GWT: Cannot Convert From DockLayoutPanel to Composite - gwt

Question

First, I understand what this means: DockLayoutPanel does not extend any class that in turn extends Composite. I just don't know how to fix it.
I have a class, Mapmaker2.java, which is the primary user interface for my entire application. The base is a DockLayoutPanel, which in turn contains VerticalPanels, StackLayoutPanels, etc. Since this is an MVP application, I'd prefer not to mark up my EntryPoint class with a uibinder template.
Here is the java class:
public class MapmakerView2 extends Composite {
#UiTemplate("MapmakerView2.ui.xml")
interface Binder extends UiBinder<Composite, MapmakerView2> {}
private static Binder binder = GWT.create(Binder.class);
#UiField StackLayoutPanel interfaceStack;
public MapmakerView2() {
initWidget(binder.createAndBindUi(this));
}
}
And here is the uibinder template:
<ui:UiBinder> <!-- snipped out xmlns stuff -->
<g:DockLayoutPanel unit="PX">
<g:north size="100">
<g:VerticalPanel>
<!-- Logo -->
<!-- Login Link -->
</g:VerticalPanel>
</g:north>
<g:west size="150">
<g:StackLayoutPanel ui:field="interfaceStack" styleName="{style.shortcuts}" unit="PX">
<g:stack>
<g:header size="10">
<b>Features</b>
</g:header>
<mapmaker:FeaturesForm/>
</g:stack>
<g:stack size="10">
<g:header size="10">
<b>Export</b>
</g:header>
<mapmaker:ExportForm/>
</g:stack>
<g:stack>
<g:header size="10">
<b>Admin</b>
</g:header>
<mapmaker:AdminForm/>
</g:stack>
<g:stack>
<g:header size="10">
<b>Help</b>
</g:header>
<mapmaker:HelpForm/>
</g:stack>
</g:StackLayoutPanel>
</g:west>
<g:center>
<!-- Display Map Here -->
<mapmaker:MapBox/>
</g:center>
<g:south size="100">
<!-- Display i18n disclaimer stuff here -->
<mapmaker:Disclaimer/>
</g:south>
</g:DockLayoutPanel>
</ui:UiBinder>
Can anyone assist?

Answer 1

Just replace
interface Binder extends UiBinder<Composite, MapmakerView2> {}
with
interface Binder extends UiBinder<Widget, MapmakerView2> {}
or
interface Binder extends UiBinder<DockLayoutPanel, MapmakerView2> {}