org.gvsig.fmap.mapcontext

Class ExtentHistory

java.lang.Object

org.gvsig.fmap.mapcontext.ExtentHistory

All Implemented Interfaces:

Persistent

public class ExtentHistory
extends Object
implements Persistent

ExtentHistory is designed for managing a history of extents.

Note: An extent is a rectangular area, with information of its top-left 2D corner.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ExtentHistory.RegisterPersistence

Constructor Summary

Constructors

Constructor and Description
ExtentHistory() Creates a new instance of ExtentsHistory with an history of 10 extents.
ExtentHistory(int numEntries) Creates a new instance of ExtentsHistory with an history of numEntries extents.

Method Summary

Modifier and Type	Method and Description
Rectangle2D	getCurrent() Returns the current extent.
Rectangle2D	getNext() Returns the last next extent from the history.
Rectangle2D	getPrev() Returns the last previous extent from the history.
boolean	hasNext() Returns true if there are next extents registered.
boolean	hasPrevious() Returns true if there are previous extents registered.
void	loadFromState(PersistentState state) Set the state of the object from the state passed as parameter.
void	put(Rectangle2D ext) Appends the specified extent at the end of the array of previous zooms.
void	saveToState(PersistentState state) Returns information of this object.
Rectangle2D	setNextExtent() Adds the current extent to the previous extent history and sets the last next extent as the new current extent.
Rectangle2D	setPreviousExtent() Adds the current extent to the next extent history and sets the last previous extent as the new current extent.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExtentHistory

public ExtentHistory()

Creates a new instance of ExtentsHistory with an history of 10 extents.

ExtentHistory

public ExtentHistory(int numEntries)

Creates a new instance of ExtentsHistory with an history of numEntries extents.

Parameters:

numEntries - the maximum number of extents that will store the instance

Method Detail

put

public void put(Rectangle2D ext)

Appends the specified extent at the end of the array of previous zooms.

Parameters:

ext - the new extent

hasPrevious

public boolean hasPrevious()

Returns true if there are previous extents registered.

Returns:

true if there are previous extents registered; false otherwise

hasNext

public boolean hasNext()

Returns true if there are next extents registered.

Returns:

true if there are next extents registered; false otherwise

getPrev

public Rectangle2D getPrev()

Returns the last previous extent from the history.

Returns:

the last previous extent from the history

getNext

public Rectangle2D getNext()

Returns the last next extent from the history.

Returns:

the last next extent from the history

setPreviousExtent

public Rectangle2D setPreviousExtent()

Adds the current extent to the next extent history and sets the last previous extent as the new current extent.

Returns:

the last previous extent as the new current extent

setNextExtent

public Rectangle2D setNextExtent()

Adds the current extent to the previous extent history and sets the last next extent as the new current extent.

Returns:

the last next extent as the new current extent

getCurrent

public Rectangle2D getCurrent()

Returns the current extent.

Returns:

the current extent

loadFromState

public void loadFromState(PersistentState state)
                   throws PersistenceException

Description copied from interface: Persistent

Set the state of the object from the state passed as parameter.

Specified by:

loadFromState in interface Persistent

Throws:

PersistenceException

saveToState

public void saveToState(PersistentState state)
                 throws PersistenceException

Returns information of this object. All information is stored as properties:

Properties:

• className: name of this class.
• num: number of extents registered.
• numrec: maximum number of extents that can register.
• extents: .

Specified by:

saveToState in interface Persistent

Throws:

PersistenceException