Develop Reference

Android Floating Action button screen ignore screen scale

i have problem with FloatingActionButton in RelatieLayout. I use DP for margin top and left. When i change device button is not on it's place. You can see on screens. First one is from editor, second from device.
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="3dp"
android:paddingLeft="3dp"
android:paddingRight="3dp"
android:paddingTop="3dp">
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerViewFloor5"
android:layout_width="match_parent"
android:layout_height="match_parent"></android.support.v7.widget.RecyclerView>
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="430dp"
android:layout_marginLeft="300dp"
app:backgroundTint="#color/primaryColor"
android:src="#drawable/ic_action_calendar"
app:fabSize="normal"
android:id="#+id/floorActionButton"/>
</RelativeLayout>
[
I also tried android:gravity="center|bottom" but nothing happens.

I also tried android:gravity="center|bottom" but nothing happens.
Since you are using RelativeLayout - gravity won't work. Instead use android:layout_alignParentBottom along with the margins
<RelativeLayout
....
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_margin="16dp"
app:backgroundTint="#color/primaryColor"
android:src="#drawable/ic_action_calendar"
app:fabSize="normal"
android:id="#+id/floorActionButton"/>
</RelativeLayout>

Try this...Don't use margin to set FloatingActionButton position always use gravity.
Follow this tutorial from androidhive.
https://www.androidhive.info/2015/12/android-material-design-floating-action-button/
I have set layoutgravity but use appropriately according to the parentlayout properties for gravity.
If you follow the tutorial above it will be easy for in my case i placed the fab in a </android.support.design.widget.CoordinatorLayout> and included the layout inside it like in the tutorial.
Just follow it it will be easy just don't use margin to set its position it will break in different screens like your above error .
<android.support.design.widget.FloatingActionButton
android:id="#+id/floorActionButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="#dimen/fab_margin"
app:backgroundTint="#color/primaryColor"
android:src="#drawable/ic_action_calendar"
app:fabSize="normal"/>

How to remove grey shadow color below FloatingActionButton

I am getting light grey color below the FloatingActionButton as shown in image. Any one know how to remove it. I tested it on Lollipop version.
My xml code
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:src="#drawable/ic_add_black"
app:borderWidth="0dp"
app:fabSize="mini"
app:rippleColor="#color/colorPrimaryDark" />

Try set elevation:
app:elevation="0dp"

It happens when you set an elevation and the fab element has not space enough to display the "shadow".
Then you can set the elevation as 0dp as suggested above, or set a margin like
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_build_white_36dp"
android:id="#+id/build"
app:elevation="4dp"
android:clickable="true"
android:layout_margin="10dp"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true" />
In this way the "elevation-effect" will appear correctly

My FloatingActionButton has some weird lines coming out of it on 4.4 and lower

As the title says, my FloatingActionButton has some weird lines coming out of it only on 4.4 or lower. On Lollipop it works fine.
This is a picture of the issue:
The play image doesn't have those lines in it. My xml:
<android.support.design.widget.FloatingActionButton
android:id="#+id/play"
android:layout_width="48dp"
android:layout_height="48dp"
android:src="#drawable/ic_av_play_arrow"
app:borderWidth="0dp"
app:elevation="6dp"
app:layout_anchor="#+id/image"
app:layout_anchorGravity="center_vertical|right|end"
app:rippleColor="#color/color_primary_light" />
So what am I doing wrong?
EDIT: goes away if I set my elevation to 0dp so I think I'll do that just for older phones

Your problem here is that you're making the FloatingActionButton an unexpected size. The FloatingActionButton in the support library only supports two sizes, and it must be set using the fabSize attribute.
You should change:
<android.support.design.widget.FloatingActionButton
android:id="#+id/play"
android:layout_width="48dp"
android:layout_height="48dp"
to be:
<android.support.design.widget.FloatingActionButton
android:id="#+id/play"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
If you want a smaller version:
<android.support.design.widget.FloatingActionButton
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/play"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:fabSize="mini"
Source: http://developer.android.com/reference/android/support/design/widget/FloatingActionButton.html

FloatingActionButton shadow not being drawn properly

I am using FloatingActionButton - http://developer.android.com/reference/android/support/design/widget/FloatingActionButton.html
Randomly I see that the shadow is not being drawn properly - it comes out in solid grey as opposed to a gradient.
Here is my markup:
<android.support.design.widget.FloatingActionButton
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_marginBottom="24dp"
android:layout_marginRight="24dp"
app:borderWidth="0dp"
android:id="#+id/fabButton"
android:src="#drawable/search"
android:clickable="true" />
Has anybody else faced this?

I think, you forgot these attributes:
...
app:elevation="6dp"
app:pressedTranslationZ="12dp"
...
See this answer for more information about FloatingActionButton design guides

No elevation For FloatingActionButton ( FAB ) in Support Material Design

With the help of this question I built a Floating Action Button to add elements to my Listview
The code is easy:
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
app:backgroundTint="#color/spg_rosa"
app:borderWidth="0dp"
app:elevation="4dp"
app:fabSize="normal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_add_white_48dp"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
/>
The thing is
app:elevation="4dp"
is not working, I can't see any shadow!
I grab the icon from Google : https://www.google.com/design/icons/
Any idea?
EDIT: I'm using it in Samsung S3 Mini ( API 16 )

I just tested your sample on a Samsung S3 Mini (API 16).
For me the elevation works.
because the elevation value is so small it's not very visible, try to increase the value. As BrentM says the elevation is not working if app:borderWidth="0dp" is not added.

Your problem is the "android:layout_alignParentBottom="true", that means your button is right at the bottom edge, try adding at least 10dp of margin at the bottom and it will fix your problem.
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
app:backgroundTint="#color/spg_rosa"
app:borderWidth="0dp"
app:elevation="4dp"
app:fabSize="normal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_add_white_48dp"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_marginBottom="10dp"
/>
Regards!

Thing was My Listview were black!
I changed color theme to white, and I could see the shadow !