net.mumie.mathletfactory.action

Class DefaultCanvasController

java.lang.Object

net.mumie.mathletfactory.action.DefaultCanvasController

All Implemented Interfaces:

java.awt.event.KeyListener, java.awt.event.MouseListener, java.awt.event.MouseMotionListener, java.awt.event.MouseWheelListener, java.lang.Cloneable, java.util.EventListener, CanvasControllerIF

public class DefaultCanvasController
extends java.lang.Object
implements CanvasControllerIF

This class implements the functionality for translating Java AWT-events to mumie MMEvents. It does so by implementing the Java Mouse[Motion]Listener, KeyListener and ComponentListener (bundled together in CanvasControllerIF) and making them call controlAction(), which walks through the potential targets (CanvasObjects or MMHandler) and calls for each MMObject.doAction() until the event reaches its target.
This class is always associated to exactly one MMCanvas, for which it catches and delegates the events.

Author:

vossbeck

Document status:

finished

Field Summary

Fields inherited from interface net.mumie.mathletfactory.action.CanvasControllerIF

SELECTION_RENDER_UPDATE_PAUSE

Constructor Summary

Constructors

Constructor and Description
DefaultCanvasController() Creates a new instance of a DefaultCanvasController without specifying the MMCanvas for which it shall work.
DefaultCanvasController(MMCanvas aCanvas) Creates a new instance of a DefaultCanvasController that explicitly shall work for the traversed aCanvas.

Method Summary

Methods

Modifier and Type	Method and Description
void	addPreSelectedObject(MMCanvasObjectIF object)
java.lang.Object	clone()
void	controlAction(MMEvent event) This is really the central method of any controller: It checks which handler (global or object related) must receive the event and calls the handler's doAction()-method The sequence of delivering the event is the following: deliver event to active object(with fitting handler), if there is any check for objects that are selected by a mousePressedEvent and store them.
protected boolean	distributeEvent(MMEvent event) called by controlAction(net.mumie.mathletfactory.action.MMEvent), walks through the list of preselected Objects and invokes [@link net.mumie.mathletfactory.mmobject.MMObjectIF#doAction doAction()} in them.
void	finishAction()
void	flashObject(MMCanvasObjectIF object) The flash methods should be used to attract interest by the user.
void	flashObjects(MMCanvasObjectIF[] objects)
void	flashObjects(MMCanvasObjectIF[] objects, long duration)
void	flashObjects(MMCanvasObjectIF[] objects, long duration, int flashNum)
MMCanvas	getCanvas() Returns the MMCanvas for which this DefaultCanvasController is dedicted to work.
int	getLastClickedX()
int	getLastClickedY()
int	getLastPressedX()
int	getLastPressedY()
MMCanvasObjectIF	getPreselectedObject(int index) Which Objects have been selected by the user?
int	getPreselectedObjectCount()
MMCanvasObjectIF	getSelectedObject()
MMCanvasObjectIF[]	getSelectedObjects()
boolean	isEnabled()
void	keyPressed(java.awt.event.KeyEvent ke) This method extracts the keycode and the modifier of the KeyEvent by using the methods getKeyCode() and getModifiers() from KeyEvent.
void	keyReleased(java.awt.event.KeyEvent ke)
void	keyTyped(java.awt.event.KeyEvent ke) This method has an empty implementation in the moment.
void	mouseClicked(java.awt.event.MouseEvent me) This method only will store the x,y position of the MouseEvent.
void	mouseDragged(java.awt.event.MouseEvent me) When a mouseMotionEvent occurs this method is invoked and will initialize the @see DefautlController's internal @see MMEvent and finally call the controller's @see controlAction(MMEvent event) method.
void	mouseEntered(java.awt.event.MouseEvent me) When the mouse enters the canvas, the component of the canvas that is used to draw onto will request for KeyEvents also.
void	mouseExited(java.awt.event.MouseEvent me) This method is an empty implementation in the moment.
void	mouseMoved(java.awt.event.MouseEvent me) This method has an empty implementation in the moment.
void	mousePressed(java.awt.event.MouseEvent me) When a mousePressend event occurs, this method is invoked and will initialize the DefaultCanvasController's internal MMEvent and finally call the controller's controlAction(net.mumie.mathletfactory.action.MMEvent) method.
void	mouseReleased(java.awt.event.MouseEvent me) When a mouseReleased event occurs the action process due to the current MMEvent will be finished.
void	mouseWheelMoved(java.awt.event.MouseWheelEvent mwe)
protected void	resetHandlerAndInternalData() Restores state variables (current key-code and modifiers) and calls MMHandler.finish().
void	setCanvas(MMCanvas aCanvas) Makes this MMCanvasControllerIF be the MouseListener, MouseMotionListener and KeyListener of the drawing board of aCanvas.
void	setEnabled(boolean aFlag)
void	setSelectedObject(MMCanvasObjectIF object) Sets the "focus" on the given CanvasObject, which results in a visual mark on the Canvas and a higher priority in the Queue of event-targets.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultCanvasController

public DefaultCanvasController()

Creates a new instance of a DefaultCanvasController without specifying the MMCanvas for which it shall work. This new instance can be used in the setController method of a MMCanvas.

DefaultCanvasController

public DefaultCanvasController(MMCanvas aCanvas)

Creates a new instance of a DefaultCanvasController that explicitly shall work for the traversed aCanvas.
Obsever however, that you still have to call the method setController of MMCanvas to register this DefaultCanvasController as the controller used by aCanvas.

See Also:

MMCanvas

Method Detail

setEnabled

public void setEnabled(boolean aFlag)

Specified by:

setEnabled in interface CanvasControllerIF

isEnabled

public boolean isEnabled()

Specified by:

isEnabled in interface CanvasControllerIF

setCanvas

public void setCanvas(MMCanvas aCanvas)

Description copied from interface: CanvasControllerIF

Makes this MMCanvasControllerIF be the MouseListener, MouseMotionListener and KeyListener of the drawing board of aCanvas.
Observe: Although this method has modifier public it is not really intended for public use. The call of this method should only occur from within the setController method from the MMCanvas.

Specified by:

setCanvas in interface CanvasControllerIF

See Also:

CanvasControllerIF.setCanvas(net.mumie.mathletfactory.display.MMCanvas)

Side effects:

the internal field for the MMCanvas will point to aCanvas after the method call.

getCanvas

public MMCanvas getCanvas()

Returns the MMCanvas for which this DefaultCanvasController is dedicted to work.

Specified by:

getCanvas in interface CanvasControllerIF

Returns:

See Also:

CanvasControllerIF.getCanvas()

getPreselectedObject

public MMCanvasObjectIF getPreselectedObject(int index)

Which Objects have been selected by the user?

getPreselectedObjectCount

public int getPreselectedObjectCount()

Specified by:

getPreselectedObjectCount in interface CanvasControllerIF

addPreSelectedObject

public void addPreSelectedObject(MMCanvasObjectIF object)

Specified by:

addPreSelectedObject in interface CanvasControllerIF

setSelectedObject

public void setSelectedObject(MMCanvasObjectIF object)

Sets the "focus" on the given CanvasObject, which results in a visual mark on the Canvas and a higher priority in the Queue of event-targets.

Specified by:

setSelectedObject in interface CanvasControllerIF

getSelectedObject

public MMCanvasObjectIF getSelectedObject()

Specified by:

getSelectedObject in interface CanvasControllerIF

getSelectedObjects

public MMCanvasObjectIF[] getSelectedObjects()

flashObject

public void flashObject(MMCanvasObjectIF object)

Description copied from interface: CanvasControllerIF

The flash methods should be used to attract interest by the user. It is the Controllers job to find a appropriate method for it. Blinking could be a possibility.

An empty implementation could be used as a first step.

Specified by:

flashObject in interface CanvasControllerIF

flashObjects

public void flashObjects(MMCanvasObjectIF[] objects)

Specified by:

flashObjects in interface CanvasControllerIF

flashObjects

public void flashObjects(MMCanvasObjectIF[] objects,
                long duration)

Specified by:

flashObjects in interface CanvasControllerIF

flashObjects

public void flashObjects(MMCanvasObjectIF[] objects,
                long duration,
                int flashNum)

Specified by:

flashObjects in interface CanvasControllerIF

distributeEvent

protected boolean distributeEvent(MMEvent event)

called by controlAction(net.mumie.mathletfactory.action.MMEvent), walks through the list of preselected Objects and invokes [@link net.mumie.mathletfactory.mmobject.MMObjectIF#doAction doAction()} in them.

controlAction

public void controlAction(MMEvent event)

This is really the central method of any controller: It checks which handler (global or object related) must receive the event and calls the handler's doAction()-method The sequence of delivering the event is the following:

1. deliver event to active object(with fitting handler), if there is any
2. check for objects that are selected by a mousePressedEvent and store them.
3. deliver event to active global handler (if there is any)
4. check if there is any global handler that fits to the event
5. if the are stored selected objects, check for the first with a handler that can work with the event and mark (only) this as active object.

Specified by:

controlAction in interface CanvasControllerIF

finishAction

public void finishAction()

Specified by:

finishAction in interface CanvasControllerIF

resetHandlerAndInternalData

protected void resetHandlerAndInternalData()

Restores state variables (current key-code and modifiers) and calls MMHandler.finish().

getLastClickedX

public int getLastClickedX()

Specified by:

getLastClickedX in interface CanvasControllerIF

Returns:

the x position measured in pixel of the last mouseClicked event.

getLastClickedY

public int getLastClickedY()

Specified by:

getLastClickedY in interface CanvasControllerIF

Returns:

the y position measured in pixel of the last mouseClicked event.

getLastPressedX

public int getLastPressedX()

Specified by:

getLastPressedX in interface CanvasControllerIF

Returns:

the x position measured in pixel of the last mousePressed event.

getLastPressedY

public int getLastPressedY()

Specified by:

getLastPressedY in interface CanvasControllerIF

Returns:

the y position measured in pixel of the last mousePressed event.

mouseClicked

public void mouseClicked(java.awt.event.MouseEvent me)

This method only will store the x,y position of the MouseEvent.

Specified by:

mouseClicked in interface java.awt.event.MouseListener

mouseEntered

public void mouseEntered(java.awt.event.MouseEvent me)

When the mouse enters the canvas, the component of the canvas that is used to draw onto will request for KeyEvents also. For example this is necessary to use mouseDragged(java.awt.event.MouseEvent) for scaling of a scene.

Specified by:

mouseEntered in interface java.awt.event.MouseListener

mouseExited

public void mouseExited(java.awt.event.MouseEvent me)

This method is an empty implementation in the moment.

Specified by:

mouseExited in interface java.awt.event.MouseListener

mousePressed

public void mousePressed(java.awt.event.MouseEvent me)

When a mousePressend event occurs, this method is invoked and will initialize the DefaultCanvasController's internal MMEvent and finally call the controller's controlAction(net.mumie.mathletfactory.action.MMEvent) method.

Specified by:

mousePressed in interface java.awt.event.MouseListener

mouseReleased

public void mouseReleased(java.awt.event.MouseEvent me)

When a mouseReleased event occurs the action process due to the current MMEvent will be finished. This method cleans up and resets all internally changed fields (i.e. keycode, mouse event type, selected MMObject).

Specified by:

mouseReleased in interface java.awt.event.MouseListener

mouseDragged

public void mouseDragged(java.awt.event.MouseEvent me)

When a mouseMotionEvent occurs this method is invoked and will initialize the @see DefautlController's internal @see MMEvent and finally call the controller's @see controlAction(MMEvent event) method.

Specified by:

mouseDragged in interface java.awt.event.MouseMotionListener

mouseMoved

public void mouseMoved(java.awt.event.MouseEvent me)

This method has an empty implementation in the moment.

Specified by:

mouseMoved in interface java.awt.event.MouseMotionListener

mouseWheelMoved

public void mouseWheelMoved(java.awt.event.MouseWheelEvent mwe)

Specified by:

mouseWheelMoved in interface java.awt.event.MouseWheelListener

keyPressed

public void keyPressed(java.awt.event.KeyEvent ke)

This method extracts the keycode and the modifier of the KeyEvent by using the methods getKeyCode() and getModifiers() from KeyEvent. The derived values are internally stored in the controller's MMEvent and by that way may be used for further processing.
In the moment the controller's controlAction() method will not be called automatically: That means, that a single KeyEvent will not start any action in our applets.

Specified by:

keyPressed in interface java.awt.event.KeyListener

keyReleased

public void keyReleased(java.awt.event.KeyEvent ke)

Specified by:

keyReleased in interface java.awt.event.KeyListener

keyTyped

public void keyTyped(java.awt.event.KeyEvent ke)

This method has an empty implementation in the moment.

Specified by:

keyTyped in interface java.awt.event.KeyListener

clone

public java.lang.Object clone()

Specified by:

clone in interface CanvasControllerIF

Overrides:

clone in class java.lang.Object