--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/org.eclipse.core.commands/src/org/eclipse/core/commands/common/HandleObjectManager.d	Sat Mar 14 18:23:29 2009 +0100
@@ -0,0 +1,94 @@
+/*******************************************************************************
+ * Copyright (c) 2005, 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
+ * Port to the D programming language:
+ *     Frank Benoit <benoit@tionex.de>
+ *******************************************************************************/
+
+module org.eclipse.core.commands.common.HandleObjectManager;
+
+import org.eclipse.core.commands.common.HandleObject;
+import org.eclipse.core.commands.common.EventManager;
+import java.lang.all;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * <p>
+ * A manager of {@link HandleObject} instances. This has some common behaviour
+ * which is shared between all such managers.
+ * </p>
+ * <p>
+ * Clients may extend.
+ * </p>
+ *
+ * @since 3.2
+ */
+public abstract class HandleObjectManager : EventManager {
+
+    /**
+     * The set of handle objects that are defined. This value may be empty, but
+     * it is never <code>null</code>.
+     */
+    protected const Set definedHandleObjects;
+
+    /**
+     * The map of identifiers (<code>String</code>) to handle objects (
+     * <code>HandleObject</code>). This collection may be empty, but it is
+     * never <code>null</code>.
+     */
+    protected const Map handleObjectsById;
+
+    public this(){
+        definedHandleObjects = new HashSet();
+        handleObjectsById = new HashMap();
+    }
+
+    /**
+     * Verifies that the identifier is valid. Exceptions will be thrown if the
+     * identifier is invalid in some way.
+     *
+     * @param id
+     *            The identifier to validate; may be anything.
+     */
+    protected final void checkId(String id) {
+        if (id is null) {
+            throw new NullPointerException(
+                    "A handle object may not have a null identifier"); //$NON-NLS-1$
+        }
+
+        if (id.length < 1) {
+            throw new IllegalArgumentException(
+                    "The handle object must not have a zero-length identifier"); //$NON-NLS-1$
+        }
+    }
+
+    /**
+     * Returns the set of identifiers for those handle objects that are defined.
+     *
+     * @return The set of defined handle object identifiers; this value may be
+     *         empty, but it is never <code>null</code>.
+     */
+    protected final HashSet getDefinedHandleObjectIds() {
+        HashSet definedHandleObjectIds = new HashSet(definedHandleObjects
+                .size());
+        Iterator handleObjectItr = definedHandleObjects.iterator();
+        while (handleObjectItr.hasNext()) {
+            HandleObject handleObject = cast(HandleObject) handleObjectItr
+                    .next();
+            String id = handleObject.getId();
+            definedHandleObjectIds.add(id);
+        }
+        return definedHandleObjectIds;
+    }
+}