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Difference between revisions of "Eclipse4/RCP/Modeled UI/Listening to Model Changes"
< Eclipse4 | RCP | Modeled UI
(→Subscribing to model changes) |
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| Line 6: | Line 6: | ||
<source lang="java"> | <source lang="java"> | ||
// subscribe to all events generated from MUILabels | // subscribe to all events generated from MUILabels | ||
| − | eventBroker.subscribe(UIEvents.buildTopic(UIEvents.UILabel.TOPIC), | + | eventBroker.subscribe(UIEvents.buildTopic(UIEvents.UILabel.TOPIC), |
| + | labelEventHandler); | ||
// subscribe only to events generated from MItems's selected attribute being switched | // subscribe only to events generated from MItems's selected attribute being switched | ||
| − | eventBroker.subscribe(UIEvents.buildTopic(UIEvents.Item.TOPIC, UIEvents,Item.SELECTED), | + | eventBroker.subscribe(UIEvents.buildTopic(UIEvents.Item.TOPIC, UIEvents,Item.SELECTED), |
| + | itemSelectionEventHandler); | ||
</source> | </source> | ||
Latest revision as of 14:07, 14 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), labelEventHandler); // subscribe only to events generated from MItems's selected attribute being switched eventBroker.subscribe(UIEvents.buildTopic(UIEvents.Item.TOPIC, UIEvents,Item.SELECTED), itemSelectionEventHandler);
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); } } } } );