--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwtx/core/commands/contexts/ContextManagerEvent.d	Wed Mar 26 00:57:19 2008 +0100
@@ -0,0 +1,168 @@
+/*******************************************************************************
+ * Copyright (c) 2003, 2005 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 dwtx.core.commands.contexts.ContextManagerEvent;
+import tango.util.collection.model.Set;
+
+import dwtx.core.commands.contexts.ContextManager;
+import dwtx.core.commands.common.AbstractBitSetEvent;
+
+import dwt.dwthelper.utils;
+
+/**
+ * <p>
+ * An event indicating that the set of defined context identifiers has changed.
+ * </p>
+ *
+ * @since 3.1
+ * @see IContextManagerListener#contextManagerChanged(ContextManagerEvent)
+ */
+public final class ContextManagerEvent : AbstractBitSetEvent {
+
+    /**
+     * The bit used to represent whether the set of defined contexts has
+     * changed.
+     */
+    private static const int CHANGED_CONTEXT_DEFINED = 1 << 1;
+
+    /**
+     * The bit used to represent whether the set of active contexts has changed.
+     */
+    private static const int CHANGED_CONTEXTS_ACTIVE = 1;
+
+    /**
+     * The context identifier that was added or removed from the list of defined
+     * context identifiers.
+     */
+    private const String contextId;
+
+    /**
+     * The context manager that has changed.
+     */
+    private const ContextManager contextManager;
+
+    /**
+     * The set of context identifiers (strings) that were active before the
+     * change occurred. If the active contexts did not changed, then this value
+     * is <code>null</code>.
+     */
+    private const Set!(String) previouslyActiveContextIds;
+
+    /**
+     * Creates a new instance of this class.
+     *
+     * @param contextManager
+     *            the instance of the interface that changed; must not be
+     *            <code>null</code>.
+     * @param contextId
+     *            The context identifier that was added or removed; may be
+     *            <code>null</code> if the active contexts are changing.
+     * @param contextIdAdded
+     *            Whether the context identifier became defined (otherwise, it
+     *            became undefined).
+     * @param activeContextsChanged
+     *            Whether the list of active contexts has changed.
+     * @param previouslyActiveContextIds
+     *            the set of identifiers of previously active contexts. This set
+     *            may be empty. If this set is not empty, it must only contain
+     *            instances of <code>String</code>. This set must be
+     *            <code>null</code> if activeContextChanged is
+     *            <code>false</code> and must not be null if
+     *            activeContextChanged is <code>true</code>.
+     */
+    public this(ContextManager contextManager,
+            String contextId, bool contextIdAdded,
+            bool activeContextsChanged,
+            Set!(String) previouslyActiveContextIds) {
+        if (contextManager is null) {
+            throw new NullPointerException();
+        }
+
+        this.contextManager = contextManager;
+        this.contextId = contextId;
+        this.previouslyActiveContextIds = previouslyActiveContextIds;
+
+        if (contextIdAdded) {
+            changedValues |= CHANGED_CONTEXT_DEFINED;
+        }
+        if (activeContextsChanged) {
+            changedValues |= CHANGED_CONTEXTS_ACTIVE;
+        }
+    }
+
+    /**
+     * Returns the context identifier that was added or removed.
+     *
+     * @return The context identifier that was added or removed. This value may
+     *         be <code>null</code> if no context identifier was added or
+     *         removed.
+     */
+    public final String getContextId() {
+        return contextId;
+    }
+
+    /**
+     * Returns the instance of the interface that changed.
+     *
+     * @return the instance of the interface that changed. Guaranteed not to be
+     *         <code>null</code>.
+     */
+    public final ContextManager getContextManager() {
+        return contextManager;
+    }
+
+    /**
+     * Returns the set of identifiers to previously active contexts.
+     *
+     * @return the set of identifiers to previously active contexts. This set
+     *         may be empty. If this set is not empty, it is guaranteed to only
+     *         contain instances of <code>String</code>. This set is
+     *         guaranteed to be <code>null</code> if
+     *         haveActiveContextChanged() is <code>false</code> and is
+     *         guaranteed to not be <code>null</code> if
+     *         haveActiveContextsChanged() is <code>true</code>.
+     */
+    public final Set!(String) getPreviouslyActiveContextIds() {
+        return previouslyActiveContextIds;
+    }
+
+    /**
+     * Returns whether the active context identifiers have changed.
+     *
+     * @return <code>true</code> if the collection of active contexts changed;
+     *         <code>false</code> otherwise.
+     */
+    public final bool isActiveContextsChanged() {
+        return ((changedValues & CHANGED_CONTEXTS_ACTIVE) !is 0);
+    }
+
+    /**
+     * Returns whether the list of defined context identifiers has changed.
+     *
+     * @return <code>true</code> if the list of context identifiers has
+     *         changed; <code>false</code> otherwise.
+     */
+    public final bool isContextChanged() {
+        return (contextId !is null);
+    }
+
+    /**
+     * Returns whether the context identifier became defined. Otherwise, the
+     * context identifier became undefined.
+     *
+     * @return <code>true</code> if the context identifier became defined;
+     *         <code>false</code> if the context identifier became undefined.
+     */
+    public final bool isContextDefined() {
+        return (((changedValues & CHANGED_CONTEXT_DEFINED) !is 0) && (contextId !is null));
+    }
+}