create inbox viewmodel and bind the inbox task to Inbox Activity

app/src/main/java/gr/thmmy/mthmmy/activities/inbox/InboxActivity.java

@@ -2,11 +2,16 @@ package gr.thmmy.mthmmy.activities.inbox;
 
 import android.os.Bundle;
 
+import androidx.lifecycle.ViewModelProviders;
+
 import gr.thmmy.mthmmy.R;
 import gr.thmmy.mthmmy.base.BaseActivity;
+import gr.thmmy.mthmmy.viewmodel.InboxViewModel;
 
 public class InboxActivity extends BaseActivity {
 
+    InboxViewModel inboxViewModel;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -23,5 +28,14 @@ public class InboxActivity extends BaseActivity {
 
         createDrawer();
         drawer.setSelection(INBOX_ID);
+
+        inboxViewModel = ViewModelProviders.of(this).get(InboxViewModel.class);
+        subscribeUI();
+    }
+
+    private void subscribeUI() {
+        inboxViewModel.setOnInboxTaskFinishedListener((resultCode, data) -> {
+
+        });
     }
 }

app/src/main/java/gr/thmmy/mthmmy/activities/topic/TopicActivity.java

@@ -652,7 +652,7 @@ public class TopicActivity extends BaseActivity implements TopicAdapter.OnPostFo
                 Toast.makeText(this, "Failed to remove vote", Toast.LENGTH_LONG).show();
             }
         });
-        // observe the chages in data
+        // observe the changes in data
         viewModel.getPageIndicatorIndex().observe(this, pageIndicatorIndex -> {
             if (pageIndicatorIndex == null) return;
             pageIndicator.setText(String.valueOf(pageIndicatorIndex) + "/" +

app/src/main/java/gr/thmmy/mthmmy/viewmodel/InboxViewModel.java

@@ -0,0 +1,36 @@
+package gr.thmmy.mthmmy.viewmodel;
+
+import androidx.lifecycle.ViewModel;
+
+import gr.thmmy.mthmmy.activities.inbox.tasks.InboxTask;
+import gr.thmmy.mthmmy.model.Inbox;
+
+public class InboxViewModel extends ViewModel implements InboxTask.OnNetworkTaskFinishedListener<Inbox> {
+    private static final String INBOX_URL = "https://www.thmmy.gr/smf/index.php?action=pm";
+
+    private InboxTask currentInboxTask;
+
+    private Inbox inbox;
+    private InboxTask.OnNetworkTaskFinishedListener<Inbox> onInboxTaskFinishedListener;
+
+    private void loadInbox() {
+        currentInboxTask = new InboxTask();
+        currentInboxTask.setOnNetworkTaskFinishedListener(this);
+        currentInboxTask.execute(INBOX_URL);
+    }
+
+    public void setOnInboxTaskFinishedListener(InboxTask.OnNetworkTaskFinishedListener<Inbox> onInboxTaskFinishedListener) {
+        this.onInboxTaskFinishedListener = onInboxTaskFinishedListener;
+    }
+
+    @Override
+    public void onNetworkTaskFinished(int resultCode, Inbox inbox) {
+        this.inbox = inbox;
+        onInboxTaskFinishedListener.onNetworkTaskFinished(resultCode, inbox);
+    }
+
+    public Inbox getInbox() {
+        if (inbox == null) throw new NullPointerException("Inbox has not been loaded yet");
+        return inbox;
+    }
+}