title: Blur Surrounding Of Expanded RecyclerView Item (Blur RecyclerView Except Of One Of Its Items)
body: <p>I have a <code>RecyclerView</code> containing its children:</p>
  
  <p><a href="https://i.stack.imgur.com/0vIdi.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0vIdi.jpg" alt="enter image description here"></a></p>
  
  <p>As you can see in the picture, each item can be expanded (for example item i in the picture).
  In my project I use <a href="https://github.com/mmin18/RealtimeBlurView" rel="nofollow noreferrer">this blur library</a> to blur things, for example, clicking the <code>FloatingActionButton</code> expands it to a dialog, and the dialog's surrounding is blurred, like this:</p>
  
  <p><a href="https://i.stack.imgur.com/1w8Wx.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1w8Wx.jpg" alt="enter image description here"></a></p>
  
  <p>I want that an expanded <code>RecyclerView</code>s item will have its surrounding blurred as well. I tried this:</p>
  
  <p>(<code>Item.xml</code>:)</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout 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"&gt;
  
      &lt;com.github.mmin18.widget.RealtimeBlurView
          android:id="@+id/blur_view_per_active_goal_card"
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          app:realtimeBlurRadius="20dp"
          app:realtimeOverlayColor="#8000"
          android:visibility="visible"/&gt;
  
      &lt;androidx.cardview.widget.CardView
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:layout_margin="5dp"
          app:cardCornerRadius="15dp"
          app:cardElevation="10dp"&gt;
  
          &lt;RelativeLayout
              android:id="@+id/root_view"
              android:layout_width="match_parent"
              android:layout_height="match_parent"&gt;
  
              &lt;LinearLayout
                  android:id="@+id/active_goal_card"
                  android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  android:layout_margin="4dp"
                  android:orientation="horizontal"
                  android:padding="10dp"
                  android:weightSum="10"&gt;
  
                  &lt;com.example.performancemeasurement.customViews.CustomProgressBar.CustomProgressBar
                      android:id="@+id/active_goal_item_progress_bar"
                      android:layout_width="0dp"
                      android:layout_height="50dp"
                      android:layout_weight="9"
                      android:transitionName="progressBar"
                      android:visibility="visible"
                      app:enable_gradient="true" /&gt;
  
                  &lt;ImageButton
                      android:id="@+id/active_goal_item_open_close_image_button"
                      android:layout_width="0dp"
                      android:layout_height="match_parent"
                      android:layout_weight="1"
                      android:background="?attr/selectableItemBackground"
                      android:scaleType="fitCenter"
                      android:src="@drawable/down_vector" /&gt;
  
              &lt;/LinearLayout&gt;
  
              &lt;RelativeLayout
                  android:id="@+id/expanded_active_goal_card"
                  android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  android:layout_margin="4dp"
                  android:visibility="gone"&gt;
  
  
                  &lt;TextView
                      android:id="@+id/expanded_active_goal_card_label"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:layout_margin="10dp"
                      android:layout_centerHorizontal="true"
                      android:text="Goal Name"
                      android:textColor="@android:color/black"
                      android:textSize="40sp"
                      android:textStyle="bold" /&gt;
  
  
                  &lt;com.example.performancemeasurement.customViews.CustomProgressBar.CustomProgressBar
                      android:id="@+id/expanded_active_goal_card_progress_bar"
                      android:layout_width="wrap_content"
                      android:layout_height="30dp"
                      android:layout_below="@id/expanded_active_goal_card_label"
                      android:layout_alignParentStart="true"
                      android:layout_alignParentEnd="true"
                      android:layout_marginStart="20dp"
                      android:layout_marginEnd="20dp"
                      android:layout_centerHorizontal="true"
                      android:transitionName="progressBar"
                      app:enable_gradient="true" /&gt;
  
                  &lt;TextView
                      android:id="@+id/expanded_active_goal_card_description"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:layout_below="@id/expanded_active_goal_card_progress_bar"
                      android:layout_centerHorizontal="true"
                      android:layout_margin="10dp"
                      android:maxLines="3"
                      android:text="Goal's Description"
                      android:textColor="#6F6F6F"
                      android:textSize="20sp"
                      android:textStyle="normal" /&gt;
  
                  &lt;LinearLayout
                      android:id="@+id/expanded_active_goal_card_sub_goals_label_container"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:layout_below="@id/expanded_active_goal_card_description"
                      android:layout_centerHorizontal="true"
                      android:layout_margin="5dp"
                      android:gravity="center_vertical"
                      android:orientation="horizontal"
                      android:weightSum="14"&gt;
  
                      &lt;View
                          android:id="@+id/expanded_active_goal_card_sub_goal_label_left"
                          android:layout_width="0dp"
                          android:layout_height="3dp"
                          android:layout_weight="4"
                          android:background="@color/light_gray" /&gt;
  
                      &lt;TextView
                          android:id="@+id/expanded_active_goal_card_sub_goals_label"
                          android:layout_width="0dp"
                          android:layout_height="wrap_content"
                          android:layout_margin="5dp"
                          android:layout_weight="6"
                          android:gravity="center"
                          android:text="SubGoals"
                          android:textColor="#5A5A5A"
                          android:textSize="25sp"
                          android:textStyle="bold" /&gt;
  
                      &lt;View
                          android:id="@+id/expanded_active_goal_card_sub_goal_label_right"
                          android:layout_width="0dp"
                          android:layout_height="3dp"
                          android:layout_weight="4"
                          android:background="@color/light_gray" /&gt;
  
                  &lt;/LinearLayout&gt;
  
                  &lt;RelativeLayout
                      android:id="@+id/expanded_active_goal_card_sub_goals_container"
                      android:layout_width="match_parent"
                      android:layout_height="wrap_content"
                      android:layout_below="@+id/expanded_active_goal_card_sub_goals_label_container"
                      android:layout_centerHorizontal="true"
                      android:layout_margin="10dp"
                      android:animateLayoutChanges="true"
                      android:elevation="15dp"
                      android:gravity="center"&gt;
  
                      &lt;androidx.recyclerview.widget.RecyclerView
                          android:id="@+id/expanded_active_goal_card_sub_goals_recycler_view"
                          android:layout_width="match_parent"
                          android:layout_height="100dp" /&gt;
  
                  &lt;/RelativeLayout&gt;
  
              &lt;/RelativeLayout&gt;
  
          &lt;/RelativeLayout&gt;
  
      &lt;/androidx.cardview.widget.CardView&gt;
  
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>(putting the blurred view behind the item's content, and then in the <code>RecyclerView</code>s <code>ViewHolder</code> handle the blur visibility as I did in the Dialog example every time the item is expanded/shrunk, but even when I make it visible without handling it, the blur won't show. I tried to handle it programmatically as planned, but still, the blur didn't show up.</p>
  
  <p>So the question is: Specifically in my case - where is the problem? Why won't the blur show? 
  And in general... how can I blur the surrounding of a <code>RecyclerView</code>s expanded/focused item (using the <code>RealtimeBlurView</code> library or any other that suits the solution for this problem), or in other words, how can I blur the whole <code>Recyclerview</code> except of one of its items / how can I blur the background of specific <code>View</code>(blur everything except this <code>View</code>.</p>
  
  <p>Help would be highly appreciated! (:</p>