BehaviorService.java

package org.csstudio.sds.internal.eventhandling;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.csstudio.sds.SdsPlugin;
import org.csstudio.sds.eventhandling.AbstractBehavior;
import org.csstudio.sds.model.AbstractWidgetModel;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.Platform;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class BehaviorService implements IBehaviorService {
	private static final String ALL_WIDGETS_ID = "*";

	private final Map<String, Map<String, BehaviorDescriptor>> _behaviors;

    private static final Logger LOG = LoggerFactory.getLogger(BehaviorService.class);

	public BehaviorService() {
		_behaviors = new HashMap<String, Map<String, BehaviorDescriptor>>();
		lookup();
	}

	@SuppressWarnings("unchecked")
	protected void lookup() {
		IConfigurationElement[] configurationElements = Platform.getExtensionRegistry()
				.getConfigurationElementsFor(SdsPlugin.EXTPOINT_BEHAVIORS);

		for (IConfigurationElement e : configurationElements) {
			String behaviorId = e.getAttribute("id");
			String widgetTypeId = e.getAttribute("widgetTypeId");
			String description = e.getAttribute("description");
			AbstractBehavior<AbstractWidgetModel> behavior;
			
			
			try {
				behavior = (AbstractBehavior<AbstractWidgetModel>) e.createExecutableExtension("class");
			} catch (CoreException e1) {
				String msg = "Behavior ["+e.getAttribute("class")+"] could not be instantiated.";
				LOG.error(msg);
				throw new IllegalArgumentException(msg);
			}
			
			assert behaviorId!=null;
			assert widgetTypeId!=null;
			assert description!=null;
			assert behavior!=null;
			
			Set<String> shadowedProperties = new HashSet<String>();
			shadowedProperties.addAll(Arrays.asList(behavior.getInvisiblePropertyIds()));
			assert shadowedProperties!=null;
			
			addBehaviour(new BehaviorDescriptor(behaviorId, widgetTypeId, description, shadowedProperties, e));
		}
	}

	private void addBehaviour(BehaviorDescriptor descriptor) {
		assert descriptor != null : "behavior != null";

		String widgetId = descriptor.getWidgetTypeId();

		// .. create inner map if necessary
		Map<String, BehaviorDescriptor> widgetBehaviors = _behaviors.get(widgetId);

		if (widgetBehaviors == null) {
			widgetBehaviors = new HashMap<String, BehaviorDescriptor>();
			_behaviors.put(widgetId, widgetBehaviors);
		}

		assert widgetBehaviors != null;

		// .. add descriptor to inner map
		if (!widgetBehaviors.containsKey(descriptor.getBehaviorId())) {
			widgetBehaviors.put(descriptor.getBehaviorId(), descriptor);
		} else {
			throw new IllegalArgumentException("Only one behavior for the widget-type >>" + widgetId + "<< and id >>"
					+ descriptor.getBehaviorId() + "<< should be registered.");
		}
	}

	@Override
	@SuppressWarnings("unchecked")
	public AbstractBehavior<AbstractWidgetModel> getBehavior(String behaviorId, String widgetId) {
		assert behaviorId != null : "behaviorId != null";
		assert behaviorId.trim().length() > 0 : "behaviorId.trim().length() > 0";
		assert widgetId != null : "widgetId != null";
		assert widgetId.trim().length() > 0 : "widgetId.trim().length() > 0";

		AbstractBehavior<AbstractWidgetModel> behavior = null;

		BehaviorDescriptor descriptor = getDescriptor(behaviorId, widgetId);

		if (descriptor != null) {
			IConfigurationElement e = descriptor.getConfigurationElement();
			
			try {
				behavior = (AbstractBehavior<AbstractWidgetModel>) e.createExecutableExtension("class");
			} catch (CoreException e1) {
				throw new IllegalArgumentException("Behavior ["+e.getAttribute("class")+"] could not be instantiated.");
			}
		}

		return behavior;
	}

	@Override
	public List<BehaviorDescriptor> getBehaviors(String widgetId) {
		assert widgetId != null : "widgetId != null";
		assert widgetId.trim().length() > 0 : "widgetId.trim().length() > 0";

		List<BehaviorDescriptor> result = new ArrayList<BehaviorDescriptor>();

		// .. add behaviors for that specific widget id
		result.addAll(getDescriptorsByWidgetId(widgetId));

		// .. add global behaviors
		result.addAll(getDescriptorsByWidgetId(ALL_WIDGETS_ID));

		return result;
	}

	@Override
	public String[] getInvisiblePropertyIds(String behaviorId, String widgetId) {
		assert behaviorId != null : "behaviorId != null";
		assert widgetId != null : "widgetId != null";
		assert widgetId.trim().length() > 0 : "widgetId.trim().length() > 0";

		if (behaviorId.length() > 0) {
			AbstractBehavior<AbstractWidgetModel> behavior = getBehavior(behaviorId, widgetId);
			if (behavior != null) {
				return behavior.getInvisiblePropertyIds();
			}
		}
		return new String[0];
	}

	private BehaviorDescriptor getDescriptor(String behaviorId, String widgetId) {
		assert behaviorId != null : "behaviorId != null";
		assert behaviorId.trim().length() > 0 : "behaviorId.trim().length() > 0";
		assert widgetId != null : "widgetId != null";
		assert widgetId.trim().length() > 0 : "widgetId.trim().length() > 0";

		BehaviorDescriptor descriptor = null;

		Map<String, BehaviorDescriptor> tmp = _behaviors.get(widgetId);

		if (tmp != null && tmp.containsKey(behaviorId)) {
			descriptor = tmp.get(behaviorId);
		}

		return descriptor;
	}

	private List<BehaviorDescriptor> getDescriptorsByWidgetId(String widgetId) {
		List<BehaviorDescriptor> result = Collections.emptyList();

		if (_behaviors.containsKey(widgetId)) {
			result = new ArrayList<BehaviorDescriptor>(_behaviors.get(widgetId).values());
		}

		assert result != null;
		return result;

	}

}