Java Code:
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.ToolBar;
import org.eclipse.swt.widgets.ToolItem;

public class Snippet49 {

  public static void main(String[] args) {
    Display display = new Display();
    final Shell shell = new Shell(display);
    final ToolBar toolBar = new ToolBar(shell, SWT.WRAP);
    for (int i = 0; i < 12; i++) {
      ToolItem item = new ToolItem(toolBar, SWT.PUSH);
      item.setText("Item " + i);
    }
    shell.addListener(SWT.Resize, new Listener() {
      public void handleEvent(Event e) {
        Rectangle rect = shell.getClientArea();
        Point size = toolBar.computeSize(rect.width, SWT.DEFAULT);
        toolBar.setSize(size);
      }
    });
    toolBar.pack();
    shell.pack();
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}