title: Calling method of another class using contexts
body: <p>I have a custom titlebar with an ImageButton, which produces a dialogbox, and I want to be able to show location(place itemizedOverlay) on a map(in another class) when list item is selected from dialog box, and titlebar and map are in the same context. I read somewhere that I could call a method of another class using contexts. How can I do so? </p>
  
  <pre><code>public class MyTitleBar extends RelativeLayout{
  
  private Context context;
  
  
  public MyTitleBar(Context context, AttributeSet attrs) {
      super(context, attrs);
      this.context = context;
  }
  
  @Override
  protected void onFinishInflate() {
  
      super.onFinishInflate();
  
      initViews();
  }
  
  // set up all the buttons  &amp; clicks
  private void initViews() {
  
      final ImageButton listImgBtn = (ImageButton) findViewById(R.id.more);
      final CharSequence [] listItems = {"Elderly","Events"};
  
      listImgBtn.setOnClickListener(new  View.OnClickListener() {
          @Override
          public void onClick(View v) {
              if(context instanceof UserHome)
              {
                  AlertDialog.Builder builder = new AlertDialog.Builder(context);
                  builder.setTitle("List");
                  builder.setItems(listItems, new DialogInterface.OnClickListener() {
  
                  @Override
                  public void onClick(DialogInterface dialog, int item) {
                      // TODO Auto-generated method stub
                      if(item == 0)
                      {
                          //show location of elderly
                         //DisplayLocation()
  
                      }
                      else if(item == 1)
                      {
                          //show location of events
                      }
                  }
              });
              AlertDialog alert = builder.create();
              alert.show();
            }
          }
      });
  </code></pre>