Android-Zorn

February 20, 2016 · View on GitHub

Asynchronous Workers and Worker Managers for Android.

How to use

simply fork or download the project, you can also download and create .aar file yourself.

Notable Features

use Worker API as a replacement for AsyncTask
workers run on background threads and return callbacks on the main(calling) thread.
automate a batch of workers with two worker managers:
- PriorityWorkerManager - workers are processed according to their priority both serially or unbounded.
- TopologicalWorkerManager - workers are processed according to a binary topological relation and order.

Using a Worker

1. Simply anonymously instantiate `AbstractWorker`

AbstractWorker worker = new AbstractWorker() {
    @Override
    protected void onProgress() {
        // runs on the calling/main thread
    }

    @Override
    protected void onComplete() {
        // runs on the calling/main thread
    }

    @Override
    public void work() {
        // here you put work to be done in a background thread
    }
};

// run async
worker.process();

2. Simply extend `AbstractWorker`

MyWorker worker = new MyWorker();

worker.process(new WorkerObserver() {
    @Override
    public void onWorkerComplete(IWorker worker) {
        // runs on the calling/main thread
    }

    @Override
    public void onWorkerProgress(IWorker worker) {
        // runs on the calling/main thread
    }

    @Override
    public void onWorkerError(IWorker worker) {
        // runs on the calling/main thread
    }
});

3. use `SimpleWorker` with a `IWork` object (like `Runnable`)

SimpleWorker sw = new SimpleWorker(new IWork() {
    @Override
    public void work() {
        // here you put work to be done in a background thread
    }
});

sw.process();

notes

IWorker.process(..) method also have an overloaded version where one can pass ExecutorService
IWorker supports many more methods and ideas. I did not go through all.
in the future, I will add support for Java native FutureTask and Callable so worker can have cancelling feature.

Worker managers support a lot of functionality such as pause, start, stop etc.. You can also implement a Worker manager using BaseAbstractWorkerManager, it is very easy. Contributions of new Worker managers are most welcome.

Priority Worker Manager.

pm = new PriorityWorkerManager("myId");
// serial mode
pm.setExecutionMode(AbstractWorkerManager.EXECUTION_MODE.SERIAL);

IWorker worker = null;
String  id;
int     priority;

for(int ix = 0; ix < 20; ix++) {
    id        = String.valueOf(ix);
    priority  = ix;
    
    worker    = new TestWorker(id, priority);

    pm.enqueue(worker);
}

pm.setListener(new WorkerManagerObserver() {
    @Override
    public void onComplete(IWorkerManager wm) {
        // runs on the calling/main thread
    }

    @Override
    public void onProgress(String id) {
        // runs on the calling/main thread
    }

    @Override
    public void onError(WorkerManagerErrorInfo err) {
        // runs on the calling/main thread
    }
});

pm.start();

Topological Worker Manager.

Use the TopologicalWorkerManager.Builder or Zorn.newTopologicalWorkerManager() to create a worker manager that takes into account a directed binary relation among workers.

TestWorker a1 = new TestWorker("a1");
TestWorker a2 = new TestWorker("a2");
TestWorker a3 = new TestWorker("a3");
TestWorker a4 = new TestWorker("a4");
TestWorker a5 = new TestWorker("a5");

TopologicalWorkerManager tm = new TopologicalWorkerManager.Builder().id("topological_test")
                                                          .listener(this)
                                                          .before(a1, a3)
                                                          .before(a2, a3)
                                                          .after(a4, a3)
                                                          .after(a5, a4)
                                                          .build();
                                                          
tm.setListener(...);

tm.start();