org.jdesktop.swingx
Class JXGraph.Plot

java.lang.Object
  org.jdesktop.swingx.JXGraph.Plot

Enclosing class:

JXGraph

public abstract static class JXGraph.Plot
extends Object

A plot represents a mathematical transformation used by JXGraph. When a plot belongs to a graph, the graph component asks for the transformation of a value along the X axis. The resulting value defines the Y coordinates at which the graph must draw a spot of color.

Here is a sample implemention of this class that draws a straight line once added to a graph (it follows the well-known equation y=a.x+b):

 class LinePlot extends JXGraph.Plot {
     public double compute(double value) {
         return 2.0 * value + 1.0;
     }
 }
 

More information about plots usage can be found in JXGraph in the section entitled Plots.

See Also:

JXGraph, JXGraph.addPlots(Color, JXGraph.Plot...)

Field Summary

protected PropertyChangeSupport

support List of property change listeners listening to this plot's instance.

Constructor Summary

protected

JXGraph.Plot() Creates a new, parameter-less plot.

Method Summary

void	addPropertyChangeListener(PropertyChangeListener listener) Registers a new property change listener with the current plot.
abstract double	compute(double value) This method must return the result of a mathematical transformation of its sole parameter.
protected void	firePropertyChange(String propertyName, double oldValue, double newValue) Notifies property change listeners that a property has changed.
void	removePropertyChangeListener(PropertyChangeListener listener) Removes a new property change listener from the current plot.

Methods inherited from class java.lang.Object

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

Field Detail

support

protected PropertyChangeSupport support

List of property change listeners listening to this plot's instance. When this plot is added to an instance of JXGraph, the JXGraph automatically becomes a new property change listener of this plot.

Constructor Detail

JXGraph.Plot

protected JXGraph.Plot()

Creates a new, parameter-less plot.

Method Detail

compute

public abstract double compute(double value)

This method must return the result of a mathematical transformation of its sole parameter.

Parameters:

value - a value along the X axis of the graph currently drawing this plot

Returns:

the result of the mathematical transformation of value

addPropertyChangeListener

public void addPropertyChangeListener(PropertyChangeListener listener)

Registers a new property change listener with the current plot.

Parameters:

listener - the new property change listener to be notified of property changes

removePropertyChangeListener

public void removePropertyChangeListener(PropertyChangeListener listener)

Removes a new property change listener from the current plot.

Parameters:

listener - the property change listener to be removed

firePropertyChange

protected void firePropertyChange(String propertyName,
                                  double oldValue,
                                  double newValue)

Notifies property change listeners that a property has changed. This method must be used to notify the graph that a parameter of the mathematical transformation of this plot has changed. Failing to do so, a plot will be refreshed when its internal parameters change.

Parameters:

propertyName - the name of the property known to have changed

oldValue - the value of the property prior to the change

newValue - the value of the property after the change