Android FLAG_ACTIVITY_NEW_TASK not working

Question

I'm having an issue with calling startActivity() on an Intent from within my custom onClick Listener. The code compiles fine, but when it gets to that point in the execution, I get a nullPointerException.

Code

private static class ProverbAdapter extends ArrayAdapter<String> {
    MainActivity ma;
    public ProverbAdapter(Context context, int layout, int resId, String[] items) {
        super(context, layout, resId, items);
        this.ma = new MainActivity();
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;
        Context context = getContext();
        if(row == null) {
            row = LayoutInflater.from(context).inflate(R.layout.proverb_layout, parent, false);
        }

        String item = getItem(position);
        TextView proverbDate = (TextView)row.findViewById(R.id.proverb_date);
        TextView proverbText = (TextView)row.findViewById(R.id.proverb_content);
        String[] data = item.split("----");
        proverbDate.setText(data[0]);
        proverbText.setText(data[1]);

        ImageButton emailButton = (ImageButton)row.findViewById(R.id.emailButton);
        ImageButton twitterButton = (ImageButton)row.findViewById(R.id.twitterButton);
        ImageButton facebookButton = (ImageButton)row.findViewById(R.id.facebookButton);

        emailButton.setOnClickListener(this.ma.new ProverbOnClickListener(data[0], data[1], "email", context));
        twitterButton.setOnClickListener(this.ma.new ProverbOnClickListener(data[0], data[1], "twitter", context));
        facebookButton.setOnClickListener(this.ma.new ProverbOnClickListener(data[0], data[1], "facebook", context));

        return row;
    }
}

public class ProverbOnClickListener implements OnClickListener {

     String proverb_date, proverb_content, eventType;
     Context context;

     public ProverbOnClickListener(String proverb_date, String proverb_content, String eventType, Context context) {
          this.proverb_date = proverb_date;
          this.proverb_content = proverb_content;
          this.eventType = eventType;
          this.context = context;
     }

     @Override
     public void onClick(View v) {
         Toast.makeText(this.context, this.eventType + ": " + this.proverb_content, Toast.LENGTH_SHORT).show();
         if(this.eventType == "email") {
             Intent i = new Intent(Intent.ACTION_SEND);
                     i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
             i.setType("message/rfc822");
             i.putExtra(Intent.EXTRA_EMAIL  , new String[]{"recipient@example.com"});
             i.putExtra(Intent.EXTRA_SUBJECT, "subject of email");
             i.putExtra(Intent.EXTRA_TEXT   , "body of email");
             try {
                 context.startActivity(Intent.createChooser(i, "Send mail..."));
             } catch (android.content.ActivityNotFoundException ex) {
                 Toast.makeText(this.context, "There are no email clients installed.", Toast.LENGTH_SHORT).show();
             }
         }
     }

  }

Exception

FATAL EXCEPTION: main android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?

I added the new flag as the compiler suggested, but it still crashes with the same error.

* *EDIT ****

After following advice in the first response, my adapter now looks like:

private static class ProverbAdapter extends ArrayAdapter<String> {
    Context context;
    public ProverbAdapter(Context context, int layout, int resId, String[] items) {
        super(context, layout, resId, items);
        this.context = context;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;
        if(row == null) {
            LayoutInflater li = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            row = li.inflate(R.layout.proverb_layout, parent, false);
        }

        String item = getItem(position);
        TextView proverbDate = (TextView)row.findViewById(R.id.proverb_date);
        TextView proverbText = (TextView)row.findViewById(R.id.proverb_content);
        String[] data = item.split("----");
        proverbDate.setText(data[0]);
        proverbText.setText(data[1]);

        ImageButton emailButton = (ImageButton)row.findViewById(R.id.emailButton);
        ImageButton twitterButton = (ImageButton)row.findViewById(R.id.twitterButton);
        ImageButton facebookButton = (ImageButton)row.findViewById(R.id.facebookButton);

        emailButton.setOnClickListener(new ProverbOnClickListener(data[0], data[1], "email", context));
        twitterButton.setOnClickListener(new ProverbOnClickListener(data[0], data[1], "twitter", context));
        facebookButton.setOnClickListener(new ProverbOnClickListener(data[0], data[1], "facebook", context));

        return row;
    }
}

However I'm receiving a compilation error.

No enclosing instance type of MainActivity is accessible.

Answer 1

Try Few modifications

this.ma = new MainActivity(); //it is wrong

Don't instantiate Activity

try like this

 Context context;
    public ProverbAdapter(Context context, int layout, int resId, String[] items) {
        super(context, layout, resId, items);
       this.context=context;
    }

use this variable context where ever you need context