How to declare dependent style names with UiBinder

Question

I have a simple UiBinder widget containing a TextArea:

<!DOCTYPE ui:UiBinder SYSTEM "http://dl.google.com/gwt/DTD/xhtml.ent">
<ui:UiBinder xmlns:ui="urn:ui:com.google.gwt.uibinder"
    xmlns:g="urn:import:com.google.gwt.user.client.ui">

    <g:TextArea visibleLines="3" />
</ui:UiBinder>

I want to control the background color of this textarea for writeable and read only states. GWT uses the "-readonly" style name decorator to achieve this. So I try this:

<!DOCTYPE ui:UiBinder SYSTEM "http://dl.google.com/gwt/DTD/xhtml.ent">
<ui:UiBinder xmlns:ui="urn:ui:com.google.gwt.uibinder"
    xmlns:g="urn:import:com.google.gwt.user.client.ui">

    <ui:style>
        .textBoxStyle {
            background-color:yellow;
        }
        .textBoxStyle-readonly {
            background-color:lightgray;
        }
    </ui:style>

    <g:TextArea styleName="{style.textBoxStyle}" visibleLines="3" />
</ui:UiBinder>

Obviously this won't work because style names are obfuscated for CssResources resulting in something like this:

.G1x26wpeN {
    background-color:yellow
 }
.G1x26wpeO {
    background-color: lightgray;
}

The result HTML for writeable textarea looks like this:

<textarea tabindex="0" class="G1x26wpeN" rows="3"/>

The read only textarea looks like this:

<textarea tabindex="0" class="G1x26wpeN G1x26wpeN-readonly" readonly="" rows="3"/>

How do I declare the style so GWT will obfuscate the primary part but not the "-readonly" decdorator?

I know that I can disable the obfuscation for the entire style name. But I'd like to keep the obfuscation while making use of the decorators.

Answer 1

At this moment (GWT 2.4) it is not supported, and it's not clear if/when it will be supported, see issue 4746 in the GWT issue tracker.

The workaround is to add @external, which disables obfuscation for those styles. In this case that would be:

@external textBoxStyle, textBoxStyle-readonly;