Improve netplay setup dialog UX

* Focus "Hash Code" / "IP address" text box by default in "Connect"
* Focus game list in "Host" tab
* RETURN keypress now host/join depending on selected tab
* Remember last hosted game
* Remove PanicAlertT:
	* Simply log message to netplay window
	* Remove them when they are useless
* Show some netplay message in OSD
	* Chat messages
	* Pad buffer changes
	* Desync alerts
* Stop the game consistently when another player disconnects / crashes
* Prettify chat textbox
* Log netplay ping to OSD

Join scenario:
* Copy netplay code
* Open netplay
* Paste code
* Press enter

Host scenario:
* Open netplay
* Go to host tab
* Press enter

Source/Core/Core/NetPlayClient.cpp

@@ -27,6 +27,8 @@
 #include "Core/Movie.h"
 #include "Core/NetPlayClient.h"
 #include "InputCommon/GCAdapter.h"
+#include "VideoCommon/OnScreenDisplay.h"
+#include "VideoCommon/VideoConfig.h"
 
 static std::mutex crit_netplay_client;
 static NetPlayClient* netplay_client = nullptr;
@@ -351,6 +353,7 @@ unsigned int NetPlayClient::OnData(sf::Packet& packet)
     packet >> size;
 
     m_target_buffer_size = size;
+    m_dialog->OnPadBufferChanged(size);
   }
   break;
 
@@ -428,17 +431,10 @@ unsigned int NetPlayClient::OnData(sf::Packet& packet)
   break;
 
   case NP_MSG_STOP_GAME:
-  {
-    m_dialog->OnMsgStopGame();
-  }
-  break;
-
   case NP_MSG_DISABLE_GAME:
   {
-    PanicAlertT("Other client disconnected while game is running!! NetPlay is disabled. You must "
-                "manually stop the game.");
-    m_is_running.store(false);
-    NetPlay_Disable();
+    StopGame();
+    m_dialog->OnMsgStopGame();
   }
   break;
 
@@ -466,6 +462,7 @@ unsigned int NetPlayClient::OnData(sf::Packet& packet)
       packet >> player.ping;
     }
 
+    DisplayPlayersPing();
     m_dialog->Update();
   }
   break;
@@ -476,18 +473,15 @@ unsigned int NetPlayClient::OnData(sf::Packet& packet)
     u32 frame;
     packet >> pid_to_blame;
     packet >> frame;
-    const char* blame_str = "";
-    const char* blame_name = "";
+
+    std::string player = "??";
     std::lock_guard<std::recursive_mutex> lkp(m_crit.players);
-    if (pid_to_blame != -1)
     {
       auto it = m_players.find(pid_to_blame);
-      blame_str = " from player ";
-      blame_name = it != m_players.end() ? it->second.name.c_str() : "??";
+      if (it != m_players.end())
+        player = it->second.name;
     }
-
-    m_dialog->AppendChat(StringFromFormat("/!\\ Possible desync detected%s%s on frame %u",
-                                          blame_str, blame_name, frame));
+    m_dialog->OnDesync(frame, player);
   }
   break;
 
@@ -571,6 +565,24 @@ void NetPlayClient::Send(sf::Packet& packet)
   enet_peer_send(m_server, 0, epac);
 }
 
+void NetPlayClient::DisplayPlayersPing()
+{
+  if (!g_ActiveConfig.bShowNetPlayPing)
+    return;
+
+  OSD::AddTypedMessage(OSD::MessageType::NetPlayPing,
+                       StringFromFormat("Ping: %u", GetPlayersMaxPing()), OSD::Duration::SHORT,
+                       OSD::Color::CYAN);
+}
+
+u32 NetPlayClient::GetPlayersMaxPing() const
+{
+  return std::max_element(
+             m_players.begin(), m_players.end(),
+             [](const auto& a, const auto& b) { return a.second.ping < b.second.ping; })
+      ->second.ping;
+}
+
 void NetPlayClient::Disconnect()
 {
   ENetEvent netEvent;
@@ -636,13 +648,11 @@ void NetPlayClient::ThreadFunc()
         enet_packet_destroy(netEvent.packet);
         break;
       case ENET_EVENT_TYPE_DISCONNECT:
-        m_is_running.store(false);
-        NetPlay_Disable();
-        m_dialog->AppendChat("< LOST CONNECTION TO SERVER >");
-        PanicAlertT("Lost connection to server!");
-        m_do_loop.store(false);
+        m_dialog->OnConnectionLost();
+
+        if (m_is_running.load())
+          StopGame();
 
-        netEvent.peer->data = nullptr;
         break;
       default:
         break;
@@ -786,8 +796,6 @@ bool NetPlayClient::StartGame(const std::string& path)
     return false;
   }
 
-  m_dialog->AppendChat(" -- STARTING GAME -- ");
-
   m_timebase_frame = 0;
 
   m_is_running.store(true);
@@ -895,6 +903,7 @@ void NetPlayClient::OnTraversalStateChanged()
            m_traversal_client->m_State == TraversalClient::Failure)
   {
     Disconnect();
+    m_dialog->OnTraversalError(m_traversal_client->m_FailureReason);
   }
 }
 
@@ -1080,8 +1089,6 @@ bool NetPlayClient::StopGame()
     return false;
   }
 
-  m_dialog->AppendChat(" -- STOPPING GAME -- ");
-
   m_is_running.store(false);
   NetPlay_Disable();