Persistent Bottom Sheet Tutorial

activity_main.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"
    tools:context="com.codinginflow.persistentbottomsheetexample.MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center_horizontal"
        android:orientation="vertical">

        <Button
            android:id="@+id/button_expand"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="expand" />

        <Button
            android:id="@+id/button_collapse"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="collapse" />

        <TextView
            android:id="@+id/text_view_state"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:text="State"
            android:textColor="@android:color/black"
            android:textSize="30sp" />

    </LinearLayout>

    <android.support.v4.widget.NestedScrollView
        android:id="@+id/bottom_sheet"
        android:layout_width="match_parent"
        android:layout_height="350dp"
        android:background="@android:color/holo_blue_light"
        app:behavior_hideable="true"
        app:behavior_peekHeight="55dp"
        app:layout_behavior="@string/bottom_sheet_behavior">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:padding="16dp"
            android:text="This is a Bottom Sheet\n\nLorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.
Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis at vero eros et accumsan et iusto odio dignissim qui blandit praesent luptatum zzril delenit augue duis dolore te feugait nulla facilisi. Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat.
Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat. Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis at vero eros et accumsan et iusto odio dignissim qui blandit praesent luptatum zzril delenit augue duis dolore te feugait nulla facilisi.
Nam liber tempor cum soluta nobis eleifend option congue nihil imperdiet doming id quod mazim placerat facer"
            android:textSize="16sp" />

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

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

MainActivity.java

package com.codinginflow.persistentbottomsheetexample;

import android.support.annotation.NonNull;
import android.support.design.widget.BottomSheetBehavior;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private BottomSheetBehavior mBottomSheetBehavior;
    private TextView mTextViewState;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        View bottomSheet = findViewById(R.id.bottom_sheet);

        mBottomSheetBehavior = BottomSheetBehavior.from(bottomSheet);

        mTextViewState = findViewById(R.id.text_view_state);

        Button buttonExpand = findViewById(R.id.button_expand);
        Button buttonCollapse = findViewById(R.id.button_collapse);

        buttonExpand.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
            }
        });

        buttonCollapse.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
            }
        });

        mBottomSheetBehavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
            @Override
            public void onStateChanged(@NonNull View bottomSheet, int newState) {
                switch (newState) {
                    case BottomSheetBehavior.STATE_COLLAPSED:
                        mTextViewState.setText("Collapsed");
                        break;
                    case BottomSheetBehavior.STATE_DRAGGING:
                        mTextViewState.setText("Dragging...");
                        break;
                    case BottomSheetBehavior.STATE_EXPANDED:
                        mTextViewState.setText("Expanded");
                        break;
                    case BottomSheetBehavior.STATE_HIDDEN:
                        mTextViewState.setText("Hidden");
                        break;
                    case BottomSheetBehavior.STATE_SETTLING:
                        mTextViewState.setText("Settling...");
                        break;
                }
            }

            @Override
            public void onSlide(@NonNull View bottomSheet, float slideOffset) {
                mTextViewState.setText("Sliding...");
            }
        });
    }
}