activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:width="100dp"/>

LineBackgroundSpanSampleActivity.java

public class MainActivity extends Activity {

  @Override protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    SpannableString spannable = new SpannableString("aasdfasasdfasdfasdf span span");
    spannable.setSpan(
      new LineBackgroundSpan() {
        @Override public void drawBackground(Canvas c, Paint p, int left, int right, int top, int baseline, int bottom,
                                             CharSequence text, int start, int end, int lnum) {
          Log.d("Sample", lnum + "line called");
        }
      }, 19, 28, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE
    );

    TextView textView = (TextView) findViewById(R.id.text);
    textView.setText(spannable);
  }
}