LostFilter.java + activity_lost_filter.xml

package com.example.chat;

import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.NavigationView;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.SeekBar;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;

public class LostFilter extends AppCompatActivity  implements AdapterView.OnItemSelectedListener {
    Spinner category;
    TextView timeText;
    SeekBar timeBar;
    Button find;
    FloatingActionButton add;
    String categorySelect;
    int progressValue;
    CheckBox selectAll;

    private NavigationView nav_view;
    private DrawerLayout dl;
    private ActionBarDrawerToggle t;

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

        //spinner
        category = findViewById(R.id.categorySpinner);
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, R.array.lostFoundCategories, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        category.setAdapter(adapter);
        category.setOnItemSelectedListener(this);
        selectAll = findViewById(R.id.selectAll);
        //seek bar
        seekBar();
        //add and delete buttons
        addButtonActions();
        findButtonActions();
        addNavigationDrawer();
    }

    public void findButtonActions() {
        find = findViewById(R.id.findButton);
        find.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(LostFilter.this, FoundItemsPage.class);

                //create item and add extra to intent
                //Item item = new Item(categorySelect, progressValue);
                //intent.putExtra("item", item);
                startActivity(intent);
            }
        });
    }

    public void addButtonActions() {
        add = findViewById(R.id.floatingActionButton);
        add.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(LostFilter.this, FoundAddItem.class);
                startActivity(intent);
            }
        });
    }

    public void seekBar() {
        timeBar = findViewById(R.id.timeSeekBar);
        timeText = findViewById(R.id.timeView);
        //to make the time bar max 1 month the max value is set to 30
        timeBar.setMax(30);
        timeBar.setOnSeekBarChangeListener(
                new SeekBar.OnSeekBarChangeListener() {

                    @Override
                    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                        progressValue = progress;
                        if (progressValue == 30) {
                            timeText.setText("Latest: 1 month");
                        } else if (progressValue == 0 || progressValue == 1) {
                            timeText.setText("Latest: 1 day");
                        } else {
                            timeText.setText("Latest: " + progressValue + " days");
                        }
                    }

                    @Override
                    public void onStartTrackingTouch(SeekBar seekBar) {
                    }

                    @Override
                    public void onStopTrackingTouch(SeekBar seekBar) {
                        if (progressValue == 30) {
                            timeText.setText("Latest: 1 month");
                        } else if (progressValue == 0 || progressValue == 1) {
                            timeText.setText("Latest: " + progressValue + " day");
                        } else {
                            timeText.setText("Latest: " + progressValue + " days");
                        }
                    }
                }
        );

        if (selectAll.isChecked())
        {
            timeBar.setEnabled(false);
        }
        else
        {
            timeBar.setEnabled(true);
        }
    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        categorySelect = parent.getItemAtPosition(position).toString();
        //THE SELECTED CATEGORY INFORMATION
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {
    }

    private void addNavigationDrawer() {
        dl = (DrawerLayout) findViewById(R.id.activity_main);
        t = new ActionBarDrawerToggle(LostFilter.this, dl, R.string.Open, R.string.Close);

        dl.addDrawerListener(t);
        t.syncState();

        nav_view = (NavigationView) findViewById(R.id.nv);
        nav_view.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                int id = item.getItemId();
                switch (id) {
                    case R.id.logout:
                        Toast.makeText(LostFilter.this, "Logout", Toast.LENGTH_SHORT).show();
                        break;
                    case R.id.buy_sell:
                        Toast.makeText(LostFilter.this, "Buy / Sell", Toast.LENGTH_SHORT).show();
                        startActivity(new Intent(LostFilter.this, LostFilter.class));
                        finish();
                        break;
                    case R.id.lost_found:
                        Toast.makeText(LostFilter.this, "Lost & Found", Toast.LENGTH_SHORT).show();
                        dl.closeDrawers();
                        break;
                    case R.id.chats:
                        Toast.makeText(LostFilter.this, "Chats", Toast.LENGTH_SHORT).show();
                        startActivity(new Intent(LostFilter.this, ChatActivity.class));
                        finish();
                        break;
                    case R.id.settings:
                        Toast.makeText(LostFilter.this, "Settings", Toast.LENGTH_SHORT).show();
                        startActivity(new Intent(LostFilter.this, SettingsActivity.class));
                        finish();
                        break;
                    default:
                        dl.closeDrawers();
                        return true;
                }
                return true;
            }
        });
    }
}


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

<android.support.v4.widget.DrawerLayout
    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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorAccent"
    tools:context=".MainActivity">

<android.support.constraint.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".LostFilter">

    <android.support.constraint.Guideline
        android:id="@+id/guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_begin="20dp" />

    <android.support.constraint.Guideline
        android:id="@+id/guideline2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_begin="20dp" />

    <TextView
        android:id="@+id/sellText"
        android:layout_width="163dp"
        android:layout_height="29dp"
        android:text="I FOUND AN ITEM"
        android:textColor="#000000"
        android:textSize="18sp"
        android:textStyle="bold|italic"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.649"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.126"
        tools:text="I FOUND AN ITEM" />

    <TextView
        android:id="@+id/buyTitle"
        android:layout_width="237dp"
        android:layout_height="48dp"
        android:text="LOST SOMETHING?"
        android:textColor="#050505"
        android:textSize="24sp"
        android:textStyle="bold"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.211"
        tools:text="LOST SOMETHING?" />

    <TextView
        android:id="@+id/categoriesLost"
        android:layout_width="119dp"
        android:layout_height="31dp"
        android:text="CATEGORIES:"
        android:textColor="#030303"
        android:textSize="18sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.236"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.38"
        tools:text="CATEGORIES:" />

    <TextView
        android:id="@+id/priceRange"
        android:layout_width="146dp"
        android:layout_height="21dp"
        android:textSize="18sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.241"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:text="Time of Loss:" />

    <SeekBar
        android:id="@+id/timeSeekBar"
        android:layout_width="249dp"
        android:layout_height="30dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.537"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.697" />

    <TextView
        android:id="@+id/minPrice"
        android:layout_width="85dp"
        android:layout_height="26dp"
        android:text="1 Day"
        android:textSize="18sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.248"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.635" />

    <TextView
        android:id="@+id/maxPrice"
        android:layout_width="85dp"
        android:layout_height="27dp"
        android:text="1 Month"
        android:textSize="18sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.797"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.636"
        tools:text="1 Month" />

    <TextView
        android:id="@+id/timeView"
        android:layout_width="150dp"
        android:layout_height="40dp"
        android:editable="true"
        android:textSize="18sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.562" />

    <Button
        android:id="@+id/findButton"
        android:layout_width="130dp"
        android:layout_height="67dp"
        android:text="Let's Find!"
        android:textAllCaps="false"
        android:textSize="18sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.855"
        tools:text="Let's Find!" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/floatingActionButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:clickable="true"
        android:focusable="true"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.892"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.115"
        app:srcCompat="@android:drawable/ic_input_add" />

    <Spinner
        android:id="@+id/categorySpinner"
        android:layout_width="158dp"
        android:layout_height="41dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.778"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.385" />

    <CheckBox
        android:id="@+id/selectAll"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Select all dates"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.501"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.755" />

</android.support.constraint.ConstraintLayout>
    <android.support.design.widget.NavigationView
        android:id="@+id/nv"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:fitsSystemWindows="true"

        app:headerLayout="@layout/nav_header"
        app:menu="@menu/nav_menu">

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