edu.umd.cs.jazz.event
Class ZoomEventHandler

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

All Implemented Interfaces:

ZEventHandler

public class ZoomEventHandler

extends ZDragSequenceEventHandler

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.

Author:

Benjamin B. Bederson, Jesse Grosjean

Inner classes inherited from class edu.umd.cs.jazz.event.ZFilteredEventHandler

ZFilteredEventHandler.ZFilteredEventDispatcher

Fields inherited from class edu.umd.cs.jazz.event.ZFilteredEventHandler

fFilteredEventDispatcher, fMouseFilter

Constructor Summary

ZoomEventHandler(ZSceneGraphObject aFilteredMouseEventSource)
Constructs a new ZoomEventHandler.

Method Summary

protected void	endDrag(ZMouseEvent e) When the dragging action ends invoke stopZooming.
protected java.awt.geom.AffineTransform	generateNextViewTransform() Return the next view transform for the current cameras zooming sequence.
double	getMaxMagnification() Return the max magnification that the zooming action is bound by.
double	getMinMagnification() Return the min magnification that the zooming action is bound by.
ZMouseFilter	getMouseFilter() Return the current event filter.
protected boolean	isZooming() Return if is zooming.
protected void	isZooming(boolean aBoolean) Set if is zooming.
void	setMaxMagnification(double aMagnification) Set the maximum magnification that the camera can be set to with this event handler.
void	setMinMagnification(double aMagnification) Set the minimum magnification that the camera can be set to with this event handler.
protected void	startDrag(ZMouseEvent e) When the dragging action starts invoke startZooming.
protected void	startZooming(ZMouseEvent e) Start zooming around the given mouse point with the interaction camera.
protected void	stopZooming(ZMouseEvent e) Stop animated zooming.
protected void	zoomOneStep() Do one zooming step, sleep a short amount, and schedule the next zooming step.

Methods inherited from class edu.umd.cs.jazz.event.ZDragSequenceEventHandler

drag, dragInScreenCoords, filteredMouseDragged, filteredMousePressed, filteredMouseReleased, getCurrentScreenDelta, getCurrentScreenPoint, getDragStartScreenPoint, getMinDragStartDistance, getMousePressedScreenPoint, getPreviousScreenPoint, isDragging, setIsDragging, setMinDragStartDistance, shouldStartDragInteraction

Methods inherited from class edu.umd.cs.jazz.event.ZFilteredEventHandler

filteredKeyPressed, filteredKeyReleased, filteredKeyTyped, filteredMouseClicked, filteredMouseEntered, filteredMouseExited, filteredMouseMoved, getCurrentFilteredMouseEvent, getCurrentSelection, getFilteredEventDispatcher, getFilteredKeyEventSource, getFilteredMouseEventSource, getInteractionCamera, getTopCamera, isActive, setActive, setFilteredKeyEventSource, setFilteredMouseEventSource, setMouseFilter, wantsKeyEvents, wantsMouseEvents, wantsMouseMotionEvents

Methods inherited from class java.lang.Object

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

Constructor Detail

ZoomEventHandler

public ZoomEventHandler(ZSceneGraphObject aFilteredMouseEventSource)

Constructs a new ZoomEventHandler.

Parameters:

aFilteredMouseEventSource - the source for filtered ZMouseEvents and ZMouseMotionEvents. See the ZFilteredEventHandler class comment to customize this behavior.

Method Detail

getMouseFilter

public ZMouseFilter getMouseFilter()

Return the current event filter. If no filter is specified then return a filter that only accepts BUTTON3 by default.

Overrides:

getMouseFilter in class ZFilteredEventHandler

Returns:

the filter that is currently in effect.

getMinMagnification

public double getMinMagnification()

Return the min magnification that the zooming action is bound by. The default value is 0.

Returns:

the min camera magnification.

setMinMagnification

public void setMinMagnification(double aMagnification)

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 is 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

getMaxMagnification

public double getMaxMagnification()

Return the max magnification that the zooming action is bound by. If the value is <= 0 then this feature is disabled. The default value is -1.

Returns:

the max camera magnification.

setMaxMagnification

public void setMaxMagnification(double aMagnification)

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

startDrag

protected void startDrag(ZMouseEvent e)

When the dragging action starts invoke startZooming.

Overrides:

startDrag in class ZDragSequenceEventHandler

Parameters:

the - event starting the drag.

endDrag

protected void endDrag(ZMouseEvent e)

When the dragging action ends invoke stopZooming.

Overrides:

endDrag in class ZDragSequenceEventHandler

Parameters:

the - event ending the drag.

startZooming

protected void startZooming(ZMouseEvent e)

Start zooming around the given mouse point with the interaction camera.

Parameters:

the - event starting the zoom.

zoomOneStep

protected 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.

stopZooming

protected void stopZooming(ZMouseEvent e)

Stop animated zooming.

Parameters:

the - event stopping the zoom.

isZooming

protected boolean isZooming()

Return if is zooming.

Returns:

true if new zoom steps are currently being scheduled.

isZooming

protected void isZooming(boolean aBoolean)

Set if is zooming.

generateNextViewTransform

protected java.awt.geom.AffineTransform generateNextViewTransform()

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

Returns:

the next view transform for the zooming camera.