How to fix view position inside ViewPager and CoordinatorLayout

Question

I have activity with layout:

<android.support.design.widget.CoordinatorLayout android:layout_width="match_parent" android:layout_height="match_parent"> <android.support.design.widget.AppBarLayout android:layout_height="wrap_content" android:layout_width="match_parent" android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"> <android.support.v7.widget.Toolbar android:id="@+id/toolbar" android:layout_height="56dp" android:layout_width="match_parent" app:popupTheme="@style/ThemeOverlay.AppCompat.Light" app:layout_scrollFlags="scroll|enterAlways" app:contentInsetLeft="0dp" app:contentInsetStart="0dp" app:layout_collapseMode="pin"/> <android.support.design.widget.TabLayout android:id="@+id/tabs" android:layout_width="wrap_content" app:tabIndicatorColor="@color/indicator" app:tabMode="scrollable" android:layout_height="wrap_content" /> </android.support.design.widget.AppBarLayout> <android.support.v4.view.ViewPager android:id="@+id/viewpager" android:layout_width="match_parent" android:layout_height="match_parent" app:layout_behavior="@string/appbar_scrolling_view_behavior" /> </android.support.design.widget.CoordinatorLayout> 

A fragment loaded in ViewPager has a layout:

 <RelativeLayout android:layout_width="match_parent" android:layout_height="match_parent" xmlns:android="http://schemas.android.com/apk/res/android"> <android.support.v4.widget.SwipeRefreshLayout android:id="@+id/refresh_layout" android:layout_width="match_parent" android:layout_height="match_parent"> <android.support.v7.widget.RecyclerView android:id="@+id/gridView" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingTop="10dp" android:scrollbars="vertical" /> </android.support.v4.widget.SwipeRefreshLayout> <android.support.design.widget.FloatingActionButton android:id="@+id/download_btn" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_marginBottom="16dp" android:layout_marginLeft="16dp" android:src="@drawable/ic_btn_download" /> </RelativeLayout> 

How can I fix the position (prevent scrolling) of a FloatingActionButton inside a fragment (it scrolls with its parent)?

Note that I could not move the FloatingActionButton into the action layout.

Answer 1

You must use FAB in the action layout .. If you need different colors or actions, you can define the FAB in your fragment and set the color or action for each fragment.

Answer 2

You have to transfer your floating action button from your view pager to the coordinator layout. From there you can set the position of the floating action button using

 android:layout_gravity="end|bottom" 

or

 app:layout_anchor="@id/yourViewToAnchor" app:layout_anchorGravity="bottom|right|end" 

And don't forget to add your floating action button to the very bottom of your XML coordinator to make sure your floating action button is at the top of your layout.