Reveal animation, bound in framelayout, but works pre 5.0

gistfile1.txt

package com.derp.revealanimationdemo;

import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.util.AttributeSet;
import android.util.Log;
import android.widget.FrameLayout;

/**
 * Created by fdoyle on 3/23/15.
 */
public class RevealingFrameLayout extends FrameLayout {

    Paint paint;

    public float radius = 0;
    boolean isRevealed = false;

    public RevealingFrameLayout(Context context) {
        super(context);
        init();
    }

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

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

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

    private void init() {
        setLayerType(LAYER_TYPE_SOFTWARE, null);
        paint = new Paint();
        PorterDuffXfermode mode = new PorterDuffXfermode(PorterDuff.Mode.DST_ATOP);
        paint.setXfermode(mode);
        paint.setColor(Color.TRANSPARENT);

    }

    public boolean isRevealed() {
        return isRevealed;
    }


    public float getRadius() {
        return radius;
    }

    private void setRadius(float radius) {
        this.radius = radius;
        invalidate();
    }

    public void setRevealed(boolean revealed) {
        if (revealed) {
            Log.d("TAG", "expanding");
            isRevealed = true;
            ObjectAnimator.ofFloat(this, "radius", 1f).setDuration(200).start();
        } else {
            Log.d("TAG", "contracting");
            isRevealed = false;
            ObjectAnimator.ofFloat(this, "radius", 0f).setDuration(200).start();
        }
    }


    @Override
    protected void dispatchDraw(Canvas canvas) {
        int w = canvas.getWidth();
        int h = canvas.getHeight();
        float hypotenuse = (float) Math.sqrt(w * w + h * h);
        super.dispatchDraw(canvas);
        Path rect = new Path();
        rect.addRect(0, 0, w, h, Path.Direction.CW);
        Path circlePath = new Path();
        circlePath.addCircle(w * .9f, h * .9f, radius * hypotenuse, Path.Direction.CCW);
        circlePath.setFillType(Path.FillType.EVEN_ODD);
        rect.addPath(circlePath);
        canvas.drawPath(rect, paint);
    }
}