Patch sumbitted by Linus Wallgren. This patch includes two methods allowing other bundles than the gui to obtain existing chats and the contact corresponding to a chat. Thanks Linus!

src/net/java/sip/communicator/impl/gui/UIServiceImpl.java

@@ -1137,4 +1137,39 @@ public boolean dispatchKeyEvent(KeyEvent e)
             return false;
         }
     }
+
+    /**
+     * Returns a list containing all open Chats
+     *
+     * @return  A list of all open Chats.
+     */
+    public List<Chat> getChats()
+    {
+        List<Chat> chats = new ArrayList<Chat>();
+        for (ChatPanel chat : chatWindowManager.getChatPanels())
+        {
+            chats.add(chat);
+        }
+        return chats;
+    }
+
+    /**
+     * Get the MetaContact corresponding to the chat.
+     * The chat must correspond to a one on one conversation, otherwise this
+     * method will return null.
+     *
+     * @param chat  The chat to get the MetaContact from
+     * @return      The MetaContact corresponding to the chat or null in case
+     *              it is a chat with more then one person.
+     */
+    public MetaContact getChatContact(Chat chat)
+    {
+        Object contact = ((ChatPanel) chat).getChatSession().getDescriptor();
+        // If it is a one on one conversation this would be a MetaContact
+        if (contact instanceof MetaContact)
+            return (MetaContact) contact;
+        // If not, we are talking to more then one person and we return null
+        else
+            return null;
+    }
 }

src/net/java/sip/communicator/impl/gui/main/chat/ChatWindowManager.java

@@ -542,6 +542,16 @@ public ChatPanel getMultiChat(  ChatRoom chatRoom,
         }
     }
 
+    /**
+     * Returns all open ChatPanel´s
+     *
+     * @return  A list of ChatPanels
+     */
+    public List<ChatPanel> getChatPanels()
+    {
+        return chatPanels;
+    }
+
     /**
      * Closes the selected chat tab or the window if there are no tabs.
      *

src/net/java/sip/communicator/service/gui/UIService.java

@@ -8,8 +8,10 @@
 
 import java.awt.*;
 import java.util.*;
+import java.util.List;
 
 import net.java.sip.communicator.service.protocol.*;
+import net.java.sip.communicator.service.contactlist.*;
 
 /**
  * The <tt>UIService</tt> offers generic access to the graphical user interface
@@ -211,6 +213,23 @@ public ExportedWindow getExportedWindow(WindowID windowID, Object[] params)
      */
     public Chat getChat(ChatRoom chatRoom);
 
+    /**
+     * Returns a list of all open Chats
+     *
+     * @return A list of all open Chats
+     */
+    public List<Chat> getChats();
+
+    /**
+     * Get the MetaContact corresponding to the chat.
+     * The chat must correspond to a one on one conversation. If it is a
+     * group chat an exception will be thrown.
+     *
+     * @param chat  The chat to get the MetaContact from
+     * @return      The MetaContact corresponding to the chat.
+     */
+    public MetaContact getChatContact(Chat chat);
+
     /**
      * Returns the selected <tt>Chat</tt>.
      *