net.mumie.mathletfactory.action.handler.global.g2d

Class GlobalMouseWheelZoomHandler

java.lang.Object

net.mumie.mathletfactory.action.handler.global.GlobalHandler

net.mumie.mathletfactory.action.handler.global.Global2DHandler

net.mumie.mathletfactory.action.handler.global.g2d.GlobalMouseWheelZoomHandler

public class GlobalMouseWheelZoomHandler
extends Global2DHandler

This handler allows the user to zoom in and out of the canvas by scrolling with the mouse wheel.

Author:

Gronau

Document status:

finished

Field Summary

Fields inherited from class net.mumie.mathletfactory.action.handler.global.GlobalHandler

m_active, m_canvas

Constructor Summary

Constructors

Constructor and Description
GlobalMouseWheelZoomHandler(MM2DCanvas aCanvas) Constructs the handler to work in the given canvas.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	doAction(MMEvent event) Processes the incoming MMEvent by executing the user defined actions, if this GlobalHandler can work with it (see dealsWith ).
void	finish() This method is called, when an action finishes (a mouse button is released after dragging or klicking, a previously pressed key is released, etc.).
protected boolean	userDefinedDealsWith(MMEvent event) Returns whether this instance is able to work with the given MMEvent.

Methods inherited from class net.mumie.mathletfactory.action.handler.global.Global2DHandler

getCanvas2D

Methods inherited from class net.mumie.mathletfactory.action.handler.global.GlobalHandler

dealsWith, getCanvas, isActive, setActive

Methods inherited from class java.lang.Object

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

Constructor Detail

GlobalMouseWheelZoomHandler

public GlobalMouseWheelZoomHandler(MM2DCanvas aCanvas)

Constructs the handler to work in the given canvas.

Method Detail

userDefinedDealsWith

protected boolean userDefinedDealsWith(MMEvent event)

Description copied from class: GlobalHandler

Returns whether this instance is able to work with the given MMEvent.

This method will typically be called from within the controlAction(MMEvent) method of a CanvasControllerIF (e.g. DefaultCanvasController), to check if this instance can be invoked by calling this GlobalHandler's doAction method with the given MMEvent.
Attention: This method will always return false if GlobalHandler.isActive() returns false, i.e. if this GlobalHandler was deactivated.

Specified by:

userDefinedDealsWith in class GlobalHandler

doAction

public boolean doAction(MMEvent event)

Description copied from class: GlobalHandler

Processes the incoming MMEvent by executing the user defined actions, if this GlobalHandler can work with it (see dealsWith ).

Specified by:

doAction in class GlobalHandler

See Also:

GlobalHandler.dealsWith(net.mumie.mathletfactory.action.MMEvent), net.mumie.mathletfactory.action.DefaultCanvasController#controlAction()

finish

public void finish()

Description copied from class: GlobalHandler

This method is called, when an action finishes (a mouse button is released after dragging or klicking, a previously pressed key is released, etc.). This method must be called when an action cycle shall be properly terminated, typically it will be called within the finishAction method in CanvasControllerIF.

This method is dedicated to clean up internal settings in this GlobalHandler, so that it will be prepared for properly processing a new action cycle.

Specified by:

finish in class GlobalHandler