background设置为transparent，不知道为什么有条线。除了visible/gone以外，videoViewHandler里也没有手动设置authorInfo的布局。

<com.google.android.material.button.MaterialButton
android:layout_width=“wrap_content"
android:layout_height=“wrap_content"
android:layout_marginEnd=”@dimen/dp_16"
android:gravity=“center"
android:onClick=”@{() -> InteractionPresenter.toggleFollowUser(lifeCycleOwner, feed)}“
android:paddingLeft=”@dimen/dp_16"
android:paddingRight=”@dimen/dp_16"
android:paddingTop="@dimen/dp_5"
android:paddingBottom="@dimen/dp_5"
android:text="@{feed.author.hasFollow ? @string/has_follow : @string/unfollow}“
android:textColor=”@color/color_fff"
android:textSize="@dimen/sp_14"
android:backgroundTint="@{fullscreen ? @color/transparent : @color/color_theme}“
app:backgroundTint=”@color/color_theme"
app:cornerRadius="@dimen/dp_13"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf=“parent"
app:strokeColor=”@{fullscreen ? @color/color_fff : @color/transparent}"
app:strokeWidth="1dp"
tools:text=“关注” />