com.ppetrie.paintfx.events

Class PastHandler

java.lang.Object

com.ppetrie.paintfx.events.PastHandler

public class PastHandler
extends java.lang.Object

Field Summary

Fields

Modifier and Type	Field and Description
private FixedStack<javafx.scene.image.Image>	future The stack containing future images for redo
private static int	NUM_STEPS The number of steps forward/backward which will be saved
private Paint	paint The main class of the program
private FixedStack<javafx.scene.image.Image>	past The stack containing past images for undo

Constructor Summary

Constructors

Constructor and Description
PastHandler(Paint paint) Create a PastHandler

Method Summary

Modifier and Type	Method and Description
void	addImage(javafx.scene.image.Image image) Adds a new image to the past
boolean	canRedo() Checks whether a redo can be performed
boolean	canUndo() Checks whether an undo can be performed
boolean	hasBeenChanged() Returns whether the current image has been changed
javafx.scene.image.Image	redo() Get the image after redoing
void	reset(javafx.scene.image.Image image) Reset the past handler, such as when a new image is loaded
javafx.scene.image.Image	undo() Gets the image after undoing
private void	updateButtons() Update the state of the undo and redo buttons

Methods inherited from class java.lang.Object

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

Field Detail

paint

private Paint paint

The main class of the program

NUM_STEPS

private static final int NUM_STEPS

The number of steps forward/backward which will be saved

See Also:

Constant Field Values

past

private FixedStack<javafx.scene.image.Image> past

The stack containing past images for undo

future

private FixedStack<javafx.scene.image.Image> future

The stack containing future images for redo

Constructor Detail

PastHandler

public PastHandler(Paint paint)

Create a PastHandler

Parameters:

paint - the main class of the program

Method Detail

addImage

public void addImage(javafx.scene.image.Image image)

Adds a new image to the past

Parameters:

image - the new image

undo

public javafx.scene.image.Image undo()

Gets the image after undoing

Returns:

the image after undoing

canUndo

public boolean canUndo()

Checks whether an undo can be performed

Returns:

true if an undo can be performed, false otherwise

redo

public javafx.scene.image.Image redo()

Get the image after redoing

Returns:

the image after redoing

canRedo

public boolean canRedo()

Checks whether a redo can be performed

Returns:

true if a redo can be performed, false otherwise

reset

public void reset(javafx.scene.image.Image image)

Reset the past handler, such as when a new image is loaded

Parameters:

image - the starting image

updateButtons

private void updateButtons()

Update the state of the undo and redo buttons

hasBeenChanged

public boolean hasBeenChanged()

Returns whether the current image has been changed

Returns:

true if the image has been changed, false otherwise