res/layout/widgets_search_bar.xml

<?xml version="1.0" encoding="utf-8"?>
<com.android.launcher3.widget.picker.search.LauncherWidgetsSearchBar
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/widgets_search_bar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:layout_marginTop="16dp"
    android:background="@drawable/bg_widgets_searchbox">

    <com.android.launcher3.ExtendedEditText
        android:id="@+id/widgets_search_bar_edit_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="12dp"
        android:drawablePadding="8dp"
        android:drawableStart="@drawable/ic_allapps_search"
        android:background="@null"
        android:hint="@string/widgets_full_sheet_search_bar_hint"
        android:maxLines="1"
        android:layout_weight="1"
        android:inputType="text"/>

    <ImageButton
        android:id="@+id/widgets_search_cancel_button"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:src="@drawable/ic_gm_close_24"
        android:background="?android:selectableItemBackground"
        android:layout_gravity="center"
        android:visibility="gone"/>
</com.android.launcher3.widget.picker.search.LauncherWidgetsSearchBar>