Simplified multi-server roomId selection cache on multi-server

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

@@ -14,6 +14,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.UUID;
 
+import chat.rocket.android.helper.Logger;
 import chat.rocket.android.helper.TextUtils;
 import chat.rocket.android.log.RCLog;
 import chat.rocket.core.utils.Pair;
@@ -106,11 +107,33 @@ public class RocketChatCache {
   }
 
   public String getSelectedRoomId() {
-    return getString(getSelectedServerHostname() + KEY_SELECTED_ROOM_ID, null);
+    try {
+      JSONObject jsonObject = getSelectedRoomIdJsonObject();
+      return jsonObject.optString(getSelectedServerHostname(), null);
+    } catch (JSONException e) {
+      RCLog.e(e);
+      Logger.report(e);
+    }
+    return null;
   }
 
   public void setSelectedRoomId(String roomId) {
-    setString(getSelectedServerHostname() + KEY_SELECTED_ROOM_ID, roomId);
+    try {
+      JSONObject jsonObject = getSelectedRoomIdJsonObject();
+      jsonObject.put(getSelectedServerHostname(), roomId);
+      setString(KEY_SELECTED_ROOM_ID, jsonObject.toString());
+    } catch (JSONException e) {
+      RCLog.e(e);
+      Logger.report(e);
+    }
+  }
+
+  private JSONObject getSelectedRoomIdJsonObject() throws JSONException {
+    String json = getString(KEY_SELECTED_ROOM_ID, null);
+    if (json == null) {
+      return new JSONObject();
+    }
+    return new JSONObject(json);
   }
 
   public String getOrCreatePushId() {
@@ -131,7 +154,7 @@ public class RocketChatCache {
   }
 
   public Flowable<Optional<String>> getSelectedRoomIdPublisher() {
-    return getValuePublisher(getSelectedServerHostname() + KEY_SELECTED_ROOM_ID);
+    return getValuePublisher(KEY_SELECTED_ROOM_ID);
   }
 
   private SharedPreferences getSharedPreferences() {

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

@@ -6,6 +6,9 @@ import android.support.annotation.Nullable;
 
 import com.hadisatrio.optional.Optional;
 
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import java.util.List;
 
 import chat.rocket.android.LaunchUtil;
@@ -196,7 +199,8 @@ abstract class AbstractAuthedActivity extends AbstractFragmentActivity {
     compositeDisposable.add(
         rocketChatCache.getSelectedRoomIdPublisher()
             .map(Optional::get)
-            .distinctUntilChanged()
+            .map(this::convertStringToJsonObject)
+            .map(jsonObject -> jsonObject.optString(rocketChatCache.getSelectedServerHostname(), null))
             .subscribeOn(Schedulers.io())
             .observeOn(AndroidSchedulers.mainThread())
             .subscribe(
@@ -206,17 +210,10 @@ abstract class AbstractAuthedActivity extends AbstractFragmentActivity {
     );
   }
 
-  protected void subscribeToNewConfigChanges() {
-    compositeDisposable.add(
-            rocketChatCache.getSelectedRoomIdPublisher()
-                    .map(Optional::get)
-                    .distinctUntilChanged()
-                    .subscribeOn(Schedulers.io())
-                    .observeOn(AndroidSchedulers.mainThread())
-                    .subscribe(
-                            this::updateRoomIdIfNeeded,
-                            Logger::report
-                    )
-    );
+  private JSONObject convertStringToJsonObject(String json) throws JSONException {
+    if (json == null) {
+      return new JSONObject();
+    }
+    return new JSONObject(json);
   }
 }

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

@@ -203,10 +203,8 @@ public class MainActivity extends AbstractAuthedActivity implements MainContract
     if (sidebarFragment == null) {
       sidebarFragment = SidebarMainFragment.create(selectedServerHostname);
     }
-    subscribeToNewConfigChanges();
     getSupportFragmentManager().beginTransaction()
         .replace(R.id.sidebar_fragment_container, sidebarFragment, selectedServerHostname)
-        .addToBackStack(null)
         .commit();
     getSupportFragmentManager().executePendingTransactions();
   }
@@ -229,11 +227,7 @@ public class MainActivity extends AbstractAuthedActivity implements MainContract
 
   @Override
   public void showRoom(String hostname, String roomId) {
-    Fragment roomFragment = findFragmentByTag(roomId);
-    if (roomFragment == null) {
-      roomFragment = RoomFragment.create(hostname, roomId);
-    }
-    showFragmentWithTag(roomFragment, roomId);
+    showFragment(RoomFragment.create(hostname, roomId));
     closeSidebarIfNeeded();
     KeyboardHelper.hideSoftKeyboard(this);
   }