fr.lri.swingstates.sm

Class Tag

java.lang.Object

fr.lri.swingstates.sm.Tag

All Implemented Interfaces:

java.util.Iterator

Direct Known Subclasses:

ATag, CTag, JTag

public abstract class Tag
extends java.lang.Object
implements java.util.Iterator

Tags are labels associated to objects or animations.

A tag is an object corresponding to a set of objects that can be browsed (i.e. a collection and an iterator on it).

Some tags are extensional (CExtensionalTag and JExtensionalTag), they can be explicitely attached to and detached from an object, i.e. an object can be added to or removed from the tag's collection. Some other tags are intentional and can not be explicitely added or removed, they tag objects that verify a given property. Thus, the collection of objects tagged by an intentional tag is computed at each use of this tag.

A tag can be attached to any number of objects. An object have any number of tags attached to it.

Tags are used for two main purposes : grouping and interaction.

• In order to create a group of objects in the canvas, one creates a new tag and attaches it to each object in the group.
• Tags are also used in connection with state machines to describe interaction.
  • For example, if some objects in the canvas can be moved but not others, one creates a tag called, say, movable and attaches it to those objects that can be moved. Then, in the canvas' state machine, one can specify transitions such as ClickOnTag(BUTTON1, movable) that will fire only when the user is clicking on an object with tag "movable".
  • Transitions in state machines can also be fired on any object having a tag of a given class. One can define a ColoredTag class (with a color field) and attach many instances of this class to many shapes. Then, transitions like:

     Transition onAnyColor = new Press(ColoredTag.class, BUTTON1) {
                    public void action() {
                            System.out.println("This object has a "+((ColoredTag)getTag()).color+" tag");
                    }
     };
      

    can be used in a state machine.

Author:

Caroline Appert

Constructor Summary

Constructors

Constructor and Description
Tag()

Method Summary

Methods

Modifier and Type	Method and Description
java.util.Collection<java.lang.Object>	getCollection()
abstract boolean	hasNext() Tests if there is other objects tagged by this tag.
abstract java.lang.Object	next()
void	remove() This methods is not supported by a Tag.
abstract void	reset() Inits the tag's iterator.
int	size() Counts how many objects are tagged by this tag.

Methods inherited from class java.lang.Object

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

Constructor Detail

Tag

public Tag()

Method Detail

getCollection

public java.util.Collection<java.lang.Object> getCollection()

Returns:

shapes tagged by this tag as a collection.

reset

public abstract void reset()

Inits the tag's iterator.

hasNext

public abstract boolean hasNext()

Tests if there is other objects tagged by this tag.

Specified by:

hasNext in interface java.util.Iterator

Returns:

true if there is other objects tagged by this tag, false otherwise.

See Also:

Iterator.hasNext()

next

public abstract java.lang.Object next()

Specified by:

next in interface java.util.Iterator

remove

public final void remove()

This methods is not supported by a Tag. To remove a tag of a shape, take a look at removeFrom

Specified by:

remove in interface java.util.Iterator

See Also:

CExtensionalTag.removeFrom(fr.lri.swingstates.canvas.CShape)

size

public final int size()

Counts how many objects are tagged by this tag.

Returns:

the number of objects that are tagged by this tag.