android - Setting minimum width of a RecyclerView item -

i trying set minimum width items of recyclerview gridmanagerlayout

if put 5 items per row looks great when put 20 items per row size of item 20 dp want @ least 120 dp, how can that?

 gridlayoutmanager manager = new gridlayoutmanager(actividadescolectivasplazasactivity.this, columnas);    adapter = new plazasadapter(ctx, listaplazas);   mrecyclerview.setlayoutmanager(manager);  mrecyclerview.sethasfixedsize(true); 

layout

<horizontalscrollview     android:layout_width="fill_parent"     android:layout_height="fill_parent"     android:layout_below="@+id/app_bar">      <linearlayout         android:orientation="vertical"         android:layout_width="wrap_content"         android:layout_height="match_parent">         <view             android:layout_width="wrap_content"             android:layout_height="fill_parent"             class="android.support.v7.widget.recyclerview"             android:layout_margintop="10dp"             android:minwidth="500dp"             android:id="@+id/recycler_view" />     </linearlayout>      </horizontalscrollview> 

adapter xml

<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="80dp" android:minwidth="120dp" android:background="@drawable/fondo_stroke_gris" android:orientation="vertical" android:gravity="center"  tools:context="com.psapp_provisport.activity.menuactivity" >   <relativelayout     android:layout_width="wrap_content"     android:layout_height="match_parent"     android:layout_margintop="10dp"     android:layout_weight="1" >      <imageview         android:id="@+id/imagen"         android:layout_width="wrap_content"         android:layout_height="match_parent"         android:layout_centerhorizontal="true"         android:src="@drawable/ic_launcher"/>      <progressbar         android:id="@+id/pb1"         style="?android:attr/progressbarstylelarge"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_centerhorizontal="true"         android:visibility="invisible" /> </relativelayout>  <textview     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_margintop="5dp"     android:layout_marginbottom="5dp"     android:gravity="center"     android:id="@+id/nombre" /> 

to acomplish change miniumwidth of recycler view programatically number of columns*300

gridlayoutmanager manager = new gridlayoutmanager(actividadescolectivasplazasactivity.this, columnas); mrecyclerview.setminimumwidth(columnas*300);