diff options
Diffstat (limited to 'documentation/architecture/architecture-events.asciidoc')
| -rw-r--r-- | documentation/architecture/architecture-events.asciidoc | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/documentation/architecture/architecture-events.asciidoc b/documentation/architecture/architecture-events.asciidoc index e832c581fe..e273a28e97 100644 --- a/documentation/architecture/architecture-events.asciidoc +++ b/documentation/architecture/architecture-events.asciidoc @@ -37,7 +37,6 @@ corresponding listener class. For example, the [classname]#Button# has In the following, we handle button clicks with a listener implemented as an anonymous class: - [source, java] ---- final Button button = new Button("Push it!"); @@ -60,15 +59,21 @@ in this case the [classname]#Button#. [[figure.eventlistenerdiagram]] .Class Diagram of a Button Click Listener -image::img/events-classdiagram-hi.png[] +image::img/events-classdiagram-hi.png[width=50%, scaledwidth=75%] + +In Java 8, you can implement such functional interfaces with a lambda expression: + +[source, java] +---- +Button button = new Button("Push it!"); + +button.addClickListener(event -> + button.setCaption("You pushed it!")); +---- In the ancient times of C programming, __callback functions__ filled largely the same need as listeners do now. In object-oriented languages, we usually only have classes and methods, not functions, so the application has to give a class interface instead of a callback function pointer to the framework. -<<dummy/../../../framework/application/application-events#application.events,"Handling -Events with Listeners">> goes into details of handling events in practice. - - - +<<dummy/../../../framework/application/application-events#application.events,"Handling Events with Listeners">> goes into details of handling events in practice. |