com.siteview.mde.internal.ui.editor.schema.ElementSectionDragAdapter.java Source code

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Here is the source code for com.siteview.mde.internal.ui.editor.schema.ElementSectionDragAdapter.java

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/*******************************************************************************
 *  Copyright (c) 2000, 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 com.siteview.mde.internal.ui.editor.schema;

import java.util.ArrayList;
import java.util.Iterator;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import com.siteview.mde.internal.core.ischema.ISchemaObject;
import com.siteview.mde.internal.ui.editor.ModelDataTransfer;
import org.eclipse.swt.dnd.*;
import org.eclipse.swt.widgets.Control;

public class ElementSectionDragAdapter extends DragSourceAdapter {
    private ISelectionProvider fSelectionProvider;
    private Object fDragData;

    /**
     * NavigatorDragAction constructor comment.
     */
    public ElementSectionDragAdapter(ISelectionProvider provider) {
        fSelectionProvider = provider;

    }

    /**
     * Returns the data to be transferred in a drag and drop
     * operation.
     */
    public void dragSetData(DragSourceEvent event) {
        if (event.doit == false)
            return;
        if (ModelDataTransfer.getInstance().isSupportedType(event.dataType)) {
            event.data = getSelectedModelObjects();
            fDragData = event.data;
            return;
        }
        if (TextTransfer.getInstance().isSupportedType(event.dataType)) {
            event.data = createTextualRepresentation((IStructuredSelection) fSelectionProvider.getSelection());
            fDragData = null;
            return;
        }
    }

    private String createTextualRepresentation(IStructuredSelection sel) {
        StringBuffer buf = new StringBuffer();
        for (Iterator iter = sel.iterator(); iter.hasNext();) {
            String name = iter.next().toString();
            buf.append(name);
            buf.append(" "); //$NON-NLS-1$
        }
        return buf.toString();
    }

    /**
     * All selection must be named model objects.
     */
    public void dragStart(DragSourceEvent event) {

        // Workaround for 1GEUS9V
        DragSource dragSource = (DragSource) event.widget;
        Control control = dragSource.getControl();
        if (control != control.getDisplay().getFocusControl()) {
            event.doit = false;
            return;
        }

        event.doit = canDrag();
    }

    public void dragFinished(DragSourceEvent event) {
        if (event.doit == false || fDragData == null)
            return;
        fDragData = null;
    }

    private boolean canDrag() {
        return canCopy((IStructuredSelection) fSelectionProvider.getSelection());
    }

    private boolean canCopy(IStructuredSelection selection) {
        Object prev = null;
        for (Iterator iter = selection.iterator(); iter.hasNext();) {
            Object obj = iter.next();
            if (!(obj instanceof ISchemaObject))
                return false;
            if (prev != null) {
                if (prev.getClass().equals(obj.getClass()) == false)
                    return false;
            } else
                prev = obj;
        }
        return true;
    }

    private ISchemaObject[] getSelectedModelObjects() {
        return createObjectRepresentation((IStructuredSelection) fSelectionProvider.getSelection());
    }

    private ISchemaObject[] createObjectRepresentation(IStructuredSelection selection) {
        ArrayList objects = new ArrayList();
        for (Iterator iter = selection.iterator(); iter.hasNext();) {
            Object obj = iter.next();
            if (obj instanceof ISchemaObject)
                objects.add(obj);
            else
                return new ISchemaObject[0];
        }
        return (ISchemaObject[]) objects.toArray(new ISchemaObject[objects.size()]);
    }

    public Object[] getDragData() {
        if (fDragData instanceof Object[])
            return (Object[]) fDragData;
        return new Object[] { fDragData };
    }
}