRunning()

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Clock.ClockTickListener ClockTick interface for receiving clock Tick events The Clock.ClockTickListener.clockTick(double, Clock) receives the scheduled event and is usually represented as a Lambda.

Constructor Summary

Constructors

Constructor and Description
Clock(double interval) Constructor using default Scheduler and an interval
Clock(double interval, HBScheduler scheduler) Constructor

Method Summary

Modifier and Type	Method and Description
Clock	addClockTickListener(Clock.ClockTickListener listener) Add a Clock.ClockTickListener for this clock.
static double	BPM2Interval(double beats_per_minute) Calculate the interval required to create a clock with a defined beats per minute Will throw an illegal argument exception if you pass in zero
void	clearClockTickListener() Clears all Clock.ClockTickListener for this clock
void	doScheduledEvent(double scheduledTime, java.lang.Object param) Notification interface that a scheduled event is occuring
double	getClockInterval() The interval of the clock in milliseconds
long	getNumberTicks() Return the number of clock ticks since the clock was started
static double	Interval2BPM(double milliseconds) Calculate number of Beats Per Minute given an interval between beats
boolean	isRunning() See if clock is running
void	removeClockTickListener(Clock.ClockTickListener listener) Removes a Clock.ClockTickListener for this clock previously added using addClockTickListener(ClockTickListener)
void	reset() Reset clock.
void	setInterval(double interval) Change the interval of the clock and start from now
void	shiftTime(double shift_time) Shift the clock forwards or backwards an amount of time
Clock	start() Start the clock
void	stop()
double	synchronizeClock(Clock master) Synchronise this clock to another one

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Clock

public Clock(double interval)

Constructor using default Scheduler and an interval

Parameters:

interval - the interval in milliseconds Must be greater than 2 milliseconds otherwise could lock up

Clock

public Clock(double interval,
             HBScheduler scheduler)

Constructor

Parameters:

interval - the interval in milliseconds Must be greater than 2 milliseconds otherwise could lock up

scheduler - the scheduler to use

Method Detail

getClockInterval

public double getClockInterval()

The interval of the clock in milliseconds

Returns:

the clock interval

getNumberTicks

public long getNumberTicks()

Return the number of clock ticks since the clock was started

Returns:

number of ticks

isRunning

public boolean isRunning()

See if clock is running

Returns:

true if clock is running

reset

public void reset()

Reset clock. If clock is running, it will restart the clock to current time

stop

public void stop()

setInterval

public void setInterval(double interval)

Change the interval of the clock and start from now

Parameters:

interval - the new clock interval

start

public Clock start()

Start the clock

Returns:

this

addClockTickListener

public Clock addClockTickListener(Clock.ClockTickListener listener)

Add a Clock.ClockTickListener for this clock. More than one listener can be attached to a Clock and they can be added after the clock is already started. For example:

 final int TICKS_PER_BEAT = 4;
 double interval = Clock.BPM2Interval(120 * TICKS_PER_BEAT);

 Clock testclock1 = new Clock(interval);

 // create a listener for each Beat
 testclock1.addClockTickListener((offset, clock) - > {
   if (clock.getNumberTicks() % TICKS_PER_BEAT == 0){
     System.out.println("Beat " + clock.getNumberTicks() / TICKS_PER_BEAT);
   }

 });

 testclock1.start();

 // We can even add listeners after clock is started
 // Create a Listener for every Tick not on the beat
 testclock1.addClockTickListener((offset, clock) - > {
    long tickNum = clock.getNumberTicks() % TICKS_PER_BEAT;
    System.out.println("tick " + tickNum);
 });

 

Listeners are removed using removeClockTickListener(ClockTickListener)

Parameters:

listener - the listener to add

Returns:

this

removeClockTickListener

public void removeClockTickListener(Clock.ClockTickListener listener)

Removes a Clock.ClockTickListener for this clock previously added using addClockTickListener(ClockTickListener)

Parameters:

listener - the listener to remove

clearClockTickListener

public void clearClockTickListener()

Clears all Clock.ClockTickListener for this clock

shiftTime

public void shiftTime(double shift_time)

Shift the clock forwards or backwards an amount of time

Parameters:

shift_time - the amount of milliseconds to shift clock

BPM2Interval

public static double BPM2Interval(double beats_per_minute)
                           throws java.lang.IllegalArgumentException

Calculate the interval required to create a clock with a defined beats per minute Will throw an illegal argument exception if you pass in zero

Parameters:

beats_per_minute - beats per minute

Returns:

the number of microseconds between beats

Throws:

java.lang.IllegalArgumentException - if the beats_per minute is zero

Interval2BPM

public static double Interval2BPM(double milliseconds)
                           throws java.lang.IllegalArgumentException

Calculate number of Beats Per Minute given an interval between beats

Parameters:

milliseconds - the number of milliseconds between beats

Returns:

the calculated beats per minute

Throws:

java.lang.IllegalArgumentException - if milliseconds is zero

synchronizeClock

public double synchronizeClock(Clock master)

Synchronise this clock to another one

Parameters:

master - the clock we are synchronising with

Returns:

the amount of time we have shifted this clock

doScheduledEvent

public void doScheduledEvent(double scheduledTime,
                             java.lang.Object param)

Description copied from interface: ScheduledEventListener

Notification interface that a scheduled event is occuring

Specified by:

doScheduledEvent in interface ScheduledEventListener

Parameters:

scheduledTime - the time that was scheduled for the callback to occur

param - the parameter to pass to the listener.