Loader for email list

src/i2p/bote/BoteHelper.java

@@ -4,9 +4,16 @@ import java.util.List;
 
 import android.content.Context;
 
+import i2p.bote.email.AddressDisplayFilter;
+import i2p.bote.email.Email;
+import i2p.bote.email.EmailAttribute;
+import i2p.bote.email.Identities;
+import i2p.bote.fileencryption.PasswordException;
 import i2p.bote.folder.EmailFolder;
 
 public class BoteHelper {
+    private static AddressDisplayFilter ADDRESS_DISPLAY_FILTER;
+
     public static EmailFolder getMailFolder(String folderName) {
         List<EmailFolder> folders = I2PBote.getInstance().getEmailFolders();
         for (EmailFolder folder : folders) {
@@ -37,4 +44,15 @@ public class BoteHelper {
         else
             return name;
     }
+
+    public static List<Email> getEmails(EmailFolder folder, EmailAttribute sortColumn, boolean descending) throws PasswordException {
+        return folder.getElements(getAddressDisplayFilter(), sortColumn, descending);
+    }
+
+    private static AddressDisplayFilter getAddressDisplayFilter() throws PasswordException {
+        Identities identities = I2PBote.getInstance().getIdentities();
+        if (ADDRESS_DISPLAY_FILTER == null)
+            ADDRESS_DISPLAY_FILTER = new AddressDisplayFilter(identities, I2PBote.getInstance().getAddressBook());
+        return ADDRESS_DISPLAY_FILTER;
+    }
 }

src/i2p/bote/EmailListAdapter.java

@@ -0,0 +1,47 @@
+package i2p.bote;
+
+import java.util.List;
+
+import javax.mail.MessagingException;
+
+import i2p.bote.email.Email;
+import i2p.bote.folder.EmailFolder;
+import android.content.Context;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ArrayAdapter;
+import android.widget.TextView;
+
+public class EmailListAdapter extends ArrayAdapter<Email> {
+    private final LayoutInflater mInflater;
+
+    public EmailListAdapter(Context context) {
+        super(context, android.R.layout.simple_list_item_2);
+        mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+    }
+
+    public void setData(List<Email> emails) {
+        clear();
+        if (emails != null) {
+            for (Email email : emails) {
+                add(email);
+            }
+        }
+    }
+
+    @Override
+    public View getView(int position, View convertView, ViewGroup parent) {
+        View v = mInflater.inflate(R.layout.listitem_email, parent, false);
+        Email email = getItem(position);
+
+        TextView name = (TextView) v.findViewById(R.id.email_subject);
+        try {
+            name.setText(email.getSubject());
+        } catch (MessagingException e) {
+            name.setText("ERROR: " + e.getMessage());
+        }
+
+        return v;
+    }
+}

src/i2p/bote/EmailListLoader.java

@@ -0,0 +1,155 @@
+package i2p.bote;
+
+import i2p.bote.email.Email;
+import i2p.bote.fileencryption.PasswordException;
+import i2p.bote.folder.EmailFolder;
+import i2p.bote.folder.FolderListener;
+
+import java.util.List;
+
+import android.content.Context;
+import android.support.v4.content.AsyncTaskLoader;
+
+public class EmailListLoader extends AsyncTaskLoader<List<Email>> implements
+        FolderListener {
+    private EmailFolder mFolder;
+    private List<Email> mData;
+
+    public EmailListLoader(Context context, EmailFolder folder) {
+        super(context);
+        mFolder = folder;
+    }
+
+    @Override
+    public List<Email> loadInBackground() {
+        try {
+            return BoteHelper.getEmails(mFolder, null, false);
+        } catch (PasswordException pe) {
+            // TODO: Handle this error properly (get user to log in)
+            return null;
+        }
+    }
+
+    /**
+     * Called when there is new data to deliver to the client.  The
+     * super class will take care of delivering it; the implementation
+     * here just adds a little more logic.
+     */
+    @Override
+    public void deliverResult(List<Email> data) {
+        if (isReset()) {
+            // An async query came in while the loader is stopped.  We
+            // don't need the result.
+            if (data != null) {
+                releaseResources(data);
+            }
+        }
+
+        // Hold a reference to the old data so it doesn't get garbage collected.
+        // We must protect it until the new data has been delivered.
+        List<Email> oldData = mData;
+        mData = data;
+
+        if (isStarted()) {
+            // If the Loader is currently started, we can immediately
+            // deliver its results.
+            super.deliverResult(data);
+        }
+
+        // Invalidate the old data as we don't need it any more.
+        if (oldData != null && oldData != data) {
+            releaseResources(oldData);
+        }
+    }
+
+    /**
+     * Handles a request to start the Loader.
+     */
+    @Override
+    protected void onStartLoading() {
+        if (mData != null) {
+            // Deliver any previously loaded data immediately.
+            deliverResult(mData);
+        }
+
+        // Start watching for changes in the folder
+        mFolder.addFolderListener(this);
+
+        if (takeContentChanged() || mData == null) {
+            // When the observer detects a change, it should call onContentChanged()
+            // on the Loader, which will cause the next call to takeContentChanged()
+            // to return true. If this is ever the case (or if the current data is
+            // null), we force a new load.
+            forceLoad();
+        }
+    }
+
+    /**
+     * Handles a request to stop the Loader.
+     */
+    @Override
+    protected void onStopLoading() {
+        // The Loader is in a stopped state, so we should attempt to cancel the 
+        // current load (if there is one).
+        cancelLoad();
+
+        // Note that we leave the observer as is. Loaders in a stopped state
+        // should still monitor the data source for changes so that the Loader
+        // will know to force a new load if it is ever started again.
+    }
+
+    /**
+     * Handles a request to completely reset the Loader.
+     */
+    @Override
+    protected void onReset() {
+        super.onReset();
+
+        // Ensure the loader has been stopped.
+        onStopLoading();
+
+        // At this point we can release the resources associated with 'mData'.
+        if (mData != null) {
+            releaseResources(mData);
+            mData = null;
+        }
+
+        // Stop monitoring for changes.
+        mFolder.removeFolderListener(this);
+    }
+
+    /**
+     * Handles a request to cancel a load.
+     */
+    @Override
+    public void onCanceled(List<Email> data) {
+        // Attempt to cancel the current asynchronous load.
+        super.onCanceled(data);
+
+        // The load has been canceled, so we should release the resources
+        // associated with 'data'.
+        releaseResources(data);
+    }
+
+    /**
+     * Helper function to take care of releasing resources associated
+     * with an actively loaded data set.
+     */
+    private void releaseResources(List<Email> data) {
+        // For a simple List, there is nothing to do. For something like a Cursor, we 
+        // would close it in this method. All resources associated with the Loader
+        // should be released here.
+    }
+
+    // FolderListener
+
+    @Override
+    public void elementAdded() {
+        onContentChanged();
+    }
+
+    @Override
+    public void elementRemoved() {
+        onContentChanged();
+    }
+}

src/i2p/bote/FolderFragment.java

@@ -1,12 +1,23 @@
 package i2p.bote;
 
+import java.util.List;
+
+import i2p.bote.email.Email;
 import i2p.bote.folder.EmailFolder;
 import android.os.Bundle;
 import android.support.v4.app.ListFragment;
+import android.support.v4.app.LoaderManager;
+import android.support.v4.content.Loader;
 
-public class FolderFragment extends ListFragment {
+public class FolderFragment extends ListFragment implements
+        LoaderManager.LoaderCallbacks<List<Email>> {
     public static final String FOLDER_NAME = "folder_name";
 
+    private static final int EMAIL_LIST_LOADER = 1;
+
+    private EmailListAdapter mAdapter;
+    private EmailFolder mFolder;
+
     public static FolderFragment newInstance(String folderName) {
         FolderFragment f = new FolderFragment();
         Bundle args = new Bundle();
@@ -16,10 +27,37 @@ public class FolderFragment extends ListFragment {
     }
 
     @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-
+    public void onActivityCreated(Bundle savedInstanceState) {
+        super.onActivityCreated(savedInstanceState);
+        mAdapter = new EmailListAdapter(getActivity());
         String folderName = getArguments().getString(FOLDER_NAME);
-        EmailFolder folder = BoteHelper.getMailFolder(folderName);
+        mFolder = BoteHelper.getMailFolder(folderName);
+
+        setListAdapter(mAdapter);
+
+        setListShown(false);
+        if (mFolder != null)
+            getLoaderManager().initLoader(EMAIL_LIST_LOADER, null, this);
+    }
+
+    // LoaderManager.LoaderCallbacks<List<Email>>
+
+    public Loader<List<Email>> onCreateLoader(int id, Bundle args) {
+        return new EmailListLoader(getActivity(), mFolder);
+    }
+
+    public void onLoadFinished(Loader<List<Email>> loader,
+            List<Email> data) {
+        mAdapter.setData(data);
+
+        if (isResumed()) {
+            setListShown(true);
+        } else {
+            setListShownNoAnimation(true);
+        }
+    }
+
+    public void onLoaderReset(Loader<List<Email>> loader) {
+        mAdapter.setData(null);
     }
 }