added connection compositor base implementation

org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/compose/HierarchicElementConnectionCompositorBase.java

+/*--------------------------------------------------------------------------+
+$Id$
+|                                                                          |
+| Copyright 2011 ForTISS GmbH                     |
+|                                                                          |
+| Licensed under the Apache License, Version 2.0 (the "License");          |
+| you may not use this file except in compliance with the License.         |
+| You may obtain a copy of the License at                                  |
+|                                                                          |
+|    http://www.apache.org/licenses/LICENSE-2.0                            |
+|                                                                          |
+| Unless required by applicable law or agreed to in writing, software      |
+| distributed under the License is distributed on an "AS IS" BASIS,        |
+| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
+| See the License for the specific language governing permissions and      |
+| limitations under the License.                                           |
++--------------------------------------------------------------------------*/
+package org.fortiss.tooling.base.ui.compose;
+
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.gef.RootEditPart;
+import org.fortiss.tooling.base.model.element.IConnection;
+import org.fortiss.tooling.base.model.element.IConnector;
+import org.fortiss.tooling.base.model.element.IHierarchicElement;
+import org.fortiss.tooling.base.ui.dnd.DragContext;
+import org.fortiss.tooling.base.ui.dnd.DropContext;
+import org.fortiss.tooling.base.ui.editpart.RootEditPartBase;
+import org.fortiss.tooling.kernel.interfaces.IConnectionContext;
+import org.fortiss.tooling.kernel.services.ICompositorService;
+
+/**
+ * Base implementation for supporting direct connection of two
+ * {@link IHierarchicElement}s.
+ * 
+ * <p>
+ * Sub-classes must implement:
+ * <UL>
+ * <LI>
+ * {@link #createConnection(IHierarchicElement, IHierarchicElement, IConnectionContext)}
+ * <LI>
+ * {@link #createSourceConnector(IHierarchicElement, IHierarchicElement, IConnectionContext)}
+ * <LI>
+ * {@link #createTargetConnector(IHierarchicElement, IHierarchicElement, IConnectionContext)}
+ * <LI>
+ * {@link #getParent(IHierarchicElement, IHierarchicElement, IConnectionContext)}
+ * </UL>
+ * These methods are called in order to create specific model elements.
+ * 
+ * <p>
+ * Sub-classes may implement {@link #canConnectInterally()} to support internal
+ * connections. By default connectors of the parent element cannot be connected
+ * in internal view of the element.
+ * 
+ * @author hoelzl
+ * @author $Author$
+ * @version $Rev$
+ * @ConQAT.Rating RED Hash:
+ */
+public abstract class HierarchicElementConnectionCompositorBase<HE extends IHierarchicElement, S extends IHierarchicElement, T extends IHierarchicElement>
+		implements org.fortiss.tooling.kernel.interfaces.IConnector<S, T> {
+
+	/**
+	 * Determines whether connectors of the component may be connected
+	 * internally. The default value is <code>false</code>.
+	 */
+	protected boolean canConnectInterally() {
+		return false;
+	}
+
+	/** Creates the application specific {@link IConnection} model element. */
+	protected abstract IConnection createConnection(S source, T target,
+			IConnectionContext context);
+
+	/**
+	 * Creates the application specific source {@link IConnector} model element.
+	 */
+	protected abstract IConnector createSourceConnector(S source, T target,
+			IConnectionContext context);
+
+	/**
+	 * Creates the application specific target {@link IConnector} model element.
+	 */
+	protected abstract IConnector createTargetConnector(S source, T target,
+			IConnectionContext context);
+
+	/** Returns the parent model element used to compose the connection. */
+	protected abstract HE getParent(S source, T target,
+			IConnectionContext context);
+
+	/** {@inheritDoc} */
+	@Override
+	public boolean canConnect(S source, T target, EObject connection,
+			IConnectionContext context) {
+		if (context instanceof DragContext) {
+			DragContext dc = (DragContext) context;
+			// Is an internal feedback connection allowed?
+			if (dc.getSource() instanceof RootEditPartBase
+					&& dc.getTarget() instanceof RootEditPart) {
+				return canConnectInterally();
+			}
+		}
+		// all other connections are allowed by default
+		return true;
+	}
+
+	/** {@inheritDoc} */
+	@Override
+	public void connect(S source, T target, EObject conn,
+			IConnectionContext context) {
+
+		// create application specific connection
+		IConnection connection = createConnection(source, target, context);
+		// TODO (FH): use ID fixing here
+		getParent(source, target, context).getConnectionsList().add(connection);
+
+		// create application specific connectors
+		IConnector sourceConnector = createSourceConnector(source, target,
+				context);
+		IConnector targetConnector = createTargetConnector(source, target,
+				context);
+		// TODO (FH): use ID fixing here
+
+		// drop source connector
+		DropContext sourceDrop = context instanceof DragContext ? ((DragContext) context)
+				.getSourceDropContext() : null;
+		ICompositorService.INSTANCE
+				.compose(source, sourceConnector, sourceDrop);
+
+		// drop target target connector
+		DropContext targetDrop = context instanceof DragContext ? ((DragContext) context)
+				.getTargetDropContext() : null;
+		ICompositorService.INSTANCE
+				.compose(target, targetConnector, targetDrop);
+
+		// link connection to connectors
+		connection.setSource(sourceConnector);
+		connection.setTarget(targetConnector);
+	}
+}