SWT/JFace: remove widgets

Group group = new Group(parent, SWT.NONE);
StyledText comment = new StyledText(group, SWT.BORDER_DASH);

This creates a group with a text area inside.

How can I later delete the text (remove it from the screen so that I can replace it with something else)?

From stackoverflow

• You have to either call comment.changeParent(newParent) or comment.setVisible(false) to remove/hide it from the Group. I am unsure if comment.changeParent(null) would work but I would give that a try.

  We do it this way because SWT uses the Composite Pattern.

  Thilo : comment.changeParent(null) does indeed raise SWT.ERROR_NULL_ARGUMENT ...

• Use Widget.dispose.

  public class DisposeDemo {
  
    private static void addControls(final Shell shell) {
      shell.setLayout(new GridLayout());
      Button button = new Button(shell, SWT.PUSH);
      button
          .setText("Click to remove all controls from shell");
      button.addSelectionListener(new SelectionListener() {
        @Override
        public void widgetDefaultSelected(SelectionEvent event) {
        }
  
        @Override
        public void widgetSelected(SelectionEvent event) {
          for (Control kid : shell.getChildren()) {
            kid.dispose();
          }
        }
      });
  
      for (int i = 0; i < 5; i++) {
        Label label = new Label(shell, SWT.NONE);
        label.setText("Hello, World!");
      }
  
      shell.pack();
    }
  
    public static void main(String[] args) {
      Display display = new Display();
      Shell shell = new Shell(display);
      addControls(shell);
      shell.open();
      while (!shell.isDisposed()) {
        if (!display.readAndDispatch())
          display.sleep();
      }
      display.dispose();
    }
  
  }
  

• Another option is to use a StackLayout to switch between underlying controls. This prevents you from running into a "widget is disposed" error.