Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.Transferable;

import javax.swing.Box;
import javax.swing.DefaultListModel;
import javax.swing.DropMode;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.ListSelectionModel;
import javax.swing.SwingUtilities;
import javax.swing.TransferHandler;

public class Main extends JFrame {
    private JTextField newTextField = new JTextField(10);
    private JList<String> sourceList = new JList<>(new DefaultListModel<>());
    private JList<String> destList = new JList<>(new DefaultListModel<>());

    public Main() {

        for (int i = 0; i < 15; i++) {
            ((DefaultListModel<String>) sourceList.getModel()).add(i, "A " + i);
            ((DefaultListModel<String>) destList.getModel()).add(i, "B " + i);
        }
        Box nameBox = Box.createHorizontalBox();
        nameBox.add(new JLabel("New:"));
        nameBox.add(newTextField);

        Box sourceBox = Box.createVerticalBox();
        sourceBox.add(new JLabel("Source"));
        sourceBox.add(new JScrollPane(sourceList));

        Box destBox = Box.createVerticalBox();
        destBox.add(new JLabel("Destination"));
        destBox.add(new JScrollPane(destList));

        Box listBox = Box.createHorizontalBox();
        listBox.add(sourceBox);
        listBox.add(destBox);

        Box allBox = Box.createVerticalBox();
        allBox.add(nameBox);
        allBox.add(listBox);

        this.getContentPane().add(allBox, BorderLayout.CENTER);

        sourceList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        destList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

        newTextField.setDragEnabled(true);
        sourceList.setDragEnabled(true);
        destList.setDragEnabled(true);

        sourceList.setDropMode(DropMode.INSERT);
        destList.setDropMode(DropMode.INSERT);

        sourceList.setTransferHandler(new ListTransferHandler());
        destList.setTransferHandler(new ListTransferHandler());
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            Main frame = new Main();
            frame.pack();
            frame.setVisible(true);
        });
    }
}

class ListTransferHandler extends TransferHandler {
    @Override
    public int getSourceActions(JComponent c) {
        return TransferHandler.COPY_OR_MOVE;
    }

    @Override
    protected Transferable createTransferable(JComponent source) {
        JList<String> sourceList = (JList<String>) source;
        String data = sourceList.getSelectedValue();
        Transferable t = new StringSelection(data);
        return t;
    }

    @Override
    protected void exportDone(JComponent source, Transferable data, int action) {
        @SuppressWarnings("unchecked")
        JList<String> sourceList = (JList<String>) source;
        String movedItem = sourceList.getSelectedValue();
        if (action == TransferHandler.MOVE) {
            DefaultListModel<String> listModel = (DefaultListModel<String>) sourceList.getModel();
            listModel.removeElement(movedItem);
        }
    }

    @Override
    public boolean canImport(TransferHandler.TransferSupport support) {
        if (!support.isDrop()) {
            return false;
        }
        return support.isDataFlavorSupported(DataFlavor.stringFlavor);
    }

    @Override
    public boolean importData(TransferHandler.TransferSupport support) {
        if (!this.canImport(support)) {
            return false;
        }
        Transferable t = support.getTransferable();
        String data = null;
        try {
            data = (String) t.getTransferData(DataFlavor.stringFlavor);
            if (data == null) {
                return false;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
        JList.DropLocation dropLocation = (JList.DropLocation) support.getDropLocation();
        int dropIndex = dropLocation.getIndex();
        JList<String> targetList = (JList<String>) support.getComponent();
        DefaultListModel<String> listModel = (DefaultListModel<String>) targetList.getModel();
        if (dropLocation.isInsert()) {
            listModel.add(dropIndex, data);
        } else {
            listModel.set(dropIndex, data);
        }
        return true;
    }
}