Populating Listview from database when item selected in a spinner then button clicked

Question

Ok, so I'm creating an application that will use current gps location (lat/long). The user will have to select a specified radius (.5-100 miles) from a Spinner. Then, when clicked, there will be a Button (onClickListener()) that will populate the locations from a SQLite database, in that set radius, to a ListView. From there, select an item from the ListView that will call an Activity (Intent).

I have the ListView populating data from the database, but I'm having issues with it populating from an onClick event (Button). Furthermore, if anyone can figure out how to get the current location to compare the locations listed in the database based on the set radius (from the Spinner), and show the ones that match in the ListView, I would REALLY appreciate that. Thanks!

SN: I have it displaying the current location. Here's my code.

Java file

import android.content.Context;
import android.content.Intent;
import android.location.Address;
import android.location.Geocoder;
import android.net.Uri;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;


public class MetersActivity extends ActionBarActivity {

private Toolbar toolbar;
private DrawerLayout drawerLayout;

private static Button search;
private TextView myAddress;
GPSTracker gps;

//new instance of db from meter info database
MeterInfoDatabase myDb;
private Geocoder geocoder = new Geocoder(this, Locale.ENGLISH);
final MeterInfoDatabase db = new MeterInfoDatabase(this);

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

    //myDb = new MeterInfoDatabase(this);
   final ListView listView = (ListView) findViewById(R.id.MeterList);
    Log.d("LOG", "Before testing the database");
    /*
    Testing Database Part
     */

    List<MeterInfoSQL> allMeters = db.getAllMeters();
    ArrayList<String> ar = new ArrayList<String>();
    for(MeterInfoSQL m : allMeters)
    {
        //Toast.makeText(getApplicationContext(), m.getMeterNumber() + "  Saved", Toast.LENGTH_LONG).show();
        String str = "Meter #: " + m.getMeterNumber();
        ar.add(str);
    }

    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, ar);
    listView.setAdapter(adapter);

    toolbar= (Toolbar) findViewById(R.id.app_bar);
    setSupportActionBar(toolbar);

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setHomeButtonEnabled(true);

    myAddress = (TextView) findViewById(R.id.myaddress);

    //search button click
    onClickButtonListener();

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_meters, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

//Used to get location via GPS when search button is tapped
public void onClickButtonListener() {

    final Context context = this;

    search = (Button) findViewById(R.id.MeterSearch_button);

    search.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {

            gps = new GPSTracker(MetersActivity.this);

            //gps coordinates
            double latitude = gps.getLatitude();
            double longitude = gps.getLongitude();

            if (gps.canGetLocation()) {

                //Shows address
                try {
                    List<Address> addresses = geocoder.getFromLocation(latitude, longitude, 1);

                    if(addresses != null) {
                        Address returnedAddress = addresses.get(0);
                        StringBuilder strReturnedAddress = new StringBuilder("Your Current Address:\n");
                        for(int i=0; i<returnedAddress.getMaxAddressLineIndex(); i++) {
                            strReturnedAddress.append(returnedAddress.getAddressLine(i)).append("\n");
                        }
                        myAddress.setText(strReturnedAddress.toString());

                    } else{
                        myAddress.setText("No Address returned!");
                    }
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    myAddress.setText("Canont get Address!");
                }

            }
            else {
                gps.showSettingsAlert();

            }
         //want the lisview to populate when this button is clicked
         /*when i move it here I get an error at "this"
          ArrayAdapter<String> adapter = new ArrayAdapter<String>
         //---> here (this, android.R.layout.simple_list_item_1, ar);
          listView.setAdapter(adapter); */

        }
    });
}
}

The XML Layout

<android.support.v4.widget.DrawerLayout 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:background="@color/background"
tools:context="com.example.ataccofficial.MetersActivity">

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ff8a8a90"
    android:clickable="true"
    tools:context="com.example.themetest.MetersActivity">

    <include
        android:id="@+id/app_bar"
        layout="@layout/app_bar" />

    <TextView
        android:id="@+id/meterSelectRadiusText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_below="@+id/app_bar"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="10dp"
        android:inputType="none"
        android:text="Select Radius:"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:textColor="#ffffffff"
        android:textSize="25dp" />

    <Spinner
        android:id="@+id/meter_spinner"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_alignStart="@+id/textView"
        android:layout_below="@+id/meterSelectRadiusText"
        android:layout_marginRight="10dp"
        android:entries="@array/meter_array"
        android:gravity="center"
        android:spinnerMode="dialog"
        android:textColor="#ffffffff" />


    <TextView
        android:id="@+id/textView"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/meter_spinner"
        android:layout_centerHorizontal="true"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:layout_marginTop="27dp"
        android:background="#ff8a8a90"
        android:text="Location:"
        android:textColor="#ffffffff"
        android:textSize="15sp" />

    <TextView
        android:id="@+id/myaddress"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView"
        android:layout_centerHorizontal="true"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:autoText="false"
        android:editable="false"
        android:enabled="false"
        android:focusable="true"
        android:textColor="@color/primaryColor"
        android:textSize="15sp" />

    <Button
        android:id="@+id/MeterSearch_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:onClick="Search"
        android:text="Search"
        android:textSize="25dp"
        android:typeface="normal"
        android:textStyle="bold"
        android:layout_below="@+id/myaddress"
        android:layout_centerHorizontal="true" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Customer"
        android:id="@+id/lablecrm"
        android:layout_alignBottom="@+id/dailyReportDivider"
        android:layout_alignParentStart="true"
        android:textColor="#ffffffff" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Issue"
        android:id="@+id/lableIssue"
        android:layout_alignBottom="@+id/dailyReportDivider"
        android:layout_centerHorizontal="true"
        android:textColor="#ffffffff" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Distance"
        android:id="@+id/lableDistance"
        android:layout_alignBottom="@+id/dailyReportDivider"
        android:layout_alignParentEnd="true"
        android:textColor="#ffffffff" />

    <View
        android:id="@+id/dailyReportDivider"
        android:layout_width="fill_parent"
        android:layout_height="2dp"
        android:background="@android:color/darker_gray"
        android:layout_below="@+id/myaddress"
        android:layout_alignParentStart="true"
        android:layout_marginTop="84dp" />

    <ListView
        android:id="@+id/MeterList"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/dailyReportDivider"
        android:layout_centerHorizontal="true"
        android:choiceMode="singleChoice"
        android:textColor="#ffffffff"/>


</RelativeLayout>
<fragment
               android:id="@+id/fragment_navigation_drawer"
                    android:name="com.example.ataccofficial.NavigationDrawerFragment"
               android:layout_width="250dp"
               android:layout_height="match_parent"
               android:layout_gravity="start"
               android:layout="@layout/fragment_navigation_drawer"
               tools:layout="@layout/fragment_navigation_drawer" />

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

String for Spinner

<string-array name="meter_array">
    <item>.5 Miles</item>
    <item>1 Miles</item>
    <item>5 Miles</item>
    <item>10 Miles</item>
    <item>15 Miles</item>
    <item>20 Miles</item>
    <item>25 Miles</item>
    <item>50 Miles</item>
    <item>100 Miles</item>
</string-array>

Answer 1

Created a method outside of the button listener for populating the listview and called it inside of the listener.

//Used to get location via GPS when search button is tapped
public void onClickButtonListener() {

    final Context context = this;

    search.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {

            gps = new GPSTracker(MetersActivity.this);

            //gps coordinates
            double latitude = gps.getLatitude();
            double longitude = gps.getLongitude();

            if (gps.canGetLocation()) {

                //Shows address
                try {
                    List<Address> addresses = geocoder.getFromLocation(latitude, longitude, 1);

                    if (addresses != null) {
                        Address returnedAddress = addresses.get(0);
                        StringBuilder strReturnedAddress = new StringBuilder("Your Current Address:\n");
                        for (int i = 0; i < returnedAddress.getMaxAddressLineIndex(); i++) {
                            strReturnedAddress.append(returnedAddress.getAddressLine(i)).append("\n");
                        }
                        myAddress.setText(strReturnedAddress.toString());

                    } else {
                        myAddress.setText("No Address returned!");
                    }
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    myAddress.setText("Canont get Address!");
                }

            } else {
                gps.showSettingsAlert();

            }
          process_data();

        }
    });

}


  private void process_data(){

  List<MeterInfoSQL> allMeters = db.getAllMeters();
  ar = new ArrayList<String>();
  for(MeterInfoSQL m : allMeters)
  {
      //Toast.makeText(getApplicationContext(), m.getMeterNumber() + "   Saved", Toast.LENGTH_LONG).show();
      String str = "Meter #: " + m.getMeterNumber() + " Contact " + m.getAccountNumber();
      ar.add(str);
  }

  adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, ar);
  listView.setAdapter(adapter);
  doPopulate();

}

   private void doPopulate() {
    adapter.notifyDataSetChanged();
}

Answer 2

Create another method to handle your task. Inside your onClick() the this statement doesn't refer to the Activity, that's why it's throwing an error.

First of all, try to declare your ArrayAdapter, your ListView and your ArrayList<String> as globals. That can make your work easier to do.

private ArrayAdapter <String> adapter;
private ListView listView;
private ArrayList<String> ar = new ArrayList<String>();

Then, on your onCreate() method change the lines

final ListView listView = (ListView) findViewById(R.id.MeterList);
// ...
ArrayList<String> ar = new ArrayList<String>();
// ...
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, ar);

to

listView = (ListView) findViewById(R.id.MeterList);
// ...
ar = new ArrayList<String>();
// ...
adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, ar);

Later on your onClickListener().

search.setOnClickListener(new View.OnClickListener() {

    @Override
    public void onClick(View arg0) {

        // Your code.

        // Change your "ar" Array here, and later call the following method.
        doPopulate();
    }});

private void doPopulate() {
    adapter.notifyDataSetChanged();       
}

I guess you could simply call the notifyDataSetChanged() from within the onClick(), but I coudn't test this code now. Tell me later if it worked.

You can read more about this here.