add receiving of "typing" signaling messages

Signed-off-by: Marcel Hibbe <dev@mhibbe.de>

app/src/main/java/com/nextcloud/talk/chat/ChatActivity.kt

@@ -311,6 +311,24 @@ class ChatActivity :
         }
     }
 
+    private val conversationMessageListener = object : SignalingMessageReceiver.ConversationMessageListener {
+        override fun onStartTyping(session: String?) {
+            val name = webSocketInstance?.getDisplayNameForSession(session)
+
+            runOnUiThread {
+                Toast.makeText(this@ChatActivity, name + " started typing", Toast.LENGTH_SHORT).show()
+            }
+        }
+
+        override fun onStopTyping(session: String?) {
+            val name = webSocketInstance?.getDisplayNameForSession(session)
+
+            runOnUiThread {
+                Toast.makeText(this@ChatActivity, name + " stopped typing", Toast.LENGTH_SHORT).show()
+            }
+        }
+    }
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         NextcloudTalkApplication.sharedApplication!!.componentApplication.inject(this)
@@ -398,6 +416,7 @@ class ChatActivity :
 
         setupWebsocket()
         webSocketInstance?.getSignalingMessageReceiver()?.addListener(localParticipantMessageListener)
+        webSocketInstance?.getSignalingMessageReceiver()?.addListener(conversationMessageListener)
 
         if (conversationUser?.userId != "?" &&
             CapabilitiesUtilNew.hasSpreedFeatureCapability(conversationUser, "mention-flag")
@@ -1980,6 +1999,7 @@ class ChatActivity :
         eventBus.unregister(this)
 
         webSocketInstance?.getSignalingMessageReceiver()?.removeListener(localParticipantMessageListener)
+        webSocketInstance?.getSignalingMessageReceiver()?.removeListener(conversationMessageListener)
 
         findViewById<View>(R.id.toolbar)?.setOnClickListener(null)
 

app/src/main/java/com/nextcloud/talk/signaling/ConversationMessageNotifier.java

@@ -0,0 +1,54 @@
+/*
+ * Nextcloud Talk application
+ *
+ * @author Marcel Hibbe
+ * Copyright (C) 2023 Marcel Hibbe <dev@mhibbe.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.nextcloud.talk.signaling;
+
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+
+class ConversationMessageNotifier {
+
+    private final Set<SignalingMessageReceiver.ConversationMessageListener> conversationMessageListeners = new LinkedHashSet<>();
+
+    public synchronized void addListener(SignalingMessageReceiver.ConversationMessageListener listener) {
+        if (listener == null) {
+            throw new IllegalArgumentException("conversationMessageListener can not be null");
+        }
+
+        conversationMessageListeners.add(listener);
+    }
+
+    public synchronized void removeListener(SignalingMessageReceiver.ConversationMessageListener listener) {
+        conversationMessageListeners.remove(listener);
+    }
+
+    public synchronized void notifyStartTyping(String sessionId) {
+        for (SignalingMessageReceiver.ConversationMessageListener listener : new ArrayList<>(conversationMessageListeners)) {
+            listener.onStartTyping(sessionId);
+        }
+    }
+
+    public void notifyStopTyping(String sessionId) {
+        for (SignalingMessageReceiver.ConversationMessageListener listener : new ArrayList<>(conversationMessageListeners)) {
+            listener.onStopTyping(sessionId);
+        }
+    }
+}

app/src/main/java/com/nextcloud/talk/signaling/SignalingMessageReceiver.java

@@ -153,6 +153,14 @@ public abstract class SignalingMessageReceiver {
         void onUnshareScreen();
     }
 
+    /**
+     * Listener for conversation messages.
+     */
+    public interface ConversationMessageListener {
+        void onStartTyping(String session);
+        void onStopTyping(String session);
+    }
+
     /**
      * Listener for WebRTC offers.
      *
@@ -185,6 +193,8 @@ public abstract class SignalingMessageReceiver {
 
     private final CallParticipantMessageNotifier callParticipantMessageNotifier = new CallParticipantMessageNotifier();
 
+    private final ConversationMessageNotifier conversationMessageNotifier = new ConversationMessageNotifier();
+
     private final OfferMessageNotifier offerMessageNotifier = new OfferMessageNotifier();
 
     private final WebRtcMessageNotifier webRtcMessageNotifier = new WebRtcMessageNotifier();
@@ -236,6 +246,14 @@ public abstract class SignalingMessageReceiver {
         callParticipantMessageNotifier.removeListener(listener);
     }
 
+    public void addListener(ConversationMessageListener listener) {
+        conversationMessageNotifier.addListener(listener);
+    }
+
+    public void removeListener(ConversationMessageListener listener) {
+        conversationMessageNotifier.removeListener(listener);
+    }
+
     /**
      * Adds a listener for all offer messages.
      *
@@ -563,6 +581,14 @@ public abstract class SignalingMessageReceiver {
             return;
         }
 
+        if ("startedTyping".equals(type)) {
+            conversationMessageNotifier.notifyStartTyping(sessionId);
+        }
+
+        if ("stoppedTyping".equals(type)) {
+            conversationMessageNotifier.notifyStopTyping(sessionId);
+        }
+
         if ("reaction".equals(type)) {
             // Message schema (external signaling server):
             // {