hu.webarticum.chm

Class ComplexHistory

java.lang.Object

hu.webarticum.chm.ComplexHistory

All Implemented Interfaces:

History, java.lang.Iterable<Command>

public class ComplexHistory
extends java.lang.Object
implements History

Advanced history implementation. Supports tracking of dead history branches.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	ComplexHistory.CommandNode Represents a node in the history tree

Nested classes/interfaces inherited from interface hu.webarticum.chm.History

History.Listener

Constructor Summary

Constructors

Constructor and Description
ComplexHistory()
ComplexHistory(int capacity)
ComplexHistory(int capacity, boolean gcOnInsert)

Method Summary

Modifier and Type	Method and Description
boolean	addAndExecute(Command command) Appends the given command after the last executed one and execute it.
void	addListener(History.Listener listener) Appends a new listener to this history.
boolean	contains(Command command) Returns true if this list contains the specified element.
boolean	executeNext() Executes the next (most recently rolled back) command.
void	gc() Runs a clean on this history.
Command	getNext() Returns the next (most recently rolled back) command.
Command	getPrevious() Returns the previous (most recently executed) command.
ComplexHistory.CommandNode	getPreviousCommandNode() Returns node of the most recently executed command.
ComplexHistory.CommandNode	getRootCommandNode() Returns the absolute root node of this history.
boolean	hasNext() Returns true if there is a next (most recently rolled back) command.
boolean	hasPrevious() Returns true if there is a previous (most recently executed) command.
boolean	isEmpty() Returns true if this history contains no commands.
java.util.Iterator<Command>	iterator() Returns an iterator which iterates through the last executed path's commands.
boolean	moveAfter(Command command) Moves the internal pointer after the given command.
boolean	moveBefore(Command command) Moves the internal pointer before the given command.
boolean	removeListener(History.Listener listener) Removes a listener from this history.
boolean	rollBackPrevious() Rolls back the previous (most recently executed) command.
void	setCapacity(int capacity) Changes the capacity of this history.
void	setCapacity(int capacity, boolean forceGc) Changes the capacity of this history.
void	setGcOnInsert(boolean gcOnInsert) Changes the value of gcOnInsert.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

ComplexHistory

public ComplexHistory()

ComplexHistory

public ComplexHistory(int capacity)

Parameters:

capacity - maximum number of commands in this history

ComplexHistory

public ComplexHistory(int capacity,
                      boolean gcOnInsert)

Parameters:

capacity - maximum number of commands in this history

gcOnInsert - if true then a clean will be run after every insert

Method Detail

iterator

public java.util.Iterator<Command> iterator()

Description copied from interface: History

Returns an iterator which iterates through the last executed path's commands.

Specified by:

iterator in interface History

Specified by:

iterator in interface java.lang.Iterable<Command>

Returns:

an iterator which iterates through the last executed path's commands

getRootCommandNode

public ComplexHistory.CommandNode getRootCommandNode()

Returns the absolute root node of this history. All stored nodes are descendants of this node.

Returns:

the root node object

getPreviousCommandNode

public ComplexHistory.CommandNode getPreviousCommandNode()

Returns node of the most recently executed command.

Returns:

node of the most recently executed command

isEmpty

public boolean isEmpty()

Description copied from interface: History

Returns true if this history contains no commands.

Specified by:

isEmpty in interface History

Returns:

true if this history contains no commands

contains

public boolean contains(Command command)

Description copied from interface: History

Returns true if this list contains the specified element.

Specified by:

contains in interface History

Parameters:

command - the command whose presence in this list is to be tested

Returns:

true if this history contains the specified command

addAndExecute

public boolean addAndExecute(Command command)

Description copied from interface: History

Appends the given command after the last executed one and execute it.

Specified by:

addAndExecute in interface History

Returns:

true if the command successfully executed and inserted

hasNext

public boolean hasNext()

Description copied from interface: History

Returns true if there is a next (most recently rolled back) command.

Specified by:

hasNext in interface History

Returns:

true if there is a next command

getNext

public Command getNext()

Description copied from interface: History

Returns the next (most recently rolled back) command.

Specified by:

getNext in interface History

Returns:

the next command if any or null

executeNext

public boolean executeNext()

Description copied from interface: History

Executes the next (most recently rolled back) command.

Specified by:

executeNext in interface History

Returns:

true if a next command is successfully executed

hasPrevious

public boolean hasPrevious()

Description copied from interface: History

Returns true if there is a previous (most recently executed) command.

Specified by:

hasPrevious in interface History

Returns:

true if there is a previous command

getPrevious

public Command getPrevious()

Description copied from interface: History

Returns the previous (most recently executed) command.

Specified by:

getPrevious in interface History

Returns:

the previous command if any or null

rollBackPrevious

public boolean rollBackPrevious()

Description copied from interface: History

Rolls back the previous (most recently executed) command.

Specified by:

rollBackPrevious in interface History

Returns:

true if a previous command is successfully rolled back

moveBefore

public boolean moveBefore(Command command)

Description copied from interface: History

Moves the internal pointer before the given command. Commands in the shortest route between current and given command will be executed or rolled back.

Specified by:

moveBefore in interface History

Returns:

true if the command found and pointer successfully moved

moveAfter

public boolean moveAfter(Command command)

Description copied from interface: History

Moves the internal pointer after the given command. Commands in the shortest route between current and given command will be executed or rolled back.

Specified by:

moveAfter in interface History

Returns:

true if the command found and pointer successfully moved

addListener

public void addListener(History.Listener listener)

Description copied from interface: History

Appends a new listener to this history.

Specified by:

addListener in interface History

Parameters:

listener - the new listener

removeListener

public boolean removeListener(History.Listener listener)

Description copied from interface: History

Removes a listener from this history.

Specified by:

removeListener in interface History

Returns:

true if the listener found and removed

setCapacity

public void setCapacity(int capacity)

Changes the capacity of this history. If the given capacity is less then the current size, and if gcOnInsert was set to true, then a clean will be run immediately.

Parameters:

capacity -

setCapacity

public void setCapacity(int capacity,
                        boolean forceGc)

Changes the capacity of this history. If the given capacity is less then the current size, and forceGc is true, then a clean will be run immediately regardless of the set value of gcOnInsert.

Parameters:

capacity - the new capacity

forceGc - if true then a clean can be run immediately

setGcOnInsert

public void setGcOnInsert(boolean gcOnInsert)

Changes the value of gcOnInsert. If gcOnInsert is true, then overall size of this history will be keeping strictly under capacity.

Parameters:

gcOnInsert - new value of gcOnInsert

gc

public void gc()

Runs a clean on this history. Removes all the commands outside the capacity. Intelligently picks the most abandoned commands for deletion.