org.eclipse.gmf.runtime.common.ui.services.properties/src/org/eclipse/gmf/runtime/common/ui/services/properties/PropertiesService.java - gmf-runtime/org.eclipse.gmf-runtime - Git at Google

 /******************************************************************************
  * Copyright (c) 2002, 2006 IBM Corporation 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:
  *    IBM Corporation - initial API and implementation
  ****************************************************************************/

 package org.eclipse.gmf.runtime.common.ui.services.properties;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;

 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.gmf.runtime.common.core.service.ExecutionStrategy;
 import org.eclipse.gmf.runtime.common.core.service.IOperation;
 import org.eclipse.gmf.runtime.common.core.service.IProvider;
 import org.eclipse.gmf.runtime.common.core.service.Service;
 import org.eclipse.gmf.runtime.common.ui.services.properties.internal.PSFCommonUIPlugin;
 import org.osgi.framework.Bundle;

 /**
  * The property service taks all property contributions from property source
  * providers and assembles these properties into a property source object.
  *
  * @author Tauseef A. Israr
  */
 public class PropertiesService
 	extends Service
 	implements IPropertiesProvider {

 	/**
 	 * A descriptor for providers defined by a configuration element.
 	 *
 	 * @author Natalia Balaba
 	 */
 	protected static class PropertiesProviderDescriptor
 		extends Service.ProviderDescriptor {

 		private static final String A_PLUGIN_LOADED = "verifyPluginLoaded"; //$NON-NLS-1$

 		/**
 		 * Create a instance of the <code>PropertiesProviderDescriptor</code>
 		 * given the properties provider configuration element.
 		 *
 		 * @param element -
 		 *            a property provider configuration element
 		 */
 		protected PropertiesProviderDescriptor(IConfigurationElement element) {
 			super(element);

 		}

 		/*
 		 * (non-Javadoc)
 		 *
 		 * @see org.eclipse.gmf.runtime.common.core.service.IProvider#provides(org.eclipse.gmf.runtime.common.core.service.IOperation)
 		 */
 		public boolean provides(IOperation operation) {
 			String attr_value = getElement().getAttribute(A_PLUGIN_LOADED);
 			Boolean pluginLoadedVerify = Boolean.valueOf(attr_value);

 			// instead of the policy we
 			// use plugin loaded test
 			if (pluginLoadedVerify.booleanValue() && !isPluginLoaded())
 				return false;

 			// the provider does not care if the plugin is loaded - use its
 			// provides() test
 			IProvider theProvider = getProvider();
 			return null != theProvider && theProvider.provides(operation);

 		}

 		/*
 		 * Verify if the declaring pluging of the propety provider is loaded.
 		 *
 		 * @return - true if the declaring pluging of the propety provider is
 		 * loaded, false otherwise
 		 */
 		private boolean isPluginLoaded() {
 			String pluginId = ((IExtension) getElement().getParent())
 				.getContributor().getName();
 			Bundle bundle = Platform.getBundle(pluginId);

 			return null != bundle
 				&& bundle.getState() == org.osgi.framework.Bundle.ACTIVE;

 		}
 	}

 	/**
 	 * The modifiers services are created per isntance of properties provider if
 	 * it has any modifiers associated with it. All instances of the
 	 * ModifiersService are kept in a private cache of the PropertiesService
 	 * singleton.
 	 *
 	 * @author nbalaba
 	 */
 	static class ModifiersService
 		extends Service {

 		/**
 		 * Create an isntance of the ModifierService
 		 */
 		public ModifiersService() {
 			super();
 		}

 		/**
 		 * Apply modifiers to the property source
 		 *
 		 * @param propertySource -
 		 *            a property source object which contains properties
 		 *            contributed by a single properties provider.
 		 * @return - a property source object after modifiers are applied to it
 		 */
 		public ICompositePropertySource applyModifiers(
 				ICompositePropertySource propertySource) {
 			ApplyModifiersOperation operation = new ApplyModifiersOperation(
 				propertySource);
 			this.execute(ExecutionStrategy.FORWARD, operation);
 			return operation.getPropertySource();

 		}

 	}

 	private static final String E_MODIFIER_PROVIDER = "Provider"; //$NON-NLS-1$

 	private static final String A_CLASS = "class"; //$NON-NLS-1$

 	private static final String STAR = "*"; //$NON-NLS-1$

 	/**
 	 * This attribute stores the instance of the Singleton class.
 	 */
 	private static PropertiesService uniqueInstance;

 	/*
 	 * a private cache of the modifier service objects. A ModifierService
 	 * instance will be created one per properties provider, given that there
 	 * are modifiers for that provider.
 	 */
 	private Map modifiersServices = new HashMap();

 	/*
 	 * A private cache of the modifier configuration elements per provider
 	 */
 	private Map modifiersMap = new HashMap();

 	/**
 	 * Extension point name for the properties providers extension point.
 	 */
 	private static final String PROPERTY_PROVIDERS_EXT_P_NAME = "propertiesProviders"; //$NON-NLS-1$

 	/**
 	 * Extension point name for the properties modifiers extension point.
 	 */
 	private static final String PROPERTY_MODIFIERS_EXT_P_NAME = "propertyModifiers"; //$NON-NLS-1$

 	/**
 	 * This operation implements the logic for returning the same instance of
 	 * the Singleton pattern.
 	 *
 	 * @return the singleton instance of <code>PropertiesService</code>
 	 */
 	public static PropertiesService getInstance() {

 		if (uniqueInstance == null) {
 			uniqueInstance = new PropertiesService();
 		}

 		return uniqueInstance;
 	}

 	/**
 	 * Constructor for PropertiesService.
 	 *
 	 */
 	private PropertiesService() {
 		super();

 		String pluginId = PSFCommonUIPlugin.getPluginId();

 		configureProviders(pluginId, PROPERTY_PROVIDERS_EXT_P_NAME);

 		configureModifiers(Platform.getExtensionRegistry()
 									.getExtensionPoint(pluginId, PROPERTY_MODIFIERS_EXT_P_NAME)
 									.getConfigurationElements());
 	}

 	/**
 	 * Return a property source for the given object
 	 *
 	 * @see org.eclipse.gmf.runtime.common.ui.services.properties.IPropertiesProvider#getPropertySource(Object)
 	 */
 	public ICompositePropertySource getPropertySource(Object object) {

 		GetPropertySourceOperation operation = new GetPropertySourceOperation(
 			object);
 		this.execute(ExecutionStrategy.FORWARD, operation);
 		return operation.getPropertySource();
 	}

 	/**
 	 * Apply property source modifiers appropriate for the given provider
 	 *
 	 * @param provider -
 	 *            a property provider which contributed the properties
 	 * @param propertySource -
 	 *            a property source object containing properties, contributed by
 	 *            the given provider
 	 */
 	public void applyModifiers(IPropertiesProvider provider,
 			ICompositePropertySource propertySource) {

 		ModifiersService modifiersService = getModifiersService(provider);
 		if (modifiersService != null)
 			modifiersService.applyModifiers(propertySource);

 	}

 	/**
 	 * Retrieve an instance of the ModifierService, appropriate for the given
 	 * provider.
 	 *
 	 * @param provider an instance of <code>IPropertiesProvider</code>
 	 * @return an instance of the ModifierService, appropriate for the given
 	 * provider.
 	 */
 	protected ModifiersService getModifiersService(IPropertiesProvider provider) {
 		return (ModifiersService) modifiersServices.get(provider.getClass()
 			.getName());
 	}

 	/**
 	 * Configure all modifier elements.
 	 *
 	 * @param elements -
 	 *            modifier configuration elements
 	 */
 	public final void configureModifiers(IConfigurationElement[] elements) {

 		List modifiersApplicableForAllProviders = new ArrayList();

 		for (int i = 0; i < elements.length; i++) {
 			IConfigurationElement element = elements[i];

 			IConfigurationElement[] associatedProviders = element
 				.getChildren(E_MODIFIER_PROVIDER);

 			for (int p = 0; p < associatedProviders.length; p++) {
 				IConfigurationElement associatedProvider = associatedProviders[p];
 				String providerId = associatedProvider.getAttribute(A_CLASS);

 				if (providerId.equals(STAR)) // the modifier specified that it
 					// is applicable to all (*)
 					// providers
 					modifiersApplicableForAllProviders.add(element);
 				else {
 					if (!modifiersMap.containsKey(providerId))
 						modifiersMap.put(providerId, new ArrayList());

 					((List) modifiersMap.get(providerId)).add(element);
 				}
 			}
 		}

 		for (Iterator e = modifiersMap.keySet().iterator(); e.hasNext();) {
 			String providerId = (String) e.next();
 			ArrayList modifierElements = (ArrayList) modifiersMap
 				.get(providerId);
 			modifierElements.addAll(modifiersApplicableForAllProviders); // add
 			// modifiers
 			// for all (*)
 			// providers
 			int modifiersForProvider = modifierElements.size();
 			if (modifiersForProvider > 0) {
 				IConfigurationElement[] elementsArray = new IConfigurationElement[modifiersForProvider];
 				System.arraycopy(modifierElements.toArray(), 0, elementsArray,
 					0, modifierElements.size());

 				initModifierServiceFor(providerId, elementsArray);

 			}
 		}

 	}

 	/*
 	 * Initialize a ModifierService for the property provider with the given Id.
 	 * This provider has modifiers attached to it, so it will need a Modifier
 	 * service.
 	 *
 	 * @param providerId - an id (a full class name) of the properties provider
 	 * who needs ModifersService @param modifierElements - configuratoion
 	 * elements
 	 */
 	private void initModifierServiceFor(String providerId,
 			IConfigurationElement[] modifierElements) {
 		ModifiersService modifierService = new ModifiersService();

 		modifierService.configureProviders(modifierElements);
 		modifiersServices.put(providerId, modifierService);
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.gmf.runtime.common.core.internal.service.Service#newProviderDescriptor(org.eclipse.core.runtime.IConfigurationElement)
 	 */
 	protected ProviderDescriptor newProviderDescriptor(
 			IConfigurationElement element) {

 		String providerId = element.getAttribute(A_CLASS);
 		modifiersMap.put(providerId, new ArrayList()); // create modifiers entry
 		// for each property
 		// provider
 		// the entry may be empty - if there are no modifiers for the given
 		// provider

 		// return whatever super does
 		return new PropertiesProviderDescriptor(element);
 	}

 }
	/******************************************************************************
	* Copyright (c) 2002, 2006 IBM Corporation 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:
	* IBM Corporation - initial API and implementation
	****************************************************************************/

	package org.eclipse.gmf.runtime.common.ui.services.properties;

	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Map;

	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtension;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.gmf.runtime.common.core.service.ExecutionStrategy;
	import org.eclipse.gmf.runtime.common.core.service.IOperation;
	import org.eclipse.gmf.runtime.common.core.service.IProvider;
	import org.eclipse.gmf.runtime.common.core.service.Service;
	import org.eclipse.gmf.runtime.common.ui.services.properties.internal.PSFCommonUIPlugin;
	import org.osgi.framework.Bundle;

	/**
	* The property service taks all property contributions from property source
	* providers and assembles these properties into a property source object.
	*
	* @author Tauseef A. Israr
	*/
	public class PropertiesService
	extends Service
	implements IPropertiesProvider {

	/**
	* A descriptor for providers defined by a configuration element.
	*
	* @author Natalia Balaba
	*/
	protected static class PropertiesProviderDescriptor
	extends Service.ProviderDescriptor {

	private static final String A_PLUGIN_LOADED = "verifyPluginLoaded"; //$NON-NLS-1$

	/**
	* Create a instance of the <code>PropertiesProviderDescriptor</code>
	* given the properties provider configuration element.
	*
	* @param element -
	* a property provider configuration element
	*/
	protected PropertiesProviderDescriptor(IConfigurationElement element) {
	super(element);

	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.gmf.runtime.common.core.service.IProvider#provides(org.eclipse.gmf.runtime.common.core.service.IOperation)
	*/
	public boolean provides(IOperation operation) {
	String attr_value = getElement().getAttribute(A_PLUGIN_LOADED);
	Boolean pluginLoadedVerify = Boolean.valueOf(attr_value);

	// instead of the policy we
	// use plugin loaded test
	if (pluginLoadedVerify.booleanValue() && !isPluginLoaded())
	return false;

	// the provider does not care if the plugin is loaded - use its
	// provides() test
	IProvider theProvider = getProvider();
	return null != theProvider && theProvider.provides(operation);

	}

	/*
	* Verify if the declaring pluging of the propety provider is loaded.
	*
	* @return - true if the declaring pluging of the propety provider is
	* loaded, false otherwise
	*/
	private boolean isPluginLoaded() {
	String pluginId = ((IExtension) getElement().getParent())
	.getContributor().getName();
	Bundle bundle = Platform.getBundle(pluginId);

	return null != bundle
	&& bundle.getState() == org.osgi.framework.Bundle.ACTIVE;

	}
	}

	/**
	* The modifiers services are created per isntance of properties provider if
	* it has any modifiers associated with it. All instances of the
	* ModifiersService are kept in a private cache of the PropertiesService
	* singleton.
	*
	* @author nbalaba
	*/
	static class ModifiersService
	extends Service {

	/**
	* Create an isntance of the ModifierService
	*/
	public ModifiersService() {
	super();
	}

	/**
	* Apply modifiers to the property source
	*
	* @param propertySource -
	* a property source object which contains properties
	* contributed by a single properties provider.
	* @return - a property source object after modifiers are applied to it
	*/
	public ICompositePropertySource applyModifiers(
	ICompositePropertySource propertySource) {
	ApplyModifiersOperation operation = new ApplyModifiersOperation(
	propertySource);
	this.execute(ExecutionStrategy.FORWARD, operation);
	return operation.getPropertySource();

	}

	}

	private static final String E_MODIFIER_PROVIDER = "Provider"; //$NON-NLS-1$

	private static final String A_CLASS = "class"; //$NON-NLS-1$

	private static final String STAR = "*"; //$NON-NLS-1$

	/**
	* This attribute stores the instance of the Singleton class.
	*/
	private static PropertiesService uniqueInstance;

	/*
	* a private cache of the modifier service objects. A ModifierService
	* instance will be created one per properties provider, given that there
	* are modifiers for that provider.
	*/
	private Map modifiersServices = new HashMap();

	/*
	* A private cache of the modifier configuration elements per provider
	*/
	private Map modifiersMap = new HashMap();

	/**
	* Extension point name for the properties providers extension point.
	*/
	private static final String PROPERTY_PROVIDERS_EXT_P_NAME = "propertiesProviders"; //$NON-NLS-1$

	/**
	* Extension point name for the properties modifiers extension point.
	*/
	private static final String PROPERTY_MODIFIERS_EXT_P_NAME = "propertyModifiers"; //$NON-NLS-1$

	/**
	* This operation implements the logic for returning the same instance of
	* the Singleton pattern.
	*
	* @return the singleton instance of <code>PropertiesService</code>
	*/
	public static PropertiesService getInstance() {

	if (uniqueInstance == null) {
	uniqueInstance = new PropertiesService();
	}

	return uniqueInstance;
	}

	/**
	* Constructor for PropertiesService.
	*
	*/
	private PropertiesService() {
	super();

	String pluginId = PSFCommonUIPlugin.getPluginId();

	configureProviders(pluginId, PROPERTY_PROVIDERS_EXT_P_NAME);

	configureModifiers(Platform.getExtensionRegistry()
	.getExtensionPoint(pluginId, PROPERTY_MODIFIERS_EXT_P_NAME)
	.getConfigurationElements());
	}

	/**
	* Return a property source for the given object
	*
	* @see org.eclipse.gmf.runtime.common.ui.services.properties.IPropertiesProvider#getPropertySource(Object)
	*/
	public ICompositePropertySource getPropertySource(Object object) {

	GetPropertySourceOperation operation = new GetPropertySourceOperation(
	object);
	this.execute(ExecutionStrategy.FORWARD, operation);
	return operation.getPropertySource();
	}

	/**
	* Apply property source modifiers appropriate for the given provider
	*
	* @param provider -
	* a property provider which contributed the properties
	* @param propertySource -
	* a property source object containing properties, contributed by
	* the given provider
	*/
	public void applyModifiers(IPropertiesProvider provider,
	ICompositePropertySource propertySource) {

	ModifiersService modifiersService = getModifiersService(provider);
	if (modifiersService != null)
	modifiersService.applyModifiers(propertySource);

	}

	/**
	* Retrieve an instance of the ModifierService, appropriate for the given
	* provider.
	*
	* @param provider an instance of <code>IPropertiesProvider</code>
	* @return an instance of the ModifierService, appropriate for the given
	* provider.
	*/
	protected ModifiersService getModifiersService(IPropertiesProvider provider) {
	return (ModifiersService) modifiersServices.get(provider.getClass()
	.getName());
	}

	/**
	* Configure all modifier elements.
	*
	* @param elements -
	* modifier configuration elements
	*/
	public final void configureModifiers(IConfigurationElement[] elements) {

	List modifiersApplicableForAllProviders = new ArrayList();

	for (int i = 0; i < elements.length; i++) {
	IConfigurationElement element = elements[i];

	IConfigurationElement[] associatedProviders = element
	.getChildren(E_MODIFIER_PROVIDER);

	for (int p = 0; p < associatedProviders.length; p++) {
	IConfigurationElement associatedProvider = associatedProviders[p];
	String providerId = associatedProvider.getAttribute(A_CLASS);

	if (providerId.equals(STAR)) // the modifier specified that it
	// is applicable to all (*)
	// providers
	modifiersApplicableForAllProviders.add(element);
	else {
	if (!modifiersMap.containsKey(providerId))
	modifiersMap.put(providerId, new ArrayList());

	((List) modifiersMap.get(providerId)).add(element);
	}
	}
	}

	for (Iterator e = modifiersMap.keySet().iterator(); e.hasNext();) {
	String providerId = (String) e.next();
	ArrayList modifierElements = (ArrayList) modifiersMap
	.get(providerId);
	modifierElements.addAll(modifiersApplicableForAllProviders); // add
	// modifiers
	// for all (*)
	// providers
	int modifiersForProvider = modifierElements.size();
	if (modifiersForProvider > 0) {
	IConfigurationElement[] elementsArray = new IConfigurationElement[modifiersForProvider];
	System.arraycopy(modifierElements.toArray(), 0, elementsArray,
	0, modifierElements.size());

	initModifierServiceFor(providerId, elementsArray);

	}
	}

	}

	/*
	* Initialize a ModifierService for the property provider with the given Id.
	* This provider has modifiers attached to it, so it will need a Modifier
	* service.
	*
	* @param providerId - an id (a full class name) of the properties provider
	* who needs ModifersService @param modifierElements - configuratoion
	* elements
	*/
	private void initModifierServiceFor(String providerId,
	IConfigurationElement[] modifierElements) {
	ModifiersService modifierService = new ModifiersService();

	modifierService.configureProviders(modifierElements);
	modifiersServices.put(providerId, modifierService);
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.gmf.runtime.common.core.internal.service.Service#newProviderDescriptor(org.eclipse.core.runtime.IConfigurationElement)
	*/
	protected ProviderDescriptor newProviderDescriptor(
	IConfigurationElement element) {

	String providerId = element.getAttribute(A_CLASS);
	modifiersMap.put(providerId, new ArrayList()); // create modifiers entry
	// for each property
	// provider
	// the entry may be empty - if there are no modifiers for the given
	// provider

	// return whatever super does
	return new PropertiesProviderDescriptor(element);
	}

	}