Develop Reference

Why does the toolbar disappear when the background of the fragment is set to a certain color?

I'm working on a drawer layout. I want to replace the main activity screen with a fragment when I click a menu item, but it doesn't show a toolbar when I set the background of a fragment on some color app. Work done so far ...
<!-- activity_main.xml-->
<?xml version="1.0" encoding="utf-8"?>
<androidx.drawerlayout.widget.DrawerLayout
android:id="#+id/drawer"
tools:openDrawer="start"
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=".MainActivity">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<androidx.appcompat.widget.Toolbar
android:background="#ff9100"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:title="News Time"
android:id="#+id/toolbar"
/>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/replacer"
/>
</RelativeLayout>
<com.google.android.material.navigation.NavigationView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/navmenu"
app:menu="#menu/menu"
app:headerLayout="#layout/navheader"
android:layout_gravity="start"
android:background="#ffaa00"
/>
</androidx.drawerlayout.widget.DrawerLayout>
MainActivity.java
package com.example.newsapp;
import androidx.annotation.NonNull;
import androidx.appcompat.app.ActionBarDrawerToggle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import android.os.Bundle;
import android.view.MenuItem;
import android.widget.Toast;
import com.google.android.material.navigation.NavigationView;
public class MainActivity extends AppCompatActivity {
NavigationView nav;
ActionBarDrawerToggle toggle;
DrawerLayout drawerLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
nav = (NavigationView)findViewById(R.id.navmenu);
drawerLayout = (DrawerLayout)findViewById(R.id.drawer);
toggle = new ActionBarDrawerToggle(this,drawerLayout,toolbar,R.string.open,R.string.close);
drawerLayout.addDrawerListener(toggle);
toggle.syncState();
final FragmentManager fragmentManager = getSupportFragmentManager();
final FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
nav.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem menuItem) {
Fragment temp = null;
switch (menuItem.getItemId())
{
case R.id.sporticon:
Toast.makeText(getApplicationContext(),"This is sport section",Toast.LENGTH_SHORT).show();
temp = new sportfragment();
break;
}
fragmentTransaction.replace(R.id.replacer,temp);
fragmentTransaction.commit();
return true;
}
});
}
}
This is fine when there is no background attribute but toolbar disappears when I add it
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".sportfragment"
android:background="#00c3ff"
>
<!-- TODO: Update blank fragment layout -->
<TextView
android:layout_gravity="center"
android:textSize="30sp"
android:textColor="#android:color/black"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="This is sport section"
/>
</FrameLayout>

You are using relative layout so you have to position every single child in relative layout since you are not doing it. framelayout overlapping the toolbar when there is not color in framelayout toolbar visible to you and it does not go anywhere so whenever you add a color toolbar becomes invisible to you but not from screen it will be under the framelayout...
so add below line in framelayout
android:layout_below="#id/toolbar"

Bottom Sheet is not getting overlayed on bottom App bar

I have made an bottom app bar app with fab and bottom sheet and I have implemented the state expanded and state hidden from navigation on item selected listener.The question is how to make bottom sheet overlay on bottom app bar the following result I have got is.
This is main activity xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/activity_CoordinatorLayout"
android:layout_width="match_parent"
android:background="#FFB7B7B7"
android:layout_height="match_parent"
android:orientation="vertical">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"/>
</com.google.android.material.appbar.AppBarLayout>
<com.google.android.material.bottomappbar.BottomAppBar
android:id="#+id/bottom_app_bar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
style="#style/Widget.MaterialComponents.BottomAppBar.Colored"
android:layout_gravity="bottom"
android:elevation="26dp"
app:navigationIcon="#drawable/ic_menu_black" />
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:layout_width="wrap_content"
android:elevation="26dp"
android:layout_height="wrap_content"
app:srcCompat="#android:drawable/ic_menu_add"
app:layout_anchor="#id/bottom_app_bar"
app:menu="#menu/menu_demo"
/>
<FrameLayout
android:id="#+id/bottom_drawer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:elevation="16dp"
android:visibility="visible"
app:behavior_hideable="true"
app:layout_behavior="com.google.android.material.bottomsheet.BottomSheetBehavior">
<com.google.android.material.navigation.NavigationView
android:id="#+id/navigation_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:menu="#menu/menu_demo" />
</FrameLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
Main activity class
package com.bab.BottomAppBar;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import com.google.android.material.bottomappbar.BottomAppBar;
import com.google.android.material.bottomsheet.BottomSheetBehavior;
import android.view.View;
import com.google.android.material.navigation.NavigationView;
import androidx.coordinatorlayout.widget.CoordinatorLayout;
import android.view.MenuItem;
public class MainActivity extends AppCompatActivity {
BottomAppBar bab;
BottomSheetBehavior<View> bsb;
CoordinatorLayout cl;
NavigationView nv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar=(Toolbar)findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
nv=findViewById(R.id.navigation_view);
cl=findViewById(R.id.activity_CoordinatorLayout);
View bottomDrawer=cl.findViewById(R.id.bottom_drawer);
bab=findViewById(R.id.bottom_app_bar);
bsb=BottomSheetBehavior.from(bottomDrawer);
bsb.setState(BottomSheetBehavior.STATE_HIDDEN);
bab.setNavigationIcon(R.drawable.ic_menu_black);
bab.replaceMenu(R.menu.menu_demo);
bab.setNavigationOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View p1) {
bsb.setState(BottomSheetBehavior.STATE_HALF_EXPANDED);
}
});
nv.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener(){
#Override
public boolean onNavigationItemSelected(MenuItem p1) {
return false;
}
});
}
#Override
public void onBackPressed() {
super.onBackPressed();
bsb.setState(BottomSheetBehavior.STATE_HIDDEN);
}
}
Result I got:
This is the result
Result I wanted:
See in this the frame layout as bottom sheet is overlaying on bottom app bar
Someone please help me

You need to set BottomSheet's elevation more than BottomAppBar's.
Elevation means how your views lay above each other

How to access a Button inside a Toolbar in Android

I'm pretty new to coding so I might not express myself correctly, please bear with me.
I have a fragment inflated inside a layout that includes a toolbar. When I open the fragment, I want to add a button (not a menu, just a button to navigate to another fragment).
My issue is I don't know how to instantiate the button from my Fragment class to add an icon and an onClickListener.
Here's my xml files:
The layout that contains my fragment:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
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="be.ac.ulg.mobulis.Activities.MainActivity"
android:orientation="vertical">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="#color/blue"
app:popupTheme="#style/AppTheme.PopupOverlay" >
<Button
android:id="#+id/toolbar_button"
android:layout_width="#dimen/margin"
android:layout_height="#dimen/margin"
android:layout_gravity="right"
android:layout_marginRight="#dimen/innerLargeMargin"
/>
</android.support.v7.widget.Toolbar>
</android.support.design.widget.AppBarLayout>
<include layout="#layout/content_main" />
</LinearLayout>
The layout in which the fragment is inflated:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:design="http://schemas.android.com/apk/res-auto"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="be.ac.ulg.mobulis.Activities.MainActivity"
tools:showIn="#layout/app_bar_main"
android:background="#color/orange">
<FrameLayout
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:background="#f1f1f1">
</FrameLayout>
<android.support.design.widget.BottomNavigationView
android:id="#+id/navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="start"
design:menu="#menu/bottom_nav_items"
android:background="#color/orange"
android:backgroundTint="#color/white"
design:itemIconTint="#color/white"
design:itemTextColor="#color/white"
design:itemBackground="#drawable/bottom_bar_tint_selector"
/>
</LinearLayout>
So what I want to do is something like
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
toolBarButton = (???).findViewById(R.id.toolbar_button)
}

activity_main.xml to add Button inside android.support.v7.widget.Toolbar
<?xml version="1.0" encoding="utf-8"?>
<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="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:orientation="vertical">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="56dp"
android:background="#FFA000">
<Button
android:id="#+id/toolbarbtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
android:layout_gravity="right"/>
</android.support.v7.widget.Toolbar>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!" />
</LinearLayout>
MainActivity.java
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
Button toolBarBtn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setTitle("Toolbar with button example");
toolbar.setSubtitle("Toolbar subtitle");
toolbar.setLogo(android.R.drawable.ic_menu_info_details);
toolBarBtn = (Button)findViewById(R.id.toolbarbtn);
toolBarBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(getBaseContext(),
"Button in ToolBar clicked",
Toast.LENGTH_LONG).show();
}
});
}
}

Set This onClick Listener in your parent activity of Fragment.

try this to access your button of toolbar from activity
private Toolbar toolbar;
toolbar = (Toolbar) findViewById(R.id.ar_toolbar);
Button toolbar_button = (Button) toolbar.findViewById(R.id.toolbar_button);
setSupportActionBar(toolbar);
toolbar_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Toast.makeText(ChatActivity.this, "Clicked", Toast.LENGTH_SHORT).show();
}
});

you have to write like below
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
toolBarButton = (Button) view.findViewById(R.id.toolbar_button);
where view is your view which you bind at your onCreateView in your Fragment.

What I do is to bind the View inside the activity and then create an interface who works with that View.
public class Activity implements ButtonListener{
//findViewbyId or Butterknife
void doSomething(){
toolBarButton.something()
}
Interface
}
public interface ButtonListener{
void doSomething();
}
Fragment
public class Fragment extends Fragment{
public ButtonListener mButton;
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
mButton = (ButtonListener)getActivity();
super.onCreate(savedInstanceState);
}
}

You can access button directly without toolbar using (Button) findViewById(R.id.toolbar_button).
Toolbar toolbar = (Toolbar) findViewById(R.id.ar_toolbar);
Button toolbar_button = (Button) findViewById(R.id.toolbar_button);
setSupportActionBar(toolbar);

Extra blank space on CoordinatorLayout with a ScrollView and ListView

I've created a Scrolling Activity using the Android Studio template, this created an activity.xml and also a content.xml which is included on the activity.xml who has a NestedScrollView into which I've added a ListView feed from an adapter, at first it only showed one item so I programmatically made the size of it to a fixed value so that it actually shows all the items, I was able to do that without a problem and the NestedScrollView wraps the ListView with no problem, however there is a blank space below the NestedScrollView that I realize was from the CoordinatorLayout by adding background colors to all elements, the CoordinatorLayout is the main tag in the activity.xml but I am not able to figure out how to remove this blank space since if I use wrap_content on the CoordinatorLayout it will actually trim my content to half the screen for some reason.
The other things that are worth to mention are that this blanks space is not showing if I rotate my phone horizontally, is only coming up on a vertical position. Also,
Does anyone know what might be causing this? Is not a big deal and I might even end up leaving it like this but it's just annoying to me I'm not able to figure out what's going on.
This is my activity.xml
<?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"
android:fitsSystemWindows="true"
android:background="#00ff00" //Green
tools:context=".VenueActivity">
<android.support.design.widget.AppBarLayout
android:id="#+id/app_bar"
android:layout_width="match_parent"
android:layout_height="#dimen/app_bar_height"
android:fitsSystemWindows="true"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/toolbar_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="#drawable/frog"
android:scaleType="centerCrop"
/>
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
app:popupTheme="#style/AppTheme.PopupOverlay" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<include layout="#layout/content_venue"/>
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="#dimen/fab_margin"
android:src="#drawable/ic_favorite_white_24dp"
app:layout_anchor="#id/app_bar"
app:layout_anchorGravity="bottom|end" />
</android.support.design.widget.CoordinatorLayout>
This is my content.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView 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="wrap_content"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context=".VenueActivity"
android:background="#ff0000" //Blue
tools:showIn="#layout/activity_venue">
<LinearLayout
android:id="#+id/venueList"
android:background="#ffff00" //Yellow
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<SearchView
android:layout_width="match_parent"
android:layout_height="55dp"
android:id="#+id/searchView"
android:queryHint="Search venues">
</SearchView>
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/songList" />
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
Finally my java file:
package com.example.android.myApplication;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class VenueActivity extends AppCompatActivity {
//Set up my own database manually
String[] db_ids = {"12345", "12345", "12345", "12345", "12345", "12345"};
String[] db_songs = {"Item 1", "Item 2", "Item 3", "Item 4", "Item 5", "Item 6"};
int[] db_thumbs = {R.drawable.ic_place_white_24dp, R.drawable.ic_place_white_24dp,
R.drawable.ic_place_white_24dp, R.drawable.ic_place_white_24dp,
R.drawable.ic_place_white_24dp, R.drawable.ic_place_white_24dp};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_venue);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
Toast.makeText(VenueActivity.this, getIntent().getStringExtra("venue") + " was choosen", Toast.LENGTH_SHORT).show();
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Venue has been added to your favourites", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
/**
* LISTVIEW TO DISPLAY DIFFRENT VENUES
*/
ListView lv = (ListView) findViewById(R.id.songList);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
TextView selectedSong = (TextView) view.findViewById(R.id.songName);
// TODO Third Fragment must be changed to the Venue Home or something different than this
Toast.makeText(VenueActivity.this, selectedSong.getText(), Toast.LENGTH_SHORT).show();
// Intent intent = new Intent(view.getContext(),VenueActivity.class);
// intent.putExtra("venue", selectedVenue.getText());
// startActivity(intent);
}
});
SongArrayAdapter ad = new SongArrayAdapter(db_ids, db_songs, db_thumbs, getApplicationContext());
lv.setAdapter(ad);
ListViewInScrollView.adapt(lv);
}
}

Scrolling to view in CoordinatorLayout shows only partially the view

I have made an Android app containing a CoordinatorLayout with a AppBar and a NestedScrollView. In my NestedScrollView I have a list of items, and a button which scroll to an item in my NestedScrollView.
When clicking the button, the Android app scroll down to the item, but doesn't show the whole item, only partially: http://i.stack.imgur.com/8kuq0.png
I expected something like the following: http://i.stack.imgur.com/k0A5N.png
It seems like the amount the app needs to scroll is about the same size as the AppBar, in order to show the whole view. If I remove the scroll flag in my layout file below, I get the expected behavior.
What do I do wrong?
Update (12/01/2016): I've updated the pictures, so they are bigger. Furthermore as I wrote in Herry's response, I'm in doubt if View.requestRectangleOnScreen() is the right method to call, or if I should use a different layout then NestedScrollView.
My activity is coded as follows:
package com.example.sij.coordinatorlayoutbug;
import android.graphics.Rect;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
TextView itemToNavigateTo;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
itemToNavigateTo = (TextView)findViewById(R.id.itemToNavigateTo);
Button navigatorButton = (Button)findViewById(R.id.navigator_button);
navigatorButton.setOnClickListener(navigateToItemListener());
}
View.OnClickListener navigateToItemListener() {
return new View.OnClickListener() {
#Override
public void onClick(final View v) {
new Handler(Looper.getMainLooper()).post(new Runnable() {
#Override
public void run() {
itemToNavigateTo.requestRectangleOnScreen(
new Rect(
0,
0,
itemToNavigateTo.getWidth(),
itemToNavigateTo.getHeight()));
}
});
}
};
}
}
And the layout file:
<?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"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<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_scrollFlags="scroll|enterAlways" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<Button
android:id="#+id/navigator_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/scroll_to_item" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/item1"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/lorem_ipsum"
android:paddingBottom="20dp"/>
<!-- Items 2 to 5 omitted for brevity -->
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/item6"/>
<TextView
android:id="#+id/itemToNavigateTo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/lorem_ipsum"
android:paddingBottom="20dp"/>
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
</android.support.design.widget.CoordinatorLayout>

you need to add android:fillviewport="true" in your
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:fillViewport="true">