Add Email suggestions in Create Key activity

OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/helper/ContactHelper.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2014 Dominik Schürmann <dominik@dominikschuermann.de>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.sufficientlysecure.keychain.helper;
+
+import android.accounts.Account;
+import android.accounts.AccountManager;
+import android.content.Context;
+import android.util.Patterns;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+public class ContactHelper {
+
+    public static final List<String> getMailAccounts(Context context) {
+        final Account[] accounts = AccountManager.get(context).getAccounts();
+        final Set<String> emailSet = new HashSet<String>();
+        for (Account account : accounts) {
+            if (Patterns.EMAIL_ADDRESS.matcher(account.name).matches()) {
+                emailSet.add(account.name);
+            }
+        }
+        return new ArrayList<String>(emailSet);
+    }
+}