Android: Horizontal line view in Recyclerview blinking while scrolling

Question

I am facing an issue in my Recyclerview item it contains multi views as horizontal line when scrolling the lines are blinking and i don't know why.

this video explain the problem.

this is Recyclerviewitem.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:card_view="http://schemas.android.com/tools"
    android:id="@+id/new_post_list_item_container"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="5dp"
    >

    <android.support.constraint.ConstraintLayout
        android:id="@+id/new_post_upper_part_container"
        android:layout_width="match_parent"
        android:layout_height="56dp"
        android:layout_marginTop="8dp"
        android:visibility="gone"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <de.hdodenhof.circleimageview.CircleImageView
            android:id="@+id/new_post_upper_user_image_view"
            android:layout_width="48dp"
            android:layout_height="48dp"
            android:layout_gravity="center_vertical"
            android:layout_marginStart="16dp"
            app:layout_constraintStart_toStartOf="parent" />

        <ImageView
            android:id="@+id/new_post_upper_activity_icon"
            android:layout_width="20dp"
            android:layout_height="20dp"
            android:layout_marginStart="50dp"
            android:layout_marginTop="30dp"
            android:src="@drawable/comment_notification"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <TextView
            android:id="@+id/new_post_upper_text_view"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginEnd="16dp"
            android:layout_marginStart="16dp"
            android:text="Abdulmalek Dery and two other commented Rami Issa post"
            android:textColor="@color/black"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toEndOf="@+id/new_post_upper_user_image_view"

            />
    </android.support.constraint.ConstraintLayout>

    <View
        android:id="@+id/new_post_upper_line_divider"
        android:layout_width="match_parent"
        android:layout_height="0.3dp"
        android:background="#BDBDBD"
        app:layout_constraintTop_toBottomOf="@+id/new_post_upper_part_container" />

    <de.hdodenhof.circleimageview.CircleImageView
        android:id="@+id/new_post_poster_image_circle_image_view"
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:src="@color/colorListDivider"
        android:background="?attr/selectableItemBackgroundBorderless"
        android:clickable="true"
        android:focusable="true"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/new_post_upper_part_container" />

    <TextView
        android:id="@+id/new_post_user_name_text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:text="Rami issa"
        android:textColor="@color/black"
        android:textSize="16sp"
        android:textStyle="bold"
        app:layout_constraintStart_toEndOf="@+id/new_post_poster_image_circle_image_view"
        app:layout_constraintTop_toBottomOf="@+id/new_post_upper_part_container" />

    <com.github.curioustechizen.ago.RelativeTimeTextView
        android:id="@+id/new_post_date_relative_text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:text="3 m"
        app:layout_constraintStart_toEndOf="@+id/new_post_poster_image_circle_image_view"
        app:layout_constraintTop_toBottomOf="@+id/new_post_user_name_text_view" />

    <ImageView
        android:id="@+id/new_post_option_image_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginTop="16dp"
        android:background="?attr/selectableItemBackgroundBorderless"
        android:clickable="true"
        android:focusable="true"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/new_post_upper_part_container"
        app:srcCompat="@drawable/post_options_icon" />

    <TextView
        android:id="@+id/new_post_image_description_text_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:paddingEnd="16dp"
        android:paddingStart="16dp"
        android:text="nice image right?"
        android:textColor="@color/black"
        android:textSize="14sp"
        android:visibility="visible"
        app:layout_constraintTop_toBottomOf="@+id/new_post_poster_image_circle_image_view" />
<LinearLayout
    android:id="@+id/linear_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    app:layout_constraintTop_toBottomOf="@+id/new_post_image_description_text_view">
    <ImageView
        android:id="@+id/new_post_image_view"
        android:layout_width="match_parent"
        android:layout_height="300dp"
        android:layout_marginTop="10dp"
        android:adjustViewBounds="true"
        android:visibility="visible"
        android:src="@color/colorListDivider"/>

    <me.grantland.widget.AutofitTextView
        android:id="@+id/new_post_content_auto_fit_text_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:ellipsize="end"
        android:maxLines="3"
        android:paddingEnd="16dp"
        android:paddingStart="16dp"
        android:text="some post content  that activity like that work"
        android:textColor="@color/black"
        android:textSize="40sp"
        android:visibility="gone"
        app:layout_constraintTop_toBottomOf="@+id/new_post_poster_image_circle_image_view"
        app:minTextSize="16sp" />
</LinearLayout>
    <View
        android:id="@+id/new_post_lower_line_view"
        android:layout_width="match_parent"
        android:layout_height="0.8dp"
        android:layout_marginTop="8dp"
        android:background="#BDBDBD"
        android:visibility="visible"
        app:layout_constraintTop_toBottomOf="@+id/linear_view" />

    <ImageView
        android:id="@+id/new_post_react_gray_image_view"
        android:layout_width="@dimen/post_icons_dimen"
        android:layout_height="@dimen/post_icons_dimen"
        android:layout_centerVertical="true"
        android:layout_marginStart="16dp"
        android:layout_marginTop="6dp"
        android:background="?attr/selectableItemBackgroundBorderless"
        android:clickable="true"
        android:focusable="true"
        android:visibility="visible"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/new_post_lower_line_view" />

    <ImageView
        android:id="@+id/new_post_react_red_image_view"
        android:layout_width="@dimen/post_icons_dimen"
        android:layout_height="@dimen/post_icons_dimen"
        android:layout_centerVertical="true"
        android:layout_marginStart="16dp"
        android:layout_marginTop="6dp"
        android:background="?attr/selectableItemBackgroundBorderless"
        android:clickable="true"
        android:focusable="true"
        android:src="@mipmap/love_gray_icon"
        android:visibility="visible"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/new_post_lower_line_view" />

    <ImageView
        android:id="@+id/new_post_comment_image_view"
        android:layout_width="@dimen/post_icons_dimen"
        android:layout_height="@dimen/post_icons_dimen"
        android:layout_centerVertical="true"
        android:layout_marginStart="12dp"
        android:layout_marginTop="6dp"
        android:layout_toEndOf="@+id/new_post_react_gray_image_view"
        android:background="?attr/selectableItemBackgroundBorderless"
        android:clickable="true"
        android:focusable="true"
        android:src="@mipmap/comment_icon"
        app:layout_constraintStart_toEndOf="@+id/new_post_react_gray_image_view"
        app:layout_constraintTop_toBottomOf="@+id/new_post_lower_line_view" />
    />

    <ImageView
        android:id="@+id/new_post_share_image_view"
        android:layout_width="@dimen/post_icons_dimen"
        android:layout_height="@dimen/post_icons_dimen"
        android:layout_centerVertical="true"
        android:layout_marginStart="12dp"
        android:layout_marginTop="6dp"
        android:layout_toEndOf="@+id/new_post_comment_image_view"
        android:background="?attr/selectableItemBackgroundBorderless"
        android:clickable="true"
        android:focusable="true"
        android:src="@mipmap/share_icon"
        app:layout_constraintStart_toEndOf="@+id/new_post_comment_image_view"
        app:layout_constraintTop_toBottomOf="@+id/new_post_lower_line_view" />

    <ImageView
        android:id="@+id/new_post_send_message_image_view"
        android:layout_width="@dimen/post_icons_dimen"
        android:layout_height="@dimen/post_icons_dimen"
        android:layout_centerVertical="true"
        android:layout_marginStart="12dp"
        android:layout_marginTop="6dp"
        android:layout_toEndOf="@+id/new_post_share_image_view"
        android:background="?attr/selectableItemBackgroundBorderless"
        android:clickable="true"
        android:focusable="true"
        app:layout_constraintStart_toEndOf="@+id/new_post_share_image_view"
        app:layout_constraintTop_toBottomOf="@+id/new_post_lower_line_view" />


    <TextView
        android:id="@+id/new_post_engagements_text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginTop="6dp"
        android:clickable="true"
        android:text="@string/post_engagements"
        android:textSize="14sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/new_post_lower_line_view" />

    <TextView
        android:id="@+id/new_post_engagements_count_text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_marginEnd="4dp"
        android:layout_marginTop="6dp"
        android:text="20"
        android:textSize="14sp"
        app:layout_constraintEnd_toStartOf="@+id/new_post_engagements_text_view"
        app:layout_constraintTop_toBottomOf="@+id/new_post_lower_line_view" />

    <View
        android:id="@+id/new_post_under_reacts_line_view"
        android:layout_width="match_parent"
        android:layout_height="0.1dp"
        android:layout_marginTop="6dp"
        android:background="#BDBDBD"
        app:layout_constraintTop_toBottomOf="@+id/new_post_send_message_image_view" />

    <android.support.constraint.ConstraintLayout
        android:id="@+id/new_post_comment_view_group"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#eceff1"
        android:paddingBottom="12dp"
        android:paddingStart="16dp"
        android:paddingTop="12dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/new_post_under_reacts_line_view">


        <de.hdodenhof.circleimageview.CircleImageView
            android:id="@+id/new_post_user_image_in_comments_circle_image_view"
            android:layout_width="42dp"
            android:layout_height="42dp"
            android:background="?attr/selectableItemBackgroundBorderless"
            android:clickable="true"
            android:focusable="true" />

        <TextView
            android:id="@+id/new_post_user_name_in_comments_text_view"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="16dp"
            android:text="Abdulmalek Dery"
            android:textColor="@color/black"
            android:textSize="14sp"
            android:textStyle="bold"
            app:layout_constraintStart_toEndOf="@+id/new_post_user_image_in_comments_circle_image_view" />

        <com.github.curioustechizen.ago.RelativeTimeTextView
            android:id="@+id/new_post_comment_date_relative_text_view"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="16dp"
            android:text="2 hour ago"
            android:textSize="12sp"
            app:layout_constraintStart_toEndOf="@+id/new_post_user_image_in_comments_circle_image_view"
            app:layout_constraintTop_toBottomOf="@+id/new_post_user_name_in_comments_text_view" />

        <TextView
            android:id="@+id/new_post_comment_content_text_view"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="16dp"
            android:ellipsize="end"
            android:maxLines="3"
            android:text="some comment on this nice pic"
            android:textColor="@color/black"
            android:textSize="14sp"
            app:layout_constraintStart_toEndOf="@+id/new_post_user_image_in_comments_circle_image_view"
            app:layout_constraintTop_toBottomOf="@+id/new_post_comment_date_relative_text_view" />
    </android.support.constraint.ConstraintLayout>

</android.support.constraint.ConstraintLayout>

and the problem also i have tested the app on Samsung A5 and it doesn't show any blink but in Huawei device show the blink. any help?

Answer 1

Using android:layout_height with values as low as 0.1dp is not recommended, depending on devices screen density and views position this can be rounded down below 1 pixel which can cause view to disappear.

If you want to have really thin lines you can use direct pixel height like 1px instead of dp, that will be less scalable but should prevent blinking.