src/main/java/eu/siacs/conversations/ui/ContactDetailsActivity.java

@@ -504,7 +504,7 @@ public class ContactDetailsActivity extends OmemoActivity implements OnAccountUp
                     && contact.getLastseen() > 0
                     && contact.getPresences().allOrNonSupport(Namespace.IDLE)) {
                 binding.detailsLastseen.setVisibility(View.VISIBLE);
-                binding.detailsLastseen.setText(UIHelper.lastseen(getApplicationContext(), contact.isActive(), contact.getLastseen()));
+                binding.detailsLastseen.setText(UIHelper.lastseen(getApplicationContext(), contact.isActive(), contact.getLastseen(), false));
             } else {
                 binding.detailsLastseen.setVisibility(View.GONE);
             }

src/main/java/eu/siacs/conversations/ui/ConversationsActivity.java

@@ -42,10 +42,14 @@ import android.app.FragmentTransaction;
 import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.Intent;
+import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.Handler;
+import android.os.Looper;
+import android.preference.PreferenceManager;
 import android.provider.Settings;
 import android.util.Log;
 import android.view.KeyEvent;
@@ -95,7 +99,9 @@ import eu.siacs.conversations.ui.util.PendingItem;
 import eu.siacs.conversations.utils.ExceptionHelper;
 import eu.siacs.conversations.utils.PhoneNumberUtilWrapper;
 import eu.siacs.conversations.utils.SignupUtils;
+import eu.siacs.conversations.utils.UIHelper;
 import eu.siacs.conversations.utils.XmppUri;
+import eu.siacs.conversations.xml.Namespace;
 import eu.siacs.conversations.xmpp.Jid;
 import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 import io.michaelrocks.libphonenumber.android.NumberParseException;
@@ -135,6 +141,10 @@ public class ConversationsActivity extends XmppActivity implements OnConversatio
     private boolean mActivityPaused = true;
     private final AtomicBoolean mRedirectInProcess = new AtomicBoolean(false);
 
+    private final Handler handler = new Handler(Looper.getMainLooper());
+    private final Runnable refreshTitleRunnable = this::invalidateActionBarTitle;
+    private boolean showLastSeen = false;
+
     private static boolean isViewOrShareIntent(Intent i) {
         Log.d(Config.LOGTAG, "action: " + (i == null ? null : i.getAction()));
         return i != null && VIEW_AND_SHARE_ACTIONS.contains(i.getAction()) && i.hasExtra(EXTRA_CONVERSATION);
@@ -660,6 +670,8 @@ public class ConversationsActivity extends XmppActivity implements OnConversatio
             this.mSkipBackgroundBinding = false;
         }
         mRedirectInProcess.set(false);
+        final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
+        this.showLastSeen = preferences.getBoolean("last_activity", false);
 
         BottomNavigationView bottomNavigationView = findViewById(R.id.bottom_navigation);
         bottomNavigationView.setSelectedItemId(R.id.chats);
@@ -735,6 +747,7 @@ public class ConversationsActivity extends XmppActivity implements OnConversatio
         if (actionBar == null) {
             return;
         }
+
         final FragmentManager fragmentManager = getFragmentManager();
         final Fragment mainFragment = fragmentManager.findFragmentById(R.id.main_fragment);
         if (mainFragment instanceof ConversationFragment) {
@@ -750,10 +763,38 @@ public class ConversationsActivity extends XmppActivity implements OnConversatio
                         binding.toolbar,
                         (v) -> openConversationDetails(conversation)
                 );
+
+                if (conversation.getMode() == Conversation.MODE_MULTI && conversation.getNextCounterpart() == null) {
+                    int usersCount = conversation.getMucOptions().getUserCount();
+                    if (usersCount > 0) {
+                        actionBar.setSubtitle(getResources().getQuantityString(R.plurals.x_participants, conversation.getMucOptions().getUserCount(), conversation.getMucOptions().getUserCount()));
+                    } else {
+                        actionBar.setSubtitle("");
+                    }
+
+                    handler.postDelayed(refreshTitleRunnable, 5000L);
+                } else if (conversation.getMode() == Conversation.MODE_SINGLE) {
+                    Contact contact = conversation.getContact();
+                    if (showLastSeen
+                            && contact.getLastseen() > 0
+                            && contact.getPresences().allOrNonSupport(Namespace.IDLE)) {
+                        actionBar.setSubtitle(UIHelper.lastseen(getApplicationContext(), contact.isActive(), contact.getLastseen(), true));
+                    } else {
+                        actionBar.setSubtitle("");
+                        handler.removeCallbacks(refreshTitleRunnable);
+                    }
+                } else {
+                    actionBar.setSubtitle("");
+                    handler.removeCallbacks(refreshTitleRunnable);
+                }
+
                 return;
             }
         }
+
+        handler.removeCallbacks(refreshTitleRunnable);
         actionBar.setTitle(R.string.app_name);
+        actionBar.setSubtitle("");
         actionBar.setDisplayHomeAsUpEnabled(false);
         ActionBarUtil.resetActionBarOnClickListeners(binding.toolbar);
     }

src/main/java/eu/siacs/conversations/utils/UIHelper.java

@@ -205,26 +205,60 @@ public class UIHelper {
                 .get(Calendar.DAY_OF_YEAR);
     }
 
-    public static String lastseen(Context context, boolean active, long time) {
+    public static String lastseen(Context context, boolean active, long time, boolean shortText) {
         long difference = (System.currentTimeMillis() - time) / 1000;
         if (active) {
-            return context.getString(R.string.online_right_now);
+            if (shortText) {
+                return context.getString(R.string.online_right_now_short);
+            } else {
+                return context.getString(R.string.online_right_now);
+            }
         } else if (difference < 60) {
-            return context.getString(R.string.last_seen_now);
+            if (shortText) {
+                return context.getString(R.string.last_seen_now_short);
+            } else {
+                return context.getString(R.string.last_seen_now);
+            }
         } else if (difference < 60 * 2) {
-            return context.getString(R.string.last_seen_min);
+            if (shortText) {
+                return context.getString(R.string.last_seen_min_short);
+            } else {
+                return context.getString(R.string.last_seen_min);
+            }
         } else if (difference < 60 * 60) {
-            return context.getString(R.string.last_seen_mins, Math.round(difference / 60.0));
+            if (shortText) {
+                return context.getString(R.string.last_seen_mins_short, Math.round(difference / 60.0));
+            } else {
+                return context.getString(R.string.last_seen_mins, Math.round(difference / 60.0));
+            }
         } else if (difference < 60 * 60 * 2) {
-            return context.getString(R.string.last_seen_hour);
+            if (shortText) {
+                return context.getString(R.string.last_seen_hour_short);
+            } else {
+                return context.getString(R.string.last_seen_hour);
+            }
         } else if (difference < 60 * 60 * 24) {
-            return context.getString(R.string.last_seen_hours,
+            if (shortText) {
-                    Math.round(difference / (60.0 * 60.0)));
+                return context.getString(R.string.last_seen_hours_short,
+                        Math.round(difference / (60.0 * 60.0)));
+            } else {
+                return context.getString(R.string.last_seen_hours,
+                        Math.round(difference / (60.0 * 60.0)));
+            }
         } else if (difference < 60 * 60 * 48) {
-            return context.getString(R.string.last_seen_day);
+            if (shortText) {
+                return context.getString(R.string.last_seen_day_short);
+            } else {
+                return context.getString(R.string.last_seen_day);
+            }
         } else {
-            return context.getString(R.string.last_seen_days,
+            if (shortText) {
-                    Math.round(difference / (60.0 * 60.0 * 24.0)));
+                return context.getString(R.string.last_seen_days_short,
+                        Math.round(difference / (60.0 * 60.0 * 24.0)));
+            } else {
+                return context.getString(R.string.last_seen_days,
+                        Math.round(difference / (60.0 * 60.0 * 24.0)));
+            }
         }
     }
 

src/main/res/values/strings.xml

@@ -1108,6 +1108,19 @@
     <string name="avater_shape_rounded_square">Rounded Square</string>
     <string name="avater_shape_square">Square</string>
 
+    <plurals name="x_participants">
+        <item quantity="one">%1$d participant</item>
+        <item quantity="other">%1$d participants</item>
+    </plurals>
+
+    <string name="online_right_now_short">online</string>
+    <string name="last_seen_now_short">just now</string>
+    <string name="last_seen_min_short">one minute ago</string>
+    <string name="last_seen_mins_short">%d minutes ago</string>
+    <string name="last_seen_hour_short">one hour ago</string>
+    <string name="last_seen_hours_short">%d hours ago</string>
+    <string name="last_seen_day_short">one day ago</string>
+    <string name="last_seen_days_short">%d days ago</string>
 
     <string name="clarendon" translatable="false">Clarendon</string>
     <string name="oldman" translatable="false">OldMan</string>