Develop Reference

How to make SearchView always on top in NestedScrollView?

I need to fix the place of searchView to the top. Even if user scrolls searchView must stay on the top. My xml is like that:
<?xml version="1.0" encoding="utf-8"?>
<androidx.core.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:background="#color/colorOffWhite"
tools:context=".HomeFragment"
android:fillViewport="true">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<SearchView
android:id="#+id/searchView"
android:background="#color/colorBorder"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/horizontalCategoryRV"
android:layout_width="412dp"
android:layout_height="121dp"
android:orientation="horizontal"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/searchView" />
<TextView
android:id="#+id/textView"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginStart="5dp"
android:gravity="center_vertical"
android:text="#string/recent_products"
android:textSize="18sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/horizontalCategoryRV">
</TextView>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rv_dashboard_items"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/textView"
android:layout_marginBottom="70dp"/>
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.core.widget.NestedScrollView>
How can I implement a solution for this? I tried it with toolbar but I don't know if it's right to do that in a fragment. (This is a fragment's layout and I'm on Kotlin)

you can try use property
android:iconifiedByDefault="false" on your XML

Why is my recyclerview showing a whitespace

I am practing recyclerView in a fragment in Android Studio, I made this Application;
As you can see there is a whitespace between the toolbar (appbar) and the contents (i.e the recyclerview in this case)
Please, how do I get rid of this whitespace..
Here's the .xml file of the fargment I put the recyclerview:
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".ui.newscreen.NewScreenFragment">
<!-- TODO: Update blank fragment layout -->
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerview"
android:layout_width="0dp"
android:layout_height="0dp"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:listitem="#layout/new_screen_recyclerview_look" />
</androidx.constraintlayout.widget.ConstraintLayout>
Here's the sample layout listItem;
<androidx.constraintlayout.widget.ConstraintLayout
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="wrap_content">
<androidx.cardview.widget.CardView
android:id="#+id/cardView"
android:layout_width="150dp"
android:layout_height="150dp"
android:layout_marginStart="8dp"
android:layout_marginTop="12dp"
android:layout_marginEnd="8dp"
android:layout_marginBottom="8dp"
app:cardCornerRadius="8dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<ImageView
android:id="#+id/card_image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
app:srcCompat="#drawable/nav_header_image_nature"
android:contentDescription="#string/images_for_the_stories" />
</androidx.cardview.widget.CardView>
<TextView
android:id="#+id/card_title"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginEnd="16dp"
android:text="#string/Leonardo_Del_Vecchio"
android:textSize="20sp"
android:textStyle="bold"
app:layout_constraintBottom_toBottomOf="#+id/cardView"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="#+id/cardView"
app:layout_constraintTop_toTopOf="#+id/cardView"
app:layout_constraintVertical_bias="0.04000002" />
<TextView
android:id="#+id/card_tontent"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="16dp"
android:maxLines="3"
android:text="#string/sample_story_content"
android:textSize="18sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="#+id/cardView"
app:layout_constraintTop_toBottomOf="#+id/card_title" />
</androidx.constraintlayout.widget.ConstraintLayout>
Thanks in Advance for your Help!

I have been able to solve the issue.
There was a attribute in the main_activity.xml that cause this.
which was android:paddingTop="?attr/actionBarSize
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingTop="?attr/actionBarSize">

Android app:layout_constraintDimensionRatio not working within ScrollView->LinearLayout container

I am trying to create a square LinearLayout container of id imgContainer within a ScrollView element, but I am unable to do so because the app:layout_constraintDimensionRatio doesn't seem to be working. Using the following xml code, the imgContainer renders with a height of 0dp:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
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">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:id="#+id/imgContainer"
android:layout_width="match_parent"
android:layout_weight="1"
android:layout_height="0dp"
android:orientation="vertical"
app:layout_constraintDimensionRatio="1:1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/trackName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginHorizontal="8dp"
android:layout_weight="1"
android:text="Test Name"
android:textSize="25dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/imgContainer" />
<!-- Other stuff -->
</LinearLayout>
</ScrollView>
</androidx.constraintlayout.widget.ConstraintLayout>
However, when I move the imgContainer out of the ScrollView like so, the imgContainer is square-shaped as expected.
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
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">
<LinearLayout
android:id="#+id/imgContainer"
android:layout_width="match_parent"
android:layout_weight="1"
android:layout_height="0dp"
android:orientation="vertical"
app:layout_constraintDimensionRatio="1:1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ScrollView
...>
<!-- Same as above -->
</ScrollView>
</androidx.constraintlayout.widget.ConstraintLayout>
I also tried moving out of the LinearLayout it is nested in while still having it within the ScrollView, but that didn't work either. If anyone knows how to fix this, and why this happens, that would be great. Thanks in advance.

app:layout_constraint.. only work under <androidx.constraintlayout.widget.ConstraintLayout
you can try the following:
<ScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_height="match_parent">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="#+id/imgContainer"
android:layout_width="match_parent"
android:layout_weight="1"
android:layout_height="0dp"
android:orientation="vertical"
app:layout_constraintDimensionRatio="1:1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/trackName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginHorizontal="8dp"
android:layout_weight="1"
android:text="Test Name"
android:textSize="25dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/imgContainer" />
</androidx.constraintlayout.widget.ConstraintLayout>
</ScrollView>

How to use the whole space when placing ConstraintLayout inside a NestedScrollView?

I'm trying to put a ConstraintLayout inside a NestedScrollView, but there is a line that separates the ConstraintLayout. I can't place anything underneath that invisible line. I have been trying for hours and can't find the issue.
<?xml version="1.0" encoding="utf-8"?>
<layout 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">
<androidx.core.widget.NestedScrollView
android:id="#+id/premium_layout_id"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#BFFFFFFF"
android:focusableInTouchMode="true"
android:tag="layout/fragment_premium"
app:layout_constraintTop_toTopOf="parent">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".PremiumFragment">
<ImageView
android:id="#+id/launcher_id"
android:layout_width="185dp"
android:layout_height="185dp"
android:layout_marginTop="25dp"
android:layout_marginBottom="20dp"
android:contentDescription="TODO"
app:layout_constraintBottom_toTopOf="#+id/premium_text_id"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="#drawable/launch_premium" />
<TextView
android:id="#+id/premium_text_id"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="220dp"
android:text="#string/launch_to_premium"
android:textSize="24sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView2"
android:layout_width="383dp"
android:layout_height="196dp"
android:layout_marginTop="24dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/premium_text_id" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.core.widget.NestedScrollView>
</layout>

With a little bit of messing around I was able to get what you are looking for. The key is to use android:fillViewport="true" in the NestedScrollView
<?xml version="1.0" encoding="utf-8"?>
<layout 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">
<androidx.core.widget.NestedScrollView
android:id="#+id/premium_layout_id"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#BFFFFFFF"
android:focusableInTouchMode="true"
android:fillViewport="true"
android:tag="layout/fragment_premium">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:id="#+id/launcher_id"
android:layout_width="180dp"
android:layout_height="180dp"
android:layout_marginTop="25dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="#drawable/launch_premium" />
<TextView
android:id="#+id/premium_text_id"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/launch_to_premium"
android:textSize="24sp"
android:layout_marginTop="20dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/launcher_id" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView2"
android:layout_width="383dp"
android:layout_height="196dp"
android:layout_marginTop="24dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/premium_text_id" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.core.widget.NestedScrollView>
</layout>

You need to add a attribute android:fillViewport="true" in your NestedScrollView
<androidx.core.widget.NestedScrollView
android:id="#+id/premium_layout_id"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#BFFFFFFF"
android:focusableInTouchMode="true"
android:fillViewport="true" <-- add this
android:tag="layout/fragment_premium">
why?
fillViewport allows NestedScrollView to extend its height equals to the full height of the device screen height in the cases when the child of scroll view has less height.
this blog Will explain more about it.

implementing constraint layout in scrollview

scroll view not working when implementing like this
<?xml version="1.0" encoding="utf-8"?>
<ScrollView 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:fillViewport="true"
tools:context=".MainActivity">
<android.support.constraint.ConstraintLayout
android:id="#+id/Constraint"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.constraint.Guideline
android:id="#+id/guideline"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintGuide_percent="1.05" />
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="22dp"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:text="TextView"
app:layout_constraintBottom_toBottomOf="#id/guideline"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1.0" />
</android.support.constraint.ConstraintLayout>
</ScrollView>
i saw a post where we can anchor the elements to the guideline by increasing it beyond the 100% but when i am using this the scroll isn't working even the textview isn't visible anymore how do i fix this

Actually, your code should work when there is enough elements to scroll, try to add a higher margintop to the text view and you will see the result:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView 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:gravity="center_horizontal"
tools:context=".MainActivity">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.constraint.Guideline
android:id="#+id/guideline"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginTop="630dp"
android:layout_marginBottom="32dp"
android:orientation="horizontal"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintGuide_percent="1.0"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="22dp"
android:layout_marginStart="8dp"
android:layout_marginTop="600dp"
android:layout_marginEnd="8dp"
android:layout_marginBottom="8dp"
android:text="TextView"
app:layout_constraintBottom_toBottomOf="#id/guideline"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1.0" />
</android.support.constraint.ConstraintLayout>
</ScrollView>

Can you have a try with BottomSheet ?

add the below linearlayout into scrollview and add your constraint layout in this linearlayout
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" />
i think it will work