ca.uwaterloo.gp.fmp.constraints.ui.ConstraintsViewDropAdapter.java Source code

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Here is the source code for ca.uwaterloo.gp.fmp.constraints.ui.ConstraintsViewDropAdapter.java

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/**************************************************************************************
 * Copyright (c) 2005, 2006 Generative Software Development Lab, University of Waterloo
 * 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:
 *   1. Generative Software Development Lab, University of Waterloo,
 *      http://gp.uwaterloo.ca  - initial API and implementation
 **************************************************************************************/
package ca.uwaterloo.gp.fmp.constraints.ui;

import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerDropAdapter;
import org.eclipse.swt.dnd.TransferData;

import ca.uwaterloo.gp.fmp.Constraint;
import ca.uwaterloo.gp.fmp.Feature;
import ca.uwaterloo.gp.fmp.Node;

/**
 * @author Chang Hwan Peter Kim <chpkim@swen.uwaterloo.ca>
 * Handles drag and drop of features onto ConstraintView.
 */
public class ConstraintsViewDropAdapter extends ViewerDropAdapter {
    /**
     * @param viewer
     */
    public ConstraintsViewDropAdapter(Viewer viewer) {
        super(viewer);
    }

    /* (non-Javadoc)
     * @see org.eclipse.jface.viewers.ViewerDropAdapter#performDrop(java.lang.Object)
     */
    public boolean performDrop(Object data) {
        // TODO Auto-generated method stub
        StructuredSelection structuredSelection = (StructuredSelection) data;

        // dropping only 1 feature is allowed
        if (structuredSelection.size() == 1) {
            Object toBeDroppedObj = structuredSelection.getFirstElement();

            // check the type of the feature to be dropped
            if (toBeDroppedObj instanceof Feature && !(toBeDroppedObj instanceof Node)) //to be changed
            {
                Feature toBeDroppedFeature = (Feature) toBeDroppedObj;

                // Get the constraint to be dropped onto
                Object target = getCurrentTarget();

                // if it is confirmed that the feature will be dropped onto an existing constraint
                if (target != null && target instanceof Constraint && ((Constraint) target).getText() != null) {
                    Constraint constraintToBeModified = (Constraint) target;
                    String featureName = toBeDroppedFeature.getName() == null ? "unnamed feature"
                            : toBeDroppedFeature.getName();
                    constraintToBeModified.setText(constraintToBeModified.getText() + featureName);

                    // update the view
                    ((TreeViewer) getViewer()).update(target, null);
                }
            }
        }

        return true;
    }

    /* (non-Javadoc)
     * @see org.eclipse.jface.viewers.ViewerDropAdapter#validateDrop(java.lang.Object, int, org.eclipse.swt.dnd.TransferData)
     */
    public boolean validateDrop(Object target, int operation, TransferData transferType) {
        // TODO Auto-generated method stub
        return true;
    }
}