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Difference between revisions of "Eclipse4/RCP/Modeled UI/Listening to Model Changes"
< Eclipse4 | RCP | Modeled UI
(→Retrieving information from the events) |
(→Retrieving information from the events) |
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| Line 14: | Line 14: | ||
==Retrieving information from the events== | ==Retrieving information from the events== | ||
<source lang="java"> | <source lang="java"> | ||
| − | // subscribe to | + | // subscribe to events generated from MUILabels having their labels changed |
eventBroker.subscribe(UIEvents.buildTopic(UIEvents.UILabel.TOPIC, UIEvents.UILabel.LABEL), | eventBroker.subscribe(UIEvents.buildTopic(UIEvents.UILabel.TOPIC, UIEvents.UILabel.LABEL), | ||
new EventHandler() { | new EventHandler() { | ||
Revision as of 16:05, 11 April 2011
When the model changes and it is not a no-op (for example, setting its label to its current label), an event will be dispatched to all interested event handlers. Eclipse 4 uses a global listener pattern so all handler subscriptions are done through the event broker.
Subscribing to model changes
Topics for event subscriptions can be generated from the UIEvents class.
// subscribe to all events generated from MUILabels eventBroker.subscribe(UIEvents.buildTopic(UIEvents.UILabel.TOPIC), eventHandler); // subscribe only to events generated from MItems's selected attribute being switched eventBroker.subscribe(UIEvents.buildTopic(UIEvents.Item.TOPIC, UIEvents,Item.SELECTED), eventHandler);
Retrieving information from the events
// subscribe to events generated from MUILabels having their labels changed eventBroker.subscribe(UIEvents.buildTopic(UIEvents.UILabel.TOPIC, UIEvents.UILabel.LABEL), new EventHandler() { public void handleEvent(Event event) { Object element = event.getProperty(UIEvents.EventTags.ELEMENT); if (element instanceof MToolItem) { ToolItem item = (ToolItem) ((MToolItem) element).getWidget(); String value = (String) event.getProperty(UIEvents.EventTags.NEW_VALUE); if (value == null) { item.setText(""); //$NON-NLS-1$ } else { item.setText(value); } } } } );