Problem with my Second Button

Question

Hi and Happy New Year to everyone! I have finish the interactiveStory app but I have a problem with the Button choice2. When I tap to load the previous page, loads only the 1st page and not the others. Below is my code from StoryActivity.java Thanks for any help! (I am using Android 1.5.1)

import android.content.Intent;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.method.ScrollingMovementMethod;
import android.util.Log;
import android.view.TextureView;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

import com.example.eleni.interactivestory.R;
import com.example.eleni.interactivestory.model.Page;
import com.example.eleni.interactivestory.model.Story;

import static android.widget.TextView.*;

public class StoryActivity extends AppCompatActivity {

    public static final String TAG = StoryActivity.class.getSimpleName();


    private Story mStory = new Story();
    private ImageView mImageView;
    private TextView mTextView;
    private Button mChoice1;
    private Button mChoice2;
    private String mName;
    private Page mCurrentPage;
    private Page mPeviousPage;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_story2);


        Intent intent = getIntent();
        mName = intent.getStringExtra(getString(R.string.key_name));

        if(mName == null){
            mName = "Friend";
        }

        Log.d(TAG, mName);

        mImageView = (ImageView)findViewById(R.id.storyImageView);
        mTextView = (TextView)findViewById(R.id.storyTextView);
        mChoice1 = (Button)findViewById(R.id.choiceButton1);
        mChoice2 = (Button)findViewById(R.id.choiceButton2);

        loadPage(0);
    }
    private void loadPage(int choice){
     mCurrentPage = mStory.getPage(choice);


        Drawable drawable  = getResources().getDrawable(mCurrentPage.getImageId());
        mImageView.setImageDrawable(drawable);

        String pageText = mCurrentPage.getText();
        //add the name if placeholder included.
        pageText  = String.format(pageText,mName);
        mTextView.setText(pageText);

        if(mCurrentPage.isFinal()){
            mChoice1.setVisibility(View.INVISIBLE);
            mChoice2.setText("Start From The Begining");
            mChoice2.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                   finish();
                }
            });

        }else{

        mChoice1.setText(mCurrentPage.getChoice1().getText());
        mChoice2.setText(mCurrentPage.getChoice2().getText());

       mChoice1.setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View v) {
               mCurrentPage.getChoice1().getNextPage();
               int nextPage = mCurrentPage.getChoice1().getNextPage();
               loadPage(nextPage);
           }
       });

        mChoice2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mCurrentPage.getChoice2().getPreviousPage();
                int PreviousPage = mCurrentPage.getChoice2().getPreviousPage();
                loadPage(PreviousPage);
            }
        });


    }
}}

Answer 1 · 2016-01-04T17:16:26Z

January 4, 2016 5:16pm

Hey Eleni!

It looks like the issue is being caused because you are trying to getPreviousPage() when mPreviousPage does not have a value (You haven't set this anywhere).

However, it looks like you're taking the course in a slightly different route - which I do not know whether you meant intentionally or not.

In the Treehouse course, we are given two Choices, and each Choice has a next Page which it leads to. These two choices are also the two Buttons, and Each Choice has a text for each Button (mText).

In your code, you have two Choices but your Choice classes also contain a Previous Page, which is not part of the course.

This leaves you two options:

You can follow along with the course as-is, and remove the previous page code.
You can change the course a bit and instead of having two choices, have a singular Choice that has both a previous and next page. Note that "Choice" probably wouldn't be the best name for the class in this instance, since there is actually two choices. You should probably refactor the class to call it "Choices" if you choose this method.

Hopefully this should help you out and get you back on track. I'll also provide you with the code files used in my InteractiveStory project if you require it. You can also download the Project Files at this stage and use this code instead to carry on with the future videos without having to make any amendments yourself (I recommend you try and fix your code yourself first though - it's a good learning experience, and it happens to everyone! Use this as a last-resort if you still can't get things working).

As always, if there's anything you don't quite understand about what I'm saying or if you want more guidance on how to fix the issue without having to re-download the files, give me a shout and let me know which route you want to take. I'll provide some steps to get your code back up to shape :)

Answer 2 · 2016-01-04T06:02:36Z

January 4, 2016 6:02am

Yes,of course. Thanks a lot Harry.

Page.java

public class Page {
    private int mImageId;
    private String mText;
    private Choice mChoice1;
    private Choice mChoice2;
    private Choice mChoice3;
    private boolean mIsFinal = false;

    public Page(int imageId, String text, Choice choice1, Choice choice2){
        mImageId = imageId;
        mText = text;
        mChoice1 = choice1;
        mChoice2 = choice2;


    }

    public boolean isFinal() {

        return mIsFinal;
    }

    public void setIsFinal(boolean isFinal) {

        mIsFinal = isFinal;
    }

    public Choice getChoice3() {
        return mChoice3;
    }

    public void setChoice3(Choice choice3) {
        mChoice3 = choice3;
    }

    public Page(int imageId, String text){
        mImageId = imageId;
        mText = text;
        mChoice1 = null;
        mChoice2 = null;
        mChoice3 = null;
        mIsFinal = true;
    }

    public int getImageId() {
        return mImageId;
    }

    public void setImageId(int imageId) {
        mImageId = imageId;
    }

    public String getText() {
        return mText;
    }

    public void setText(String text) {
        mText = text;
    }

    public Choice getChoice1() {
        return mChoice1;
    }

    public void setChoice1(Choice choice1) {
        mChoice1 = choice1;
    }

    public Choice getChoice2() {
        return mChoice2;
    }

    public void setChoice2(Choice choice2) {
        mChoice2 = choice2;
      }
    }

Choice.java

public class Choice {
    private String mText;
    private int mNextPage;
    private int mPreviousPage;

    public Choice(String text, int nextPage){
        mText = text;
        mNextPage = nextPage;
       // mPreviousPage = previousPage;

    }

    public String getText() {

        return mText;
    }

    public void setText(String text) {

        mText = text;
    }

    public int getNextPage() {

        return mNextPage;
    }
    public void setNextPage(int nextPage){
        mNextPage = nextPage;
    }

    public int getPreviousPage() {
        return mPreviousPage;
    }

    public void setPreviousPage(int previousPage) {
        mPreviousPage = previousPage;
    }
}

Answer 3 · 2016-01-04T18:48:39Z

January 4, 2016 6:48pm

Hello Harry, truly thank you for your very detailed answer. Is very helpful for me, a newbie. I download the files you upload. I am sorry but is something I didn't understand. What should I do to have the ability the 2nd Button loads previous pages? I Follow the lessons, but now I am trying to make a simple app based on InteractiveStory lessons for practice.The only thing I need to change from the lesson is this: The 1st button loads each time a next page as it is now, but how can it loads the previous?What should I write? Thanks again.

Answer 4 · 2016-01-04T19:20:02Z

January 4, 2016 7:20pm

That looks amazing!!!! I will study it and I 'll let you know. Thanks so much!

Answer 5 · 2016-01-05T06:12:56Z

January 5, 2016 6:12am

Hi again Harry! The diagram you sent me was very helpful to understund thinks I didn't. I need to choose the option2. Still be little confused to where and what should I write for to have the ability to see previous page each time the button has tapped. That moment, my 1st button change properly pages and the 2nd goes only 1 time back. Need to make 2nd button change in sequence previous pages. Thanks again! Below is my code after correct:

StoryActivity.java

  public static final String TAG = StoryActivity.class.getSimpleName();


    private Story mStory = new Story();
    private ImageView mImageView;
    private TextView mTextView;
    private Button mChoice1;
    private Button mChoice2;
    private String mName;
    private Page mCurrentPage;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_story2);


        Intent intent = getIntent();
       // mName = intent.getStringExtra(getString(R.string.key_name));

        if(mName == null){
            mName = "Friend";
        }

        Log.d(TAG, mName);

        mImageView = (ImageView)findViewById(R.id.storyImageView);
        mTextView = (TextView)findViewById(R.id.storyTextView);
        mChoice1 = (Button)findViewById(R.id.choiceButton1);
        mChoice2 = (Button)findViewById(R.id.choiceButton2);

        loadPage(0);
    }
    private void loadPage(int choice){
     mCurrentPage = mStory.getPage(choice);


        Drawable drawable  = getResources().getDrawable(mCurrentPage.getImageId());
        mImageView.setImageDrawable(drawable);

        String pageText = mCurrentPage.getText();
        //add the name if placeholder included.
       // pageText  = String.format(pageText,mName);
        mTextView.setText(pageText);

        if(mCurrentPage.isFinal()){
            mChoice1.setVisibility(View.INVISIBLE);
            mChoice2.setText("Start From The Begining");
            mChoice2.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                   finish();
                }
            });

        }else{

        mChoice1.setText(mCurrentPage.getChoice1().getText());
        mChoice2.setText(mCurrentPage.getChoice2().getText());

       mChoice1.setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View v) {
               mCurrentPage.getChoice1().getNextPage();
               int nextPage = mCurrentPage.getChoice1().getNextPage();
               loadPage(nextPage);
           }
       });

        mChoice2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mCurrentPage.getChoice2().getNextPage();
                int nextPage = mCurrentPage.getChoice2().getNextPage();
                loadPage(nextPage);
            }
        });


    }
}}

Page.java

public class Page {
    private int mImageId;
    private String mText;
    private Choice mChoice1;
    private Choice mChoice2;
    private boolean mIsFinal = false;

    public Page(int imageId, String text, Choice choice1, Choice choice2){
        mImageId = imageId;
        mText = text;
        mChoice1 = choice1;
        mChoice2 = choice2;


    }
    public Page(int imageId, String text){
        mImageId = imageId;
        mText = text;
        mChoice1 = null;
        mChoice2 = null;
        mIsFinal = true;
    }



    public int getImageId() {
        return mImageId;
    }

    public void setImageId(int imageId) {
        mImageId = imageId;
    }

    public String getText() {
        return mText;
    }

    public void setText(String text) {
        mText = text;
    }

    public Choice getChoice1() {
        return mChoice1;
    }

    public void setChoice1(Choice choice1) {
        mChoice1 = choice1;
    }

    public Choice getChoice2() {
        return mChoice2;
    }

    public void setChoice2(Choice choice2) {
        mChoice2 = choice2;
    }

        public boolean isFinal() {

            return mIsFinal;
        }

        public void setIsFinal(boolean isFinal) {

            mIsFinal = isFinal;
        }
      }
Choice.java
public class Choice {
    private String mText;
    private int mNextPage;


    public Choice(String text, int nextPage) {
        mText = text;
        mNextPage = nextPage;

    }

    public String getText() {

        return mText;
    }

    public void setText(String text) {

        mText = text;
    }

    public int getNextPage() {

        return mNextPage;
    }

    public void setNextPage(int nextPage) {
        mNextPage = nextPage;
    }

}

Answer 6 · 2016-01-07T19:27:57Z

January 7, 2016 7:27pm

Hi Harry! Thanks a lot that you let me know. Don't worry, when ever you have time. You have already help me a lot! Good luck with the interview!

Answer 7 · 2016-01-11T09:31:59Z

January 11, 2016 9:31am

Hi Harry! It couldn't be better! I wrote the code manually not copy - paste, from Github and it was very very helpful for me. Thanks a lot for your very important help and for the time to spend to answer me.

Welcome to the Treehouse Community

Looking to learn something new?

Eleni Minadaki

Eleni Minadaki

Problem with my Second Button

Harry James

Harry James

7 Answers

Harry James

Harry James

Eleni Minadaki

Eleni Minadaki

Eleni Minadaki

Eleni Minadaki

Harry James

Harry James

Eleni Minadaki

Eleni Minadaki

Eleni Minadaki

Eleni Minadaki

Harry James

Harry James

Eleni Minadaki

Eleni Minadaki

Harry James

Harry James

Eleni Minadaki

Eleni Minadaki