com.jp.comp.calculator
Class Calculator

java.lang.Object
  com.jp.comp.calculator.Calculator

public class Calculator

extends java.lang.Object

Performs calculator's computing. The set of operations performed by the calculator can be changed. If there is a need to calclulate x^y a new operation should be created implementing CaclulatorOperation and added to the Calculator by addOperation method

See Also:

CalculatorPanel

Field Summary

protected CalculatorEvent	fCalculatorEvent
protected java.util.Vector	fCalculatorListeners
protected java.util.HashMap	fCalculatorOperations
protected CalculatorResult	fCalculatorResult
protected CalculatorOperation	fDefaultClearOperation
protected boolean	fProcessingError
protected java.util.HashMap	fStateMap
static CalculatorOperation	MEMORY_ADDITION Default memory addition operation
static java.lang.String	MEMORY_ADDITION_KEY Memory addition operation's key
static CalculatorOperation	MEMORY_CLEAR Default memory clear operation
static java.lang.String	MEMORY_CLEAR_KEY Memory clear operation's key
static CalculatorOperation	MEMORY_RECALL Default memory recall operation
static java.lang.String	MEMORY_RECALL_KEY Memory recall operation's key
static CalculatorOperation	MEMORY_STORE Default memory store operation
static java.lang.String	MEMORY_STORE_KEY Memory store operation's key
static CalculatorOperation	MEMORY_SUBTRACTION Default memory subtaction operation
static java.lang.String	MEMORY_SUBTRACTION_KEY Memory subtraction operation's key
static java.lang.String	PROPERTY_DEFAULT_CLEAR_OPERATION Property name for the default clear operation
static java.lang.String	PROPERTY_HASHED_OPERATION Property name for the hashed operations
static java.lang.String	PROPERTY_MEMORY Property name for the memory
static java.lang.String	PROPERTY_RESULT Property name for the result
protected java.util.Vector	propertyChangeListeners
static CalculatorOperation	RESULT_ADDITION Default addition operation
static java.lang.String	RESULT_ADDITION_KEY Addition operation's key
static CalculatorOperation	RESULT_CLEAR Default clear operation
static java.lang.String	RESULT_CLEAR_KEY Clear operation's key
static CalculatorOperation	RESULT_DIVISION Default division operation
static java.lang.String	RESULT_DIVISION_KEY Division operation's key
static CalculatorOperation	RESULT_EQUAL Default equal operation
static java.lang.String	RESULT_EQUAL_KEY Equal operation's key
static CalculatorOperation	RESULT_MULTIPLICATION Default multiplication operation
static java.lang.String	RESULT_MULTIPLICATION_KEY Multiplication operation's key
static CalculatorOperation	RESULT_PERCENT Default percent operation
static java.lang.String	RESULT_PERCENT_KEY Percent operation's key
static CalculatorOperation	RESULT_RECIPROCAL Default reciprocal operation
static java.lang.String	RESULT_RECIPROCAL_KEY Reciprocal operation's key
static CalculatorOperation	RESULT_SQRT Default sqrt operation
static java.lang.String	RESULT_SQRT_KEY Sqrt operation's key
static CalculatorOperation	RESULT_SUBTRACTION Default subtaction operation
static java.lang.String	RESULT_SUBTRACTION_KEY Subtraction operation's key
static java.math.BigDecimal	VALUE_0 Default zero value

Constructor Summary

Calculator()
Creates the class instance

Method Summary

void	addCalculatorListener(CalculatorListener aListener) Adds Calculator's listener
void	addOperation(java.lang.String anOperationKey, CalculatorOperation anOperation) Adds a new operation to the calculator.
void	addPropertyChangeListener(java.beans.PropertyChangeListener aListener) Adds state map property change listener
protected void	firePropertyChange(java.beans.PropertyChangeEvent anEvent) Fired by the calculator when state map property is changed
protected void	fireResultChanged() Fired by the calculator when the result is changed
CalculatorOperation	getDefaultClearOperation() Returns default clear operation.
protected java.math.BigDecimal	getResult() Returns last caclulator's result sitting in the state map
java.lang.Object	getStateMapProperty(java.lang.String aKey) Returns state map property value specified by aKey
boolean	isOperationExist(java.lang.String anOperationKey) Returns true if operation, specified by anOperationKey, exist
protected void	performNonStandaloneOperation(java.math.BigDecimal aValue, CalculatorOperation anOperation, boolean aValueChanged) Performs nonstandalone operation.
CalculatorResult	performOperation(double aValue, java.lang.String anOperationKey, boolean aValueChanged) Seeks and performs operation specified by anOperationKey.
protected void	performStandaloneOperation(java.math.BigDecimal aValue, CalculatorOperation anOperation, boolean aValueChanged) Performs standalone operation.
void	removeCalculatorListener(CalculatorListener aListener) Removes Calculator's listener
void	removeOperation(java.lang.String anOperationKey) Removes the operation, specified by anOperationKey, from the calculator
void	removePropertyChangeListener(java.beans.PropertyChangeListener aListener) Removes state map property change listener
void	setDefaultClearOperation(CalculatorOperation aDefaultClearOperation) Sets default clear operation.
void	setStateMapProperty(java.lang.String aKey, java.lang.Object aValue) Sets a new state map property value
void	updateOperation(java.lang.String anOperationKey, CalculatorOperation anOperation) Updates an existing operation in the calculator.

Methods inherited from class java.lang.Object

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

Field Detail

PROPERTY_MEMORY

public static final java.lang.String PROPERTY_MEMORY

Property name for the memory

See Also:

Constant Field Values

PROPERTY_RESULT

public static final java.lang.String PROPERTY_RESULT

Property name for the result

See Also:

Constant Field Values

PROPERTY_HASHED_OPERATION

public static final java.lang.String PROPERTY_HASHED_OPERATION

Property name for the hashed operations

See Also:

Constant Field Values

PROPERTY_DEFAULT_CLEAR_OPERATION

public static final java.lang.String PROPERTY_DEFAULT_CLEAR_OPERATION

Property name for the default clear operation

See Also:

Constant Field Values

MEMORY_CLEAR_KEY

public static final java.lang.String MEMORY_CLEAR_KEY

Memory clear operation's key

See Also:

Constant Field Values

MEMORY_STORE_KEY

public static final java.lang.String MEMORY_STORE_KEY

Memory store operation's key

See Also:

Constant Field Values

MEMORY_RECALL_KEY

public static final java.lang.String MEMORY_RECALL_KEY

Memory recall operation's key

See Also:

Constant Field Values

MEMORY_ADDITION_KEY

public static final java.lang.String MEMORY_ADDITION_KEY

Memory addition operation's key

See Also:

Constant Field Values

MEMORY_SUBTRACTION_KEY

public static final java.lang.String MEMORY_SUBTRACTION_KEY

Memory subtraction operation's key

See Also:

Constant Field Values

RESULT_ADDITION_KEY

public static final java.lang.String RESULT_ADDITION_KEY

Addition operation's key

See Also:

Constant Field Values

RESULT_SUBTRACTION_KEY

public static final java.lang.String RESULT_SUBTRACTION_KEY

Subtraction operation's key

See Also:

Constant Field Values

RESULT_MULTIPLICATION_KEY

public static final java.lang.String RESULT_MULTIPLICATION_KEY

Multiplication operation's key

See Also:

Constant Field Values

RESULT_DIVISION_KEY

public static final java.lang.String RESULT_DIVISION_KEY

Division operation's key

See Also:

Constant Field Values

RESULT_SQRT_KEY

public static final java.lang.String RESULT_SQRT_KEY

Sqrt operation's key

See Also:

Constant Field Values

RESULT_PERCENT_KEY

public static final java.lang.String RESULT_PERCENT_KEY

Percent operation's key

See Also:

Constant Field Values

RESULT_RECIPROCAL_KEY

public static final java.lang.String RESULT_RECIPROCAL_KEY

Reciprocal operation's key

See Also:

Constant Field Values

RESULT_EQUAL_KEY

public static final java.lang.String RESULT_EQUAL_KEY

Equal operation's key

See Also:

Constant Field Values

RESULT_CLEAR_KEY

public static final java.lang.String RESULT_CLEAR_KEY

Clear operation's key

See Also:

Constant Field Values

MEMORY_CLEAR

public static final CalculatorOperation MEMORY_CLEAR

Default memory clear operation

MEMORY_STORE

public static final CalculatorOperation MEMORY_STORE

Default memory store operation

MEMORY_RECALL

public static final CalculatorOperation MEMORY_RECALL

Default memory recall operation

MEMORY_ADDITION

public static final CalculatorOperation MEMORY_ADDITION

Default memory addition operation

MEMORY_SUBTRACTION

public static final CalculatorOperation MEMORY_SUBTRACTION

Default memory subtaction operation

RESULT_ADDITION

public static final CalculatorOperation RESULT_ADDITION

Default addition operation

RESULT_SUBTRACTION

public static final CalculatorOperation RESULT_SUBTRACTION

Default subtaction operation

RESULT_MULTIPLICATION

public static final CalculatorOperation RESULT_MULTIPLICATION

Default multiplication operation

RESULT_DIVISION

public static final CalculatorOperation RESULT_DIVISION

Default division operation

RESULT_SQRT

public static final CalculatorOperation RESULT_SQRT

Default sqrt operation

RESULT_PERCENT

public static final CalculatorOperation RESULT_PERCENT

Default percent operation

RESULT_RECIPROCAL

public static final CalculatorOperation RESULT_RECIPROCAL

Default reciprocal operation

RESULT_EQUAL

public static final CalculatorOperation RESULT_EQUAL

Default equal operation

RESULT_CLEAR

public static final CalculatorOperation RESULT_CLEAR

Default clear operation

VALUE_0

public static final java.math.BigDecimal VALUE_0

Default zero value

fDefaultClearOperation

protected CalculatorOperation fDefaultClearOperation

fCalculatorOperations

protected java.util.HashMap fCalculatorOperations

fStateMap

protected java.util.HashMap fStateMap

fProcessingError

protected boolean fProcessingError

fCalculatorResult

protected CalculatorResult fCalculatorResult

fCalculatorEvent

protected CalculatorEvent fCalculatorEvent

fCalculatorListeners

protected transient java.util.Vector fCalculatorListeners

propertyChangeListeners

protected transient java.util.Vector propertyChangeListeners

Constructor Detail

Calculator

public Calculator()

Creates the class instance

Method Detail

performOperation

public CalculatorResult performOperation(double aValue,
                                         java.lang.String anOperationKey,
                                         boolean aValueChanged)

Seeks and performs operation specified by anOperationKey. Invoked by CalculatorPanel to perform an operation associated with the particular button

Parameters:

aValue - the value to perform operation on

anOperationKey - the operation key

aValueChanged - if true the value was changed in CalculatorPanel

Returns:

computing's result

performStandaloneOperation

protected void performStandaloneOperation(java.math.BigDecimal aValue,
                                          CalculatorOperation anOperation,
                                          boolean aValueChanged)

Performs standalone operation. Standalone operations perform computations and calculator's state map changes itself returning the result of its computation. The result is returned to CalculatorPanel to be shown on the display

Parameters:

aValue - the value to perform operation on

anOperation - the operation key

aValueChanged - if true the value was changed in CalculatorPanel

See Also:

CalculatorOperation.isStandalone()

performNonStandaloneOperation

protected void performNonStandaloneOperation(java.math.BigDecimal aValue,
                                             CalculatorOperation anOperation,
                                             boolean aValueChanged)

Performs nonstandalone operation. Nonstandalone operations just perform computations on two operandsands (like subtraction and multiplication), return the result of its computation and do nothing with calculator's state map. Calculator decides itself can this operation be performed immediately or put to the state map to be performed later when second operand is received. The result is returned to CalculatorPanel to be shown on the display

Parameters:

aValue - the value to perform operation on

anOperation - the operation key

aValueChanged - if true the value was changed in CalculatorPanel

See Also:

CalculatorOperation.isStandalone()

getResult

protected java.math.BigDecimal getResult()

Returns last caclulator's result sitting in the state map

Returns:

last caclulator's result sitting in the state map

getStateMapProperty

public java.lang.Object getStateMapProperty(java.lang.String aKey)

Returns state map property value specified by aKey

Parameters:

aKey - property key

Returns:

state map property value

setStateMapProperty

public void setStateMapProperty(java.lang.String aKey,
                                java.lang.Object aValue)

Sets a new state map property value

Parameters:

aKey - property key

aValue - property value

addOperation

public void addOperation(java.lang.String anOperationKey,
                         CalculatorOperation anOperation)

Adds a new operation to the calculator. If anOperationKey already exist IllegalArgumentException will be thrown

Parameters:

anOperationKey - operation key

anOperation - operation

Throws:

java.lang.IllegalArgumentException

updateOperation

public void updateOperation(java.lang.String anOperationKey,
                            CalculatorOperation anOperation)

Updates an existing operation in the calculator. If anOperationKey doesn't exist IllegalArgumentException will be thrown

Parameters:

anOperationKey - operation key

anOperation - operation

Throws:

java.lang.IllegalArgumentException

removeOperation

public void removeOperation(java.lang.String anOperationKey)

Removes the operation, specified by anOperationKey, from the calculator

Parameters:

anOperationKey - operation key

isOperationExist

public boolean isOperationExist(java.lang.String anOperationKey)

Returns true if operation, specified by anOperationKey, exist

Parameters:

anOperationKey - operation key

Returns:

true if operation exist

getDefaultClearOperation

public CalculatorOperation getDefaultClearOperation()

Returns default clear operation. Default clear operation is used by the calculator to clear its state map when an error happend during operation performance

Returns:

default clear operation

setDefaultClearOperation

public void setDefaultClearOperation(CalculatorOperation aDefaultClearOperation)

Sets default clear operation. Default clear operation is used by the calculator to clear its state map when an error happend during operation performance

Parameters:

aDefaultClearOperation - default clear operation

fireResultChanged

protected void fireResultChanged()

Fired by the calculator when the result is changed

firePropertyChange

protected void firePropertyChange(java.beans.PropertyChangeEvent anEvent)

Fired by the calculator when state map property is changed

Parameters:

anEvent - property change event

addCalculatorListener

public void addCalculatorListener(CalculatorListener aListener)

Adds Calculator's listener

Parameters:

aListener - Calculator's listener

removeCalculatorListener

public void removeCalculatorListener(CalculatorListener aListener)

Removes Calculator's listener

Parameters:

aListener - Calculator's listener

addPropertyChangeListener

public void addPropertyChangeListener(java.beans.PropertyChangeListener aListener)

Adds state map property change listener

Parameters:

aListener - state map property change listener

removePropertyChangeListener

public void removePropertyChangeListener(java.beans.PropertyChangeListener aListener)

Removes state map property change listener

Parameters:

aListener - state map property change listener