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jvx:reference [2020/06/24 15:41] cduncan [Lambdas] |
jvx:reference [2020/06/24 15:47] (current) cduncan [Fire away!] |
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| - | ==== Method references ==== | + | ==== Method References ==== |
| - | And last but not least, thanks to the new capabilities of Java 1.8, we can also use [[https://docs.oracle.com/javase/tutorial/java/javaOO/methodreferences.html|method references]]: | + | Lastly, thanks to the new capabilities of Java 1.8, we can also use [[https://docs.oracle.com/javase/tutorial/java/javaOO/methodreferences.html|method references]]: |
| <code java> | <code java> | ||
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| } | } | ||
| </code> | </code> | ||
| - | ===== Parameters or no parameters? To throw or not to throw? ===== | + | ===== Parameters or No Parameters? To Throw or Not to Throw? ===== |
| - | By default we actually support two different classes of listeners, the specified event/listener interface itself, and ''%%javax.rad.util.IRunnable%%''. Which means that you can also attach methods which do not have any parameters, like this: | + | By default we actually support two different classes of listeners, the specified event/listener interface itself and ''%%javax.rad.util.IRunnable%%''. This means you can also attach methods that do not have any parameters, like this: |
| <code java> | <code java> | ||
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| } | } | ||
| </code> | </code> | ||
| - | Additionally, all listeners and ''%%IRunnable%%'' itself do support to throw ''%%Throwable%%'', which is then handled inside the ''%%EventHandler%%''. So you are very flexible when it comes to what methods you can attach and use as listeners. | + | Additionally, all listeners and ''%%IRunnable%%'' itself support throwing ''%%Throwable%%'', which is then handled inside the ''%%EventHandler%%''. As you can see, you are very flexible when it comes to what methods you can attach and use as listeners. |
| - | ===== Creating your own events ===== | + | ===== Creating Your Own Events ===== |
| You can, of course, create your own ''%%EventHandler%%''s and listeners to create your own events. All you need are two classes, an extension of EventHandler and a listener interface. | You can, of course, create your own ''%%EventHandler%%''s and listeners to create your own events. All you need are two classes, an extension of EventHandler and a listener interface. | ||
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| event.dispatchEvent("Adam"); | event.dispatchEvent("Adam"); | ||
| </code> | </code> | ||
| - | ===== More methods! ===== | + | ===== Additional Methods ===== |
| - | You can also use an interface for listeners which has multiple methods, specifying in the constructor which method to invoke: | + | You can also use an interface for listeners that has multiple methods, specifying in the constructor which method to invoke: |
| <code java> | <code java> | ||
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| } | } | ||
| </code> | </code> | ||
| - | Now every time the event is dispatched, the ''%%somethingOtherHappened%%'' method will be invoked. Anyway, don’t use this. The upside of having a “simple” listener interface with just one method is that it allows to use lambdas with it. A listener interface with multiple methods won’t allow this. | + | Now every time the event is dispatched, the ''%%somethingOtherHappened%%'' method will be invoked. However, don’t use this. The upside of having a “simple” listener interface with just one method is that it allows us to use lambdas with it. A listener interface with multiple methods won’t allow this. |
| In [[https://sourceforge.net/projects/jvx/|JVx]] [[http://blog.sibvisions.com/2015/01/28/jvx-and-java-8-events-and-lambdas/|we reduced our listener interfaces to just one method (in a backward compatible way)]] to make sure all events can be used with lambdas. | In [[https://sourceforge.net/projects/jvx/|JVx]] [[http://blog.sibvisions.com/2015/01/28/jvx-and-java-8-events-and-lambdas/|we reduced our listener interfaces to just one method (in a backward compatible way)]] to make sure all events can be used with lambdas. | ||
| - | ===== Fire away! ===== | + | ===== Fire Away! ===== |
| - | That’s it for this short reference sheet, that is how our event system can and should be used. Of course, there is much more to it under the hood, for example listeners being wrapped in proxy classes, reflection used for invoking methods and some more stuff. If you feel adventurous, be my guest and have a good look at the internals of ''%%EventHandler%%'', it is quite an interesting read. | + | That’s it for this short reference sheet. This is how our event system can and should be used. Of course, there is much more to it under the hood (for example, listeners being wrapped in proxy classes, reflection used for invoking methods, etc.). If you feel adventurous, be my guest and have a good look at the internals of ''%%EventHandler%%''. It is quite an interesting read! |