Can I have a View as input to a data binding BindingAdapter on Android?

Question

I want to establish a relationship between a ProgressBar and a WebView Something like this in XML:

    <ProgressBar
        android:id="@+id/progressBar"/>

    <WebView
        android:id="@+id/wvb_webView"
        app:attachedProgressBar="@{@id/progressBar}"/> 

With this code I can create a BindingAdapter to do the wiring like this:

@BindingAdapter({"app:attachedProgressBar"})
public static void setAttachedProgressBar(WebView webView, @IdRes int progressBarId) {        
        ProgressBar progBar = (ProgressBar) DataBindingUtil.getBinding(webView).getRoot().findViewById(progressBarId);
        wireStuff(webView, progBar); 
}

This works, but it irks me that I have to call findViewById. Is there any way I can refactor the XML and the BindingAdapter to take a direct reference to the ProgressBar as input instead of the @IdRes int ?

Answer 1

Instead of id, directly pass ProgressBar in your BindingAdapter

@BindingAdapter({"app:attachedProgressBar"})
public static void setAttachedProgressBar(WebView webView, ProgressBar progBar) {        
    wireStuff(webView, progBar); 
}

XML code :

<ProgressBar
    android:id="@+id/progressBar"/>

<WebView
    android:id="@+id/wvb_webView"
    app:attachedProgressBar="@{progressBar}"/>