Communication between TabActivity and the embedded activity

Question

I am trying to figure out the best practice of communication between a TabActivity and the child activity embedded in this TabActivity.

In my TabActivity, there is a

Answer 1

You can use getParent() to obviate the need to do any of this.

Here's my launcher child class with buttons that switch between activities handled by the tabHost:

public class LaunchPadActivity extends Activity implements OnClickListener {

private static final int ICON_PROFILE = 0;

private static final int ICON_SEARCH = 1;

private static final int ICON_MAP = 2;

private static final int FAVOURITES = 3;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.launchpad);

    GridView launchPad = (GridView) findViewById(R.id.launchpad);
    launchPad.setAdapter(new LaunchIconAdapter(this));
}

public class LaunchIconAdapter extends BaseAdapter {
    private Context mContext;

    // references to our images
    private Integer[] mThumbIds = { R.drawable.user, R.drawable.find,
            R.drawable.map, R.drawable.favourites, R.drawable.reviews,
            R.drawable.news, R.drawable.tutorial, R.drawable.info,
            R.drawable.options, };

    public String[] texts = { "Profile", "Search", "Map", "Favourites",
            "Reviews", "News", "Tutorial", "Info", "Options" };

    public LaunchIconAdapter(Context c) {
        mContext = c;
    }

    // Number of thumbs determines number of GridView items
    public int getCount() {
        return mThumbIds.length;
    }

    public Object getItem(int position) {
        return null;
    }

    public long getItemId(int position) {
        return 0;
    }

    // create a new ImageView for each item referenced by the Adapter
    public View getView(int position, View convertView, ViewGroup parent) {
        // Icon elements
        LinearLayout launchIcon;
        ImageView launchImage;
        TextView launchText;

        if (convertView == null) {
            launchIcon = (LinearLayout) ((LayoutInflater) mContext
                    .getSystemService(LAYOUT_INFLATER_SERVICE)).inflate(
                    R.layout.launchicon, null);

        } else {
            launchIcon = (LinearLayout) convertView;
        }

        // Add ClickListener with metadata
        launchIcon.setTag(new Integer(position));
        launchIcon.setOnClickListener(LaunchPadActivity.this);

        // Get subviews
        launchImage = (ImageView) launchIcon
                .findViewById(R.id.launch_image);
        launchText = (TextView) launchIcon.findViewById(R.id.launch_text);

        // Configure subviews
        launchImage.setImageResource(mThumbIds[position]);
        launchText.setText(texts[position]);

        return launchIcon;
    }

}

@Override
public void onClick(View v) {
    int position = ((Integer) v.getTag()).intValue();
    switch (position) {
    case ICON_PROFILE:
        Toast.makeText(this, "Profile", Toast.LENGTH_LONG).show();
        break;

    case ICON_SEARCH:
        Toast.makeText(this, "Search", Toast.LENGTH_LONG).show();
        ((TabActivity) getParent()).getTabHost().setCurrentTab(1);
        break;

    case ICON_MAP:
        Toast.makeText(this, "Map", Toast.LENGTH_LONG).show();
        ((TabActivity) getParent()).getTabHost().setCurrentTab(2);
        break;

    case FAVOURITES:
        Toast.makeText(this, "Map", Toast.LENGTH_LONG).show();
        ((TabActivity) getParent()).getTabHost().setCurrentTab(3);
        break;

    }

}

}

Works like a charm.