Bottom Sheet in android

BottomSheetActivity.class

public class BottomSheetActivity extends AppCompatActivity {

private BottomSheetBehavior mBottomSheetBehavior;

private NestedScrollView mNestedScrollView;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_bottom_sheet);

mNestedScrollView = (NestedScrollView) findViewById(R.id.activity_coordinate_layout_demo_nsv);

mBottomSheetBehavior = BottomSheetBehavior.from(mNestedScrollView);

}

public void showBottomSheet(View view) {

if (mBottomSheetBehavior.getState() == BottomSheetBehavior.STATE_COLLAPSED) {

mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);

} else if(mBottomSheetBehavior.getState() == BottomSheetBehavior.STATE_EXPANDED) {

mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);

}

}

}

activity_bottom_sheet.class

<?xml version="1.0" encoding="utf-8"?>

<android.support.design.widget.CoordinatorLayout android:layout_width="match_parent"

android:layout_height="match_parent"

xmlns:app="http://schemas.android.com/apk/res-auto"

xmlns:android="http://schemas.android.com/apk/res/android">

<Button

style="@style/NormalTextView"

android:text="Show bottom sheet"

android:layout_gravity="center_horizontal"

android:layout_marginTop="25dp"

android:onClick="showBottomSheet"/>

<!-- Nested scroll view can hold one child only-->

<!--Peekhieght make child view to be visible even collapsed-->

<!--setting layout_behavior enable view to be settle at center of total height-->

<android.support.v4.widget.NestedScrollView

android:id="@+id/activity_coordinate_layout_demo_nsv"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:background="@color/colorAccent"

app:behavior_peekHeight="50dp"

app:layout_behavior="@string/bottom_sheet_behavior">

<LinearLayout

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="vertical">

<TextView

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="Hellow world"

android:textColor="#ffffff"

android:textSize="65dp"/>

<TextView

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="Hellow world"

android:textColor="#ffffff"

android:textSize="65dp"/>

</LinearLayout>

</android.support.v4.widget.NestedScrollView>

</android.support.design.widget.CoordinatorLayout>

style.xml

<resources><style name="NormalTextView">

<item name="android:layout_width">wrap_content</item>

<item name="android:layout_height">wrap_content</item>

<item name="android:textSize">16dp</item>

<item name="android:textColor">@color/colorPrimary</item>

</style></resources>