Android : Calculate margins from coordinates in android screen

i have a library to insert floating buttons in a layout (http://prolificinteractive.com/blog/2014/07/24/android-floating-action-button-aka-fab/)

Then, i have this layout:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:fontawesometext="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="32dp"
        android:layout_marginBottom="16dp"
        android:layout_marginRight="16dp">

        <com.beardedhen.androidbootstrap.FontAwesomeText
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="4dp"
            android:textSize="45sp"
            android:textColor="#737373"
            android:id="@+id/faIcon"
            fontawesometext:fa_icon="fa-question" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text='"texto de ejemplo de pregunta"'
            android:id="@+id/tvQuestion"
            android:textColor="@color/primary"
            android:textStyle="bold"
            android:textSize="28sp"
            android:typeface="monospace"
            android:layout_marginLeft="16dp"
            android:layout_marginTop="32dp"
            android:layout_marginBottom="16sp" />
    </LinearLayout>

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/frameConainter"
        android:background="@color/dark_grey" />

</LinearLayout>

And i need to set the center of the button in the middle of framelayout top, like as the left image:

I have this in a custom view:

public class YesNoReplyView extends ReplyParentView {

    private FloatingActionButton buttonYes;
    private FloatingActionButton buttonNo;

    public YesNoReplyView(Context context) {
        super(context);
    }

    public YesNoReplyView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    public YesNoReplyView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public void initializeComponents() {

        int[] position = new int[2];
        getLocationOnScreen(position);

        buttonYes = new FloatingActionButton.Builder((Activity)getContext())
                .withDrawable(getResources().getDrawable(R.drawable.ic_plus))
                .withButtonColor(getResources().getColor(R.color.green_success))
                .withGravity(Gravity.BOTTOM | Gravity.RIGHT)
                .withMargins(0, 0, 16, 16)
                .create();

        buttonNo = new FloatingActionButton.Builder((Activity)getContext())
                .withDrawable(getResources().getDrawable(R.drawable.ic_plus))
                .withButtonColor(getResources().getColor(R.color.primary))
                .withGravity(Gravity.BOTTOM | Gravity.RIGHT)
                .withMargins(0, 0, 26, 26)
                .create();

    }


    @Override
    public String getResult() {
        String result = "";
        return result;
    }
}

But i dont know how can i calculate the margins from the coordinates to set the view in the position i want..

Anyone knows any way better to do it this?(I cant use a XML layout..)