1 files changed, 108 insertions, 0 deletions
diff --git a/plugins/views/properties/org.eclipse.papyrus.views.properties/src/org/eclipse/papyrus/views/properties/runtime/SectionDiscriminator.java b/plugins/views/properties/org.eclipse.papyrus.views.properties/src/org/eclipse/papyrus/views/properties/runtime/SectionDiscriminator.java
new file mode 100644
index 00000000000..07dba74905e
--- /dev/null
+++ b/plugins/views/properties/org.eclipse.papyrus.views.properties/src/org/eclipse/papyrus/views/properties/runtime/SectionDiscriminator.java
@@ -0,0 +1,108 @@
+/*****************************************************************************
+ * Copyright (c) 2014 CEA LIST 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:
+ *   CEA LIST - Initial API and implementation
+ *   
+ *****************************************************************************/
+
+package org.eclipse.papyrus.views.properties.runtime;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.InternalEObject;
+import org.eclipse.papyrus.views.properties.contexts.Section;
+
+/**
+ * A proxy for {@link Section}s that distinguishes multiple occurrences of the same instance via an arbitrary discriminator.
+ */
+class SectionDiscriminator implements InvocationHandler {
+	private static final Class<?>[] PROXY_INTERFACES = { Section.class, EObject.class, InternalEObject.class };
+
+	private final Section section;
+	private final Object discriminator;
+
+	SectionDiscriminator(Section section, Object discriminator) {
+		this.section = section;
+		this.discriminator = discriminator;
+	}
+
+	static Section discriminate(Section section, Object discriminator) {
+		return (Section) Proxy.newProxyInstance(section.getClass().getClassLoader(), PROXY_INTERFACES, new SectionDiscriminator(section, discriminator));
+	}
+
+	static Object getDiscriminator(Section section) {
+		Object result = null;
+
+		if (Proxy.isProxyClass(section.getClass())) {
+			InvocationHandler handler = Proxy.getInvocationHandler(section);
+			if (handler instanceof SectionDiscriminator) {
+				result = ((SectionDiscriminator) handler).discriminator;
+			}
+		}
+
+		return result;
+	}
+
+	static boolean isDiscriminated(Section section) {
+		boolean result = false;
+
+		if ((section != null) && Proxy.isProxyClass(section.getClass())) {
+			InvocationHandler handler = Proxy.getInvocationHandler(section);
+			result = handler instanceof SectionDiscriminator;
+		}
+
+		return result;
+	}
+
+	public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+		Object result = null;
+
+		if (method.getDeclaringClass() == Object.class) {
+			// Don't delegate equals(), hashCode(), and monitor protocol
+			if (method.getName().equals("equals")) { //$NON-NLS-1$
+				if ((args[0] != null) && Proxy.isProxyClass(args[0].getClass())) {
+					result = this.equals(Proxy.getInvocationHandler(args[0]));
+				} else {
+					result = proxy == args[0];
+				}
+			} else if (method.getName().equals("hashCode")) { //$NON-NLS-1$
+				result = this.hashCode();
+			} else {
+				result = method.invoke(this, args);
+			}
+		} else {
+			result = method.invoke(section, args);
+		}
+
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		boolean result = obj == this;
+		if (!result && (obj instanceof SectionDiscriminator)) {
+			SectionDiscriminator other = (SectionDiscriminator) obj;
+			result = other.section == this.section && other.discriminator.equals(this.discriminator);
+		}
+		return result;
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + discriminator.hashCode();
+		result = prime * result + section.hashCode();
+		return result;
+	}
+
+}