CODEWITHSUNDEEP
javaandroidandroid-recyclerview
nutella_eater
nutella_eater

Reputation: 3572

Show Floating Action Button on a specified elements in a RecyclerView

I'm trying to show fab only when I scroll to a particular element of recyclerView. This is my layout which I thought out all the stuff for shorting purpose. So what I want it to show fab on 2,3,3... items and do not show it on zero and first items of my RecyclerView.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appBarLayout">

        <android.support.v7.widget.Toolbar
        android:id="@+id/details_toolbar"/>

        <include layout="@layout/divider" />

    </android.support.design.widget.AppBarLayout>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/topic_content_recycler"/>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"/>
</android.support.design.widget.CoordinatorLayout>

What I found is to hide fab on scrolling, which looks like this:

recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener(){
        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy){
            if (dy > 0)
                fabAddNew.hide();
            else if (dy < 0)
                fabAddNew.show();
        }
    });

I want well written solution. (I assume there is one, provided by google, but I can't fund it) Thank you.

Upvotes: 1

Views: 356

Answers (1)

Digvijay Singh
Digvijay Singh

Reputation: 621

add the RecyclerView.OnScrollListener and use the onScrollStateChanged(RecyclerView recyclerView, int newState) callback which gives you the newState, you should use SCROLL_STATE_IDLE to fetch its position. which means position changed and scrolling stopped now you can check which item is visible with the help of this

recyclerView.getLayoutManager().findFirstVisibleItemPosition();

now you can use the following code and change it accordingly 

   recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {

    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);
        if (dy > 0) {
            // Scrolling up
        } else {
            // Scrolling down
        }
    }

    @Override
    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
        super.onScrollStateChanged(recyclerView, newState);

        if (newState == AbsListView.OnScrollListener. SCROLL_STATE_IDLE) {
          //you can change the position according to your need 
       if(recyclerView.getLayoutManager().findFirstVisibleItemPosition()<2)
          {
           fabAddNew.hide();
          }  
         else{
           fabAddNew.show();
          }              
        } 
    }
});

you can read the documentation here for more detail

Upvotes: 3

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