class YourConverter implements IValueConverter {
  String text1
  String text2

  Object convert(Object value) {
    return text1 is empty and text2 is empty ? RED_COLOR : null;
  }

  ... getters/setters for text1 and text2
}

<Composite.Resources>
	<y:YourConverter x:key="sharedConverter" text1="{Binding elementName=text1, path=text, updateSourceTrigger=PropertyChanged}"
		text2="{Binding elementName=text2, path=text, updateSourceTrigger=PropertyChanged}"/>
</Composite.Resources>

<text x:name="text1" background="{Binding converter={StaticResource sharedConverter}}" />
<text x:name="text2" background="{Binding converter={StaticResource sharedConverter}}"/>

Hello!

First of all, thanks for all the help so far.
But now i ran into following problem and i think it is more of the conceptual kind .

I have a gui with a lot of controlls and some of them must be specified by the user. To show him which one are mandatory they are marked with a different background color. As soon as he fills them they get back to their normal state. This all works great via xwt and is done by the bindingcontexts, validationrules and some converters. (don't need anything additional).

Now my problem is that i have two Textboxes where the user has to fill at least one of them. So if nothing is in the textboxes both are marked as mandatory and if one gets filled both should get to their normal state.

How could i manage this? I think with the jface databinding i would solve that by using a Multivalidator (only a guess because of some googeling). Is there something in xwt like this?

Any help or hint would be appreciated.
Thanks to all in advanced
and best regards weinma

Hey! Thanks for the tip.
I built the "converter" now the way you suggested. The only difference i made is that i pluged the statuses of the bindingcontexts into that converter. By the way in my case its not a converter, it is a custom widget inherited from a composite. (But it doesn't matter)

My only thought was that the ValidationRules do the validation and that the Widget only shows the status. Now my widget is a little more inteligence
and links the two bindingcontext statuses with a logical or (So that only one rule must be valid). I thought it would be nicer if a rule would do this but for now i can live with that solution:

<StatusLabel>
<StatusLabel.status>
<Binding source="{StaticResource context1}" path="status"/>
</StatusLabel.status>
<StatusLabel.secondStatus>
<Binding source="{StaticResource context2}" path="status"/>
</StatusLabel.secondStatus>
</StatusLabel>

public class StatusLabel extends Composite {
..

public void setStatus(IStatus) {
..
}

public IStatus getStatus() {
..
}

public void setSecondStatus(IStatus) {
..
}

public IStatus getSecondStatus() {
..
}

}

And there comes another question
I think it would be nicer if it was possible to plug an array or List<> of IStatus into that Composite/Converter something like that:

<StatusLabel>
<StatusLabel.statuses>
<Binding source="{StaticResource context1}" path="status"/>
<Binding source="{StaticResource context2}" path="status"/>
<Binding source="{StaticResource context3}" path="status"/>
...
</StatusLabel.statuses>
</StatusLabel>

public class StatusLabel extends Composite {
..

public void setStatuses(IStatus[] statuses) {
..
}

public IStatus[] getStatuses() {
..
}

}

Is something like that possible how would i have to declare this in the xml and java code?

Thanks a lot for the hint again!
best regards weinma