Android `@BindingAdapter` setter not being called

Question

Here is my BindingAdapter:

public class Bindings{
    @BindingAdapter({"font"})
    public static void setFont(TextView textView, String fontName) {
        textView.setTypeface(FontCache.getInstance(textView.getContext()).get(fontName));
    }
}

*Instead of using "font" as the annotation parameter, I've tried "bind:font", "android:font", and "app:font", and made all the corresponding changes in the layout, but the BindingAdapter is still not called

Here is the layout where I use the BindingAdapter (bind_layout.xml):

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto">

    <data></data>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal">

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@null"
            font="@{`fontawesome-webfront`}"
            android:text="@string/double_left"/>
    </LinearLayout>
</layout>

*this layout is included in the Activity's layout which is set using DatabindingUtils.setContentView

Here is the activity whose layout includes bind_layout.xml:

public class ACreateSemester extends AppCompatActivity {
    private List<CreateItemView> mCreateItemViews;
    private LinearLayout mItemContainer;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        DataBindingUtil.setContentView(this,R.layout.a_create_items);
        mItemContainer = (LinearLayout) findViewById(R.id.item_container);
        mItemContainer.addView(new CreateItemView(this, Item.getDefaultItem()));
    }

}

The three files I referenced here are listed in their entirety.

The way I know the BindingAdapter is not being called is because I set a breakpoint on the method and also in the body, and the breakpoint is never reached.

Any idea why the BindingAdapter is not firing?

Answer 1

Please, also make sure that you have made this steps.

1. Apply plugin: 'kotlin-kapt' in your app level build.gradle.
2. Set lifecycle owner to binding from your activity's onCreate() method e.g. binding.lifecycleOwner = this, where this is your Activity.
3. Change font="@{fontawesome-webfront}" to app:font="@{fontawesome-webfront}" in your xml.
4. Add some Id to your button in xml layout.

Answer 2

I think you missed to connect your view with viewModel in activity.

public class ACreateSemester extends AppCompatActivity {
private List<CreateItemView> mCreateItemViews;
private LinearLayout mItemContainer;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ACreateItemsBinding binding =  DataBindingUtil.setContentView(this,R.layout.a_create_items);
    mItemContainer = (LinearLayout) findViewById(R.id.item_container);
    mItemContainer.addView(new  CreateItemView(this,Item.getDefaultItem()));
    binding.setView(YourViewHere);
}