
/**
     * Specifies a content URI to watch for changes.
     *
     * @param cr The content resolver from the caller's context.
     * @param notifyUri The URI to watch for changes. This can be a
     * specific row URI, or a base URI for a whole class of content.
     */
    public void setNotificationUri(ContentResolver cr, Uri notifyUri) {
        synchronized (mSelfObserverLock) {
            mNotifyUri = notifyUri;
            mContentResolver = cr;
            if (mSelfObserver != null) {
                mContentResolver.unregisterContentObserver(mSelfObserver);
            }
            mSelfObserver = new SelfContentObserver(this);
            mContentResolver.registerContentObserver(mNotifyUri, true, mSelfObserver);
            mSelfObserverRegistered = true;
        }
    }

satya - Wednesday, April 22, 2009 1:47:18 PM

registerContentObserver


void registerContentObserver 
(Uri uri, boolean notifyForDescendents, ContentObserver observer)

satya - Wednesday, April 22, 2009 1:48:21 PM

notifyForDescendents argument

If true changes to URIs beginning with uri will also cause notifications to be sent. If false only changes to the exact URI specified by uri will cause notifications to be sent. If true, then any URI values at or below the specified URI will also trigger a match.

satya - Wednesday, April 22, 2009 1:56:18 PM

Here is the code for selfcontentobserver


protected static class SelfContentObserver extends ContentObserver {
        WeakReference<AbstractCursor> mCursor;

        public SelfContentObserver(AbstractCursor cursor) {
            super(null);
            mCursor = new WeakReference<AbstractCursor>(cursor);
        }

        @Override
        public boolean deliverSelfNotifications() {
            return false;
        }

        @Override
        public void onChange(boolean selfChange) {
            AbstractCursor cursor = mCursor.get();
            if (cursor != null) {
                cursor.onChange(false);
            }
        }
    }

satya - Wednesday, April 22, 2009 1:57:15 PM

Here is onChange


protected void onChange(boolean selfChange) {
        synchronized (mSelfObserverLock) {
            mContentObservable.dispatchChange(selfChange);
            if (mNotifyUri != null && selfChange) {
                mContentResolver.notifyChange(mNotifyUri, mSelfObserver);
            }
        }
    }

satya - Wednesday, April 22, 2009 1:58:14 PM

who ever is watchin this cursor...

will be notified of the change.

satya - Wednesday, April 22, 2009 1:59:43 PM

Here is the code in the cursor adapter


private class ChangeObserver extends ContentObserver {
        public ChangeObserver() {
            super(new Handler());
        }

        @Override
        public boolean deliverSelfNotifications() {
            return true;
        }

        @Override
        public void onChange(boolean selfChange) {
            if (mAutoRequery && mCursor != null) {
                if (Config.LOGV) Log.v("Cursor", "Auto requerying " + mCursor +
                        " due to update");
                mDataValid = mCursor.requery();
            }
        }
    }

satya - Wednesday, April 22, 2009 2:53:34 PM

requery

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