org.opensourcephysics.cabrillo.tracker
Class CenterOfMass

java.lang.Object
  org.opensourcephysics.cabrillo.tracker.TTrack
      org.opensourcephysics.cabrillo.tracker.PointMass
          org.opensourcephysics.cabrillo.tracker.CenterOfMass

All Implemented Interfaces:

java.beans.PropertyChangeListener, java.util.EventListener, Drawable, Interactive, Measurable, Trackable

public class CenterOfMass
extends PointMass

A CenterOfMass tracks the position, velocity and acceleration of the center of mass of a set of point mass objects.

Author:

Douglas Brown

Nested Class Summary

Nested classes/interfaces inherited from class org.opensourcephysics.cabrillo.tracker.TTrack

TTrack.StepArray

Field Summary

protected CenterOfMassInspector	inspector
protected javax.swing.JMenuItem	inspectorItem
protected PointMass[]	masses
protected java.util.ArrayList	massNames
protected DatasetManager	newData

Fields inherited from class org.opensourcephysics.cabrillo.tracker.PointMass

accelerationMenu, aDeriv, aFootprint, aFootprints, aMap, aTailsToOriginItem, aTailsToPositionItem, aVisibleItem, aVisibleOnAll, aVisMap, colorIndex, colors, dataDescriptions, derivData, labelsVisibleItem, mass, massField, massLabel, mSeparator, names, namesIndex, params, validData, vDeriv, velocityMenu, vFootprint, vFootprints, vMap, vTailsToOriginItem, vTailsToPositionItem, vVisibleItem, vVisibleOnAll, vVisMap, xData, xVisibleOnAll, xVisMap, yData

Fields inherited from class org.opensourcephysics.cabrillo.tracker.TTrack

angleField, angleLabel, angleSeparator, autoAdvance, autoAdvanceItem, colorItem, data, dataColumnsItem, dataProp, dataValid, defaultColor, defaultFootprint, deleteItem, description, descriptionItem, enabled, footprint, footprintListener, footprintMenu, footprints, labelFont, locked, lockedItem, magField, magLabel, magSeparator, markByDefault, markByDefaultItem, menu, name, nameAction, nameDialog, nameField, nameItem, panels, point, properties, stepField, stepLabel, steps, stepSeparator, support, tField, tLabel, toolbarPointComponents, toolbarTrackComponents, trackerPanel, trailLength, trailVisible, trailVisibleItem, tSeparator, viewable, visible, visibleItem, worldBounds, xField, xLabel, xSeparator, xSpinner, yField, yLabel, ySeparator, ySpinner

Constructor Summary

CenterOfMass()
Constructs an empty CenterOfMass.

CenterOfMass(PointMass[] masses)
Constructs a CenterOfMass with specified masses.

Method Summary

void	addMass(PointMass m) Adds a mass to the cm system.
protected void	cleanup() Cleans up associated resources when this track is deleted or cleared.
boolean	containsMass(PointMass m) Determines if the specified point mass is in this center of mass.
void	draw(DrawingPanel panel, java.awt.Graphics _g) Overrides PointMass draw method.
CenterOfMassInspector	getInspector() Gets the center of mass inspector.
static XML.ObjectLoader	getLoader() Returns an ObjectLoader to save and load data for this class.
PointMass[]	getMasses() Gets the array of masses in this cm.
javax.swing.JMenu	getMenu(TrackerPanel trackerPanel) Returns a menu with items that control this track.
java.util.ArrayList	getToolbarPointComponents(TrackerPanel trackerPanel, TPoint point) Overrides TTrack getToolbarPointComponents method.
java.util.ArrayList	getToolbarTrackComponents(TrackerPanel trackerPanel) Overrides TTrack getToolbarTrackComponents method.
boolean	isDependent() Overrides TTrack isDependent method to return true.
boolean	isStepComplete(int n) Overrides TTrack isStepComplete method.
void	propertyChange(java.beans.PropertyChangeEvent e) Responds to property change events.
void	removeMass(PointMass m) Removes a mass from the cm system.
void	setLocked(boolean locked) Overrides TTrack setLocked method.
void	setMass(double mass) Overrides PointMass setMass method.
java.lang.String	toString() Overrides PointMass toString method.

Methods inherited from class org.opensourcephysics.cabrillo.tracker.PointMass

createStep, deleteStep, erase, erase, findInteractive, getAcceleration, getAccelerationFootprint, getAccelerationFootprints, getAccelerations, getDataDescription, getFootprint, getFootprintLength, getFootprints, getMass, getNextVisibleStep, getPreviousVisibleStep, getRotationData, getStep, getVelocities, getVelocity, getVelocityFootprint, getVelocityFootprints, getWorldAcceleration, getWorldPosition, getWorldVelocity, isAcceleration, isAVisible, isLabelsVisible, isPosition, isPositionVisible, isStepVisible, isVelocity, isVVisible, refreshData, remark, remark, setAccelerationFootprint, setAccelerationFootprints, setAVisible, setAVisibleOnAll, setColor, setFootprint, setLabelsVisible, setPositionVisible, setPositionVisibleOnAll, setVelocityFootprint, setVelocityFootprints, setVVisible, setVVisibleOnAll, updateDerivatives, updateNumberFields

Methods inherited from class org.opensourcephysics.cabrillo.tracker.TTrack

addFootprint, addPropertyChangeListener, addPropertyChangeListener, delete, firePropertyChange, getColor, getData, getDataName, getDescription, getFootprint, getFootprints, getName, getProperty, getPropertyNames, getStep, getSteps, getTrailLength, getWorldBounds, getX, getXMax, getXMax, getXMin, getXMin, getY, getYMax, getYMax, getYMin, getYMin, isAutoAdvance, isEmpty, isEnabled, isLocked, isMarkByDefault, isMeasured, isTrailVisible, isViewable, isVisible, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, setAutoAdvance, setDescription, setEnabled, setFootprint, setFootprints, setFootprints, setMarkByDefault, setName, setProperty, setTrackerPanel, setTrailLength, setTrailVisible, setViewable, setVisible, setX, setXY, setY

Methods inherited from class java.lang.Object

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

Field Detail

masses

protected PointMass[] masses

massNames

protected java.util.ArrayList massNames

inspectorItem

protected javax.swing.JMenuItem inspectorItem

newData

protected DatasetManager newData

inspector

protected CenterOfMassInspector inspector

Constructor Detail

CenterOfMass

public CenterOfMass()

Constructs an empty CenterOfMass.

CenterOfMass

public CenterOfMass(PointMass[] masses)

Constructs a CenterOfMass with specified masses.

Parameters:

masses - an array of point masses

Method Detail

draw

public void draw(DrawingPanel panel,
                 java.awt.Graphics _g)

Overrides PointMass draw method.

Specified by:

draw in interface Drawable

Overrides:

draw in class PointMass

Parameters:

panel - the drawing panel requesting the drawing

_g - the graphics context on which to draw

addMass

public void addMass(PointMass m)

Adds a mass to the cm system.

Parameters:

m - the mass

removeMass

public void removeMass(PointMass m)

Removes a mass from the cm system.

Parameters:

m - the mass

getMasses

public PointMass[] getMasses()

Gets the array of masses in this cm.

Returns:

a shallow clone of the masses array

containsMass

public boolean containsMass(PointMass m)

Determines if the specified point mass is in this center of mass.

Parameters:

m - the point mass

Returns:

true if m is in this cm

setLocked

public void setLocked(boolean locked)

Overrides TTrack setLocked method. CenterOfMass is always locked.

Overrides:

setLocked in class TTrack

Parameters:

locked - ignored

setMass

public void setMass(double mass)

Overrides PointMass setMass method. Mass is determined by masses.

Overrides:

setMass in class PointMass

Parameters:

mass - ignored

isStepComplete

public boolean isStepComplete(int n)

Overrides TTrack isStepComplete method. Always returns true.

Overrides:

isStepComplete in class TTrack

Parameters:

n - the frame number

Returns:

true always since cm gets data from point masses

isDependent

public boolean isDependent()

Overrides TTrack isDependent method to return true.

Overrides:

isDependent in class TTrack

Returns:

true if this track is dependent

propertyChange

public void propertyChange(java.beans.PropertyChangeEvent e)

Responds to property change events. CenterOfMass responds to the following events: "track" from tracker panel, "mass" and "step" from PointMass, "steps" from ParticleModel.

Specified by:

propertyChange in interface java.beans.PropertyChangeListener

Overrides:

propertyChange in class PointMass

Parameters:

e - the property change event

cleanup

protected void cleanup()

Cleans up associated resources when this track is deleted or cleared.

Overrides:

cleanup in class TTrack

getMenu

public javax.swing.JMenu getMenu(TrackerPanel trackerPanel)

Returns a menu with items that control this track.

Overrides:

getMenu in class PointMass

Parameters:

trackerPanel - the tracker panel

Returns:

a menu

getToolbarTrackComponents

public java.util.ArrayList getToolbarTrackComponents(TrackerPanel trackerPanel)

Overrides TTrack getToolbarTrackComponents method.

Overrides:

getToolbarTrackComponents in class PointMass

Parameters:

trackerPanel - the tracker panel

Returns:

the DataSetManager

getToolbarPointComponents

public java.util.ArrayList getToolbarPointComponents(TrackerPanel trackerPanel,
                                                     TPoint point)

Overrides TTrack getToolbarPointComponents method.

Overrides:

getToolbarPointComponents in class PointMass

Parameters:

trackerPanel - the tracker panel

point - the TPoint

Returns:

a list of components

toString

public java.lang.String toString()

Overrides PointMass toString method.

Overrides:

toString in class PointMass

Returns:

a description of this object

getLoader

public static XML.ObjectLoader getLoader()

Returns an ObjectLoader to save and load data for this class.

Returns:

the object loader

getInspector

public CenterOfMassInspector getInspector()

Gets the center of mass inspector.

Returns:

the center of mass inspector