Java Swing JTable; Right Click Menu (How do I get it to "select" aka highlight the row)

Question

Short: I need a "right-click event" to highlight the cell row.

I am using a JTable inside a ScrollPane in Java Swing (Netbeans Matisse). I have a MouseClicked event listener on the JTable that does the following:

if (evt.getButton() == java.awt.event.MouseEvent.BUTTON3) {
          System.out.println("Right Click");
          JPopUpMenu.show(myJTable, evt.getX(), evt.getY())
}

The problem is... whenever I execute a right click on the JTable, the row isn't highlighted (I set the selection to rows only btw). I have looked for several setSelected() functions but could not find a suitable one. By default, left clicking automatically highlights the row. How do I set it up for right clicks?

Solution 1

like this:

table.addMouseListener(new MouseAdapter() {
    @Override
    public void mouseReleased(MouseEvent e) {
        int r = table.rowAtPoint(e.getPoint());
        if (r >= 0 && r < table.getRowCount()) {
            table.setRowSelectionInterval(r, r);
        } else {
            table.clearSelection();
        }

        int rowindex = table.getSelectedRow();
        if (rowindex < 0)
            return;
        if (e.isPopupTrigger() && e.getComponent() instanceof JTable ) {
            JPopupMenu popup = createYourPopUp();
            popup.show(e.getComponent(), e.getX(), e.getY());
        }
    }
});

......

Solution 2

The accepted answer does not take modifier keys like ctrl or shift into account, yet they indicate that the current selection should not be replaced, but extended.

Also, I added multi-OS support by checking mousePressed and mouseReleased.

Following, you can find a complete example on how to adjust the selected rows, using the ListSelectionModel, including MouseEvent#getModifiers checks. After that, it is possible to open a (optional) JPopupMenu.

JPopupMenu contextMenu = new JPopupMenu();
// ...
// add elements to the popup menu
// ...

table.addMouseListener(new MouseAdapter() {
  @Override
  public void mousePressed(MouseEvent e) {
    handleRowClick(e);
    if (e.isPopupTrigger()) {
      doPop(e);
    } else {
      hidePop();
    }
  }

  @Override
  public void mouseReleased(MouseEvent e) {
    if (e.isPopupTrigger()) {
      doPop(e);
    }
  }

  private void handleRowClick(MouseEvent e) {
    ListSelectionModel selectionModel = table.getSelectionModel();
    Point contextMenuOpenedAt = e.getPoint();
    int clickedRow = table.rowAtPoint(contextMenuOpenedAt);

    if (clickedRow < 0) {
      // No row selected
      selectionModel.clearSelection();
    } else {
      // Some row selected
      if ((e.getModifiers() & InputEvent.SHIFT_MASK) == InputEvent.SHIFT_MASK) {
        int maxSelect = selectionModel.getMaxSelectionIndex();

        if ((e.getModifiers() & InputEvent.CTRL_MASK) == InputEvent.CTRL_MASK) {
          // Shift + CTRL
          selectionModel.addSelectionInterval(maxSelect, clickedRow);
        } else {
          // Shift
          selectionModel.setSelectionInterval(maxSelect, clickedRow);
        }
      } else if ((e.getModifiers() & InputEvent.CTRL_MASK) == InputEvent.CTRL_MASK) {
        // CTRL
        selectionModel.addSelectionInterval(clickedRow, clickedRow);
      } else {
        // No modifier key pressed
        selectionModel.setSelectionInterval(clickedRow, clickedRow);
      }
    }
  }

  private void doPop(MouseEvent e) {
    if (table.getSelectedRowCount() == 0) {
      return;
    }
    contextMenu.setVisible(true);
    contextMenu.show(e.getComponent(), e.getX(), e.getY());
  }

  private void hidePop() {
    contextMenu.setVisible(false);
  }
});