setting the username on the drawer header for startup and coming back from the preferences screen for account switching

res/layout/drawer.xml

@@ -67,12 +67,12 @@
             android:paddingTop="100dp" />
 
         <TextView
-            android:id="@+id/tv_header"
+            android:id="@+id/drawer_username"
             android:layout_width="fill_parent"
             android:layout_height="100dp"
             android:layout_alignParentTop="true"
             android:layout_centerHorizontal="true"
-            android:background="@color/owncloud_blue"
+            android:background="@color/owncloud_blue_accent"
             android:gravity="bottom"
             android:orientation="vertical"
             android:text="@string/app_name"

src/com/owncloud/android/ui/activity/FileActivity.java

@@ -47,6 +47,7 @@ import android.view.View;
 import android.widget.AdapterView;
 import android.widget.ListView;
 import android.widget.RelativeLayout;
+import android.widget.TextView;
 import android.widget.Toast;
 
 import com.owncloud.android.BuildConfig;
@@ -346,6 +347,14 @@ public class FileActivity extends AppCompatActivity
 //            username.setText(account.name.substring(0, lastAtPos));
 //        }
 
+        // Display username in drawer
+        Account account = AccountUtils.getCurrentOwnCloudAccount(getApplicationContext());
+        if (account != null) {
+            TextView username = (TextView) navigationDrawerLayout.findViewById(R.id.drawer_username);
+            int lastAtPos = account.name.lastIndexOf("@");
+            username.setText(account.name.substring(0, lastAtPos));
+        }
+
         // load slide menu items
         mDrawerTitles = getResources().getStringArray(R.array.drawer_items);
 

src/com/owncloud/android/ui/activity/FileDisplayActivity.java

@@ -54,6 +54,8 @@ import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.widget.ProgressBar;
+import android.widget.RelativeLayout;
+import android.widget.TextView;
 import android.widget.Toast;
 
 import com.owncloud.android.MainApp;
@@ -259,7 +261,16 @@ public class FileDisplayActivity extends HookActivity
                 file = getStorageManager().getFileByPath(OCFile.ROOT_PATH);  // never returns null
             }
             setFile(file);
-            
+
+            if (mAccountWasSet) {
+                RelativeLayout navigationDrawerLayout = (RelativeLayout) findViewById(R.id.left_drawer);
+                if (navigationDrawerLayout != null && getAccount() != null) {
+                    TextView username = (TextView) navigationDrawerLayout.findViewById(R.id.drawer_username);
+                    int lastAtPos = getAccount().name.lastIndexOf("@");
+                    username.setText(getAccount().name.substring(0, lastAtPos));
+                }
+            }
+
             if (!stateWasRecovered) {
                 Log_OC.d(TAG, "Initializing Fragments in onAccountChanged..");
                 initFragmentsWithFile();