title: How do I make the back button I created in the activity change the text in the textView to the previous text created by the random generator?
body: <p>When I start the activity on my phone, it says that the app is not responding. The problem is the back button which I can't seem to program to make it gather the previous text from the textView.</p>
  
  <p>Xml code for activity</p>
  
  <pre><code>&lt;RelativeLayout 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="@drawable/background"
  android:paddingBottom="@dimen/activity_vertical_margin"
  android:paddingLeft="@dimen/activity_horizontal_margin"
  android:paddingRight="@dimen/activity_horizontal_margin"
  android:paddingTop="@dimen/activity_vertical_margin"
  tools:context=".Author" &gt;
  
  &lt;TextView
      android:id="@+id/textView1"
      android:layout_width="300dp"
      android:layout_height="300dp"
      android:layout_alignParentTop="true"
      android:layout_centerHorizontal="true"
      android:background="@drawable/button_shape"
      android:text="@string/Getstarted"
      android:textColor="#FFFFFF"
      android:textSize="23sp" /&gt;
  
  &lt;ImageButton
      android:id="@+id/next"
      android:layout_width="90dp"
      android:layout_height="50dp"
      android:layout_alignRight="@+id/textView1"
      android:layout_below="@+id/textView1"
      android:layout_marginTop="14dp"
      android:background="@drawable/button_shape"
      android:contentDescription="@string/Next"
      android:onClick="NextQuote"
      android:src="@drawable/navigationnextitem" /&gt;
  
  &lt;ImageButton
      android:id="@+id/share"
      android:layout_width="90dp"
      android:layout_height="50dp"
      android:layout_alignTop="@+id/next"
      android:layout_centerHorizontal="true"
      android:background="@drawable/button_shape"
      android:contentDescription="@string/share"
      android:onClick="Sharing"
      android:src="@drawable/socialshare" /&gt;
  
      &lt;ImageButton
          android:id="@+id/back"
          android:layout_width="90dp"
          android:layout_height="50dp"
          android:layout_alignLeft="@+id/textView1"
          android:layout_alignTop="@+id/next"
          android:background="@drawable/button_shape"
          android:contentDescription="@string/Back"
          android:onClick="PreviousQuote"
          android:src="@drawable/navigationpreviousitem" /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>Java code for activity</p>
  
  <pre><code>package com.android.motivateme3;
  
  import java.util.Random;
  
  import android.os.Bundle;
  import android.app.Activity;
  import android.view.Menu;
  import android.view.MenuItem;
  import android.view.View;
  import android.widget.Button;
  import android.widget.ImageButton;
  import android.widget.TextView;
  import android.support.v4.app.NavUtils;
  import android.annotation.TargetApi;
  import android.content.Intent;
  import android.os.Build;
  
  public class Author extends Activity {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_author);
          // Show the Up button in the action bar.
          setupActionBar();
      }
  
      /**
       * Set up the {@link android.app.ActionBar}, if the API is available.
       */
      @TargetApi(Build.VERSION_CODES.HONEYCOMB)
      private void setupActionBar() {
          if (Build.VERSION.SDK_INT &gt;= Build.VERSION_CODES.HONEYCOMB) {
              getActionBar().setDisplayHomeAsUpEnabled(true);
  
               Button NextQuote = (Button)findViewById(R.id.next);
                  final TextView display = (TextView) findViewById(R.id.textView1);
                  NextQuote.setOnClickListener(new View.OnClickListener() {
                      public void onClick(View v) {
                          // TODO Auto-generated method stub
                           Random numGen = new Random();
                          int rNumber = numGen.nextInt(10);
                      if (rNumber  == 0)
                      {   
                          display.setText(R.string.Author1);
                      }
                      else if (rNumber  == 1)
                      {   
                          display.setText(R.string.Author2);
                      }
                      else if (rNumber  == 2)
                      { 
                          display.setText(R.string.Author3);
                      }
                      else if (rNumber  == 3)
                      {
                          display.setText(R.string.Author4);
                      }
                      else if (rNumber  == 4)
                      {
                          display.setText(R.string.Author5);
                      }
                      else if (rNumber  == 5)
                      {
                          display.setText(R.string.Author6);
                      }
                      else if (rNumber  == 6)
                      {
                          display.setText(R.string.Author7);
                      }
                      else if (rNumber  == 7)
                      {
                          display.setText(R.string.Author8);
                      }
                      else if (rNumber  == 8)
                      {
                          display.setText(R.string.Author9);
                      }
                      else if (rNumber  == 9)
                      {
                          display.setText(R.string.Author10);
                      }       }
                  });
                          }
  
                      ImageButton Sharing = (ImageButton)findViewById(R.id.share);
                      Sharing.setOnClickListener(new View.OnClickListener() {
                          public void onClick(View v){
  
                          TextView text = (TextView)findViewById(R.id.textView1);
                          String quote = text.getText().toString();{
                          Intent shareIntent = new Intent(android.content.Intent.ACTION_SEND);
                          shareIntent.setType("plain/text");
                          shareIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, "This is a great quote (from the Motivate Me! app)");
                          shareIntent.putExtra(android.content.Intent.EXTRA_TEXT, quote);
                          startActivity(Intent.createChooser(shareIntent, "Share via:"));}}});
  
  
  
                          Button BackQuote = (Button)findViewById(R.id.back);
                          final TextView display = (TextView) findViewById(R.id.textView1);
                          BackQuote.setOnClickListener(new View.OnClickListener() {
                              public void onClick(View v) {
                                  String prev = (String) display.getText();
                                  display.setText(prev);
                              }
                      });}
  
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          // Inflate the menu; this adds items to the action bar if it is present.
          getMenuInflater().inflate(R.menu.author, menu);
          return true;
      }
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          switch (item.getItemId()) {
          case android.R.id.home:
              // This ID represents the Home or Up button. In the case of this
              // activity, the Up button is shown. Use NavUtils to allow users
              // to navigate up one level in the application structure. For
              // more details, see the Navigation pattern on Android Design:
              //
              // http://developer.android.com/design/patterns/navigation.html#up-vs-back
              //
              NavUtils.navigateUpFromSameTask(this);
              return true;
          }
          return super.onOptionsItemSelected(item);
      }
  }
  </code></pre>
  
  <p>This is the stack trace</p>
  
  <pre><code>04-03 14:29:34.174: E/AndroidRuntime(17383):    at android.app.ActivityThread.main(ActivityThread.java:4441)
  04-03 14:29:34.174: E/AndroidRuntime(17383):    at java.lang.reflect.Method.invokeNative(Native Method)
  04-03 14:29:34.174: E/AndroidRuntime(17383):    at java.lang.reflect.Method.invoke(Method.java:511)
  04-03 14:29:34.174: E/AndroidRuntime(17383):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:823)
  04-03 14:29:34.174: E/AndroidRuntime(17383):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:590)
  04-03 14:29:34.174: E/AndroidRuntime(17383):    at dalvik.system.NativeStart.main(Native Method)
  04-03 14:29:34.174: E/AndroidRuntime(17383): Caused by: java.lang.ClassCastException: android.widget.ImageButton cannot be cast to android.widget.Button
  04-03 14:29:34.174: E/AndroidRuntime(17383):    at com.android.motivateme3.Author.setupActionBar(Author.java:36)
  04-03 14:29:34.174: E/AndroidRuntime(17383):    at com.android.motivateme3.Author.onCreate(Author.java:25)
  04-03 14:29:34.174: E/AndroidRuntime(17383):    at android.app.Activity.performCreate(Activity.java:4465)
  04-03 14:29:34.174: E/AndroidRuntime(17383):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
  04-03 14:29:34.174: E/AndroidRuntime(17383):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1931)
  04-03 14:29:34.174: E/AndroidRuntime(17383):    ... 11 more
  04-03 14:29:41.664: I/Process(17383): Sending signal. PID: 17383 SIG: 9
  </code></pre>