edu.umd.cs.jazz.event
Class ZoomEventHandler

java.lang.Object
  |
  +--edu.umd.cs.jazz.event.ZoomEventHandler

All Implemented Interfaces:

java.util.EventListener, java.io.Serializable, ZEventHandler, ZMouseListener, ZMouseMotionListener

public class ZoomEventHandler

extends java.lang.Object

implements ZEventHandler, ZMouseListener, ZMouseMotionListener, java.io.Serializable

ZoomEventhandler provides event handlers for basic zooming of a Jazz camera with the right button. The interaction is that the initial mouse press defines the zoom anchor point, and then moving the mouse to the right zooms with a speed proportional to the amount the mouse is moved to the right of the anchor point. Similarly, if the mouse is moved to the left, the the camera is zoomed out.

This event handler will properly pan within internal cameras if the clicked within an internal camera.

Warning: Serialized and ZSerialized objects of this class will not be compatible with future Jazz releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Jazz. A future release of Jazz will provide support for long term persistence.

Author:

Benjamin B. Bederson

See Also:

Serialized Form

Inner Class Summary

protected class

ZoomEventHandler.ZoomEventState Provides indirect access this event handlers private state.

Constructor Summary

ZoomEventHandler(ZNode node)
Constructs a new ZoomEventHandler.

ZoomEventHandler(ZNode node, ZCamera camera)
Constructs a new ZoomEventHandler.

Method Summary

protected java.awt.geom.AffineTransform	generateNextViewTransform(ZoomEventHandler.ZoomEventState state) Return the next view transform for the interaction cameras zooming sequence.
boolean	isActive() Determines if this event handler is active.
void	mouseClicked(ZMouseEvent e) Invoked when the mouse has been clicked on a component.
void	mouseDragged(ZMouseEvent e) Mouse drag event handler
void	mouseEntered(ZMouseEvent e) Invoked when the mouse enters a component.
void	mouseExited(ZMouseEvent e) Invoked when the mouse exits a component.
void	mouseMoved(ZMouseEvent e) Invoked when the mouse button has been moved on a node (with no buttons no down).
void	mousePressed(ZMouseEvent e) Mouse press event handler
void	mouseReleased(ZMouseEvent e) Mouse release event handler
void	setActive(boolean active) Specifies whether this event handler is active or not.
void	setMaxMagnification(double newMaxMag) Set the maximum magnification that the camera can be set to with this event handler.
void	setMinMagnification(double newMinMag) Set the minimum magnification that the camera can be set to with this event handler.
void	startZooming() Start animated zooming.
void	stopZooming() Stop animated zooming.
void	zoomOneStep() Do one zooming step, sleep a short amount, and schedule the next zooming step.

Methods inherited from class java.lang.Object

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

Constructor Detail

ZoomEventHandler

public ZoomEventHandler(ZNode node)

Constructs a new ZoomEventHandler.

Parameters:

node - The node this event handler attaches to.

ZoomEventHandler

public ZoomEventHandler(ZNode node,
                        ZCamera camera)

Constructs a new ZoomEventHandler.

Parameters:

node - The node this event handler attaches to.

camera - The camera to which this event handler attaches

Method Detail

setActive

public void setActive(boolean active)

Specifies whether this event handler is active or not.

Specified by:

setActive in interface ZEventHandler

Parameters:

active - True to make this event handler active

isActive

public boolean isActive()

Determines if this event handler is active.

Specified by:

isActive in interface ZEventHandler

Returns:

True if active

mousePressed

public void mousePressed(ZMouseEvent e)

Mouse press event handler

Specified by:

mousePressed in interface ZMouseListener

Parameters:

e - The event.

mouseDragged

public void mouseDragged(ZMouseEvent e)

Mouse drag event handler

Specified by:

mouseDragged in interface ZMouseMotionListener

Parameters:

e - The event.

mouseReleased

public void mouseReleased(ZMouseEvent e)

Mouse release event handler

Specified by:

mouseReleased in interface ZMouseListener

Parameters:

e - The event.

mouseEntered

public void mouseEntered(ZMouseEvent e)

Invoked when the mouse enters a component.

Specified by:

mouseEntered in interface ZMouseListener

mouseExited

public void mouseExited(ZMouseEvent e)

Invoked when the mouse exits a component.

Specified by:

mouseExited in interface ZMouseListener

mouseClicked

public void mouseClicked(ZMouseEvent e)

Invoked when the mouse has been clicked on a component.

Specified by:

mouseClicked in interface ZMouseListener

mouseMoved

public void mouseMoved(ZMouseEvent e)

Invoked when the mouse button has been moved on a node (with no buttons no down).

Specified by:

mouseMoved in interface ZMouseMotionListener

startZooming

public void startZooming()

Start animated zooming.

setMinMagnification

public void setMinMagnification(double newMinMag)

Set the minimum magnification that the camera can be set to with this event handler. Setting the min mag to <= 0 disables this feature. If the min mag if set to a value which is greater than the current camera magnification, then the camera is left at its current magnification.

Parameters:

newMinMag - the new minimum magnification

setMaxMagnification

public void setMaxMagnification(double newMaxMag)

Set the maximum magnification that the camera can be set to with this event handler. Setting the max mag to <= 0 disables this feature. If the max mag if set to a value which is less than the current camera magnification, then the camera is left at its current magnification.

Parameters:

newMaxMag - the new maximum magnification

stopZooming

public void stopZooming()

Stop animated zooming.

zoomOneStep

public void zoomOneStep()

Do one zooming step, sleep a short amount, and schedule the next zooming step. This effectively continuously zooms while still accepting input events so that the zoom center point can be changed, and zooming can be stopped.

generateNextViewTransform

protected java.awt.geom.AffineTransform generateNextViewTransform(ZoomEventHandler.ZoomEventState state)

Return the next view transform for the interaction cameras zooming sequence.

Parameters:

state - provides access to the current state of the event handler. ZoomEventState is declared as a protected inner class in ZoomEventHandler.