salvo.jesus.graph.visual

Class GraphPanelState

java.lang.Object

salvo.jesus.graph.visual.GraphPanelState

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

GraphPanelEdgeState, GraphPanelNormalState, GraphPanelVertexState

public abstract class GraphPanelState
extends Object
implements Serializable

Abstract state object of GraphPanel, applying the state design pattern.

Implementations of this class now also acts as state machines, in that an input to a state may return a new state. The input can be mouse and keyboard events or a ChangeStateEvent.

For mouse and keyboard events, after a state has processed the input, the input is then passed on to the VisualGraphComponent, if any, to process the input. These are done via the mouseXXX() and keyEvent() methods.

For ChangeStateEvents, they can be passed to the method recommendState() where a new state may or may not be returned.

Author:

Jesus M. Salvo Jr., Armin Groll

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
void	informTargetVisualGraphComponentOfKeyEvent(KeyEvent e) This method calls processKeyEvent(e) upon the target (if any) VisualGraphComponent of a key action.
void	informTargetVisualGraphComponentOfMouseEvent(MouseEvent e) This method calls processMouseEvent(e) upon the target (if any) VisualGraphComponent of a mouse action.
GraphPanelState	keyPressed(KeyEvent e)
GraphPanelState	keyReleased(KeyEvent e)
GraphPanelState	keyTyped(KeyEvent e)
GraphPanelState	mouseClicked(MouseEvent e) GraphPanel delegates all MouseEvents to its current state.
GraphPanelState	mouseDragged(MouseEvent e) GraphPanel delegates all MouseEvents to its current state.
GraphPanelState	mouseEntered(MouseEvent e) GraphPanel delegates all MouseEvents to its current state.
GraphPanelState	mouseExited(MouseEvent e) GraphPanel delegates all MouseEvents to its current state.
GraphPanelState	mouseMoved(MouseEvent e) GraphPanel delegates all MouseEvents to its current state.
GraphPanelState	mousePressed(MouseEvent e) GraphPanel delegates all MouseEvents to its current state.
GraphPanelState	mouseReleased(MouseEvent e) GraphPanel delegates all MouseEvents to its current state.
abstract void	paint(Graphics2D ged) Different painting actions may occur depending on the GraphPanel's state.
GraphPanelState	recommendState(ChangeStateEvent cse) Returns a state depending on the ChangeStateEvent.
void	setGraphPanel(GraphPanel gpanel)

Methods inherited from class java.lang.Object

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

Method Detail

setGraphPanel

public void setGraphPanel(GraphPanel gpanel)

recommendState

public GraphPanelState recommendState(ChangeStateEvent cse)

Returns a state depending on the ChangeStateEvent. Implementations may ignore the event, by simply returning itself. Implementations may also return a different state than that indicated by the event. Callers of this method should therefore check the new state returned by this method.

This method is called by GraphPanel from within the GraphPanel's processChangeStateEvent method.

Parameters:

cse - an event object that gives this state a hint on the direction of the transition.

Returns:

the resulting state, either this state again, or a new state. GraphPanel will take this as the new state.

mousePressed

public GraphPanelState mousePressed(MouseEvent e)

GraphPanel delegates all MouseEvents to its current state. The state will do the actions desired. It will inform the targeted VisualGraphComponent via informTargetVisualGraphComponentOfMouseEvent(e) and return itself as the resulting state, if you don't override it.

Parameters:

e - the MouseEvent, as it was received by the GraphPanel.

Returns:

the resulting state, either this state again, or a new state. GraphPanel will take this as the new state.

mouseReleased

public GraphPanelState mouseReleased(MouseEvent e)

GraphPanel delegates all MouseEvents to its current state. The state will do the actions desired. It will inform the targeted VisualGraphComponent via informTargetVisualGraphComponentOfMouseEvent(e) and return itself as the resulting state, if you don't override it.

Parameters:

e - the MouseEvent, as it was received by the GraphPanel.

Returns:

the resulting state, either this state again, or a new state. GraphPanel will take this as the new state.

mouseDragged

public GraphPanelState mouseDragged(MouseEvent e)

GraphPanel delegates all MouseEvents to its current state. The state will do the actions desired. It will inform the targeted VisualGraphComponent via informTargetVisualGraphComponentOfMouseEvent(e) and return itself as the resulting state, if you don't override it.

Parameters:

e - the MouseEvent, as it was received by the GraphPanel.

Returns:

the resulting state, either this state again, or a new state. GraphPanel will take this as the new state.

mouseEntered

public GraphPanelState mouseEntered(MouseEvent e)

GraphPanel delegates all MouseEvents to its current state. The state will do the actions desired. It will inform the targeted VisualGraphComponent via informTargetVisualGraphComponentOfMouseEvent(e) and return itself as the resulting state, if you don't override it.

Parameters:

e - the MouseEvent, as it was received by the GraphPanel.

Returns:

the resulting state, either this state again, or a new state. GraphPanel will take this as the new state.

mouseExited

public GraphPanelState mouseExited(MouseEvent e)

GraphPanel delegates all MouseEvents to its current state. The state will do the actions desired. It will inform the targeted VisualGraphComponent via informTargetVisualGraphComponentOfMouseEvent(e) and return itself as the resulting state, if you don't override it.

Parameters:

e - the MouseEvent, as it was received by the GraphPanel.

Returns:

the resulting state, either this state again, or a new state. GraphPanel will take this as the new state.

mouseClicked

public GraphPanelState mouseClicked(MouseEvent e)

GraphPanel delegates all MouseEvents to its current state. The state will do the actions desired. It will inform the targeted VisualGraphComponent via informTargetVisualGraphComponentOfMouseEvent(e) and return itself as the resulting state, if you don't override it.

Parameters:

e - the MouseEvent, as it was received by the GraphPanel.

Returns:

the resulting state, either this state again, or a new state. GraphPanel will take this as the new state.

mouseMoved

public GraphPanelState mouseMoved(MouseEvent e)

GraphPanel delegates all MouseEvents to its current state. The state will do the actions desired. It will inform the targeted VisualGraphComponent via informTargetVisualGraphComponentOfMouseEvent(e) and return itself as the resulting state, if you don't override it.

Parameters:

e - the MouseEvent, as it was received by the GraphPanel.

Returns:

the resulting state, either this state again, or a new state. GraphPanel will take this as the new state.

keyPressed

public GraphPanelState keyPressed(KeyEvent e)

keyReleased

public GraphPanelState keyReleased(KeyEvent e)

keyTyped

public GraphPanelState keyTyped(KeyEvent e)

informTargetVisualGraphComponentOfMouseEvent

public void informTargetVisualGraphComponentOfMouseEvent(MouseEvent e)

This method calls processMouseEvent(e) upon the target (if any) VisualGraphComponent of a mouse action.

Parameters:

e - the MouseEvent.

informTargetVisualGraphComponentOfKeyEvent

public void informTargetVisualGraphComponentOfKeyEvent(KeyEvent e)

This method calls processKeyEvent(e) upon the target (if any) VisualGraphComponent of a key action.

Since this method is only called when the focus is on GraphPanel, and VisualGraphComponents are themselves not AWT or Swing components, it is up to this class to determine which VisualGraphComponent is the current "focus". Therefore, currently, this method is empty, and even though there is a processKeyEvent() method in VisualGraphComponent, we still have a devise a scheme to determine the currently focused VisualGraphComponent based on the key event. A simple solution may be to simply query GraphPanelNormalState for the component in focus.

Parameters:

e - the KeyEvent.

paint

public abstract void paint(Graphics2D ged)

Different painting actions may occur depending on the GraphPanel's state.