Android Floating Action Button (FAB). Based on this: https://github.com/FaizMalkani/FloatingActionButton with a couple of additions

attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="Fab">
        <attr name="fabDrawable" format="reference"/>
        <attr name="fabColor" format="color"/>
        <attr name="fabDepth" format="integer"/>
        <attr name="fabShadowRadius" format="float"/>
    </declare-styleable>
</resources>

Fab.java

import android.animation.ObjectAnimator;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.Display;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.DecelerateInterpolator;

public class Fab extends View {

    Context _context;
    Paint mButtonPaint, mDrawablePaint;
    Bitmap  mBitmap;
    int mScreenHeight;
    int mScreenWidth;
    float currentY;
    float currentX;
    float shadowRadius = 10.0f;
    int distance = 2;
    float pressedAlpha = 0.6f;
    boolean mHidden = false;
    int fabColor = Color.WHITE;
    float DEPTH_1 = 1.0f;
    float DEPTH_2 = 3.0f;
    float DEPTH_3 = 10.0f;
    float DEPTH_4 = 14.0f;
    float DEPTH_5 = 19.0f;

    private float mDepth = 3.0f;
    Drawable myDrawable;

    public static final int MODE_FROM_BOTTOM = 0;
    public static final int MODE_FROM_TOP = 1;
    public static final int MODE_FROM_LEFT = 2;
    public static final int MODE_FROM_RIGHT = 3;

    private int mMode = 0;

    public Fab(Context context, AttributeSet attributeSet)
    {
        super(context, attributeSet);
        _context = context;
        parseAttrs(attributeSet,0);
        init(fabColor);
    }

    public Fab(Context context, AttributeSet attributeSet, int defStyle)
    {
        super(context, attributeSet, defStyle);
        _context = context;
        parseAttrs(attributeSet, defStyle);
        init(fabColor);
    }

    public Fab(Context context)
    {
        super(context);
        _context = context;
        init(fabColor);
    }

    private void parseAttrs(AttributeSet attrs, int defStyle) {
        TypedArray a = _context.obtainStyledAttributes(attrs, R.styleable.Fab, defStyle, 0);
        myDrawable = a.getDrawable(R.styleable.Fab_fabDrawable);
        mBitmap = ((BitmapDrawable) myDrawable).getBitmap();
        fabColor = a.getColor(R.styleable.Fab_fabColor, Color.WHITE);
        distance = a.getInt(R.styleable.Fab_fabDepth, distance);
        shadowRadius = a.getFloat(R.styleable.Fab_fabShadowRadius, 10.0f);
        switch(distance) {
        case 0:
            mDepth = DEPTH_1;
            break;
        case 1:
            mDepth = DEPTH_2;
            break;
        case 2:
            mDepth = DEPTH_3;
            break;
        case 3:
            mDepth = DEPTH_4;
            break;
        case 4:
            mDepth = DEPTH_5;
            break;
            default:
                mDepth = DEPTH_2;
        }
        a.recycle();
    }

    public void setFabColor(int color)
    {
        this.fabColor = color;
        invalidate();
    }

    public void setFabDrawable(Drawable fabDrawable)
    {
        myDrawable = fabDrawable;
        mBitmap = ((BitmapDrawable) myDrawable).getBitmap();
        invalidate();
    }

    public void setFabShadowRadius(float radius) {
        this.shadowRadius = radius;
        invalidate();
    }

    public void setFabDepth(int depth) {
        this.distance = depth;
        invalidate();
    }

    public void setPressedAlpha(float alpha) {
        this.pressedAlpha = alpha;
        invalidate();
    }

    public void setAnimationMode(int mode) {
        this.mMode = mode;
    }


    public void init(int fabColor)
    {
        setWillNotDraw(false);
        this.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
        mButtonPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mButtonPaint.setColor(fabColor);
        mButtonPaint.setStyle(Paint.Style.FILL);
        mButtonPaint.setShadowLayer(shadowRadius, 0.0f, mDepth, Color.argb(100, 0, 0, 0));
        mDrawablePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        invalidate();

        WindowManager mWindowManager = (WindowManager) _context.getSystemService(Context.WINDOW_SERVICE);
        Display display = mWindowManager.getDefaultDisplay();
        Point size = new Point();
        display.getSize(size);
        mScreenHeight = size.y;
        mScreenWidth = size.x;

    }

    @Override
    protected void onDraw(Canvas canvas) 
    {
        setClickable(true);
        canvas.drawCircle(getWidth()/2, getHeight()/2,(float) (getWidth()/2.6), mButtonPaint);
        canvas.drawBitmap(mBitmap, (getWidth() - mBitmap.getWidth()) / 2, (getHeight() - mBitmap.getHeight()) / 2, mDrawablePaint);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) 
    {
        if(event.getAction() == MotionEvent.ACTION_UP)
        {
            setAlpha(1.0f);
        }
        else if(event.getAction() == MotionEvent.ACTION_DOWN)
        {
            setAlpha(pressedAlpha);
        }
        return super.onTouchEvent(event);
    }

    public int dpToPx(int dp) 
    {
        DisplayMetrics displayMetrics = getContext().getResources().getDisplayMetrics();
        int px = Math.round(dp * (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT));       
        return px;
    }

    public boolean isHidden() {
        return this.mHidden;
    }

    public void hideFab() {
        if(mHidden == false) {
            currentY = getY();
            currentX = getX();

            ObjectAnimator mHideAnimation = null;
            switch(mMode) {
            case MODE_FROM_BOTTOM:
                mHideAnimation = ObjectAnimator.ofFloat(this, "Y", mScreenHeight);
                break;
            case MODE_FROM_TOP:
                mHideAnimation = ObjectAnimator.ofFloat(this, "Y", -mScreenHeight);
                break;
            case MODE_FROM_LEFT:
                mHideAnimation = ObjectAnimator.ofFloat(this, "X", -mScreenWidth);
                break;
            case MODE_FROM_RIGHT:
                mHideAnimation = ObjectAnimator.ofFloat(this, "X", mScreenWidth);
                break;
                default:
                    mHideAnimation = ObjectAnimator.ofFloat(this, "Y", mScreenHeight);
                    break;
            }   
            mHideAnimation.setInterpolator(new AccelerateInterpolator());
            mHideAnimation.start();
            mHidden = true;
        }
    }

    public void showFab()
    {
        if(mHidden == true)
        {
            ObjectAnimator mShowAnimation = null;

            switch(mMode) {
            case MODE_FROM_BOTTOM:
                mShowAnimation = ObjectAnimator.ofFloat(this, "Y", currentY);
                break;
            case MODE_FROM_TOP:
                mShowAnimation = ObjectAnimator.ofFloat(this, "Y", -currentY);
                break;
            case MODE_FROM_LEFT:
                mShowAnimation = ObjectAnimator.ofFloat(this, "X", currentX);
                break;
            case MODE_FROM_RIGHT:
                mShowAnimation = ObjectAnimator.ofFloat(this, "X", currentX);
                break;
                default:
                    mShowAnimation = ObjectAnimator.ofFloat(this, "Y", currentY);
                    break;
            }

            mShowAnimation.setInterpolator(new DecelerateInterpolator());
            mShowAnimation.start();
            mHidden = false;
        }
    }

}

layout_sample.xml

<com.your.package.Fab
        android:id="@+id/fabbutton"
        android:layout_width="72dp"
        android:layout_height="72dp"
        android:layout_margin="16dp"
        app:fabColor="@android:color/white"
        app:fabDepth="1"
        app:fabDrawable="@drawable/ic_content_new"
        app:fabShadowRadius="12" />

Sample.java

//***Your code***

mFab = (Fab) rootView.findViewById(R.id.fabbutton);
mFab.setAnimationMode(Fab.MODE_FROM_RIGHT);

//***Your code***