Making Dialog Class recognize variable values from MainActivity class in Android

Question

I am working on an app that will display a random joke when the user clicks on the "joke" button on the top of the page. When the user clicks this button, a dialog will appear that will display the title of the joke, the setup, and a punchline button to display another dialog, that will display the punchline of the joke. When I create my dialogs, I am trying to figure out how to set the title and message to the values of the arrays that are declared in the MainActivity.java file. So far, I was able to figure out the code to switch back and forth between the 2 dialogs and exit them at any time. However, I am stuck on how to retrieve the array values in the dialog java files from the MainActivity java file. I have tried to add code to the buttonShowDialog() and onOKClick methods in the MainActivity file, but this doesn't make the dialog files recognize the array values. I am thinking this is an OOP problem, but I am stuck. Any suggestions would be appreciated.

Main Activity.java

package edu.psu.jjb24.csjokes;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.MenuInflater;
import android.view.MenuItem;

import java.util.Random;

public class MainActivity<currentJoke> extends AppCompatActivity implements DisplaySetupDialog.OKClickListener,
        DisplayPunchlineDialog.OKClickListener{
    String[] joke_title;
    String[] joke_setup;
    String[] joke_punchline;
    int currentJoke = -1;

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

        // Set the action bar
        Toolbar myToolbar = findViewById(R.id.toolbar);
        setSupportActionBar(myToolbar);

        joke_title = getResources().getStringArray(R.array.JokeTitle);
        joke_setup = getResources().getStringArray(R.array.JokeSetup);
        joke_punchline = getResources().getStringArray(R.array.JokePunchline);
    }


    public int getCurrentJoke(String[] array){
        int random = new Random().nextInt(array.length);
        currentJoke = random;
        return currentJoke;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.activity_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.menu_joke:
                buttonShowDialog();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    public void buttonShowDialog() {
        DisplaySetupDialog setupDialog = new DisplaySetupDialog();
        setupDialog.show(getSupportFragmentManager(), "setupDialog");
    }

    public void onOKClick() {
        DisplayPunchlineDialog punchlineDialog = new DisplayPunchlineDialog();
        punchlineDialog.show(getSupportFragmentManager(), "punchlineDialog");
    }

    public void onOKClick2() {
        buttonShowDialog();
    }
}

DisplaySetupDialog.java

package edu.psu.jjb24.csjokes;

import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.Context;
import android.os.Bundle;

import androidx.fragment.app.DialogFragment;

public class DisplaySetupDialog extends DialogFragment{
    public interface OKClickListener {
        public void onOKClick();
    }

    private OKClickListener mListener;
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState){
        AlertDialog.Builder setup = new AlertDialog.Builder(getActivity());

        setup.setTitle("joke_title").setMessage("joke_setup")
                .setPositiveButton("Punchline", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id){
                        mListener.onOKClick();
                    }

                })
                .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {

                    }
                });
        return setup.create();
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);

        try {
            mListener = (OKClickListener) context;
        }
        catch (ClassCastException e) {
            throw new ClassCastException(context.toString() + "must implement OKClickListener");
        }
    }

}

DiplayPunchlineDialog.java

import android.os.Bundle;

import androidx.fragment.app.DialogFragment;

public class DisplayPunchlineDialog extends DialogFragment {
    public interface OKClickListener {
        public void onOKClick2();
    }

    private DisplayPunchlineDialog.OKClickListener mListener2;

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

        setup.setTitle("joke_title").setMessage("joke punchline")
                .setPositiveButton("Setup", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id){
                        mListener2.onOKClick2();
                    }

                })
                .setNegativeButton("Done", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {

                    }
                });
        return setup.create();
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);

        try {
            mListener2 = (DisplayPunchlineDialog.OKClickListener) context;
        }
        catch (ClassCastException e) {
            throw new ClassCastException(context.toString() + "must implement OKClickListener");
        }
    }

}

score 0 · Answer 1 · answered Mar 10 '21 at 19:12

You should pass the information the Fragment needs (the joke) to it when you create the new instance of it. And to make the Fragment handle runtime configuration changes properly you should use the special pattern we use in Android when creating new Fragment instances:

https://stackoverflow.com/a/56544233/2104665

Making Dialog Class recognize variable values from MainActivity class in Android

1 Answers1