On Mon, Aug 10, 2009 at 11:09 PM, Henri Yandell<flame...@gmail.com> wrote:
> On Sun, Aug 9, 2009 at 1:37 PM, Michael Wooten<mwooten....@gmail.com> wrote:
>>
>> I would also like to propose some support be added to Lang for basic event
>> handling. This would be based on the way that PropertyChangeSupport can be
>> used to add and remove listeners and post events.
>>
>> Add interface EventSupport<L extends EventListener>
>>
>> - addListener(L listener)
>> - The signature for the method that can add a listener of some subtype of
>> EventListener
>> - removeListener(L listener)
>> - The signature for the method that can remove a listener of some subtype
>> of EventListener
>>
>>
>> Add class AbstractEventSupport implements EventSupport<L>, Iterable<L>
>>
>> - AbstractEventSupport(Object eventSource)
>> - Constructs a new AbstractEventSupport object and associates it with the
>> object that will be used as the source of all events (much like
>> PropertyChangeSupport).
>> - addListener(L)
>> - An implementation that adds a listener to an internal collection.
>> - removeListener(L)
>> - An implementation that removes a listener from an internal collection.
>> - iterator()
>> - Returns an iterator over the attached listeners.
>> - getSource()
>> - Returns a reference to the source object of all events.
>>
>>
>> The best way to describe this would be to demonstrate an example of how it
>> can be used.
>>
>> public class ButtonPressedEventSupport extends
>> AbstractEventSupport<ButtonPressedListener> {
>>
>> public ButtonPressedEventSupport(Object source) { super(source); }
>>
>> public void fireButtonPressed(Button button) {
>> ButtonPressedEvent bpe = new ButtonPressedEvent(getSource(),
>> button);
>> for (ButtonPressedListener listener : this)
>> {
>> listener.buttonPressed(bpe);
>> }
>> }
>> }
>>
>> public class MyWindow implements EventSupport<ButtonPressedListener> {
>> private final ButtonPressedEventSupport buttonPressedEventSupport;
>>
>> public MyWindow { buttonPressedEventSupport = new
>> ButtonPressedEventSupport(this); }
>>
>> public void addListener(ButtonPressedListener listener) {
>> buttonPressedEventSupport.addListener(listener); }
>>
>> public void removeListener(ButtonPressedListener listener) {
>> buttonPressedEventSupport.removeListener(listener); }
>>
>> ...
>>
>> private void onDetectButtonPressed(Button button) {
>> buttonPressedEventSupport.fireButtonPressed(button);
>> }
>> }
>>
>> I haven't compiled the above code. It's just an example of how these classes
>> could be used so that you're not constantly rewriting the code and
>> interfaces for adding and removing listeners, and it provides a fairly easy
>> method of creating methods to fire events.
>
> Worth a JIRA to solicit more feedback :) Seems good, in the 'this
> doesn't exist?' way :)
This'll be why I like the idea I guess :)
http://code.google.com/p/osjava/source/browse/trunk/genjava/gj-core/src/java/com/generationjava/lang/Notifier.java
Hen
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