cz.auderis.tools.change

Class BasicChangeTracker

java.lang.Object

cz.auderis.tools.change.BasicChangeTracker

All Implemented Interfaces:

ChangeTracker

public class BasicChangeTracker
extends Object
implements ChangeTracker

Basic implementation of change tracking mechanism that provides implicit change recording.

Explicit change recording (i.e. using markChange()) works as intended. A new mode, implicit change recording, works as follows:

• TR is an instance of BasicChangeTracker.
• There is a property Prop in object A and XXX is its type.
• NV is a new value for that property.
• The idiom is A.setProp(TR.updateXXX(A.getProp(), NV)

The updateXXX group of methods determine whether the new value is different from the old value. If there is a difference, the change is recorded. In any case, the new value is returned and may be fed into an appropriate property setter.

Version:

1.0

Author:

Boleslav Bobcik <bbobcik@gmail.com>

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BasicChangeTracker(boolean enablePropertyGathering) Instantiates a new change tracker with optional recording of changed properties.

Method Summary

Modifier and Type	Method and Description
static BasicChangeTracker	gatheringPropertyNames() Creates a new instance of change tracker that records names of changed properties.
int	getChangeCount() Determines number of detected changes
Set<String>	getChangedProperties() Returns a set of changed property names.
boolean	isChanged() Determines whether any change has happened so far.
void	markChange() Marks a change without specific binding to a named property.
void	markChange(String propertyName) Marks a change in a named property.
void	resetChanges() Reset the tracker to initial state, where there are no changes recorded.
static BasicChangeTracker	simple() Creates a new instance of change tracked that does not record names of changed properties.
boolean	updateBoolean(boolean origValue, boolean newValue) Equivalent of updateBoolean(origValue, newValue, null).
boolean	updateBoolean(boolean origValue, boolean newValue, String propertyName) Implicitly records a change of the given property if the provided original and new values are different.
byte	updateByte(byte origValue, byte newValue) Equivalent of updateByte(origValue, newValue, null).
byte	updateByte(byte origValue, byte newValue, String propertyName) Implicitly records a change of the given property if the provided original and new values are different.
int	updateInt(int origValue, int newValue) Equivalent of updateInt(origValue, newValue, null).
int	updateInt(int origValue, int newValue, String propertyName) Implicitly records a change of the given property if the provided original and new values are different.
long	updateLong(long origValue, long newValue) Equivalent of updateLong(origValue, newValue, null).
long	updateLong(long origValue, long newValue, String propertyName) Implicitly records a change of the given property if the provided original and new values are different.
<T> T	updateObject(T origValue, T newValue) Equivalent of updateObject(origValue, newValue, null).
<T> T	updateObject(T origValue, T newValue, String propertyName) Implicitly records a change of the given property if the provided original and new values are different.
short	updateShort(short origValue, short newValue) Equivalent of updateShort(origValue, newValue, null).
short	updateShort(short origValue, short newValue, String propertyName) Implicitly records a change of the given property if the provided original and new values are different.
String	updateString(String origValue, String newValue) Equivalent of updateString(origValue, newValue, null).
String	updateString(String origValue, String newValue, String propertyName) Implicitly records a change of the given property if the provided original and new values are different.

Methods inherited from class java.lang.Object

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

Constructor Detail

BasicChangeTracker

protected BasicChangeTracker(boolean enablePropertyGathering)

Instantiates a new change tracker with optional recording of changed properties.

Parameters:

enablePropertyGathering - enables recording of changed property names

Method Detail

simple

public static BasicChangeTracker simple()

Creates a new instance of change tracked that does not record names of changed properties.

Returns:

new change tracker instance

gatheringPropertyNames

public static BasicChangeTracker gatheringPropertyNames()

Creates a new instance of change tracker that records names of changed properties.

Returns:

new change tracker instance

resetChanges

public void resetChanges()

Description copied from interface: ChangeTracker

Reset the tracker to initial state, where there are no changes recorded.

Specified by:

resetChanges in interface ChangeTracker

isChanged

public boolean isChanged()

Description copied from interface: ChangeTracker

Determines whether any change has happened so far.

Specified by:

isChanged in interface ChangeTracker

Returns:

true if a change was recorded

getChangeCount

public int getChangeCount()

Description copied from interface: ChangeTracker

Determines number of detected changes

Specified by:

getChangeCount in interface ChangeTracker

Returns:

number of detected changes

getChangedProperties

public Set<String> getChangedProperties()

Description copied from interface: ChangeTracker

Returns a set of changed property names.

Specified by:

getChangedProperties in interface ChangeTracker

Returns:

set of changed property names

markChange

public void markChange()

Description copied from interface: ChangeTracker

Marks a change without specific binding to a named property.

Specified by:

markChange in interface ChangeTracker

markChange

public void markChange(String propertyName)

Description copied from interface: ChangeTracker

Marks a change in a named property.

Specified by:

markChange in interface ChangeTracker

Parameters:

propertyName - name of changed property

updateInt

public int updateInt(int origValue,
                     int newValue)

Equivalent of updateInt(origValue, newValue, null).

Parameters:

origValue - original value of some property

newValue - new value for the property

Returns:

new value for the property

updateInt

public int updateInt(int origValue,
                     int newValue,
                     String propertyName)

Implicitly records a change of the given property if the provided original and new values are different.

Parameters:

origValue - original value of property with name specified by propertyName

newValue - new value for the property

propertyName - name of the manipulated property

Returns:

new value for the property

updateShort

public short updateShort(short origValue,
                         short newValue)

Equivalent of updateShort(origValue, newValue, null).

Parameters:

origValue - original value of some property

newValue - new value for the property

Returns:

new value for the property

updateShort

public short updateShort(short origValue,
                         short newValue,
                         String propertyName)

Implicitly records a change of the given property if the provided original and new values are different.

Parameters:

origValue - original value of property with name specified by propertyName

newValue - new value for the property

propertyName - name of the manipulated property

Returns:

new value for the property

updateLong

public long updateLong(long origValue,
                       long newValue)

Equivalent of updateLong(origValue, newValue, null).

Parameters:

origValue - original value of some property

newValue - new value for the property

Returns:

new value for the property

updateLong

public long updateLong(long origValue,
                       long newValue,
                       String propertyName)

Implicitly records a change of the given property if the provided original and new values are different.

Parameters:

origValue - original value of property with name specified by propertyName

newValue - new value for the property

propertyName - name of the manipulated property

Returns:

new value for the property

updateByte

public byte updateByte(byte origValue,
                       byte newValue)

Equivalent of updateByte(origValue, newValue, null).

Parameters:

origValue - original value of some property

newValue - new value for the property

Returns:

new value for the property

updateByte

public byte updateByte(byte origValue,
                       byte newValue,
                       String propertyName)

Implicitly records a change of the given property if the provided original and new values are different.

Parameters:

origValue - original value of property with name specified by propertyName

newValue - new value for the property

propertyName - name of the manipulated property

Returns:

new value for the property

updateBoolean

public boolean updateBoolean(boolean origValue,
                             boolean newValue)

Equivalent of updateBoolean(origValue, newValue, null).

Parameters:

origValue - original value of some property

newValue - new value for the property

Returns:

new value for the property

updateBoolean

public boolean updateBoolean(boolean origValue,
                             boolean newValue,
                             String propertyName)

Implicitly records a change of the given property if the provided original and new values are different.

Parameters:

origValue - original value of property with name specified by propertyName

newValue - new value for the property

propertyName - name of the manipulated property

Returns:

new value for the property

updateString

public String updateString(String origValue,
                           String newValue)

Equivalent of updateString(origValue, newValue, null).

Parameters:

origValue - original value of some property

newValue - new value for the property

Returns:

new value for the property

updateString

public String updateString(String origValue,
                           String newValue,
                           String propertyName)

Implicitly records a change of the given property if the provided original and new values are different.

Parameters:

origValue - original value of property with name specified by propertyName

newValue - new value for the property

propertyName - name of the manipulated property

Returns:

new value for the property

updateObject

public <T> T updateObject(T origValue,
                          T newValue)

Equivalent of updateObject(origValue, newValue, null).

Parameters:

origValue - original value of some property

newValue - new value for the property

Returns:

new value for the property

updateObject

public <T> T updateObject(T origValue,
                          T newValue,
                          String propertyName)

Implicitly records a change of the given property if the provided original and new values are different.

Type Parameters:

T - type of the manipulated property

Parameters:

origValue - original value of property with name specified by propertyName

newValue - new value for the property

propertyName - name of the manipulated property

Returns:

new value for the property