refactor(ui-core): move ping state into PingEngine

Single in-flight ping + last result move from UITask to
ui-core/PingEngine.h; MyMesh's ping callback routes to the engine
instead of casting the Listener back to UITask. UITask keeps thin
wrappers (and the "not supported" alert), NearbyScreen is unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

examples/companion_radio/ui-core/PingEngine.h

@@ -0,0 +1,76 @@
+#pragma once
+// Ping engine: one on-device ping in flight at a time (MyMesh::sendPing), its
+// result (RTT + SNR both ways) kept after the in-flight slot is released so the
+// view can keep showing it. The reply arrives through MyMesh's ping callback,
+// which is a plain function pointer -- routed here via a single static instance.
+//
+// The ping timeout is still decided by the view (NearbyScreen's
+// PING_TIMEOUT_MS), which calls clear() when it gives up.
+
+class PingEngine {
+public:
+  enum StartResult : uint8_t { STARTED = 0, BUSY, UNSUPPORTED, SEND_FAILED };
+
+  void begin(NodePrefs* prefs) { _prefs = prefs; s_instance = this; }
+
+  StartResult start(const uint8_t* pub_key) {
+    if (_active || !pub_key) return BUSY;
+    if (_prefs && _prefs->path_hash_mode > 1) return UNSUPPORTED;   // no 3-byte path hash support
+
+    _active = true;
+    _tag = 0;
+    _snr_out_x4 = 0;
+    _snr_back_x4 = 0;
+    _rtt_ms = 0;
+
+    // Always install the callback before sending so the response cannot race it.
+    the_mesh.setPingCallback(onPingResult, NULL);
+    _tag = the_mesh.sendPing(pub_key, _prefs ? _prefs->path_hash_mode + 1 : 1);
+    if (_tag == 0) {
+      clear();
+      return SEND_FAILED;
+    }
+    return STARTED;
+  }
+
+  // Release the in-flight slot (result values are kept).
+  void clear() {
+    if (_tag != 0) the_mesh.clearPingResult(_tag);
+    _active = false;
+    _tag = 0;
+  }
+
+  bool isActive() const { return _active; }
+  void getResult(int16_t& snr_out_x4, int16_t& snr_back_x4, uint32_t& rtt_ms) const {
+    snr_out_x4 = _snr_out_x4;
+    snr_back_x4 = _snr_back_x4;
+    rtt_ms = _rtt_ms;
+  }
+
+private:
+  void handleResult(uint32_t tag, int16_t snr_out_x4, int16_t snr_back_x4, uint32_t rtt_ms) {
+    if (_active && _tag == tag) {
+      _snr_out_x4 = snr_out_x4;
+      _snr_back_x4 = snr_back_x4;
+      _rtt_ms = rtt_ms;
+      // Release the in-flight slot immediately; the view keeps the result values.
+      clear();
+    }
+  }
+
+  static void onPingResult(uint32_t tag, int16_t snr_out_x4, int16_t snr_back_x4, uint32_t rtt_ms) {
+    if (s_instance) s_instance->handleResult(tag, snr_out_x4, snr_back_x4, rtt_ms);
+  }
+
+  static PingEngine* s_instance;
+
+  NodePrefs* _prefs = nullptr;
+  bool     _active = false;
+  uint32_t _tag = 0;
+  int16_t  _snr_out_x4 = 0;
+  int16_t  _snr_back_x4 = 0;
+  uint32_t _rtt_ms = 0;
+};
+
+// Header-only Core, single TU (see UiCore.h) -- the one definition lives here.
+PingEngine* PingEngine::s_instance = nullptr;

examples/companion_radio/ui-core/UiCore.h

@@ -11,11 +11,13 @@
 #include "DmUnreadTable.h"
 #include "UiEvents.h"
 #include "ClockEngine.h"
+#include "PingEngine.h"
 
 class UiCore {
 public:
   void begin(NodePrefs* prefs) {
     clock.begin(prefs, &events);
+    ping.begin(prefs);
   }
 
   // Driven from the frontend's loop(), before it drains `events`.
@@ -27,6 +29,7 @@ public:
 
   // ── Engines ───────────────────────────────────────────────────────────────
   ClockEngine clock;        // alarm / countdown / ring
+  PingEngine  ping;         // single in-flight ping + last result
 
   // ── Models ────────────────────────────────────────────────────────────────
   MessageHistory history;   // channel + DM rings, delivery state, channel unread

examples/companion_radio/ui-new/UITask.cpp

@@ -1646,14 +1646,6 @@ void UITask::begin(DisplayDriver* display, SensorManager* sensors, NodePrefs* no
     }
   }
 
-  // Initialize ping state
-  _ping_active = false;
-  _ping_tag = 0;
-  _ping_sent_ms = 0;
-  _ping_snr_out_x4 = 0;
-  _ping_snr_back_x4 = 0;
-  _ping_rtt_ms = 0;
-
   _core = new UiCore();   // before any screen -- MessagesScreen binds to its history
   _core->begin(node_prefs);
   splash = new SplashScreen(this);
@@ -1775,57 +1767,16 @@ void UITask::gotoMapScreen() {
 void UITask::gotoLocatorScreen()    { setCurrScreen(locator_screen); }
 void UITask::gotoAutoAdvertScreen() { setCurrScreen(auto_advert_screen); }
 
-// Public method to handle ping result callback
-void UITask::handlePingResult(uint32_t tag, int16_t snr_out_x4, int16_t snr_back_x4, uint32_t rtt_ms) {
-  if (_ping_active && _ping_tag == tag) {
-    _ping_snr_out_x4 = snr_out_x4;
-    _ping_snr_back_x4 = snr_back_x4;
-    _ping_rtt_ms = rtt_ms;
-    // Release the in-flight slot immediately; the UI keeps the result values.
-    clearPing();
-  }
-}
-
-// Static ping callback (for MyMesh)
-static void onPingResult(uint32_t tag, int16_t snr_out_x4, int16_t snr_back_x4, uint32_t rtt_ms) {
-  MyMesh::Listener* ui = the_mesh.getListener();
-  if (ui) {
-    UITask* task = static_cast<UITask*>(ui);
-    task->handlePingResult(tag, snr_out_x4, snr_back_x4, rtt_ms);
-  }
-}
-
-void UITask::clearPing() {
-  if (_ping_tag != 0) {
-    the_mesh.clearPingResult(_ping_tag);
-  }
-  _ping_active = false;
-  _ping_tag = 0;
-}
-
 bool UITask::startPing(const uint8_t* pub_key) {
-  if (_ping_active || !pub_key) return false;
-  if (_node_prefs && _node_prefs->path_hash_mode > 1) {
-    showAlert("Ping not supported with 3-byte path hashes", 3000);
-    return false;
-  }
-
-  _ping_active = true;
-  _ping_tag = 0;
-  _ping_sent_ms = millis();
-  _ping_snr_out_x4 = 0;
-  _ping_snr_back_x4 = 0;
-  _ping_rtt_ms = 0;
-
-  // Always install the callback before sending so the response cannot race it.
-  the_mesh.setPingCallback(onPingResult, NULL);
-  _ping_tag = the_mesh.sendPing(pub_key, _node_prefs ? _node_prefs->path_hash_mode + 1 : 1);
-  if (_ping_tag == 0) {
-    clearPing();
-    return false;
-  }
-  return true;
+  PingEngine::StartResult r = _core->ping.start(pub_key);
+  if (r == PingEngine::UNSUPPORTED) showAlert("Ping not supported with 3-byte path hashes", 3000);
+  return r == PingEngine::STARTED;
 }
+bool UITask::isPingActive() const { return _core->ping.isActive(); }
+void UITask::getPingResult(int16_t& snr_out_x4, int16_t& snr_back_x4, uint32_t& rtt_ms) const {
+  _core->ping.getResult(snr_out_x4, snr_back_x4, rtt_ms);
+}
+void UITask::clearPing() { _core->ping.clear(); }
 
 void UITask::playMelody(const char* melody) {
 #ifdef PIN_BUZZER

examples/companion_radio/ui-new/UITask.h

@@ -168,13 +168,6 @@ class UITask : public AbstractUITask {
   uint32_t _next_cog_sample_ms = 0;
   void pushCogFix(int32_t lat, int32_t lon);
 
-  // Ping state
-  bool _ping_active = false;
-  uint32_t _ping_tag = 0;
-  unsigned long _ping_sent_ms = 0;
-  int16_t _ping_snr_out_x4 = 0;
-  int16_t _ping_snr_back_x4 = 0;
-  uint32_t _ping_rtt_ms = 0;
 
   void userLedHandler();
 
@@ -447,16 +440,11 @@ public:
   bool hasDisplay() const { return _display != NULL; }
   DisplayDriver* getDisplay() const { return _display; }
 
-  // Ping helpers
+  // Ping helpers (engine in ui-core/PingEngine.h)
   bool startPing(const uint8_t* pub_key);
-  bool isPingActive() const { return _ping_active; }
-  void getPingResult(int16_t& snr_out_x4, int16_t& snr_back_x4, uint32_t& rtt_ms) const {
-    snr_out_x4 = _ping_snr_out_x4;
-    snr_back_x4 = _ping_snr_back_x4;
-    rtt_ms = _ping_rtt_ms;
-  }
+  bool isPingActive() const;
+  void getPingResult(int16_t& snr_out_x4, int16_t& snr_back_x4, uint32_t& rtt_ms) const;
   void clearPing();
-  void handlePingResult(uint32_t tag, int16_t snr_out_x4, int16_t snr_back_x4, uint32_t rtt_ms);
 
   // Favourites dial helpers. Slot index 0..FAVOURITES_COUNT-1. A slot holds
   // either a contact/room (pubkey prefix) or a channel (index), per