Disable AND grey out an SWT composite

Question

I have a Composite that I want to be able to enable/disable programatically. The Control.setEnabled(boolean enabled) method works fine, but it does not give any visual information that the widget(s) are disabled.

What I would like to do is to have the disabled state mean the widgets are greyed out. Right now they just enter a weird state where the user is unable to click or perform any action on them.

Answer 1

A Composite is a container control that hold other controls using a layout - you can't see a composite really, you can only see the controls it holds. To disable and visually see then disabled, you'll have to call setEnabled(false) on all the children, assuming they're not containers too. Basically, to have to enable/disable the leaf widgets and you will see visual indication.

The reason you can't do anything with the widgets when disabling the Composite is because the Composite is eating all the events. Although the child widgets are not getting the events forwarded, they know nothing about the state of their parent, so they aren't greyed out.

Answer 2

The problem was indeed that I was disabling the composite and not the controls inside it. What I ended up doing was something like this:

public void recursiveSetEnabled(Control ctrl, boolean enabled) {
   if (ctrl instanceof Composite) {
      Composite comp = (Composite) ctrl;
      for (Control c : comp.getChildren())
         recursiveSetEnabled(c, enabled);
   } else {
      ctrl.setEnabled(enabled);
   }
}