Android Programming Tutorials

Your Friends Seem Remote

At this point, if you recompile each project, you will see they both have

compiler errors – PostMonitor cannot find IPostListener and Patchy cannot

find PostMonitor, for example.

Step #4: Implement and Copy the AIDL..........................................

Now, we need to implement AIDL to represent the interface that the

service exposes to the client and the callback that the client exposes to the

service.

We already almost have the callback AIDL, since AIDL closely resembles

Java interfaces. Move Patchy/src/apt/tutorial/two/IPostListener.java to

Patchy/src/apt/tutorial/IPostListener.aidl, moving it up one directory

and changing the file extension to .aidl. Then, remove the public

keywords, and the AIDL is set. Repeat this process with IPostMonitor.java

as well.

Then, copy the new IPostListener.aidl and IPostMonitor.aidl files to the

corresponding directory in TMonitor (TMonitor/src/apt/tutorial). We also

have to deal with the possibility of an android.os.RemoteException when

using the callback, since the calling process might have unexpectedly

terminated. So, we need to wrap our callback use in a try/catch block as

follows:

private void poll(Account l) {

try {

Twitter client=new Twitter(l.user, l.password);

client.setAPIRootUrl("https://identi.ca/api");

List<Twitter.Status> timeline=client.getFriendsTimeline();

for (Twitter.Status s : timeline) {

if (!seenStatus.contains(s.id)) {

try {

l.callback.newFriendStatus(s.user.screenName, s.text,

s.createdAt.toString());

seenStatus.add(s.id);

}

catch (Throwable t) {

Log.e("PostMonitor", "Exception in callback", t);

}

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