org.netbeans.spi.actions

Class AbstractSavable

java.lang.Object

org.netbeans.spi.actions.AbstractSavable

All Implemented Interfaces:

Savable

public abstract class AbstractSavable
extends Object
implements Savable

Default implementation of Savable interface and additional contracts, including dealing with Savable.REGISTRY. The human presentable name of the object to be saved is provided by implementing AbstractSavable.findDisplayName(). In case this object wants to be visually represented with an icon, it can also implement Icon interface (and delegate to ImageUtilities.loadImageIcon(java.lang.String, boolean) result). Here is example of typical implementation:

class MySavable extends AbstractSavable {
    private final Object obj;
    public MySavable(Object obj) {
        this.obj = obj;
        register();
    }
    protected String findDisplayName() {
        return "My name is " + obj.toString(); // get display name somehow
    }
    protected void handleSave() throws IOException {
        // save 'obj' somehow
    }
    public boolean equals(Object other) {
        if (other instanceof MySavable) {
            return ((MySavable)other).obj.equals(obj);
        }
        return false;
    }
    public int hashCode() {
        return obj.hashCode();
    }
}
 

Since:

7.33

Field Summary

Fields inherited from interface org.netbeans.api.actions.Savable

REGISTRY

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractSavable() Constructor for subclasses.

Method Summary

Modifier and Type	Method and Description
abstract boolean	equals(Object obj) Equals and AbstractSavable.hashCode() need to be properly implemented by subclasses to correctly implement equality contract.
protected abstract String	findDisplayName() Finds suitable display name for the object this Savable represents.
protected abstract void	handleSave() To be overriden by subclasses to handle the actual save of the object.
abstract int	hashCode() HashCode and AbstractSavable.equals(java.lang.Object) need to be properly implemented by subclasses, so two Savables representing the same object beneath are really equal and have the same AbstractSavable.hashCode().
protected void	register() Tells the system to register this Savable into Savable.REGISTRY.
void	save() Implementation of Savable.save() contract.
String	toString() Human descriptive, localized name of the savable.
protected void	unregister() Removes this Savable from the Savable.REGISTRY (if it is present there, by relying on AbstractSavable.equals(java.lang.Object) and AbstractSavable.hashCode()).

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

AbstractSavable

protected AbstractSavable()

Constructor for subclasses.

Method Detail

save

public final void save()
                throws IOException

Implementation of Savable.save() contract. Calls AbstractSavable.handleSave() and AbstractSavable.unregister().

Specified by:

save in interface Savable

Throws:

IOException - if call to AbstractSavable.handleSave() throws IOException

findDisplayName

protected abstract String findDisplayName()

Finds suitable display name for the object this Savable represents.

Returns:

human readable, localized short string name

handleSave

protected abstract void handleSave()
                            throws IOException

To be overriden by subclasses to handle the actual save of the object.

Throws:

IOException

equals

public abstract boolean equals(Object obj)

Equals and AbstractSavable.hashCode() need to be properly implemented by subclasses to correctly implement equality contract. Two Savables should be equal if they represent the same underlying object beneath them. Without correct implementation proper behavior of AbstractSavable.register() and AbstractSavable.unregister() cannot be guaranteed.

Overrides:

equals in class Object

Parameters:

obj - object to compare this one to,

Returns:

true or false

hashCode

public abstract int hashCode()

HashCode and AbstractSavable.equals(java.lang.Object) need to be properly implemented by subclasses, so two Savables representing the same object beneath are really equal and have the same AbstractSavable.hashCode().

Overrides:

hashCode in class Object

Returns:

integer hash

See Also:

AbstractSavable.equals(java.lang.Object)

register

protected final void register()

Tells the system to register this Savable into Savable.REGISTRY. Only one Savable (according to AbstractSavable.equals(java.lang.Object) and AbstractSavable.hashCode()) can be in the registry. New call to AbstractSavable.register() replaces any previously registered and equal Savables. After this call the Savable.REGISTRY holds a strong reference to this which prevents this object to be garbage collected until it is unregistered or replaced by equal one.

unregister

protected final void unregister()

Removes this Savable from the Savable.REGISTRY (if it is present there, by relying on AbstractSavable.equals(java.lang.Object) and AbstractSavable.hashCode()).

toString

public final String toString()

Description copied from interface: Savable

Human descriptive, localized name of the savable. It is advised that all implementations of Savable override the toString method to provide human readable name.

Specified by:

toString in interface Savable

Overrides:

toString in class Object

Returns:

human readable name representing the savable