1 files changed, 113 insertions, 0 deletions
diff --git a/plugins/core/org.eclipse.papyrus.modelexplorer/src/org/eclipse/papyrus/modelexplorer/handler/DeleteCommandHandler.java b/plugins/core/org.eclipse.papyrus.modelexplorer/src/org/eclipse/papyrus/modelexplorer/handler/DeleteCommandHandler.java
new file mode 100644
index 00000000000..f5f0af8d0fd
--- /dev/null
+++ b/plugins/core/org.eclipse.papyrus.modelexplorer/src/org/eclipse/papyrus/modelexplorer/handler/DeleteCommandHandler.java
@@ -0,0 +1,113 @@
+/*****************************************************************************
+ * Copyright (c) 2010 CEA LIST.
+ *
+ *    
+ * 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:
+ * 
+ * 		Yann Tanguy (CEA LIST) yann.tanguy@cea.fr - Initial API and implementation
+ *
+ *****************************************************************************/
+package org.eclipse.papyrus.modelexplorer.handler;
+
+import org.eclipse.core.commands.IHandler;
+import org.eclipse.emf.common.command.Command;
+import org.eclipse.emf.common.command.UnexecutableCommand;
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.gmf.runtime.common.core.command.CompositeCommand;
+import org.eclipse.gmf.runtime.common.core.command.ICommand;
+import org.eclipse.gmf.runtime.emf.type.core.requests.DestroyElementRequest;
+import org.eclipse.papyrus.service.edit.service.ElementEditServiceUtils;
+import org.eclipse.papyrus.service.edit.service.IElementEditService;
+
+/**
+ * Default handler for Delete command used in the ModelExplorer contextual menu.
+ * 
+ */
+public class DeleteCommandHandler extends AbstractCommandHandler implements IHandler {
+
+	/** Current deleteCommand for selection (updated in {@link DeleteCommandHandler#isEnabled()}) */
+	private Command deleteCommand;
+
+	/**
+	 * <pre>
+	 * 
+	 * Build the delete command for a set of EObject selected in the ModelExplorer.
+	 * The delete command is given by the {@link IElementEditService} of selected 
+	 * elements.
+	 * 
+	 * @return the composite deletion command for current selection
+	 * 
+	 * @TODO : Manage possible Diagrams listed in the selection
+	 * 
+	 * </pre>
+	 */
+	private Command buildCommand() {
+
+		ICommand gmfCommand = null;
+		for(EObject selectedEObject : getSelectedElements()) {
+
+			IElementEditService provider = ElementEditServiceUtils.getCommandProvider(selectedEObject);
+			if(provider == null) {
+				continue;
+			}
+
+			// Retrieve delete command from the Element Edit service
+			DestroyElementRequest request = new DestroyElementRequest(selectedEObject, false);
+			ICommand deleteCommand = provider.getEditCommand(request);
+
+			// Add current EObject destroy command to the global command
+			gmfCommand = CompositeCommand.compose(gmfCommand, deleteCommand);
+		}
+
+		if(gmfCommand == null) {
+			return UnexecutableCommand.INSTANCE;
+		}
+
+		Command emfCommand = new GMFtoEMFCommandWrapper(gmfCommand.reduce());
+		return emfCommand;
+	}
+
+	/**
+	 * 
+	 * @see org.eclipse.papyrus.modelexplorer.handler.AbstractCommandHandler#getCommand()
+	 * 
+	 * @return current command (only built here when the stored command is null)
+	 */
+	protected Command getCommand() {
+
+		// Build the delete command in case it is not initialized.
+		if(deleteCommand == null) {
+			deleteCommand = buildCommand();
+		}
+
+		return deleteCommand;
+	}
+
+	/**
+	 * <pre>
+	 * 
+	 * Calculates whether the handler is enabled or not. The command is re-built on the
+	 * basis of current selection before any attempt to test if current command can be executed.
+	 * 
+	 * @see org.eclipse.papyrus.modelexplorer.handler.AbstractCommandHandler#isEnabled()
+	 * 
+	 * @return true if the command can be executed
+	 * 
+	 * </pre>
+	 */
+	public boolean isEnabled() {
+
+		// Prepare and store the delete command only when trying to find out 
+		// whether the command is enabled or not.
+		// This assumes the isEnabled() method is called each time the contextual menu
+		// opens. 
+		deleteCommand = buildCommand();
+
+		return super.isEnabled();
+	}
+}