Android Programming Tutorials

Seeking the Proper Level

• A Cursor containing the contact's ID, name, and mobile phone
  number


• The name of the field that is the contact's name, so we can supply
  this to the AlertDialog.Builder, so it knows how to display the list

With that in mind, let us define a Java interface, for which we will create

implementations using the old and new contacts API. Add the following as

LunchList/src/apt/tutorial/MobileContactsBridge.java:

package apt.tutorial;

import android.app.Activity;

import android.database.Cursor;

interface MobileContactsBridge {

Cursor getMobileNumbers(Activity host);

String getDisplayNameField();

}

Step #2: Implement the Interface: the New Way.............................

The existing code we added to DetailForm in the previous tutorial can be

largely copied-and-pasted into a NewMobileContacts class that implements

this interface. Add the following as

LunchList/src/apt/tutorial/NewMobileContacts.java:

package apt.tutorial;

import android.app.Activity;

import android.database.Cursor;

import android.provider.ContactsContract.Contacts;

import android.provider.ContactsContract.CommonDataKinds.Phone;

class NewMobileContacts implements MobileContactsBridge {

public Cursor getMobileNumbers(Activity host) {

String[] PROJECTION=new String[] { Contacts._ID,

Contacts.DISPLAY_NAME,

Phone.NUMBER

};

String[] ARGS={String.valueOf(Phone.TYPE_MOBILE)};

return(host.managedQuery(Phone.CONTENT_URI,

PROJECTION, Phone.TYPE+"=?",

ARGS, Contacts.DISPLAY_NAME));

}

372