GWT uibinder composite

I'm creating a composite uibinder widget with a Label and a TextBox.

The intented use is:

<x:XTextBox ui:field="fieldName" label="a caption" >
    The text to be put in the box.
</x:XTextBox>

I've found how to catch the label with a custom @UiConstructor constructor, I might add another parameter to the constructor, but I would like to know how t开发者_StackOverflow中文版o get the text from the xml, just like the GWT tag <g:Label>a caption</g:Label> does.

Any help is greatly appreciated.

I've found a possible implementation by looking at the Label widget source code.

The key point is that the composite widget must implement the HasText interface. so in the declaration and in the body:

public class XTextBox extends Composite implements HasText ...
...
@UiField TextBox textBox;
...
public void setText(String text) {
    textBox.setText(text);
}
public String getText() {
    return textBox.getText();
}
...

Just put the text into another parameter of your widget and have your @UiConstructor take that parameter. That is:

<x:XTextBox ui:field="fieldName" label="a caption" 
  text="The text to be put in the box." />

Then your XTextBox.java will have this:

@UiField TextBox textBox;

@UiConstructor XTextBox(String label, String text) {
  initWidget(uiBinder.createAndBindUi(this));
  textBox.setValue(text);
}

Han is right; HasText is what you need to implement. One thing I found handy is to browse the source if you know a Google widget does something you'd like to do also. e.g.

http://www.google.com/codesearch/p?hl=en#A1edwVHBClQ/user/src/com/google/gwt/user/client/ui/Label.java