attrs.xml

<declare-styleable name="ViewBox">
        <attr name="backgroundColor" format="reference" />
        <attr name="radius" format="reference|dimension" />
        <attr name="paddingBox" format="reference|dimension" />
    </declare-styleable>

ViewBox.java

public class ViewBox extends LinearLayout {

    private float radiusCorner = 0f;
    private int backgroundRes = -1;
    private int paddingBox = 0;

    public ViewBox(Context context) {
        super(context);
        init(null);
    }

    public ViewBox(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(attrs);
    }

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

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public ViewBox(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init(attrs);
    }

    private void init(AttributeSet attrs) {

        if (attrs != null) {
            TypedArray typedArray = getContext().getTheme().obtainStyledAttributes(attrs, R.styleable.ViewBox, 0, 0);
            try {
                backgroundRes = typedArray.getResourceId(R.styleable.ViewBox_backgroundColor, -1);
                radiusCorner = typedArray.getDimension(R.styleable.ViewBox_radius, getContext().getResources().getDimension(R.dimen.radius_box));
                paddingBox = (int) typedArray.getDimension(R.styleable.ViewBox_paddingBox, getContext().getResources().getDimension(R.dimen.padding_box));
            } finally {
                typedArray.recycle();
            }
        }

        if (backgroundRes == -1) {
            backgroundRes = android.R.color.white;
        }

        setBackgroundResource(backgroundRes);
    }

    @Override
    public void setBackgroundResource(int resid) {
        backgroundRes = resid;

        setBackground(null);
        setBackground(ViewUtils.generateBackgroundWithShadow(this, resid, radiusCorner, R.color.shadowColor, R.dimen.elevation, Gravity.BOTTOM));

        setPadding(this.paddingBox, this.paddingBox, this.paddingBox, this.paddingBox);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    public void setRadiusCorner(float radiusCorner) {
        this.radiusCorner = radiusCorner;
        setBackgroundResource(backgroundRes);
    }

    public void setPaddingBox(int paddingBox) {
        this.paddingBox = paddingBox;
        setBackgroundResource(backgroundRes);
    }
}

ViewUtils.java

public class ViewUtils {
   public static Drawable generateBackgroundWithShadow(View view, @ColorRes int backgroundColor,
                                                        float cornerRadius,
                                                        @ColorRes int shadowColor,
                                                        @DimenRes int elevation,
                                                        int shadowGravity) {
        int elevationValue = (int) view.getContext().getResources().getDimension(elevation);
        int shadowColorValue = ContextCompat.getColor(view.getContext(), shadowColor);
        int backgroundColorValue = ContextCompat.getColor(view.getContext(), backgroundColor);

        float[] outerRadius = {cornerRadius, cornerRadius, cornerRadius,
                cornerRadius, cornerRadius, cornerRadius, cornerRadius,
                cornerRadius};

        Rect shapeDrawablePadding = new Rect();
        shapeDrawablePadding.left = elevationValue;
        shapeDrawablePadding.right = elevationValue;

        int DY;
        switch (shadowGravity) {
            case Gravity.CENTER:
                shapeDrawablePadding.top = elevationValue;
                shapeDrawablePadding.bottom = elevationValue;
                DY = 0;
                break;
            case Gravity.TOP:
                shapeDrawablePadding.top = elevationValue * 2;
                shapeDrawablePadding.bottom = elevationValue;
                DY = -1 * elevationValue / 3;
                break;
            default:
            case Gravity.BOTTOM:
                shapeDrawablePadding.top = elevationValue;
                shapeDrawablePadding.bottom = elevationValue * 2;
                DY = elevationValue / 3;
                break;
        }

        ShapeDrawable shapeDrawable = new ShapeDrawable();
        shapeDrawable.setPadding(shapeDrawablePadding);
        shapeDrawable.getPaint().setColor(backgroundColorValue);
        shapeDrawable.getPaint().setShadowLayer(cornerRadius / 3, 0, DY, shadowColorValue);

        view.setLayerType(LAYER_TYPE_SOFTWARE, shapeDrawable.getPaint());

        shapeDrawable.setShape(new RoundRectShape(outerRadius, null, null));

        LayerDrawable drawable = new LayerDrawable(new Drawable[]{shapeDrawable});
        drawable.setLayerInset(0, elevationValue, elevationValue * 2, elevationValue, elevationValue * 2);

        return drawable;
    }

}