Moved communication with DownloadService into DownloadObserver

2 files changed, 170 insertions, 92 deletions

diff --git a/src/de/danoeh/antennapod/activity/DownloadActivity.java b/src/de/danoeh/antennapod/activity/DownloadActivity.java
index ee5bb502c..f5986baf5 100644
--- a/src/de/danoeh/antennapod/activity/DownloadActivity.java
+++ b/src/de/danoeh/antennapod/activity/DownloadActivity.java
@@ -1,18 +1,9 @@
 package de.danoeh.antennapod.activity;
 
-import android.annotation.SuppressLint;
-import android.content.BroadcastReceiver;
-import android.content.ComponentName;
-import android.content.Context;
 import android.content.Intent;
-import android.content.IntentFilter;
-import android.content.ServiceConnection;
 import android.content.res.TypedArray;
-import android.os.AsyncTask;
-import android.os.Build;
 import android.os.Bundle;
-import android.os.IBinder;
-import android.support.v4.app.NavUtils;
+import android.os.Handler;
 import android.support.v4.view.MenuItemCompat;
 import android.support.v7.app.ActionBarActivity;
 import android.support.v7.view.ActionMode;
@@ -22,17 +13,18 @@ import android.view.MenuItem;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.AdapterView.OnItemLongClickListener;
-
 import android.widget.ListView;
-
 import de.danoeh.antennapod.AppConfig;
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.adapter.DownloadlistAdapter;
+import de.danoeh.antennapod.asynctask.DownloadObserver;
 import de.danoeh.antennapod.preferences.UserPreferences;
 import de.danoeh.antennapod.service.download.DownloadRequest;
-import de.danoeh.antennapod.service.download.DownloadService;
+import de.danoeh.antennapod.service.download.Downloader;
 import de.danoeh.antennapod.storage.DownloadRequester;
 
+import java.util.List;
+
 /**
  * Shows all running downloads in a list. The list objects are DownloadStatus
  * objects created by a DownloadObserver.
@@ -49,13 +41,10 @@ public class DownloadActivity extends ActionBarActivity implements
     private ActionMode mActionMode;
     private DownloadRequest selectedDownload;
 
-    private DownloadService downloadService = null;
-    boolean mIsBound;
-
-    private AsyncTask<Void, Void, Void> contentRefresher;
-
     private ListView listview;
 
+    private DownloadObserver downloadObserver;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         setTheme(UserPreferences.getTheme());
@@ -68,22 +57,19 @@ public class DownloadActivity extends ActionBarActivity implements
             Log.d(TAG, "Creating Activity");
         requester = DownloadRequester.getInstance();
         getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+        downloadObserver = new DownloadObserver(this, new Handler(), observerCallback);
     }
 
     @Override
     protected void onPause() {
         super.onPause();
-        unbindService(mConnection);
-        unregisterReceiver(contentChanged);
+        downloadObserver.onPause();
     }
 
     @Override
     protected void onResume() {
         super.onResume();
-        registerReceiver(contentChanged, new IntentFilter(
-                DownloadService.ACTION_DOWNLOADS_CONTENT_CHANGED));
-        bindService(new Intent(this, DownloadService.class), mConnection, 0);
-        startContentRefresher();
+        downloadObserver.onResume();
         if (dla != null) {
             dla.notifyDataSetChanged();
         }
@@ -94,72 +80,8 @@ public class DownloadActivity extends ActionBarActivity implements
         super.onStop();
         if (AppConfig.DEBUG)
             Log.d(TAG, "Stopping Activity");
-        stopContentRefresher();
-    }
-
-    private ServiceConnection mConnection = new ServiceConnection() {
-        public void onServiceDisconnected(ComponentName className) {
-            downloadService = null;
-            mIsBound = false;
-            Log.i(TAG, "Closed connection with DownloadService.");
-        }
-
-        public void onServiceConnected(ComponentName name, IBinder service) {
-            downloadService = ((DownloadService.LocalBinder) service)
-                    .getService();
-            mIsBound = true;
-            if (AppConfig.DEBUG)
-                Log.d(TAG, "Connection to service established");
-            dla = new DownloadlistAdapter(DownloadActivity.this, 0,
-                    downloadService.getDownloads());
-            listview.setAdapter(dla);
-            dla.notifyDataSetChanged();
-        }
-    };
-
-    @SuppressLint("NewApi")
-    private void startContentRefresher() {
-        if (contentRefresher != null) {
-            contentRefresher.cancel(true);
-        }
-        contentRefresher = new AsyncTask<Void, Void, Void>() {
-            private static final int WAITING_INTERVAL = 1000;
-
-            @Override
-            protected void onProgressUpdate(Void... values) {
-                super.onProgressUpdate(values);
-                if (dla != null) {
-                    if (AppConfig.DEBUG)
-                        Log.d(TAG, "Refreshing content automatically");
-                    dla.notifyDataSetChanged();
-                }
-            }
-
-            @Override
-            protected Void doInBackground(Void... params) {
-                while (!isCancelled()) {
-                    try {
-                        Thread.sleep(WAITING_INTERVAL);
-                        publishProgress();
-                    } catch (InterruptedException e) {
-                        return null;
-                    }
-                }
-                return null;
-            }
-        };
-        if (android.os.Build.VERSION.SDK_INT > android.os.Build.VERSION_CODES.GINGERBREAD_MR1) {
-            contentRefresher.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
-        } else {
-            contentRefresher.execute();
-        }
     }
 
-    private void stopContentRefresher() {
-        if (contentRefresher != null) {
-            contentRefresher.cancel(true);
-        }
-    }
 
     @Override
     protected void onPostCreate(Bundle savedInstanceState) {
@@ -247,16 +169,22 @@ public class DownloadActivity extends ActionBarActivity implements
         dla.setSelectedItemIndex(DownloadlistAdapter.SELECTION_NONE);
     }
 
-    private BroadcastReceiver contentChanged = new BroadcastReceiver() {
 
+    private DownloadObserver.Callback observerCallback = new DownloadObserver.Callback() {
         @Override
-        public void onReceive(Context context, Intent intent) {
+        public void onContentChanged() {
             if (dla != null) {
-                if (AppConfig.DEBUG)
-                    Log.d(TAG, "Refreshing content");
                 dla.notifyDataSetChanged();
             }
         }
+
+        @Override
+        public void onDownloadDataAvailable(List<Downloader> downloaderList) {
+            dla = new DownloadlistAdapter(DownloadActivity.this, 0,
+                    downloaderList);
+            listview.setAdapter(dla);
+            dla.notifyDataSetChanged();
+        }
     };
 
 }
diff --git a/src/de/danoeh/antennapod/asynctask/DownloadObserver.java b/src/de/danoeh/antennapod/asynctask/DownloadObserver.java
new file mode 100644
index 000000000..26e405615
--- /dev/null
+++ b/src/de/danoeh/antennapod/asynctask/DownloadObserver.java
@@ -0,0 +1,150 @@
+package de.danoeh.antennapod.asynctask;
+
+import android.app.Activity;
+import android.content.*;
+import android.os.Handler;
+import android.os.IBinder;
+import android.util.Log;
+import de.danoeh.antennapod.AppConfig;
+import de.danoeh.antennapod.service.download.DownloadService;
+import de.danoeh.antennapod.service.download.Downloader;
+
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * Provides access to the DownloadService's list of items that are currently being downloaded.
+ * The DownloadObserver object should be created in the activity's onCreate() method. resume() and pause()
+ * should be called in the activity's onResume() and onPause() methods
+ */
+public class DownloadObserver {
+    private static final String TAG = "DownloadObserver";
+
+    /**
+     * Time period between update notifications.
+     */
+    public static final int WAITING_INTERVAL_MS = 1000;
+
+    private final Activity activity;
+    private final Handler handler;
+    private final Callback callback;
+
+    private DownloadService downloadService = null;
+    private AtomicBoolean mIsBound = new AtomicBoolean(false);
+
+    private Thread refresherThread;
+    private AtomicBoolean refresherThreadRunning = new AtomicBoolean(false);
+
+
+    /**
+     * Creates a new download observer.
+     *
+     * @param activity Used for registering receivers
+     * @param handler  All callback methods are executed on this handler. The handler MUST run on the GUI thread.
+     * @param callback Callback methods for posting content updates
+     * @throws java.lang.IllegalArgumentException if one of the arguments is null.
+     */
+    public DownloadObserver(Activity activity, Handler handler, Callback callback) {
+        if (activity == null) throw new IllegalArgumentException("activity = null");
+        if (handler == null) throw new IllegalArgumentException("handler = null");
+        if (callback == null) throw new IllegalArgumentException("callback = null");
+
+        this.activity = activity;
+        this.handler = handler;
+        this.callback = callback;
+    }
+
+    public void onResume() {
+        if (AppConfig.DEBUG) Log.d(TAG, "DownloadObserver resumed");
+        activity.registerReceiver(contentChangedReceiver, new IntentFilter(DownloadService.ACTION_DOWNLOADS_CONTENT_CHANGED));
+        activity.bindService(new Intent(activity, DownloadService.class), mConnection, 0);
+    }
+
+    public void onPause() {
+        if (AppConfig.DEBUG) Log.d(TAG, "DownloadObserver paused");
+        activity.unregisterReceiver(contentChangedReceiver);
+        activity.unbindService(mConnection);
+        stopRefresher();
+    }
+
+    private BroadcastReceiver contentChangedReceiver = new BroadcastReceiver() {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            callback.onContentChanged();
+            startRefresher();
+        }
+    };
+
+    public interface Callback {
+        void onContentChanged();
+
+        void onDownloadDataAvailable(List<Downloader> downloaderList);
+    }
+
+    private ServiceConnection mConnection = new ServiceConnection() {
+        public void onServiceDisconnected(ComponentName className) {
+            downloadService = null;
+            mIsBound.set(false);
+            stopRefresher();
+            Log.i(TAG, "Closed connection with DownloadService.");
+        }
+
+        public void onServiceConnected(ComponentName name, IBinder service) {
+            downloadService = ((DownloadService.LocalBinder) service)
+                    .getService();
+            mIsBound.set(true);
+            if (AppConfig.DEBUG)
+                Log.d(TAG, "Connection to service established");
+            List<Downloader> downloaderList = downloadService.getDownloads();
+            if (downloaderList != null && !downloaderList.isEmpty()) {
+                callback.onDownloadDataAvailable(downloaderList);
+                startRefresher();
+            }
+        }
+    };
+
+    private void stopRefresher() {
+        if (refresherThread != null) {
+            refresherThread.interrupt();
+        }
+    }
+
+    private void startRefresher() {
+        if (refresherThread == null || refresherThread.isInterrupted()) {
+            refresherThread = new Thread(new RefresherThread());
+            refresherThread.start();
+        }
+    }
+
+    private class RefresherThread implements Runnable {
+
+        public void run() {
+            refresherThreadRunning.set(true);
+            while (!Thread.interrupted()) {
+                try {
+                    Thread.sleep(WAITING_INTERVAL_MS);
+                } catch (InterruptedException e) {
+                    Log.d(TAG, "Refresher thread was interrupted");
+                }
+                if (mIsBound.get()) {
+                    postUpdate();
+                }
+            }
+            refresherThreadRunning.set(false);
+        }
+
+        private void postUpdate() {
+            handler.post(new Runnable() {
+                @Override
+                public void run() {
+                    callback.onContentChanged();
+                    List<Downloader> downloaderList = downloadService.getDownloads();
+                    if (downloaderList == null || downloaderList.isEmpty()) {
+                        Thread.currentThread().interrupt();
+                    }
+                }
+            });
+        }
+    }
+
+}