ch.elexis.core.ui.util.PersistentObjectDragSource.java Source code

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Here is the source code for ch.elexis.core.ui.util.PersistentObjectDragSource.java

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/*******************************************************************************
 * Copyright (c) 2007-2015, G. Weirich and Elexis
 * 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:
 *    G. Weirich - initial implementation
 *      M. Descher - several changes
 *******************************************************************************/

package ch.elexis.core.ui.util;

import java.util.List;

import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredViewer;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.DragSource;
import org.eclipse.swt.dnd.DragSourceEvent;
import org.eclipse.swt.dnd.DragSourceListener;
import org.eclipse.swt.dnd.TextTransfer;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.widgets.Control;

import ch.elexis.core.constants.StringConstants;
import ch.elexis.data.PersistentObject;

public class PersistentObjectDragSource implements DragSourceListener {

    ISelectionRenderer renderer;
    Control dragSource;
    List<PersistentObject> selection;
    protected static PersistentObject draggedObject;

    Transfer myTransfer = TextTransfer.getInstance();

    public PersistentObjectDragSource(final StructuredViewer v) {
        dragSource = v.getControl();
        renderer = new ISelectionRenderer() {

            public List<PersistentObject> getSelection() {
                IStructuredSelection sel = (IStructuredSelection) v.getSelection();
                return sel.toList();
            }

        };
        setup();
    }

    public PersistentObjectDragSource(final Control source, final ISelectionRenderer renderer) {
        this.renderer = renderer;
        dragSource = source;
        setup();
    }

    private void setup() {
        DragSource mine = new DragSource(dragSource, DND.DROP_COPY);
        mine.setTransfer(new Transfer[] { myTransfer });
        mine.addDragListener(this);
    }

    public void dragFinished(final DragSourceEvent event) {
        // TODO Auto-generated method stub

    }

    public void dragSetData(final DragSourceEvent event) {
        StringBuilder sb = new StringBuilder();
        for (PersistentObject s : selection) {
            sb.append(s.storeToString()).append(StringConstants.COMMA);
        }

        event.data = sb.toString().replace(",$", StringConstants.EMPTY); //$NON-NLS-1$
    }

    public void dragStart(final DragSourceEvent event) {
        selection = renderer.getSelection();
        if ((selection == null) || (selection.isEmpty())) {
            event.doit = false;
        } else {
            event.doit = selection.get(0).isDragOK();
        }
        if (event.doit) {
            PersistentObjectDragSource.draggedObject = selection.get(0);
        }
    }

    /**
     * Externally set the dragged object; this is required to support external drag source
     * compatibility with {@link PersistentObjectDropTarget}
     * @param iPersistentObject
     * @since 3.1
     */
    public static void setDraggedObject(PersistentObject persistentObject) {
        draggedObject = persistentObject;
    }

    public static PersistentObject getDraggedObject() {
        return draggedObject;
    }

    public interface ISelectionRenderer {
        public List<PersistentObject> getSelection();
    }
}