Errata

GNU libc is *not* licensed under the GPL license as stated in the text.

It is licensed under the *LGPL* (Lesser General Public License), which is a _weak-copyleft_ license, i.e. a _compromise_ between strong-copyleft licenses such as the GPL and permissive licenses such as Apache/MIT or BSD.

There are two "Stopped" states in the diagram instead of "Stopped" and "Paused".

Note from the Author or Editor:
Correct! The "Stopped" on right side should be "Paused".

The text reads that the onClick method requires updating and shows the updated onClick method. However, the onClick method doesn't set the status. It does this:

new PostToTwitter().execute(status);

The method that should be updated instead is PostToTwitter.doInBackground()

The downloadable sample code shows this.

Note from the Author or Editor:
That is correct - we did add AsyncTask in Chapter 6. So, we should say:

... So, doInBackground() in PostToTwitter task becomes:

protected String doInBackground(String... statuses) {
try {
Twitter.Status status = getTwitter().updateStatus(statuses[0]);
return status.text;
} catch (TwitterException e) {
Log.e(TAG, e.toString());
e.printStackTrace();
return "Failed to post";
}
}

Putting Thread#start() in Service#onStartCommand(Intent, int, int) which may be invoked few times will result in IllegalThreadStateException.

Note from the Author or Editor:
That is correct. I ended up moving all the code from onStartCommand() on onCreate() and getting rid of onStartCommand() completely. Alternatively, one could catch IllegalThreadStateException.

Figure 8-3 does not display what it says it displays

Note from the Author or Editor:
Yes, this is a wrong picture. It should be image called yamba-3.png, but for some reason it got replaced somewhere.

values.put(DbHelper.C_SOURCE, status.source);

This throws an SQLiteException, trying to use the column because it isn't in the "create table" statement on page 123. Either remove from this loop, or add to the create statement.

Hi ,

the method was wrote like this :
public StatusData getStatusData() { //
return statusData;
}

this will lead to NullPointerException when you run the application

it suppose to be like this :
public StatusData getStatusData()
{ statusData = new StatusData(this);
return statusData;
}

Note from the Author or Editor:

I would actually improve it like this instead:

public StatusData getStatusData() {
if (statusData==null) {
statusData = new StatusData(this);
}
return statusData;
}

Missing the following line:

import android.widget.SimpleCursorAdapter.ViewBinder;

There are several ViewBinder classes, and if the wrong one is chosen when Eclipse offers to import one for you it won't compile.

Note from the Author or Editor:
Correct. In general, I tried to leave imports out of the book as they are more/less automatic in Eclipse, however in this case there are a view choices making it a potential issue.

((YambaApplication) getApplication()).getStatusData().delete();

The delete() method was not described in the StatusData class on pp. 130-133 or added in the intervening pages.

In fact, the capability of Yamba to delete status data is not even mentioned in the text.

Note from the Author or Editor:
It is added in the code but not discussed in the book, correct.

getPrefs() method is not defined for yamba object in code line:

// Check if preferences have been set
if (yamba.getPrefs().getString("username", null) == null) {

I added following code in YambaApplication.java, which seems to work

public SharedPreferences getPrefs() {
return prefs;
}

(Note: the code snippet containing yamba.getPrefs() first appeared on page 152.)

Note from the Author or Editor:
Yes, that is a possible fix. Another one is to make prefs be package-visible, i.e. remove "private" declaration.

Android reference for requery() in Cursor class says:
"This method is deprecated. Don't use this. Just request a new cursor, so you can do this asynchronously and update your list view once the new cursor comes back."

So instead of
@Override
public void onReceive(Context context, Intent intent) { // 2
cursor.requery(); // 3
adapter.notifyDataSetChanged(); // 4
Log.d("TimelineReceiver", "onReceived");

I tried following, which seems to work ok, and I don't see "ERROR/Cursor(145): Invalid statement in fillWindow()" in LogCat
@Override
public void onReceive(Context context, Intent intent) { // 2
cursor = yamba.getStatusData().getStatusUpdates();
adapter.changeCursor(cursor);
adapter.notifyDataSetChanged(); // 4
Log.d("TimelineReceiver", "onReceived");

Adding a network receiver as in Example 11-8 requires a code change in the UpdaterService.java class. The downloadable example code reflects this change needed, but there is no mention of that in the book.

The code change is required because the onReceive() callback in NetworkReceiver also starts the UpdaterService as seen in the following code snippet.
...
} else {
Log. d(TAG, "onReceive: connected, starting UpdaterService");
context. startService(new Intent(context, UpdaterService.class));
}

Trying to start the inner class Updater object (is-a Thread) a second time results in an Exception and a force close of the program. So the following change is required in the UpdaterService.java class, as shown below, to check whether the service is already running and if so, not to start updater again.

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
super.onStartCommand(intent, flags, startId);

if (!runFlag) { // swCL: otherwise Exception thrown when NetworkReceiver calls startService(); in downloaded code, not in book
this.runFlag = true;
this.updater.start();
this.yamba.setServiceRunning(true);

Log.d(TAG, "onStarted");
}
return Service.START_STICKY;
}

StatusData statusData;

No initialization is provided in the book. The reader is left to examine the downloaded example code for:

@Override
public boolean onCreate() {
statusData = new StatusData(getContext());
return false;
}

In Chapter 8, when testing the UpdaterService on the emulator, the app crashes when you try to start the service using the menu. It appears that onStartCommand is not available in SDKVersion 4 so in order to fix this you need to change your AndroidManifest.xml file to:

<uses-sdk android:minSdkVersion="5" />

Note from the Author or Editor:
Yes, that's correct, the minimumSdkVersion should be 5 so that onStartCommand() is available. Version 4 didn't have it.

if (!YambaApplication.LOCATION_PROVIDER_NONE.equals(provider)) { // 4
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE); // 5
}

To prevent problems when location preference is on, then turned off, should clear location member variables as follows:

else {
locationManager = null;
location = null;
}

yamba.getTwitter().setMyLocation(latlong);

The location is never cleared in situations where location preference is on, and then turned off.

Maybe call setMyLocation(null) in an else?

Note from the Author or Editor:
That should work.

App will crash if reader forgets to add uses-permission elements in the AndroidManifest.xml file for Yamba (just as for the standalone WhereAmI app discussed in the previous section).
<manifest ...>
...
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
</manifest>

Note from the Author or Editor:
That's correct. I thought this is explained in the book prior to this example already.

Above code does not appear to work; no alarm call is triggered.

The problem appears to be a mismatch of the first two parameters. Replace this line of code
alarmManager.setInexactRepeating(AlarmManager.ELAPSED_REALTIME, System
.currentTimeMillis(), interval, pendingIntent);
with this line
alarmManager.setInexactRepeating(AlarmManager.RTC, System
.currentTimeMillis(), interval, pendingIntent);

If the second parameter is to be System.currentTimeMillis(), then the first parameter has to be AlarmManager.RTC, which is described in the Android Reference as: "Alarm time in System.currentTimeMillis() (wall clock time in UTC). This alarm does not wake the device up; if it goes off while the device is asleep, it will not be delivered until the next time the device wakes up."

Note from the Author or Editor:
True.