diff options
Diffstat (limited to 'documentation/application/application-events.asciidoc')
| -rw-r--r-- | documentation/application/application-events.asciidoc | 24 |
1 files changed, 10 insertions, 14 deletions
diff --git a/documentation/application/application-events.asciidoc b/documentation/application/application-events.asciidoc index 94175d88e7..4b18201d19 100644 --- a/documentation/application/application-events.asciidoc +++ b/documentation/application/application-events.asciidoc @@ -16,8 +16,8 @@ Using anonymous class for listeners is recommended in most cases. [[application.events.anonymous]] == Using Anonymous Classes -By far the easiest and the most common way to handle events in Java 6 and 7 is -to use anonymous local classes. It encapsulates the handling of events to where +By far the easiest and the most common way to handle events in Java 8 lambdas. +It encapsulates the handling of events to where the component is defined and does not require cumbering the managing class with interface implementations. The following example defines an anonymous class that inherits the [classname]#Button.ClickListener# interface. @@ -27,7 +27,7 @@ inherits the [classname]#Button.ClickListener# interface. ---- // Have a component that fires click events final Button button = new Button("Click Me!"); - + // Handle the events with an anonymous class button.addClickListener(new Button.ClickListener() { public void buttonClick(ClickEvent event) { @@ -92,11 +92,11 @@ Directing events to handler methods is easy with method references: ---- public class Java8Buttons extends CustomComponent { public Java8Buttons() { - setCompositionRoot(new HorizontalLayout( + setCompositionRoot(new HorizontalLayout( new Button("OK", this::ok), new Button("Cancel", this::cancel))); } - + public void ok(ClickEvent event) { event.getButton().setCaption ("OK!"); } @@ -126,15 +126,15 @@ public class MyComposite extends CustomComponent public MyComposite() { Layout layout = new HorizontalLayout(); - + // Just a single component in this composition button = new Button("Do not push this"); button.addClickListener(this); layout.addComponent(button); - + setCompositionRoot(layout); } - + // The listener method implementation public void buttonClick(ClickEvent event) { button.setCaption("Do not push this again"); @@ -166,12 +166,12 @@ public class TheButtons extends CustomComponent toobutton = new Button("A Button Too", this); // Put them in some layout - Layout root = new HorizontalLayout(); + Layout root = new HorizontalLayout(); root.addComponent(onebutton); root.addComponent(toobutton); setCompositionRoot(root); } - + @Override public void buttonClick(ClickEvent event) { // Differentiate targets by event source @@ -189,7 +189,3 @@ object properties, names, or captions to separate between them. Using captions or any other visible text is generally discouraged, as it may create problems for internationalization. Using other symbolic strings can also be dangerous, because the syntax of such strings is checked only at runtime. - - - - |