Signature pad android databinding adapter: https://github.com/gcacace/android-signaturepad

SignaturePadBindingAdapter.java

import android.databinding.BindingAdapter;

import com.github.gcacace.signaturepad.views.SignaturePad;

/**
 * Example:
 *
 * <pre>
 * {@code
 * <com.github.gcacace.signaturepad.views.SignaturePad xmlns:bind="http://schemas.android.com/apk/res-auto"
 *     android:id="@+id/signature_pad"
 *     android:layout_width="match_parent"
 *     android:layout_height="match_parent"
 *     bind:onStartSigning="@{activity.onStartSigning}"
 *     bind:onClear="@{activity.onClear}"
 *     bind:onSigned="@{activity.onSigned}" />
 * }
 * </pre>
 *
 * @author Sławomir Onyszko
 */
public final class SignaturePadBindingAdapter {

    @BindingAdapter("bind:onStartSigning")
    public static void setOnSignedListener(SignaturePad view, final OnStartSigningListener onStartSigningListener) {
        setOnSignedListener(view, onStartSigningListener, null, null);
    }

    @BindingAdapter("bind:onSigned")
    public static void setOnSignedListener(SignaturePad view, final OnSignedListener onSignedListener) {
        setOnSignedListener(view, null, onSignedListener, null);
    }

    @BindingAdapter("bind:onClear")
    public static void setOnSignedListener(SignaturePad view, final OnClearListener onClearListener) {
        setOnSignedListener(view, null, null, onClearListener);
    }

    @BindingAdapter(value = {"bind:onStartSigning", "bind:onSigned", "bind:onClear"}, requireAll = false)
    public static void setOnSignedListener(SignaturePad view, final OnStartSigningListener onStartSigningListener, final OnSignedListener onSignedListener, final OnClearListener onClearListener) {
        view.setOnSignedListener(new SignaturePad.OnSignedListener() {
            @Override
            public void onStartSigning() {
                if (onStartSigningListener != null) {
                    onStartSigningListener.onStartSigning();
                }
            }

            @Override
            public void onSigned() {
                if (onSignedListener != null) {
                    onSignedListener.onSigned();
                }
            }

            @Override
            public void onClear() {
                if (onClearListener != null) {
                    onClearListener.onClear();
                }
            }
        });
    }

    public interface OnStartSigningListener {
        void onStartSigning();
    }

    public interface OnSignedListener {
        void onSigned();
    }

    public interface OnClearListener {
        void onClear();
    }

}