title: Creating a Basic Undo Manager for Integer Values
body: <p>I want to design a basic command pattern that will save integer values and be able to execute a undo method. I'm not sure where to start at all so any help would be much appreciated. Very basic interpretations like below:</p>
  
  <pre><code>package com.k.s;
  
  public class MainActivity extends Activity {
  
      public int Counter = 0; 
  
      @Override
      protected void onCreate(Bundle savedInsanceState) {
          super.onCreate(savedInsanceState);
          setContentView(R.layout.activity_main);
  
  Button.setOnClickListener (new View.OnClickListener() {
  
              @Override
              public void onClick(View v) {
                  // TODO Auto-generated method stub
                  Counter += 1;
                  }
             }
        }
   }
  </code></pre>