TriggerBoard

java.lang.Object
- stella.util.TriggerBoard

All Implemented Interfaces:

Toggling

Direct Known Subclasses:

QuadraticBoard
```
public class TriggerBoard
extends Object
implements Toggling
```
A trigger board. The functionality of a trigger board is reminiscent of a schmidt trigger but has some memory function, i.e. it triggers not on an actual value but takes also history into account.
Equal as a smith trigger it knows two states, in the following refered to as 'positive' and 'negative'. Its action can be illustrated as given below for a trigger board in the 'positive' state.
- Values that indicate negative add negatively to the trigger board.
- Readings that indicate positive add positively to the trigger board, but may not shift the trigger board to positive values.
- If the trigger board reaches a certein toggle value its state sweeps over to 'negative'. The trigger board is cleared and the process is reversed.
- Now, 'positive' values add positively to the trigger board while 'negative' values reduce the trigger boad (but not below zero). Note that the trigger switches for positive/negative do not need to be of equal absoulte value.
One application is the use of a trigger board in WeatherSensors.

Field Summary

Fields
Modifier and Type	Field and Description
`private double`	`meanTrigger` The trigger mean value.
`private double`	`negativeTrigger` The trigger switch to turn this state to 'negative'.
`private double`	`positiveTrigger` The trigger switch to turn this state to 'positive'.
`private boolean`	`triggerState` The actual trigger state.
`private double`	`triggerValue` The actual trigger value.

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`TriggerBoard()` Empty constructor.
	`TriggerBoard(double mean, double negative, double positive)` Constructs a new trigger board with the given positive and negative toggle switches.
	`TriggerBoard(String parameters)` Constructs a new trigger board with the three defining parameter packed together in a string.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`addHit(double value)` Adds a new value to this tirgger board.
`boolean`	`equalBoard(TriggerBoard that)` Two trigger boards are equal boards if they have the same trigger switches.
`boolean`	`equals(Object that)` Two trigger boards are equal if they have the same trigger switches, the same state and the same actual trigger value.
`protected double`	`getNegativeHit(double raw)` The impact of a negative value.
`double`	`getNegativeTrigger()` Returns the negative toggle value.
`protected double`	`getPositiveHit(double raw)` The impact of a positive value.
`double`	`getPositiveTrigger()` Returns the positive toggle value.
`double`	`getTriggerValue()` Returns the actual trigger value.
`boolean`	`isPositive()` Returns the state of the trigger board as a boolean.
`protected void`	`setTriggers(double negative, double positive)` Sets the toggle values.

Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - meanTrigger
```
private double meanTrigger
```
    The trigger mean value. The level around which it should oscilate.
  - positiveTrigger
```
private double positiveTrigger
```
    The trigger switch to turn this state to 'positive'.
  - negativeTrigger
```
private double negativeTrigger
```
    The trigger switch to turn this state to 'negative'.
  - triggerValue
```
private double triggerValue
```
    The actual trigger value.
  - triggerState
```
private boolean triggerState
```
    The actual trigger state.
- Constructor Detail
  - TriggerBoard
```
protected TriggerBoard()
```
    Empty constructor. Do not use.
  - TriggerBoard
```
public TriggerBoard(String parameters)
```
    Constructs a new trigger board with the three defining parameter packed together in a string. The String must be coma-separated and consist of the mean value, the negative value and the positive value in this order.
  - TriggerBoard
```
public TriggerBoard(double mean,
                    double negative,
                    double positive)
```
    Constructs a new trigger board with the given positive and negative toggle switches. The trigger value is set to zero and the trigger state to positive.
    
    Parameters:
    
    negative - The negative trigger value, ≤ 0
    
    positive - The positive trigger value, ≥ 0
- Method Detail
  - isPositive
```
public boolean isPositive()
```
    Returns the state of the trigger board as a boolean. The 'positive' state returns true while the 'negative' state returns false.
  - addHit
```
public boolean addHit(double value)
```
    Adds a new value to this tirgger board. The new state of the trigger board is returned. Note that this method calls one of the two proteced methods getPositiveHit(double) or getNegativeHit(double) to allow subclasses to add, e.g. quadratic, impact.
    
    Specified by:
    
    addHit in interface Toggling
  - getNegativeHit
```
protected double getNegativeHit(double raw)
```
    The impact of a negative value. The default implementation returns the argument. Subclasses may implement a non-linear response here.
    Always make sure that this method returns a value less equal zero!
    
    Parameters:
    
    raw - An always-negative value.
  - getPositiveHit
```
protected double getPositiveHit(double raw)
```
    The impact of a positive value. The default implementation returns the argument. Subclasses may implement a non-linear response here.
    Always make sure that this method returns a value greater equal zero!
    
    Parameters:
    
    raw - An always-positive value.
  - setTriggers
```
protected void setTriggers(double negative,
                           double positive)
```
    Sets the toggle values. Checks for allowed value, i.e. whether the negative trigger is less equal zero and the positive trigger is greater equal zero. If either of the trigger is not within the allowed range an IllegalArgumentException is thrown.
    
    Parameters:
    
    negative - The negative trigger value, ≤ 0
    
    positive - The positive trigger value, ≥ 0
    
    Throws:
    
    IllegalArgumentException - if either of the trigger has a forbidden value.
  - getPositiveTrigger
```
public double getPositiveTrigger()
```
    Returns the positive toggle value.
  - getNegativeTrigger
```
public double getNegativeTrigger()
```
    Returns the negative toggle value.
  - getTriggerValue
```
public double getTriggerValue()
```
    Returns the actual trigger value.
  - equalBoard
```
public boolean equalBoard(TriggerBoard that)
```
    Two trigger boards are equal boards if they have the same trigger switches.
    
    See Also:
    
    equals(java.lang.Object)
  - equals
```
public boolean equals(Object that)
```
    Two trigger boards are equal if they have the same trigger switches, the same state and the same actual trigger value.
    
    Overrides:
    
    equals in class Object
    
    See Also:
    
    equalBoard(stella.util.TriggerBoard)

Class TriggerBoard

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

meanTrigger

positiveTrigger

negativeTrigger

triggerValue

triggerState

Constructor Detail

TriggerBoard

TriggerBoard

TriggerBoard

Method Detail

isPositive

addHit

getNegativeHit

getPositiveHit

setTriggers

getPositiveTrigger

getNegativeTrigger

getTriggerValue

equalBoard

equals