kevings14 kevings14 - 13 days ago 8
Android Question

NestedScrollView scrolls to top on Recyclerview resized

I have a NestedScrollView containing a LinearLayout and a RecyclerView (both inside a RelativeLayout).

<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/scroll">

<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/lay_account">


<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@android:color/white"
android:paddingTop="10dp"
android:id="@+id/lay_total"
android:paddingBottom="10dp">

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/total"
android:id="@+id/lblTotal"
android:textSize="@dimen/text_medium"
android:layout_marginLeft="20dp"
android:textColor="@color/dark_eurakostheme_color"
android:textStyle="bold"/>


<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center_vertical|center_horizontal">

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/txtTotalAmount"
android:textSize="@dimen/text_extra_extra_large"
android:gravity="center_horizontal"
android:textColor="@color/eurakostheme_color"/>

<ImageView
android:layout_width="@dimen/icon_extra_extra_large"
android:layout_height="match_parent"
android:id="@+id/imageView3"
android:src="@drawable/coin_eurakos"/>
</LinearLayout>

</LinearLayout>

<View
android:layout_width="fill_parent"
android:layout_height="1dp"
android:id="@+id/divisor"
android:background="@color/dividerColor"
android:layout_alignBottom="@+id/lay_total"/>

<android.support.v7.widget.RecyclerView
android:layout_below="@id/lay_total"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/rclBasketAmounts"
android:background="@android:color/white"
android:padding="10dp">
</android.support.v7.widget.RecyclerView>

</RelativeLayout>

</android.support.v4.widget.NestedScrollView>
</android.support.design.widget.CoordinatorLayout>


After loading the data into the RecyclerView, I need to change it's height programmatically like this:

RelativeLayout.LayoutParams lay_params = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
50 + ((int) (baskets.length * getResources().getDimension(R.dimen.list_height_small))));

lay_params.addRule(RelativeLayout.BELOW, lay_total.getId());
recyclerView.setLayoutParams(lay_params);
recyclerView.setAdapter(new ListBasketAmountAdapter(baskets));


The problem is when the data has finished loading the NestedScrollView scrolls automatically scrolls to the top of the RecyclerView, hiding the LinearLayout above it. Any ideas?

Thanks.

Answer

After several days I've found a solution to the problem. You just need to add the descendantFocusability in the first layout under the ScrollView like this:

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/lay_account"
    android:descendantFocusability="blocksDescendants">