use Loader when conversation is updated instead of requery

// FREEBIE

src/org/thoughtcrime/securesms/ConversationAdapter.java

@@ -65,7 +65,7 @@ public class ConversationAdapter extends CursorAdapter implements AbsListView.Re
   public ConversationAdapter(Context context, MasterSecret masterSecret,
                              Handler failedIconClickHandler, boolean groupThread, boolean pushDestination)
   {
-    super(context, null, true);
+    super(context, null, 0);
     this.context                = context;
     this.masterSecret           = masterSecret;
     this.failedIconClickHandler = failedIconClickHandler;
@@ -84,6 +84,12 @@ public class ConversationAdapter extends CursorAdapter implements AbsListView.Re
     item.set(masterSecret, messageRecord, failedIconClickHandler, groupThread, pushDestination);
   }
 
+  @Override
+  public void changeCursor(Cursor cursor) {
+    messageRecordCache.clear();
+    super.changeCursor(cursor);
+  }
+
   @Override
   public View newView(Context context, Cursor cursor, ViewGroup parent) {
     View view;
@@ -148,12 +154,6 @@ public class ConversationAdapter extends CursorAdapter implements AbsListView.Re
     return messageRecord;
   }
 
-  @Override
-  protected void onContentChanged() {
-    super.onContentChanged();
-    messageRecordCache.clear();
-  }
-
   public void close() {
     this.getCursor().close();
   }

src/org/thoughtcrime/securesms/ConversationListAdapter.java

@@ -18,11 +18,11 @@ package org.thoughtcrime.securesms;
 
 import android.content.Context;
 import android.database.Cursor;
+import android.support.v4.widget.CursorAdapter;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AbsListView;
-import android.widget.CursorAdapter;
 
 import org.thoughtcrime.securesms.crypto.MasterCipher;
 import org.thoughtcrime.securesms.crypto.MasterSecret;
@@ -50,7 +50,7 @@ public class ConversationListAdapter extends CursorAdapter implements AbsListVie
   private       boolean   batchMode = false;
 
   public ConversationListAdapter(Context context, Cursor cursor, MasterSecret masterSecret) {
-    super(context, cursor);
+    super(context, cursor, 0);
 
     if (masterSecret != null) this.masterCipher = new MasterCipher(masterSecret);
     else                      this.masterCipher = null;

src/org/thoughtcrime/securesms/ConversationListFragment.java

@@ -32,6 +32,7 @@ import android.support.v7.app.ActionBarActivity;
 import android.support.v7.view.ActionMode;
 import android.support.v7.widget.SearchView;
 import android.util.Log;
+import android.support.v4.widget.CursorAdapter;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
@@ -39,7 +40,6 @@ import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AdapterView;
-import android.widget.CursorAdapter;
 import android.widget.ListView;
 
 import org.thoughtcrime.securesms.components.DefaultSmsReminder;

src/org/thoughtcrime/securesms/database/loaders/ConversationListLoader.java

@@ -2,26 +2,24 @@ package org.thoughtcrime.securesms.database.loaders;
 
 import android.content.Context;
 import android.database.Cursor;
-import android.support.v4.content.CursorLoader;
 
 import org.thoughtcrime.securesms.contacts.ContactAccessor;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
+import org.thoughtcrime.securesms.util.AbstractCursorLoader;
 
 import java.util.List;
 
-public class ConversationListLoader extends CursorLoader {
+public class ConversationListLoader extends AbstractCursorLoader {
 
   private final String filter;
-  private final Context context;
 
   public ConversationListLoader(Context context, String filter) {
     super(context);
-    this.filter  = filter;
-    this.context = context.getApplicationContext();
+    this.filter = filter;
   }
 
   @Override
-  public Cursor loadInBackground() {
+  public Cursor getCursor() {
     if (filter != null && filter.trim().length() != 0) {
       List<String> numbers = ContactAccessor.getInstance()
           .getNumbersForThreadSearchFilter(filter, context.getContentResolver());

src/org/thoughtcrime/securesms/database/loaders/ConversationLoader.java

@@ -2,23 +2,20 @@ package org.thoughtcrime.securesms.database.loaders;
 
 import android.content.Context;
 import android.database.Cursor;
-import android.support.v4.content.CursorLoader;
 
 import org.thoughtcrime.securesms.database.DatabaseFactory;
+import org.thoughtcrime.securesms.util.AbstractCursorLoader;
 
-public class ConversationLoader extends CursorLoader {
-
-  private final Context context;
-  private final long threadId;
+public class ConversationLoader extends AbstractCursorLoader {
+  private final long                     threadId;
 
   public ConversationLoader(Context context, long threadId) {
     super(context);
-    this.context  = context.getApplicationContext();
     this.threadId = threadId;
   }
 
   @Override
-  public Cursor loadInBackground() {
+  public Cursor getCursor() {
     return DatabaseFactory.getMmsSmsDatabase(context).getConversation(threadId);
   }
 }

src/org/thoughtcrime/securesms/util/AbstractCursorLoader.java

@@ -0,0 +1,90 @@
+package org.thoughtcrime.securesms.util;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.support.v4.content.AsyncTaskLoader;
+
+/**
+ * A Loader similar to CursorLoader that doesn't require queries to go through the ContentResolver
+ * to get the benefits of reloading when content has changed.
+ */
+public abstract class AbstractCursorLoader extends AsyncTaskLoader<Cursor> {
+  private static final String TAG = AbstractCursorLoader.class.getSimpleName();
+
+  protected final ForceLoadContentObserver observer;
+  protected final Context                  context;
+  protected       Cursor                   cursor;
+
+  public AbstractCursorLoader(Context context) {
+    super(context);
+    this.context  = context.getApplicationContext();
+    this.observer = new ForceLoadContentObserver();
+  }
+
+  public abstract Cursor getCursor();
+
+  @Override
+  public void deliverResult(Cursor newCursor) {
+    if (isReset()) {
+      if (newCursor != null) {
+        newCursor.close();
+      }
+      return;
+    }
+    Cursor oldCursor = this.cursor;
+
+    this.cursor = newCursor;
+
+    if (isStarted()) {
+      super.deliverResult(newCursor);
+    }
+    if (oldCursor != null && oldCursor != cursor && !oldCursor.isClosed()) {
+      oldCursor.close();
+    }
+  }
+
+  @Override
+  protected void onStartLoading() {
+    if (cursor != null) {
+      deliverResult(cursor);
+    }
+    if (takeContentChanged() || cursor == null) {
+      forceLoad();
+    }
+  }
+
+  @Override
+  protected void onStopLoading() {
+    cancelLoad();
+  }
+
+  @Override
+  public void onCanceled(Cursor cursor) {
+    if (cursor != null && !cursor.isClosed()) {
+      cursor.close();
+    }
+  }
+
+  @Override
+  public Cursor loadInBackground() {
+    Cursor newCursor = getCursor();
+    if (newCursor != null) {
+      newCursor.getCount();
+      newCursor.registerContentObserver(observer);
+    }
+    return newCursor;
+  }
+
+  @Override
+  protected void onReset() {
+    super.onReset();
+
+    onStopLoading();
+
+    if (cursor != null && !cursor.isClosed()) {
+      cursor.close();
+    }
+    cursor = null;
+  }
+
+}