I'm using a second JTable in the Viewport of a JScrollPane to build a RowHeader for a main table. DragAndDrop on the main table is disabled. On the rowheader table DnD is enabled.
If a Drag on the rowheader is started by the user, I want to extend the painted rowheader dropline (the black line in the image) over the main table (like the green line in the image).
Does anybody have an advice for me?
Here's the SSCCE:
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.Transferable;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.DropMode;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JViewport;
import javax.swing.TransferHandler;
import javax.swing.UIManager;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.JTableHeader;
import javax.swing.table.TableColumn;
public class DNDLinePainterExampleMain extends JFrame {
public DNDLinePainterExampleMain() {
JTable mainTable = new JTable(4, 3);
mainTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
JTable rowTable = new RowHeaderTable(mainTable);
rowTable.setAutoscrolls(true);
rowTable.setDragEnabled(true);
rowTable.setTransferHandler(new RowHeaderTransferHandler());
rowTable.setDropMode(DropMode.INSERT_ROWS);
JScrollPane scrollPane = new JScrollPane(mainTable);
scrollPane.setRowHeaderView(rowTable);
scrollPane.setCorner(JScrollPane.UPPER_LEFT_CORNER,
rowTable.getTableHeader());
this.add(scrollPane);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JFrame f = new DNDLinePainterExampleMain();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.pack();
f.setVisible(true);
}
});
}
/*
* Use a JTable as a renderer for row numbers of a given main table. This
* table must be added to the row header of the scrollpane that contains the
* main table. from:
* http://tips4java.wordpress.com/2008/11/18/row-number-table/
*/
public class RowHeaderTable extends JTable implements ChangeListener,
PropertyChangeListener {
private final JTable table;
public RowHeaderTable(JTable table) {
this.table = table;
table.addPropertyChangeListener(this);
setFocusable(false);
setAutoCreateColumnsFromModel(false);
updateRowHeight();
updateModel();
updateSelectionModel();
TableColumn column = new TableColumn();
column.setHeaderValue("");
addColumn(column);
column.setCellRenderer(new RowNumberRenderer());
getColumnModel().getColumn(0).setPreferredWidth(50);
setPreferredScrollableViewportSize(getPreferredSize());
getTableHeader().setReorderingAllowed(false);
}
@Override
public void addNotify() {
super.addNotify();
Component c = getParent();
// Keep scrolling of the row table in sync with the main table.
if (c instanceof JViewport) {
JViewport viewport = (JViewport) c;
viewport.addChangeListener(this);
}
}
/*
* Delegate method to main table
*/
@Override
public int getRowCount() {
return table.getRowCount();
}
@Override
public int getRowHeight(int row) {
return table.getRowHeight(row);
}
/*
* This table does not use any data from the main TableModel, so just return
* a value based on the row parameter.
*/
@Override
public Object getValueAt(int row, int column) {
return Integer.toString(row + 1);
}
/*
* Don't edit data in the main TableModel by mistake
*/
@Override
public boolean isCellEditable(int row, int column) {
return false;
}
// implements ChangeListener
@Override
public void stateChanged(ChangeEvent e) {
// Keep the scrolling of the row table in sync with main table
JViewport viewport = (JViewport) e.getSource();
JScrollPane scrollPane = (JScrollPane) viewport.getParent();
scrollPane.getVerticalScrollBar().setValue(viewport.getViewPosition().y);
}
// implements PropertyChangeListener
@Override
public void propertyChange(PropertyChangeEvent e) {
// Keep the row table in sync with the main table
if ("rowHeight".equals(e.getPropertyName()))
updateRowHeight();
if ("selectionModel".equals(e.getPropertyName()))
updateSelectionModel();
if ("model".equals(e.getPropertyName()))
updateModel();
}
private void updateRowHeight() {
setRowHeight(table.getRowHeight());
}
private void updateModel() {
setModel(table.getModel());
}
private void updateSelectionModel() {
setSelectionModel(table.getSelectionModel());
}
/*
* Borrow the renderer from JDK1.4.2 table header
*/
private class RowNumberRenderer extends DefaultTableCellRenderer {
public RowNumberRenderer() {
setHorizontalAlignment(JLabel.CENTER);
}
@Override
public Component getTableCellRendererComponent(JTable table,
Object value, boolean isSelected, boolean hasFocus, int row,
int column) {
if (table != null) {
JTableHeader header = table.getTableHeader();
if (header != null) {
setForeground(header.getForeground());
setBackground(header.getBackground());
setFont(header.getFont());
}
}
if (isSelected) {
setFont(getFont().deriveFont(Font.BOLD));
}
setText((value == null) ? "" : value.toString());
setBorder(UIManager.getBorder("TableHeader.cellBorder"));
return this;
}
}//class RowNumberRenderer
}//class RowHeaderTable
public class RowHeaderTransferHandler extends TransferHandler {
@Override
public int getSourceActions(JComponent c) {
return COPY_OR_MOVE;
}
@Override
protected Transferable createTransferable(JComponent c) {
return new StringSelection(c.getName());
}
@Override
public boolean canImport(TransferSupport supp) {
return true;
}
}//class RowHeaderTransferHandler
}//class DNDLinePainterExampleMain
