Use AsyncTask for password checking so UI doesn't hang

res/layout/dialog_password.xml

@@ -20,4 +20,10 @@
         <requestFocus />
     </EditText>
 
+    <TextView
+        android:id="@+id/passwordError"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:textColor="@color/error_color" />
+
 </LinearLayout>

res/values/strings.xml

@@ -8,6 +8,7 @@
     <string name="drawer_close">Close nav</string>
 
     <string name="enter_password">Enter password:</string>
+    <string name="checking_password">Checking password&#8230;</string>
     <string name="password_incorrect">Password was incorrect</string>
     <string name="password_file_error">Could not read password verification file</string>
     <string name="not_authed">Not authenticated</string>

src/i2p/bote/EmailListFragment.java

@@ -15,8 +15,10 @@ import i2p.bote.util.BetterAsyncTaskLoader;
 import i2p.bote.util.BoteHelper;
 import android.app.Activity;
 import android.app.AlertDialog;
+import android.app.ProgressDialog;
 import android.content.Context;
 import android.content.DialogInterface;
+import android.os.AsyncTask;
 import android.os.Bundle;
 import android.support.v4.app.ListFragment;
 import android.support.v4.app.LoaderManager;
@@ -25,6 +27,7 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.widget.EditText;
 import android.widget.ListView;
+import android.widget.TextView;
 
 public class EmailListFragment extends ListFragment implements
         LoaderManager.LoaderCallbacks<List<Email>> {
@@ -37,6 +40,9 @@ public class EmailListFragment extends ListFragment implements
     private EmailListAdapter mAdapter;
     private EmailFolder mFolder;
 
+    private EditText mPasswordInput;
+    private TextView mPasswordError;
+
     public static EmailListFragment newInstance(String folderName) {
         EmailListFragment f = new EmailListFragment();
         Bundle args = new Bundle();
@@ -98,25 +104,14 @@ public class EmailListFragment extends ListFragment implements
         View promptView = li.inflate(R.layout.dialog_password, null);
         AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
         builder.setView(promptView);
-        final EditText input = (EditText) promptView.findViewById(R.id.passwordInput);
+        mPasswordInput = (EditText) promptView.findViewById(R.id.passwordInput);
+        mPasswordError = (TextView) promptView.findViewById(R.id.passwordError);
 
         builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
             @Override
             public void onClick(DialogInterface dialog, int id) {
-                try {
-                    if (BoteHelper.tryPassword(input.getText().toString()))
-                        initializeList();
-                    else
-                        setEmptyText(getResources().getString(
-                                R.string.password_incorrect));
-                } catch (IOException e) {
-                    setEmptyText(getResources().getString(
-                            R.string.password_file_error));
-                } catch (GeneralSecurityException e) {
-                    setEmptyText(getResources().getString(
-                            R.string.password_file_error));
-                }
                 dialog.dismiss();
+                new PasswordWaiter().execute();
             }
         }).setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
             @Override
@@ -130,6 +125,49 @@ public class EmailListFragment extends ListFragment implements
         passwordDialog.show();
     }
 
+    private class PasswordWaiter extends AsyncTask<Void, Void, String> {
+        private final ProgressDialog dialog = new ProgressDialog(EmailListFragment.this.getActivity());
+
+        protected void onPreExecute() {
+            dialog.setMessage(getResources().getString(
+                    R.string.checking_password));
+            dialog.setCancelable(false);
+            dialog.show();
+        }
+
+        protected String doInBackground(Void... params) {
+            try {
+                if (BoteHelper.tryPassword(mPasswordInput.getText().toString()))
+                    return null;
+                else {
+                    cancel(false);
+                    return getResources().getString(
+                            R.string.password_incorrect);
+                }
+            } catch (IOException e) {
+                cancel(false);
+                return getResources().getString(
+                        R.string.password_file_error);
+            } catch (GeneralSecurityException e) {
+                cancel(false);
+                return getResources().getString(
+                        R.string.password_file_error);
+            }
+        }
+
+        protected void onCancelled(String result) {
+            dialog.dismiss();
+            requestPassword();
+            mPasswordError.setText(result);
+        }
+
+        protected void onPostExecute(String result) {
+            // Password is valid
+            initializeList();
+            dialog.dismiss();
+        }
+    }
+
     /**
      * Start loading the list of emails from this folder.
      * Only called when we have a password cached, or no