+added custom scope provider

package org.etsi.mts.tdl.scoping;

import org.eclipse.emf.common.util.BasicEList;

import org.eclipse.emf.common.util.EList;

import org.eclipse.emf.ecore.EObject;

import org.eclipse.emf.ecore.EReference;

import org.eclipse.xtext.naming.IQualifiedNameConverter;

import org.eclipse.xtext.naming.QualifiedName;

import org.eclipse.xtext.scoping.IScope;

import org.eclipse.xtext.scoping.Scopes;

import org.eclipse.xtext.scoping.impl.AbstractDeclarativeScopeProvider;

import org.etsi.mts.tdl.Assignment;

import org.etsi.mts.tdl.Behaviour;

import org.etsi.mts.tdl.Block;

import org.etsi.mts.tdl.ComponentInstance;

import org.etsi.mts.tdl.Connection;

import org.etsi.mts.tdl.DataElementMapping;

import org.etsi.mts.tdl.DataInstanceUse;

import org.etsi.mts.tdl.Element;

import org.etsi.mts.tdl.GateInstance;

import org.etsi.mts.tdl.GateReference;

import org.etsi.mts.tdl.MemberAssignment;

import org.etsi.mts.tdl.Parameter;

import org.etsi.mts.tdl.ParameterBinding;

import org.etsi.mts.tdl.ParameterMapping;

import org.etsi.mts.tdl.StructuredDataInstance;

import org.etsi.mts.tdl.StructuredDataType;

import org.etsi.mts.tdl.Target;

import org.etsi.mts.tdl.TestConfiguration;

import org.etsi.mts.tdl.TestDescription;

import org.etsi.mts.tdl.Variable;

import com.google.common.base.Function;

import com.google.inject.Inject;

/**

 * This class contains custom scoping description.

 * 

 * see : http://www.eclipse.org/Xtext/documentation/latest/xtext.html#scoping on

 * how and when to use it

 * 

 */

public class TDLan2ScopeProvider extends AbstractDeclarativeScopeProvider {

	@Inject

	private IQualifiedNameConverter qualifiedNameConverter;

	@Override

	public IScope getScope(EObject context, EReference reference) {

		if (reference.getEType().getInstanceClass() == GateInstance.class) {

			if (context instanceof GateReference) {

				GateReference gate = (GateReference) context;

				IScope scope = Scopes.scopeFor(gate.getComponent().getType().getGateInstance());

				return scope;

			}

		} else if (reference.getEType().getInstanceClass() == ComponentInstance.class) {

			if (context instanceof Behaviour || context instanceof Block) {

				TestDescription testDescription = getTestDescription((Element) context);

				if (testDescription!=null) {

					TestConfiguration configuration = testDescription.getTestConfiguration();

					IScope scope = Scopes.scopeFor(configuration.getComponentInstance());

					return scope;

				}

			} else if (context instanceof GateReference) {

				TestConfiguration configuration = getTestConfiguration((Element) context);

				EList<ComponentInstance> components = configuration.getComponentInstance();

				IScope scope = Scopes.scopeFor(components);

				return scope;

			} 

		} else if (reference.getEType().getInstanceClass() == GateReference.class) {

			//TODO: safety checks in case invalid configuration is specified

			//TODO: only suggest connected gates as targets?

			if (context instanceof Behaviour || context instanceof Target || context instanceof Block) {

				TestConfiguration configuration = getTestDescription((Element) context).getTestConfiguration();

				EList<EObject> elements = new BasicEList<>();

				for (Connection c : configuration.getConnection()) {

					elements.addAll(c.getEndPoint());

				}

				IScope scope = Scopes.scopeFor(elements, new Function<EObject, QualifiedName>() {

			        @Override 

			        public QualifiedName apply(EObject o) {

			        	GateReference r = (GateReference) o;

			        	String n = r.getComponent().getName()+"."+r.getGate().getName();

			            QualifiedName qualifiedName = qualifiedNameConverter.toQualifiedName(n);

			            return qualifiedName;

			        }

			    }, IScope.NULLSCOPE); 

				return scope;

			}

		} else if (Parameter.class.isAssignableFrom(reference.getEType().getInstanceClass())) {

			if (context instanceof MemberAssignment) {

				if (context.eContainer() instanceof StructuredDataInstance) {

					IScope scope = Scopes.scopeFor(((StructuredDataType)((StructuredDataInstance)context.eContainer()).getDataType()).getMember());

					return scope;

				}

			} else if (context instanceof ParameterMapping) {

				if (context.eContainer() instanceof DataElementMapping) {

					if (((DataElementMapping)context.eContainer()).getMappableDataElement() instanceof StructuredDataType) {

						IScope scope = Scopes.scopeFor(((StructuredDataType)((DataElementMapping)context.eContainer()).getMappableDataElement()).getMember());

						return scope;

					}

				}				

			} else if (context instanceof ParameterBinding) {

				if (context.eContainer() instanceof DataInstanceUse) {

					if (((DataInstanceUse)context.eContainer()).getDataInstance() instanceof StructuredDataInstance) {

						IScope scope = Scopes.scopeFor(((StructuredDataType)((StructuredDataInstance)((DataInstanceUse)context.eContainer()).getDataInstance()).getDataType()).getMember());

						return scope;

					}

				}

			}

		} else if (reference.getEType().getInstanceClass() == Variable.class) {

			if (context instanceof Assignment) {

				if (((Assignment)context).getComponentInstance()!=null) {

					IScope scope = Scopes.scopeFor(((Assignment)context).getComponentInstance().getType().getVariable());

					return scope;

				}

			}

		} else {

		}

		if (context instanceof Block) {

			TestDescription testDescription = getTestDescription((Element) context);

			if (testDescription!=null) {

				TestConfiguration configuration = testDescription.getTestConfiguration();

				IScope scope = Scopes.scopeFor(configuration.getComponentInstance());

				return scope;

			}

		}		

		return super.getScope(context, reference);

	}

	private TestConfiguration getTestConfiguration(Element self) {

		if (self.eContainer()!=null) {

			if (!(self.eContainer() instanceof TestConfiguration)) {

				return getTestConfiguration((Element) self.eContainer());

			} else {

				return (TestConfiguration)self.eContainer();

			}

		} 

		return null;

	}

	private TestDescription getTestDescription(Element self) {

		if (self.eContainer()!=null) {

			if (!(self.eContainer() instanceof TestDescription)) {

				return getTestDescription((Element) self.eContainer());

			} else {

				return (TestDescription)self.eContainer();

			}

		} 

		return null;

	}

}

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