bundles/runtime/org.eclipse.fx.core.di.context/src/org/eclipse/fx/core/di/context/internal/ObservableAdapterProvider_Value.java

/*******************************************************************************
 * Copyright (c) 2013 BestSolution.at and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation
 *******************************************************************************/
package org.eclipse.fx.core.di.context.internal;

import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.core.databinding.observable.value.WritableValue;
import org.eclipse.fx.core.adapter.AdapterProvider;
import org.eclipse.fx.core.adapter.AdapterService.ValueAccess;
import org.eclipse.fx.core.preferences.Value;
import org.osgi.service.component.annotations.Component;

/**
 * Eclipse Databinding Observable Adapter
 */
@SuppressWarnings("rawtypes")
@Component
public class ObservableAdapterProvider_Value implements AdapterProvider<Value, IObservableValue> {

	@Override
	public Class<Value> getSourceType() {
		return Value.class;
	}

	@Override
	public Class<IObservableValue> getTargetType() {
		return IObservableValue.class;
	}

	@Override
	public boolean canAdapt(Value sourceObject, Class<IObservableValue> targetType) {
		return true;
	}

	@SuppressWarnings({ "unchecked" })
	@Override
	public IObservableValue adapt(final Value sourceObject, Class<IObservableValue> targetType, ValueAccess... valueAccess) {
		Realm r = null;

		for( ValueAccess a : valueAccess ) {
			r = a.getValue(Realm.class);
			if( r != null ) {
				break;
			}
		}

		if( r == null ) {
			r = Realm.getDefault();
		}

		if( r == null ) {
			r = new Realm() {
				private Thread t = Thread.currentThread();

				@Override
				public boolean isCurrent() {
					return this.t == Thread.currentThread();
				}
			};
		}

		final WritableValue w = new WritableValue(r);
		w.setValue(sourceObject.getValue());

		w.addValueChangeListener( event -> sourceObject.publish(event.diff.getNewValue()));
		sourceObject.subscribeOnValueChange( value -> w.setValue(value));
		sourceObject.subscribeOnDispose(value -> w.dispose());
		return w;
	}
}