android - Unwanted padding in CollapsibleToolbarLayout -

i have following code in layout:

<?xml version="1.0" encoding="utf-8"?> <android.support.design.widget.coordinatorlayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context="global.sti.attendance.signupactivity">      <android.support.design.widget.appbarlayout         android:layout_width="match_parent"         android:layout_height="250dp"         android:theme="@style/themeoverlay.appcompat.dark.actionbar">          <android.support.design.widget.collapsingtoolbarlayout             android:id="@+id/collapsibletoolbarlayout"             android:layout_width="match_parent"             android:layout_height="match_parent"             app:layout_scrollflags="scroll|exituntilcollapsed"             app:contentscrim="?attr/colorprimary">              <imageview                 android:layout_width="match_parent"                 android:layout_height="match_parent"                 android:scaletype="centercrop"                 android:src="@mipmap/colorful_background"                 app:layout_collapsemode="parallax"                 android:adjustviewbounds="true"/>              <android.support.v7.widget.toolbar                 android:id="@+id/toolbar"                 android:layout_width="match_parent"                 android:layout_height="?attr/actionbarsize"                 android:background="?attr/colorprimary"                 app:layout_collapsemode="pin"/>          </android.support.design.widget.collapsingtoolbarlayout>      </android.support.design.widget.appbarlayout>  </android.support.design.widget.coordinatorlayout> 

the scrolling works fine there unwanted padding inside collapsingtoolbarlayout result:

what seems problem? thanks!

ps: wrapped layout inside coordinatorlayout , dont know why stackoverflow editor doesnt recognized when pasted in here.

try setting on toolbar

app:contentinsetstart="0dp"