prefuse.action.assignment
Class ShapeAction

java.lang.Object
  prefuse.activity.Activity
      prefuse.action.Action
          prefuse.action.GroupAction
              prefuse.action.ItemAction
                  prefuse.action.EncoderAction
                      prefuse.action.assignment.ShapeAction

Direct Known Subclasses:

DataShapeAction

public class ShapeAction
extends EncoderAction

Assignment Action that assigns shape values to VisualItems. Shape values are simple integer codes that indicate to appropriate renderer instances what shape should be drawn. The default list of shape values is included in the Constants class, all beginning with the prefix SHAPE. Of course, clients can always create their own shape codes that are handled by a custom Renderer.

By default, a ShapeAction simply sets each VisualItem to be a rectangle. Clients can change this default value to achieve uniform shape assignment, or can add any number of additional rules for shape assignment. Rules are specified by a Predicate instance which, if returning true, will trigger that rule, causing either the provided shape value or the result of a delegate ShapeAction to be applied. Rules are evaluated in the order in which they are added to the ShapeAction, so earlier rules will have precedence over rules added later.

In addition, subclasses can simply override getShape(VisualItem) to achieve custom shape assignment. In some cases, this may be the simplest or most flexible approach.

This Action only sets the shape field of the VisualItem. For this value to have an effect, a renderer instance that takes this shape value into account must be used (e.g., ShapeRenderer).

To automatically assign shape values based on varying values of a particular data field, consider using the DataShapeAction.

Author:

jeffrey heer

Field Summary

protected int

m_defaultShape

Fields inherited from class prefuse.action.ItemAction

m_predicate

Fields inherited from class prefuse.action.GroupAction

m_group

Fields inherited from class prefuse.action.Action

m_vis

Fields inherited from class prefuse.activity.Activity

DEFAULT_STEP_TIME, INFINITY

Constructor Summary

ShapeAction()
Constructor.

ShapeAction(java.lang.String group)
Constructor.

ShapeAction(java.lang.String group, int shape)
Constructor with a specified a default shape value.

Method Summary

void	add(Predicate p, int shape) Add a shape mapping rule to this ShapeAction.
void	add(Predicate p, ShapeAction f) Add a size mapping rule to this ShapeAction.
void	add(java.lang.String expr, int shape) Add a shape mapping rule to this ShapeAction.
void	add(java.lang.String expr, ShapeAction f) Add a shape mapping rule to this ShapeAction.
int	getDefaultSize() Returns the default shape value assigned to items.
int	getShape(VisualItem item) Returns a shape value for the given item.
void	process(VisualItem item, double frac) Processes an individual item.
void	setDefaultShape(int defaultShape) Sets the default shape value assigned to items.

Methods inherited from class prefuse.action.EncoderAction

add, clear, finish, lookup, remove, run, setup, setVisualization

Methods inherited from class prefuse.action.ItemAction

getFilterPredicate, setFilterPredicate

Methods inherited from class prefuse.action.GroupAction

getGroup, setGroup

Methods inherited from class prefuse.action.Action

getVisualization, run

Methods inherited from class prefuse.activity.Activity

addActivityListener, alwaysRunAfter, cancel, fireActivityCancelled, fireActivityFinished, fireActivityScheduled, fireActivityStarted, fireActivityStepped, getDuration, getNextTime, getPace, getPacingFunction, getStartTime, getStepTime, getStopTime, isEnabled, isRunning, isScheduled, removeActivityListener, run, runAfter, runAt, setDuration, setEnabled, setPacingFunction, setStartTime, setStepTime

Methods inherited from class java.lang.Object

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

Field Detail

m_defaultShape

protected int m_defaultShape

Constructor Detail

ShapeAction

public ShapeAction()

Constructor. A default rectangle shape will be used.

ShapeAction

public ShapeAction(java.lang.String group)

Constructor. A default rectangle shape will be used.

Parameters:

group - the data group processed by this Action.

ShapeAction

public ShapeAction(java.lang.String group,
                   int shape)

Constructor with a specified a default shape value.

Parameters:

group - the data group processed by this Action.

shape - the default shape value to use

Method Detail

getDefaultSize

public int getDefaultSize()

Returns the default shape value assigned to items.

Returns:

the default shape value

setDefaultShape

public void setDefaultShape(int defaultShape)

Sets the default shape value assigned to items. Items will be assigned the default shape if they do not match any registered rules.

Parameters:

defaultShape - the new default shape value

add

public void add(Predicate p,
                int shape)

Add a shape mapping rule to this ShapeAction. VisualItems that match the provided predicate will be assigned the given shape value (assuming they do not match an earlier rule).

Parameters:

p - the rule Predicate

shape - the shape value

add

public void add(java.lang.String expr,
                int shape)

Add a shape mapping rule to this ShapeAction. VisualItems that match the provided expression will be assigned the given shape value (assuming they do not match an earlier rule). The provided expression String will be parsed to generate the needed rule Predicate.

Parameters:

expr - the expression String, should parse to a Predicate.

shape - the shape value

Throws:

java.lang.RuntimeException - if the expression does not parse correctly or does not result in a Predicate instance.

add

public void add(Predicate p,
                ShapeAction f)

Add a size mapping rule to this ShapeAction. VisualItems that match the provided predicate will be assigned the shape value returned by the given ShapeAction's getSize() method.

Parameters:

p - the rule Predicate

f - the delegate ShapeAction to use

add

public void add(java.lang.String expr,
                ShapeAction f)

Add a shape mapping rule to this ShapeAction. VisualItems that match the provided expression will be assigned the given shape value (assuming they do not match an earlier rule). The provided expression String will be parsed to generate the needed rule Predicate.

Parameters:

expr - the expression String, should parse to a Predicate.

f - the delegate ShapeAction to use

Throws:

java.lang.RuntimeException - if the expression does not parse correctly or does not result in a Predicate instance.

process

public void process(VisualItem item,
                    double frac)

Description copied from class: ItemAction

Processes an individual item.

Specified by:

process in class ItemAction

Parameters:

item - the VisualItem to process

frac - the fraction of elapsed duration time

See Also:

ItemAction.process(prefuse.visual.VisualItem, double)

getShape

public int getShape(VisualItem item)

Returns a shape value for the given item.

Parameters:

item - the item for which to get the shape value

Returns:

the shape value for the item