Extremely Laggy RecyclerView Performance

Question

I have a RecyclerView implementation inside of a ViewPager, and its performance is pretty horrible. Here's a video of the performance in question. I have two view types, and am using the ViewHolder pattern (so it's not inflation or finding views causing the issue).

Here's the adapter.

Here's the cardview.xml file

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"

android:layout_height="wrap_content"

android:clipChildren="false"


android:orientation="vertical"

android:scrollbars="none">

<LinearLayout
    android:id="@+id/next"
    android:layout_width="match_parent"
    android:layout_height="2dp"
    android:layout_marginBottom="8dp"
    android:elevation="8dp"
    android:orientation="horizontal" />

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/top"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/card_background"
    android:orientation="horizontal">


    <LinearLayout
        android:id="@+id/dots"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"

        android:layout_alignParentTop="true"

        android:background="?attr/activity_background"
        android:orientation="horizontal">


    </LinearLayout>


    <View
        android:id="@+id/dot"
        android:layout_width="3dp"
        android:layout_height="match_parent"

        android:layout_alignParentBottom="true"
        android:layout_alignParentTop="true"
        android:layout_toRightOf="@id/dots"
        android:background="#fff" />


    <RelativeLayout
        android:id="@+id/background"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@+id/dot"
        android:orientation="vertical"
        android:paddingLeft="8dp"

        android:paddingRight="8dp"
        android:paddingTop="8dp">


        <include
            android:id="@+id/children"
            layout="@layout/commentnumber"
            android:layout_width="wrap_content"
            android:layout_height="16dp"
            android:layout_alignParentRight="true"

            android:layout_gravity="right"
            android:layout_marginBottom="-16dp"
            android:layout_marginLeft="10dp"
            android:gravity="center_horizontal"
            android:orientation="horizontal" />


        <com.wefika.flowlayout.FlowLayout
            android:id="@+id/flow"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:gravity="center_vertical"
            android:orientation="horizontal"
            android:paddingRight="10dp">

            <TextView
                android:id="@+id/author"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:gravity="center_vertical"
                android:layout_gravity="center_vertical"

                android:paddingRight="5dp"
                android:text="ccrama"

                android:textColor="?attr/font"
                android:textSize="?attr/font_commenttitle"
                android:textStyle="bold"

                />

            <TextView
                android:id="@+id/score"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:gravity="center_vertical"
                android:layout_gravity="center_vertical"
                android:paddingLeft="5dp"
                android:paddingRight="5dp"
                android:text="+49"
                android:textColor="?attr/font"
                android:textSize="?attr/font_commentinfo"

                android:textStyle="bold" />

            <TextView
                android:id="@+id/time"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:gravity="center_vertical"
                android:layout_alignParentRight="true"
                android:layout_gravity="center_vertical"
                android:paddingLeft="5dp"
                android:paddingRight="5dp"
                android:text="4 hours ago"

                android:textColor="?attr/font"

                android:textSize="?attr/font_commentinfo" />

            <include
                android:id="@+id/gild"
                layout="@layout/gilded"
                android:layout_width="wrap_content"
                android:layout_height="16dp"

                android:layout_gravity="center_vertical"
                android:gravity="center_horizontal"
                android:orientation="horizontal"
                android:paddingLeft="5dp"
                android:paddingRight="5dp" />

            <include
                android:id="@+id/flairbubble"
                layout="@layout/flair"
                android:layout_width="wrap_content"
                android:layout_height="16dp"

                android:layout_gravity="center_vertical"
                android:layout_margin="5dp"

                android:layout_toRightOf="@+id/pinned"
                android:paddingLeft="5dp"
                android:paddingRight="5dp"
                android:src="@drawable/pinned" />

            <include
                android:id="@+id/you"
                layout="@layout/you"
                android:layout_width="wrap_content"
                android:layout_height="16dp"

                android:layout_centerVertical="true"
                android:layout_gravity="center_vertical"

                android:layout_toRightOf="@+id/pinned"
                android:paddingLeft="5dp"
                android:paddingRight="5dp"
                android:src="@drawable/pinned" />

            <include
                android:id="@+id/op"
                layout="@layout/op"
                android:layout_width="wrap_content"
                android:layout_height="16dp"

                android:layout_marginLeft="4dp"
                android:layout_centerVertical="true"
                android:layout_gravity="center_vertical"

                android:layout_toRightOf="@+id/pinned"
                android:paddingLeft="5dp"
                android:paddingRight="5dp"
                android:src="@drawable/pinned" />
        </com.wefika.flowlayout.FlowLayout>


        <me.ccrama.redditslide.ActiveTextView
            android:id="@+id/content"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@+id/flow"
            android:paddingBottom="8dp"

            android:textColor="?attr/font"
            android:textSize="?attr/font_commentbody" />


    </RelativeLayout>




</LinearLayout>

<LinearLayout
    android:id="@+id/menu"
    android:layout_width="match_parent"
    android:layout_height="48dp"
    android:layout_below="@+id/background"
    android:orientation="horizontal"
    android:weightSum="4">

    <ImageView
        android:id="@+id/more"
        android:layout_width="0dp"
        android:layout_height="48dp"
        android:layout_weight="1"

        android:background="?android:selectableItemBackground"
        android:padding="12dp"
        android:src="@drawable/more"


        android:tint="?attr/tint" />


    <ImageView
        android:id="@+id/downvote"
        android:layout_width="0dp"
        android:layout_height="48dp"
        android:layout_weight="1"
        android:background="?android:selectableItemBackground"
        android:padding="12dp"

        android:src="@drawable/downvoteicon"
        android:tint="?attr/tint" />

    <ImageView
        android:id="@+id/upvote"
        android:layout_width="0dp"
        android:layout_height="48dp"
        android:layout_weight="1"
        android:background="?android:selectableItemBackground"
        android:padding="12dp"
        android:src="@drawable/upvoteicon"

        android:tint="?attr/tint" />

    <ImageView
        android:id="@+id/reply"
        android:layout_width="0dp"
        android:layout_height="48dp"
        android:layout_weight="1"
        android:background="?android:selectableItemBackground"
        android:padding="12dp"

        android:src="@drawable/reply"
        android:tint="?attr/tint" />
</LinearLayout>

<LinearLayout
    android:id="@+id/replyArea"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/menu"

    android:orientation="vertical"
    android:padding="16dp">

    <EditText
        android:id="@+id/replyLine"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:backgroundTint="?attr/tint"
        android:hint="Reply"
        android:imeOptions="actionDone|flagNoEnterAction"
        android:inputType="textMultiLine|textAutoCorrect|textCapSentences"
        android:minHeight="30dp"
        android:textColor="?attr/font"
        android:textColorHint="?attr/font" />

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <TextView
            android:id="@+id/discard"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="?android:selectableItemBackground"
            android:padding="4dp"

            android:text="DISCARD"
            android:textColor="?attr/font"
            android:textSize="14sp"
            android:textStyle="bold" />

        <TextView
            android:id="@+id/send"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:background="?android:selectableItemBackground"
            android:padding="4dp"

            android:text="SUBMIT"
            android:textColor="?attr/font"

            android:textSize="14sp"
            android:textStyle="bold" />
    </RelativeLayout>

    <LinearLayout
        android:id="@+id/innersend2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginLeft="-6dp"
        android:layout_marginRight="-6dp"
        android:alpha=".56"

        android:gravity="center"
        android:orientation="horizontal"

        android:weightSum="8">

        <ImageButton
            android:id="@+id/imagerep"
            android:layout_width="0dp"
            android:layout_height="48dp"
            android:layout_weight="1"
            android:height="48dp"
            android:background="#00000000"
            android:cropToPadding="false"
            android:padding="8dp"
            android:scaleType="fitCenter"
            android:src="@drawable/image"
            android:tint="?attr/tint" />


        <ImageButton
            android:id="@+id/link"
            android:layout_width="0dp"
            android:layout_height="48dp"
            android:layout_weight="1"

            android:height="48dp"
            android:background="#00000000"
            android:cropToPadding="false"
            android:padding="8dp"
            android:scaleType="fitCenter"
            android:src="@drawable/link"
            android:tint="?attr/tint" />

        <ImageButton
            android:id="@+id/bold"
            android:layout_width="0dp"
            android:layout_height="48dp"
            android:layout_weight="1"
            android:height="48dp"
            android:background="#00000000"

            android:cropToPadding="false"
            android:padding="8dp"
            android:scaleType="fitCenter"
            android:src="@drawable/bold"
            android:tint="?attr/tint" />

        <ImageButton
            android:id="@+id/italics"
            android:layout_width="0dp"
            android:layout_height="48dp"
            android:layout_weight="1"

            android:height="48dp"
            android:background="#00000000"
            android:cropToPadding="false"
            android:padding="8dp"
            android:scaleType="fitCenter"
            android:src="@drawable/italics"
            android:tint="?attr/tint" />

        <ImageButton
            android:id="@+id/bulletlist"
            android:layout_width="0dp"
            android:layout_height="48dp"
            android:layout_weight="1"
            android:height="48dp"
            android:background="#00000000"
            android:cropToPadding="false"

            android:padding="8dp"
            android:scaleType="fitCenter"
            android:src="@drawable/bullets"
            android:tint="?attr/tint" />

        <ImageButton
            android:id="@+id/numlist"
            android:layout_width="0dp"
            android:layout_height="48dp"
            android:layout_weight="1"
            android:height="48dp"
            android:background="#00000000"

            android:cropToPadding="false"
            android:padding="8dp"
            android:scaleType="fitCenter"
            android:src="@drawable/numbers"
            android:tint="?attr/tint" />

        <ImageButton
            android:id="@+id/quote"
            android:layout_width="0dp"

            android:layout_height="48dp"
            android:layout_weight="1"
            android:height="48dp"
            android:background="#00000000"
            android:cropToPadding="false"
            android:padding="8dp"
            android:scaleType="fitCenter"
            android:src="@drawable/quotes"
            android:tint="?attr/tint" />

        <ImageButton
            android:id="@+id/size"
            android:layout_width="0dp"

            android:layout_height="48dp"
            android:layout_weight="1"
            android:height="48dp"
            android:background="#00000000"
            android:cropToPadding="false"
            android:padding="8dp"
            android:scaleType="fitCenter"
            android:src="@drawable/fontsizedarker"
            android:tint="?attr/tint" />
    </LinearLayout>
</LinearLayout>

Removing all the adapter code except for inflation still results in noticeable lag. I really can't find the bottom of this, and any help/tips are greatly appreciated.

EDIT: Some more information: Removing the dataset "hiding" code (getRealPosition, hideAll, unhideAll) has no affect on the speed of the RecyclerView. Also, removing the FlowLayout does not make it any faster.

Answer 1

I was having the same problem with RecyclerView. It was laggy. In my case, there was a horizontal list of image buttons inside RecyclerView.

I solved it by removing the scaleType from ImageButtons or ImageViews and loading images through Picasso with resizing like :

 Picasso.with(context).load(icon.get(position)).resize(270,270).centerCrop().into(holder.iconView);

The problem of lag may occur due to runtime scaling of big sized images or no. of images. It is not advisable. Whereas Picasso takes care of resizing, and loading efficiently. Also it handles caching for you.