CODEWITHSUNDEEP
androidandroid-scrollviewandroid-coordinatorlayout
dev
dev

Reputation: 11319

Android NestedScrollView smooth scroll in CoordinatorLayout

I am using the sample ScrollingActivity (included in the SDK) for testing parallax behavior. The sample uses a NestedScrollView in a CoordinatorLayout. When I scroll up from the bottom of the screen; the scroll stops at toolbar (even if my scroll has high velocity). As you can see in the attached image, multiple scrolls are needed to show the expanded AppBarLayout.

enter image description here

I need a smooth scroll for users to see expanded AppBarLayout. Interestingly, this issue does not happen if I use RecyclerView instead of NestedScrollView.

I am using build tool 23.0.3. Here is the layout XML :

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context="me.deepakmishra.swipetests.ScrollingActivity">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar"
        android:layout_width="match_parent"
        android:layout_height="@dimen/app_bar_height"
        android:fitsSystemWindows="true"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/toolbar_layout"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|exitUntilCollapsed">

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:layout_collapseMode="pin"
                app:popupTheme="@style/AppTheme.PopupOverlay" />

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

    <android.support.v4.widget.NestedScrollView
        android:layout_gravity="fill_vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        tools:context="me.deepakmishra.swipetests.ScrollingActivity"
        tools:showIn="@layout/activity_scrolling">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="@dimen/text_margin"
        android:text="@string/large_text" />
    </android.support.v4.widget.NestedScrollView>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="@dimen/fab_margin"
        app:layout_anchor="@id/app_bar"
        app:layout_anchorGravity="bottom|end"
        app:srcCompat="@android:drawable/ic_dialog_email" />

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

Upvotes: 3

Views: 2586

Answers (2)

Payal
Payal

Reputation: 31

Add android:fillViewport="true" and android:layout_gravity="fill_vertical" to your NestedScrollView. Hope this will help you.

Upvotes: 0

dev
dev

Reputation: 11319

I could not achieve this using CoordinatorLayout, essentially because I was not able to get an event which encapsulates velocity and position at the same time. CoordinatorLayout is providing velocity and position in separate callbacks, and using them is resulting in a stuttered movement.

I implemented parallax effect in a traditional fashion with custom handlers to track all scroll/fling operations.

Upvotes: 0

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