How to create a floating action button (FAB) in android, using AppCompat v21?

Question

I would like to create a floating action button (to add items to a listview), like google calendar, maintaining compatibility with pre-lollipop Android versions (before 5.0)

Answer 1

Try this library, it supports shadow, there is minSdkVersion=7 and also supports android:elevation attribute for API-21 implicitly.

Original post is here.

Answer 2

Add padding and elevation:

 android:elevation="10dp"
 android:padding="10dp"

Answer 3

Here is one aditional free Floating Action Button library for Android It has many customizations and requires SDK version 9 and higher

Full Demo Video

Answer 4

I've generally used xml drawables to create shadow/elevation on a pre-lollipop widget. Here, for example, is an xml drawable that can be used on pre-lollipop devices to simulate the floating action button's elevation.

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:top="8px">
    <layer-list>
        <item>
            <shape android:shape="oval">
                <solid android:color="#08000000"/>
                <padding
                    android:bottom="3px"
                    android:left="3px"
                    android:right="3px"
                    android:top="3px"
                    />
            </shape>
        </item>
        <item>
            <shape android:shape="oval">
                <solid android:color="#09000000"/>
                <padding
                    android:bottom="2px"
                    android:left="2px"
                    android:right="2px"
                    android:top="2px"
                    />
            </shape>
        </item>
        <item>
            <shape android:shape="oval">
                <solid android:color="#10000000"/>
                <padding
                    android:bottom="2px"
                    android:left="2px"
                    android:right="2px"
                    android:top="2px"
                    />
            </shape>
        </item>
        <item>
            <shape android:shape="oval">
                <solid android:color="#11000000"/>
                <padding
                    android:bottom="1px"
                    android:left="1px"
                    android:right="1px"
                    android:top="1px"
                    />
            </shape>
        </item>
        <item>
            <shape android:shape="oval">
                <solid android:color="#12000000"/>
                <padding
                    android:bottom="1px"
                    android:left="1px"
                    android:right="1px"
                    android:top="1px"
                    />
            </shape>
        </item>
        <item>
            <shape android:shape="oval">
                <solid android:color="#13000000"/>
                <padding
                    android:bottom="1px"
                    android:left="1px"
                    android:right="1px"
                    android:top="1px"
                    />
            </shape>
        </item>
        <item>
            <shape android:shape="oval">
                <solid android:color="#14000000"/>
                <padding
                    android:bottom="1px"
                    android:left="1px"
                    android:right="1px"
                    android:top="1px"
                    />
            </shape>
        </item>
        <item>
            <shape android:shape="oval">
                <solid android:color="#15000000"/>
                <padding
                    android:bottom="1px"
                    android:left="1px"
                    android:right="1px"
                    android:top="1px"
                    />
            </shape>
        </item>
        <item>
            <shape android:shape="oval">
                <solid android:color="#16000000"/>
                <padding
                    android:bottom="1px"
                    android:left="1px"
                    android:right="1px"
                    android:top="1px"
                    />
            </shape>
        </item>
        <item>
            <shape android:shape="oval">
                <solid android:color="#17000000"/>
                <padding
                    android:bottom="1px"
                    android:left="1px"
                    android:right="1px"
                    android:top="1px"
                    />
            </shape>
        </item>
    </layer-list>
</item>
<item>
    <shape android:shape="oval">
        <solid android:color="?attr/colorPrimary"/>
    </shape>
</item>
</layer-list>

In place of ?attr/colorPrimary you can choose any color. Here's a screenshot of the result:

Answer 5

There are a bunch of libraries out there add a FAB(Floating Action Button) in your app, Here are few of them i Know.

makovkastar's FAB

futuersimple's Composite FAB

Material Design library which includes FAB too

All these libraries are supported on pre-lollipop devices, minimum to api 8

Answer 6

@Justin Pollard xml code works really good. As a side note you can add a ripple effect with the following xml lines.

    <item>
    <ripple
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:color="?android:colorControlHighlight" >
        <item android:id="@android:id/mask">
            <shape android:shape="oval" >
                <solid android:color="#FFBB00" />
            </shape>
        </item>
        <item>
            <shape android:shape="oval" >
                <solid android:color="@color/ColorPrimary" />
            </shape>
        </item>
    </ripple>
</item>