Question

I have my main application class as follows and what I would like to know is how to change one line to call a method either from same class or another class, whilst the others still call activities. Here is the code:

public class InfoActivity extends GDListActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setTitle(R.string.info_activity_title);

    ItemAdapter adapter = new ItemAdapter(this);
    adapter.add(createTextItem(R.string.info_about, AboutActivity.class));
    adapter.add(createTextItem(R.string.info_terms, TermsActivity.class));
    adapter.add(createTextItem(R.string.info_privacy, PrivacyActivity.class));

    setListAdapter(adapter);
}

private TextItem createTextItem(int stringId, Class<?> klass) {
    final TextItem textItem = new TextItem(getString(stringId));
    textItem.setTag(klass);
    return textItem;
}

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    final TextItem textItem = (TextItem) l.getAdapter().getItem(position);
    Intent intent = new Intent(InfoActivity.this, (Class<?>) textItem.getTag());
    startActivity(intent);
}
}

The line in question:

adapter.add(createTextItem(R.string.info_about, AboutActivity.class));

I would like to call a method which as an example does this:

Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);
    emailIntent.putExtra(android.content.Intent.EXTRA_EMAIL, new String[] { AboutActivity.this.getString(R.string.feedback_email) } );
    emailIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, AboutActivity.this.getString(R.string.feedback_subject)); 
    emailIntent.setType("plain/text"); 
    startActivity(emailIntent);

Right now I have this in the onCreate method of AboutActivity, but there naturally is no reason to have this functionality (sending email) within an activity. Instead it can just be ran as is. So, how could I do this?

Thanks!

The other two lines:

 adapter.add(createTextItem(R.string.info_terms, TermsActivity.class));
    adapter.add(createTextItem(R.string.info_privacy, PrivacyActivity.class));

they can remain the same in terms of functionality. This question is an addendum from this one (which I asked earlier and got answered):

Android – call method instead of class – sdk

Answer 1

How ever you choose to go about this, the trick is to actually move the decision making about what to do when a particular item is clicked down into the onListItemClick method. Here’s a simple approach. First, change your createTextItem method to this:

private TextItem createTextItem(int stringId) {
    final TextItem textItem = new TextItem(getString(stringId));
    return textItem;
}

Then, change your onListItemClick to this:

protected void onListItemClick(ListView l, View v, int position, long id) {
    final TextItem textItem = (TextItem) l.getAdapter().getItem(position);
    String textItemContents = textItem.getString(); //I don't know if this is actually correct. I don't know what the TextItem class is. But I think you get the idea.
    Intent intent = getIntentForString(textItemContents);
    startActivity(Intent);
}

Your getIntentForString() method would then look something like this (note we can’t use a switch because support for using switch statements with strings has only just recently been added to java):

private Intent getIntentForString(String textViewContents){
  if(textViewContents.equals(getString(R.string.info_about))){
    Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);
    emailIntent.putExtra(android.content.Intent.EXTRA_EMAIL, new String[] { 
      AboutActivity.this.getString(R.string.feedback_email) } );
    emailIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, 
      AboutActivity.this.getString(R.string.feedback_subject)); 
    emailIntent.setType("plain/text"); 
    return emailIntent;
  }
  else if(textViewContents.equals(getString(R.string.info_terms)){
    return new Intent(InfoActivity.this, TermsActivity.class);
  }
  else if(textViewContents.equals(getString(R.string.info_privacy)){
    return new Intent(InfoActivity.this, Privacy.class);
  }
  else{
    return null;
  }
}

Note this approach has a downfall though. If yous start adding a bunch of different items to your ListView you’re going to need to grow and grow your getIntentForString() method. For right now though, this should suffice. If you find yourself adding more options to your ListView though they’ll be a more complicated approach that we’ll need to take.