将选择器加载到较长位置，变量无法正确更改

Question

I'm making a simple place picker program in android. I want to save some text when user choose a point on map with place picker. And the problem is when I click on button the place picker opens too long and variable which is responsible for place can't keep up change and dialog that responses for enter text never opens. I think, maybe problem is with threads, isn't it?

MapsActivity.java

package com.example.kirill.myapplication;

import android.content.Intent;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import com.google.android.gms.location.places.Place;
import com.google.android.gms.location.places.ui.PlacePicker;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;


public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, View.OnClickListener {

private static final int PLACE_PICKER_REQUEST = 1;
private GoogleMap mMap;
private Button addEventBtn;
private PlacePicker.IntentBuilder builder;
private Place place;

@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.AddEventButton:
            place = null;
            callPlacePicker();
            if (place != null) {
                openDialog();
            }
            break;
    }
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps);
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);
    addEventBtn = (Button) findViewById(R.id.AddEventButton);
}

@Override
public void onMapReady(GoogleMap googleMap){
    mMap = googleMap;
    LatLng sydney = new LatLng(-34, 151);
    Marker marker = mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
    mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
    addEventBtn.setOnClickListener(this);
}


protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == PLACE_PICKER_REQUEST) {
        if (resultCode == RESULT_OK) {
            place = PlacePicker.getPlace(this, data);
        }
    }
}


public void openDialog() {
    DialogEventCreate dialogEventCreate = new DialogEventCreate();
    dialogEventCreate.show(getSupportFragmentManager(), "dialog Event Create");
}


public void callPlacePicker() {
    builder = new PlacePicker.IntentBuilder();
    try {
        startActivityForResult(builder.build(this), PLACE_PICKER_REQUEST);
    }
    catch (Exception e) {
        e.printStackTrace();
    }
}

}

DialogEventCreate.java

package com.example.kirill.myapplication;

import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatDialogFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.EditText;
import android.widget.Spinner;


public class DialogEventCreate extends AppCompatDialogFragment {

private EditText editEventName;

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());

    LayoutInflater inflater = getActivity().getLayoutInflater();
    View view = inflater.inflate(R.layout.layout_dialog, null);

    builder.setView(view)
            .setTitle("Create Event")
            .setNegativeButton("cancel", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {

                }
            })
            .setPositiveButton("create", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {

                }
            });

    editEventName = view.findViewById(R.id.editEventName);
    return builder.create();
    }
}

Please help me, what could go wrong?

Answer 1

Your problem is that the Place Picker communicates with your main activity asynchronously, so you're opening your dialog before it returns. Try waiting until Place Picker has returned before opening the dialog like so:

.
.
.
@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.AddEventButton:
            place = null;
            callPlacePicker();
            break;
    }
}
.
.
.
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == PLACE_PICKER_REQUEST) {
        if (resultCode == RESULT_OK) {
            place = PlacePicker.getPlace(this, data);
            openDialog();
        }
    }
}