Ch12DnDComposite.java Source code

Introduction

Here is the source code for Ch12DnDComposite.java

Source

import org.eclipse.swt.SWT;
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.DropTarget;
import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.dnd.DropTargetListener;
import org.eclipse.swt.dnd.TextTransfer;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Text;

public class Ch12DnDComposite extends Composite {

    public Ch12DnDComposite(Composite parent) {
        super(parent, SWT.NONE);

        FillLayout layout = new FillLayout();
        setLayout(layout);

        Text leftText = new Text(this, SWT.MULTI);
        Text rightText = new Text(this, SWT.MULTI);

        createDragSource(leftText);
        createDragSource(rightText);

        createDropTarget(leftText);
        createDropTarget(rightText);
    }

    private void createDropTarget(final Text targetText) {
        Transfer[] types = new Transfer[] { TextTransfer.getInstance() };
        DropTarget dropTarget = new DropTarget(targetText, DND.DROP_COPY);
        dropTarget.setTransfer(types);

        dropTarget.addDropListener(new DropTargetListener() {

            public void dragEnter(DropTargetEvent event) {
            }

            public void dragLeave(DropTargetEvent event) {
            }

            public void dragOperationChanged(DropTargetEvent event) {
            }

            public void dragOver(DropTargetEvent event) {
            }

            public void drop(DropTargetEvent event) {
                String data = (String) event.data;
                targetText.append(data);
            }

            public void dropAccept(DropTargetEvent event) {
            }
        });
    }

    private void createDragSource(final Text sourceText) {
        Transfer[] types = new Transfer[] { TextTransfer.getInstance() };
        DragSource dragSource = new DragSource(sourceText, DND.DROP_COPY);
        dragSource.setTransfer(types);
        dragSource.addDragListener(new DragSourceListener() {

            public void dragStart(DragSourceEvent event) {
                if (sourceText.getSelectionText().length() > 0) {
                    event.doit = true;
                }
            }

            public void dragSetData(DragSourceEvent event) {
                event.data = sourceText.getSelection();
            }

            public void dragFinished(DragSourceEvent event) {
                //do nothing
            }
        });
    }
}