RecyclerView上的定期更新项目

Question

I have an Activity with a Recycler view handling cards. I have a SwipeRefreshLayout so when I swipe it updates the RecyclerView with new content. So far, so good.

Howerver, I want to update the RecyclerView every X seconds so if, for instance, I leave the activity with the recylcerview opened and I forgot to swipe it, it would as well update by itself. To do that, I thought something like this: ( I ommitted necessary code ).

My main Activity which contains the recyclerview schedules a Job like this:

private void scheduleJob() {

    ComponentName serviceName = new ComponentName(this, MyJobService.class);
    JobInfo jobInfo = new JobInfo.Builder(JOB_ID, serviceName)
            .setRequiredNetworkType(JobInfo.NETWORK_TYPE_UNMETERED)
            .setRequiresDeviceIdle(false)
            .setRequiresCharging(false)
            .setPeriodic(3000)
            //.setOverrideDeadline(400) // Remove comment for faster testing.
            .build();

    JobScheduler scheduler = (JobScheduler) getSystemService(Context.JOB_SCHEDULER_SERVICE);
    int result = scheduler.schedule(jobInfo);

    if (result == JobScheduler.RESULT_SUCCESS) {
        Toast.makeText(this,"Start", Toast.LENGTH_LONG).show();
    } } }

Inside MyJobService I through a Broadcast to my Activity, to let it know it has to update the content of the RecylcerView. The responsable of receiving the broadcast is an inner class like this:

public static class MyReceiver extends BroadcastReceiver{


    @Override
    public void onReceive(Context context, Intent intent) {

        DataSource dataSource = new DataSource(context);
        items = dataSource.getItems(); // can't do this due to outter class variable
    adapter.refresh(ítems); // can't do this due to outter class variable
        Toast.makeText(context,"event",Toast.LENGTH_SHORT).show();

    }
}

Problem is on my main Activity I hold two private variable called items (which is the ArrayList ) and adapter ( which is the adapter of the recylcerview) I pass items to the adapter to update the recyclerView content.However, as I am in a static inner class I can't access outter class variables. Whats the correct way to do something like this? I think I am messing too much and I guess there must be an easiest and more straight forward way to accomplish what I want.

Thank you very much

Answer 1

Well, turns out I was complicating things too much. It can be done with a simple Handler like this:

  // Create the Handler object (on the main thread by default)
    Handler handler = new Handler();
    // Define the code block to be executed
    private Runnable runnableCode = new Runnable() {
        @Override
        public void run() {
            // Do something here on the main thread
            Toast.makeText(getApplicationContext(),"Update",Toast.LENGTH_SHORT).show();
            ItemsDS itemsDS = new ItempsDS(getApplicationContext());
            items = itemsDS.getItems();
            adapter.clear();
            adapter.addAll(items);
            handler.postDelayed(runnableCode, 1000);
        }
    };

Answer 2

There are Two ways to do this thing:

First is as mentioned by @akshayBhat, you can do it by removing static keyword from BroadcastReceiver class:

ArrayList<String> items;
Adapter adapter;
public class MyReceiver extends BroadcastReceiver {


    @Override
    public void onReceive(Context context, Intent intent) {

        DataSource dataSource = new DataSource(context);
        items = dataSource.getItems(); // can't do this due to outter class variable
        adapter.refresh(ítems); // can't do this due to outter class variable
        Toast.makeText(context, "event", Toast.LENGTH_SHORT).show();

    }
}

Second is to pass the reference of current activity state to the BroadCast Receiver and access ClassVariables there using that refernce;

ArrayList<String> items;
Adapter adapter;
public static class MyReceiver extends BroadcastReceiver {

    AboutUs mContext;

    @Override
    public void onReceive(Context context, Intent intent) {

        mContext = (AboutUs)context;
        DataSource dataSource = new DataSource(context);
        mContext.items = dataSource.getItems(); // can't do this due to outter class variable
        mContext.adapter.refresh(ítems); // can't do this due to outter class variable
        Toast.makeText(context, "event", Toast.LENGTH_SHORT).show();

    }
}