How to know that the content provider of calls has changed

Question

Hey, I'd like to know if there is a way to know if the content provider of callings has changed. I mean, if I make a call, or I answer a call, it returns a "flag" that a new log has been added to the call log, or the place where Android store informations about callings.

Because, when I make a call, Android stores the number, the contact name(if exists), the hour of the calling, the duration, blah blah blah, all in the content provider. So is there a way to capture this "flag" that says the content provider of callings is bigger, I mean, that a new data has been inserted on the content provider CallLog.Calls.

(Updated)

So, I still have a lot of doubts related to this issue. I don't know where to register the content observer. My intention is when something change in the CallLog content provider, the insert method of the code will be used.

I mean, the code wont do anything unless new data has been added to the CallLog content provider. If some data has been added to the CallLog content provider, then the code will query the new data, and then will insert. I wanna do this because withou a Content observer the application was inserting data in the database that was already inserted every time I run the application, got it?

So here is my code. If someone could tell me where to put the registerContentObserver and everything else is needed I thank you.

package com.psyhclo;

import java.text.DateFormat;
import java.util.ArrayList;
import java.util.Date;

import com.psyhclo.R;
import com.psyhclo.CallDataHelper.OpenHelper;

import android.app.Activity;
import android.app.ListActivity;
import android.database.ContentObserver;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.os.Handler;
import android.provider.ContactsContract.RawContacts;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.content.ContentValues;
import android.content.Context;
import android.content.ContentProvider;

public class RatedCalls extends ListActivity {

private SQLiteDatabase db;
private CallDataHelper dh = null;
StringBuilder sb = new StringBuilder();
OpenHelper openHelper = new OpenHelper(RatedCalls.this);

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

    Cursor cursor = getContentResolver().query(
            android.provider.CallLog.Calls.CONTENT_URI, null, null, null,
            android.provider.CallLog.Calls.DATE + " DESC ");

    dh = new CallDataHelper(this);
    db = openHelper.getWritableDatabase();

    startManagingCursor(cursor);
    int numberColumnId = cursor
            .getColumnIndex(android.provider.CallLog.Calls.NUMBER);
    int durationId = cursor
            .getColumnIndex(android.provider.CallLog.Calls.DURATION);
    int contactNameId = cursor
            .getColumnIndex(android.provider.CallLog.Calls.CACHED_NAME);
    int dateId = cursor.getColumnIndex(android.provider.CallLog.Calls.DATE);
    int numTypeId = cursor
            .getColumnIndex(android.provider.CallLog.Calls.CACHED_NUMBER_TYPE);

    Date dt = new Date();
    int hours = dt.getHours();
    int minutes = dt.getMinutes();
    int seconds = dt.getSeconds();
    String currTime = hours + ":" + minutes + ":" + seconds;

    ArrayList<String> callList = new ArrayList<String>();
    if (cursor.moveToFirst()) {

        do {

            String contactNumber = cursor.getString(numberColumnId);
            String contactName = cursor.getString(contactNameId);
            String duration = cursor.getString(durationId);
            String callDate = DateFormat.getDateInstance().format(dateId);
            String numType = cursor.getString(numTypeId);

            ContentValues values = new ContentValues();

            values.put("contact_id", 1);
            values.put("contact_name", contactName);
            values.put("number_type", numType);
            values.put("contact_number", contactNumber);
            values.put("duration", duration);
            values.put("date", callDate);
            values.put("current_time", currTime);
            values.put("cont", 1);

            this.db.insert(CallDataHelper.TABLE_NAME, null, values);

            Toast.makeText(getBaseContext(), "Inserted!", Toast.LENGTH_LONG);
            callList.add("Contact Number: " + contactNumber
                    + "\nContact Name: " + contactName + "\nDuration: "
                    + duration + "\nDate: " + callDate);

        } while (cursor.moveToNext());
    }
    setListAdapter(new ArrayAdapter<String>(this, R.layout.listitem,
            callList));
    ListView lv = getListView();
    lv.setTextFilterEnabled(true);

    lv.setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {

            Toast.makeText(getApplicationContext(),
                    ((TextView) view).getText(), Toast.LENGTH_SHORT).show();

        }
    });
}
}

Answer 1

Have a look at the method registerContentObserver() in the ContentResolver class. This allows you to register a callback if the dataset behind the content provider changes.

See also this blog posting for a working example how to observe a content provider for changes.