A custom FrameLayout that allows you to round & clip the corners of this layout, and its children, with radii that you specify either in XML or with code.

attrs_rounded_frame_layout.xml

<resources>
    <declare-styleable name="RoundedFrameLayout">
        <attr name="radius" format="dimension" />
        <attr name="top_right_radius" format="dimension" />
        <attr name="top_left_radius" format="dimension" />
        <attr name="bottom_right_radius" format="dimension" />
        <attr name="bottom_left_radius" format="dimension" />
    </declare-styleable>
</resources>

RoundedFrameLayout.java

package com.example;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Path;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.widget.FrameLayout;

import app.mongez.mongezapp.R;

/**
 * A custom {@link FrameLayout} that allows you to round & clip the corners of this layout, and its children,
 * with radii that you specify either in XML or with code.
 *
 * @author Abdallah Abdelazim
 */
public class RoundedFrameLayout extends FrameLayout {

    private float topRightRadius;
    private float topLeftRadius;
    private float bottomRightRadius;
    private float bottomLeftRadius;

    private Path path;

    public RoundedFrameLayout(Context context) {
        super(context);
        init(null, 0);
    }

    public RoundedFrameLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(attrs, 0);
    }

    public RoundedFrameLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(attrs, defStyle);
    }

    private void init(AttributeSet attrs, int defStyle) {
        // Load attributes
        final TypedArray a = getContext().obtainStyledAttributes(
                attrs, R.styleable.RoundedFrameLayout, defStyle, 0);

        if (a.hasValue(R.styleable.RoundedFrameLayout_radius)) {
            topLeftRadius = topRightRadius = bottomLeftRadius = bottomRightRadius = a.getDimension(
                    R.styleable.RoundedFrameLayout_radius,
                    0F);
        } else {
            topLeftRadius = a.getDimension(
                    R.styleable.RoundedFrameLayout_top_left_radius,
                    0F);
            topRightRadius = a.getDimension(
                    R.styleable.RoundedFrameLayout_top_right_radius,
                    0F);
            bottomLeftRadius = a.getDimension(
                    R.styleable.RoundedFrameLayout_bottom_left_radius,
                    0F);
            bottomRightRadius = a.getDimension(
                    R.styleable.RoundedFrameLayout_bottom_right_radius,
                    0F);
        }

        a.recycle();
    }

    @Override
    public void draw(Canvas canvas) {
        canvas.save();
        canvas.clipPath(path);
        super.draw(canvas);
        canvas.restore();
    }

    @Override
    protected void dispatchDraw(Canvas canvas) {
        canvas.save();
        canvas.clipPath(path);
        super.dispatchDraw(canvas);
        canvas.restore();
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        RectF r = new RectF(0, 0, w, h);
        path = new Path();

        // The corners radii in the order: top-left, top-right, bottom-right, bottom-left
        float[] radii = {topLeftRadius, topLeftRadius, topRightRadius, topRightRadius,
                bottomRightRadius, bottomRightRadius, bottomLeftRadius, bottomLeftRadius};

        path.addRoundRect(r, radii, Path.Direction.CW);
        path.close();
    }

    public float getTopRightRadius() {
        return topRightRadius;
    }

    public void setTopRightRadius(float topRightRadius) {
        this.topRightRadius = topRightRadius;
        invalidate();
    }

    public float getTopLeftRadius() {
        return topLeftRadius;
    }

    public void setTopLeftRadius(float topLeftRadius) {
        this.topLeftRadius = topLeftRadius;
        invalidate();
    }

    public float getBottomRightRadius() {
        return bottomRightRadius;
    }

    public void setBottomRightRadius(float bottomRightRadius) {
        this.bottomRightRadius = bottomRightRadius;
        invalidate();
    }

    public float getBottomLeftRadius() {
        return bottomLeftRadius;
    }

    public void setBottomLeftRadius(float bottomLeftRadius) {
        this.bottomLeftRadius = bottomLeftRadius;
        invalidate();
    }
}