org.eclipse.gmf.examples.runtime.diagram.logic/src/org/eclipse/gmf/examples/runtime/diagram/logic/internal/nonactivating/LogicLayoutProvider.java

/******************************************************************************
 * 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 
 ****************************************************************************/

package org.eclipse.gmf.examples.runtime.diagram.logic.internal.nonactivating;

import java.util.Iterator;

import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.gmf.runtime.common.core.service.IOperation;
import org.eclipse.gmf.runtime.diagram.ui.providers.CompositeTopDownProvider;
import org.eclipse.gmf.runtime.diagram.ui.services.layout.ILayoutNode;
import org.eclipse.gmf.runtime.diagram.ui.services.layout.ILayoutNodeOperation;
import org.eclipse.gmf.runtime.diagram.ui.services.layout.LayoutType;
import org.eclipse.gmf.runtime.notation.Diagram;
import org.eclipse.gmf.runtime.notation.View;


/**
 * @author mmostafa
 * Custom provider that lays out the logic Diagram in a top to down fashion.
 */

public class LogicLayoutProvider
    extends CompositeTopDownProvider {

    public boolean provides(IOperation operation) {
        // enable this provider only on logic diagrams
        if (operation instanceof ILayoutNodeOperation) {
            Iterator nodes = ((ILayoutNodeOperation) operation)
                .getLayoutNodes().listIterator();
            if (nodes.hasNext()) {
                View node = ((ILayoutNode) nodes.next()).getNode();
                Diagram container = node.getDiagram();
                if (container == null
                    || !(container.getType().equals("logic"))) //$NON-NLS-1$
                    return false;
            }
        } else {
            return false;
        }
        IAdaptable layoutHint = ((ILayoutNodeOperation) operation)
            .getLayoutHint();
        String layoutType = (String) layoutHint.getAdapter(String.class);
        return LayoutType.DEFAULT.equals(layoutType);
    }

}