org.eclipse.gmf.runtime.diagram.ui/src/org/eclipse/gmf/runtime/diagram/ui/internal/actions/PromptingDeleteAction.java

/******************************************************************************
 * Copyright (c) 2004, 2008 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 
 ****************************************************************************/


package org.eclipse.gmf.runtime.diagram.ui.internal.actions;

import java.util.List;

import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.emf.edit.domain.EditingDomain;
import org.eclipse.emf.edit.domain.IEditingDomainProvider;
import org.eclipse.emf.transaction.TransactionalEditingDomain;
import org.eclipse.emf.workspace.AbstractEMFOperation;
import org.eclipse.gef.EditPart;
import org.eclipse.gef.RequestConstants;
import org.eclipse.gef.commands.Command;
import org.eclipse.gef.commands.CompoundCommand;
import org.eclipse.gef.ui.actions.DeleteAction;
import org.eclipse.gmf.runtime.common.core.command.CommandResult;
import org.eclipse.gmf.runtime.diagram.core.util.ViewUtil;
import org.eclipse.gmf.runtime.diagram.ui.commands.CommandProxy;
import org.eclipse.gmf.runtime.diagram.ui.commands.ICommandProxy;
import org.eclipse.gmf.runtime.diagram.ui.editparts.IGraphicalEditPart;
import org.eclipse.gmf.runtime.diagram.ui.internal.DiagramUIPlugin;
import org.eclipse.gmf.runtime.diagram.ui.l10n.DiagramUIMessages;
import org.eclipse.gmf.runtime.diagram.ui.preferences.IPreferenceConstants;
import org.eclipse.gmf.runtime.diagram.ui.requests.GroupRequestViaKeyboard;
import org.eclipse.gmf.runtime.emf.commands.core.command.CompositeTransactionalCommand;
import org.eclipse.gmf.runtime.notation.View;
import org.eclipse.ui.IWorkbenchPart;


/**
 * Delete Action originating via keyboard using the 'Delete' hot/shortcut key
 * 
 * @author bagrodia
 * @canBeSeenBy org.eclipse.gmf.runtime.diagram.ui.*
 * Created on Jun 30, 2004
 */
public class PromptingDeleteAction
	extends DeleteAction {
	

	/**
	 * Constructs a <code>PromptingDeleteAction</code> using the specified part.
	 * @param part The part for this action
	 */
	public PromptingDeleteAction(IWorkbenchPart part) {
		super(part);
	}

	
	
	/**
	 * create a command for the passed list of objects
	 * @param objects objects to associate with the command
	 * @return <code>Command</code>
	 */
	
	public Command createCommand(List objects) {
		
		if(objects.isEmpty()) return null;
		
		
		/* Create the delete request */
		GroupRequestViaKeyboard deleteReq =
			new GroupRequestViaKeyboard(RequestConstants.REQ_DELETE);
		
		deleteReq.setShowInformationDialog(DiagramUIPlugin.getInstance()
			.getPreferenceStore().getBoolean(
				IPreferenceConstants.PREF_PROMPT_ON_DEL_FROM_DIAGRAM));

		CompoundCommand deleteCC =
			new CompoundCommand(DiagramUIMessages.DeleteCommand_Label);


		deleteReq.setShowInformationDialog(false);
		boolean containsSemanticElement = false;
		CompositeTransactionalCommand command = null;
        TransactionalEditingDomain editingDomain = null;
		for (int i = 0; i < objects.size(); i++) {			
			if(objects.get(i) instanceof EditPart){
				/* Get the next part */
				EditPart editPart = (EditPart) objects.get(i);
				if (editPart instanceof IGraphicalEditPart){
                    if (editingDomain == null) {
                        editingDomain = ((IGraphicalEditPart) editPart).getEditingDomain();
                    }
					if (!containsSemanticElement&&
						ViewUtil.resolveSemanticElement((View)editPart.getModel()) != null){
						containsSemanticElement = true;
						deleteReq.setShowInformationDialog(true);
					}
				}

				/* Send the request to the edit part */
				Command command2 = editPart.getCommand(deleteReq);
				if (command2 != null && editingDomain != null) {
					if (command == null)
						command = new CompositeTransactionalCommand(editingDomain, command2.getLabel());
					if ( containsSemanticElement ) {
						deleteReq.setShowInformationDialog(false);
					}
					command.compose(new CommandProxy(command2));
				}
			}
		}		
		
		
		if ((command != null)&&(command.size() > 0))
			deleteCC.add(new ICommandProxy(command));
		return deleteCC;
	}	
	
	
	
	/**
	 * This is by purpose set to true since there is no need to go to editpart 
	 * and obtain commands.
	 * @see org.eclipse.gef.ui.actions.DeleteAction#calculateEnabled()
	 * 
	 */
	protected boolean calculateEnabled() {		
		return true;
	}
	
	public void run() {
        TransactionalEditingDomain editingDomain = null;
        // try adapting the workbench part
        IWorkbenchPart part = getWorkbenchPart();
        if (part != null) {
        	IEditingDomainProvider edProvider = (IEditingDomainProvider) part
        	.getAdapter(IEditingDomainProvider.class);

        	if (edProvider != null) {
        		EditingDomain domain = edProvider.getEditingDomain();

        		if (domain instanceof TransactionalEditingDomain) {
        			editingDomain = (TransactionalEditingDomain) domain;
        		}
        	}
        }        
        if (editingDomain != null) {
        	final Command command[] = new Command[1];
        	AbstractEMFOperation operation = new AbstractEMFOperation(
        			editingDomain, DiagramUIMessages.DeleteCommand_Label) {

        		protected IStatus doExecute(IProgressMonitor monitor,
        				IAdaptable info)
        		throws ExecutionException {
        			command[0] = createCommand(getSelectedObjects());
        			return CommandResult.newOKCommandResult().getStatus();

        		}
        	};
        	try {
        		operation.execute(null, null);
        	} catch (ExecutionException e) {
        		// do nothing
        	}

        	if (command[0] != null)
        		execute(command[0]);
        }
    }


}