Stop using raw string "hostname" passing directly to param for Activity/Fragment

app/src/main/java/chat/rocket/android/LaunchUtil.java

@@ -36,7 +36,7 @@ public class LaunchUtil {
   public static void showLoginActivity(Context context, String hostname) {
     Intent intent = new Intent(context, LoginActivity.class);
     intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT | Intent.FLAG_ACTIVITY_CLEAR_TOP);
-    intent.putExtra("hostname", hostname);
+    intent.putExtra(LoginActivity.KEY_HOSTNAME, hostname);
     context.startActivity(intent);
   }
 }

app/src/main/java/chat/rocket/android/activity/LoginActivity.java

@@ -18,6 +18,7 @@ import chat.rocket.android.service.ConnectivityManager;
  * Activity for Login, Sign-up, and Retry connecting...
  */
 public class LoginActivity extends AbstractFragmentActivity {
+  public static final String KEY_HOSTNAME = "hostname";
 
   private String hostname;
   private RealmObjectObserver<Session> sessionObserver;
@@ -37,7 +38,7 @@ public class LoginActivity extends AbstractFragmentActivity {
       return;
     }
 
-    hostname = intent.getStringExtra("hostname");
+    hostname = intent.getStringExtra(KEY_HOSTNAME);
     if (TextUtils.isEmpty(hostname)) {
       finish();
       return;
@@ -98,7 +99,7 @@ public class LoginActivity extends AbstractFragmentActivity {
     if (args == null) {
       args = new Bundle();
     }
-    args.putString("hostname", hostname);
+    args.putString(LoginActivity.KEY_HOSTNAME, hostname);
     fragment.setArguments(args);
   }
 

app/src/main/java/chat/rocket/android/fragment/server_config/AbstractServerConfigFragment.java

@@ -5,6 +5,7 @@ import android.support.annotation.Nullable;
 import android.support.v4.app.Fragment;
 
 import chat.rocket.android.R;
+import chat.rocket.android.activity.LoginActivity;
 import chat.rocket.android.fragment.AbstractFragment;
 import chat.rocket.android.helper.TextUtils;
 
@@ -21,7 +22,7 @@ abstract class AbstractServerConfigFragment extends AbstractFragment {
       return;
     }
 
-    hostname = args.getString("hostname");
+    hostname = args.getString(LoginActivity.KEY_HOSTNAME);
     if (TextUtils.isEmpty(hostname)) {
       finish();
       return;

app/src/main/java/chat/rocket/android/fragment/sidebar/SidebarMainFragment.java

@@ -179,11 +179,11 @@ public class SidebarMainFragment extends AbstractFragment {
 
   private void setupAddChannelButton() {
     rootView.findViewById(R.id.btn_add_channel).setOnClickListener(view -> {
-      showAddRoomDialog(new AddChannelDialogFragment());
+      showAddRoomDialog(AddChannelDialogFragment.create(hostname));
     });
 
     rootView.findViewById(R.id.btn_add_direct_message).setOnClickListener(view -> {
-      showAddRoomDialog(new AddDirectMessageDialogFragment());
+      showAddRoomDialog(AddDirectMessageDialogFragment.create(hostname));
     });
   }
 
@@ -193,9 +193,6 @@ public class SidebarMainFragment extends AbstractFragment {
   }
 
   private void showAddRoomDialog(DialogFragment dialog) {
-    Bundle args = new Bundle();
-    args.putString("hostname", hostname);
-    dialog.setArguments(args);
     dialog.show(getFragmentManager(), AbstractAddRoomDialogFragment.class.getSimpleName());
   }
 

app/src/main/java/chat/rocket/android/fragment/sidebar/dialog/AbstractAddRoomDialogFragment.java

@@ -21,9 +21,7 @@ public abstract class AbstractAddRoomDialogFragment extends RxAppCompatDialogFra
   protected MethodCallHelper methodCall;
   protected String hostname;
 
-  protected
-  @LayoutRes
-  abstract int getLayout();
+  protected @LayoutRes abstract int getLayout();
 
   protected abstract void onSetupDialog();
 

app/src/main/java/chat/rocket/android/fragment/sidebar/dialog/AddChannelDialogFragment.java

 package chat.rocket.android.fragment.sidebar.dialog;
 
+import android.os.Bundle;
 import android.view.View;
 import android.widget.CompoundButton;
 import android.widget.TextView;
@@ -17,6 +18,15 @@ public class AddChannelDialogFragment extends AbstractAddRoomDialogFragment {
   public AddChannelDialogFragment() {
   }
 
+  public static AddChannelDialogFragment create(String hostname) {
+    Bundle args = new Bundle();
+    args.putString("hostname", hostname);
+
+    AddChannelDialogFragment fragment = new AddChannelDialogFragment();
+    fragment.setArguments(args);
+    return fragment;
+  }
+
   @Override
   protected int getLayout() {
     return R.layout.dialog_add_channel;

app/src/main/java/chat/rocket/android/fragment/sidebar/dialog/AddDirectMessageDialogFragment.java

 package chat.rocket.android.fragment.sidebar.dialog;
 
+import android.os.Bundle;
 import android.view.View;
 import android.widget.AutoCompleteTextView;
 import android.widget.TextView;
@@ -18,7 +19,13 @@ import chat.rocket.android.realm_helper.RealmAutoCompleteAdapter;
  * add Direct Message.
  */
 public class AddDirectMessageDialogFragment extends AbstractAddRoomDialogFragment {
-  public AddDirectMessageDialogFragment() {
+  public static AddDirectMessageDialogFragment create(String hostname) {
+    Bundle args = new Bundle();
+    args.putString("hostname", hostname);
+
+    AddDirectMessageDialogFragment fragment = new AddDirectMessageDialogFragment();
+    fragment.setArguments(args);
+    return fragment;
   }
 
   @Override