feat(BaseUI): show 'GPS Time Only' when GNSS has time but no position fix (#11361)

The position frame's drawGpsCoordinates() only distinguished 'No GPS
present' / 'No GPS Lock' / coordinates, so a GNSS that had decoded
valid time but no fix displayed identically to a cold chip.

- GPSStatus: add per-acquisition hasTime flag (5th ctor param,
  accessor, matches() term, updateStatus() copy)
- GPS::runOnce(): publish immediately on the gotTime rising edge so
  the flag reaches observers on the time-only path, which previously
  never published; done directly rather than via the end-of-loop
  block so fixHoldEnds is preserved and hold/power behavior is
  unchanged. Safe without a location: PositionModule ignores invalid
  positions. gotTime is already cleared on each GPS_ACTIVE entry, so
  the state is not sticky across acquisitions.
- UIRenderer::drawGpsCoordinates(): the 'No GPS Lock' line becomes
  'GPS Time Only' when time is valid.

The drawGps() header renderer is intentionally untouched (its
branches need separate de-clobbering work).


Claude-Session: https://claude.ai/code/session_01CcrasD4QsatunDreANDgCx

Co-authored-by: Claude <noreply@anthropic.com>

src/GPSStatus.h

@@ -17,6 +17,7 @@ class GPSStatus : public Status
 
     bool hasLock = false;     // default to false, until we complete our first read
     bool isConnected = false; // Do we have a GPS we are talking to
+    bool hasTime = false;     // GPS has decoded a valid time this acquisition, even without a position fix
 
     bool isPowerSaving = false; // Are we in power saving state
 
@@ -29,11 +30,12 @@ class GPSStatus : public Status
     GPSStatus() { statusType = STATUS_TYPE_GPS; }
 
     // preferred method
-    GPSStatus(bool hasLock, bool isConnected, bool isPowerSaving, const meshtastic_Position &pos) : Status()
+    GPSStatus(bool hasLock, bool isConnected, bool isPowerSaving, const meshtastic_Position &pos, bool hasTime = false) : Status()
     {
         this->hasLock = hasLock;
         this->isConnected = isConnected;
         this->isPowerSaving = isPowerSaving;
+        this->hasTime = hasTime;
 
         // all-in-one struct copy
         this->p = pos;
@@ -50,6 +52,8 @@ class GPSStatus : public Status
 
     bool getIsPowerSaving() const { return isPowerSaving; }
 
+    bool getHasTime() const { return hasTime; }
+
     int32_t getLatitude() const
     {
         if (config.position.fixed_position) {
@@ -91,7 +95,7 @@ class GPSStatus : public Status
 #ifdef GPS_DEBUG
         LOG_DEBUG("GPSStatus.match() new pos@%x to old pos@%x", newStatus->p.timestamp, p.timestamp);
 #endif
-        return (newStatus->hasLock != hasLock || newStatus->isConnected != isConnected ||
+        return (newStatus->hasLock != hasLock || newStatus->isConnected != isConnected || newStatus->hasTime != hasTime ||
                 newStatus->isPowerSaving != isPowerSaving || newStatus->p.latitude_i != p.latitude_i ||
                 newStatus->p.longitude_i != p.longitude_i || newStatus->p.altitude != p.altitude ||
                 newStatus->p.altitude_hae != p.altitude_hae || newStatus->p.PDOP != p.PDOP ||
@@ -112,6 +116,7 @@ class GPSStatus : public Status
         initialized = true;
         hasLock = newStatus->hasLock;
         isConnected = newStatus->isConnected;
+        hasTime = newStatus->hasTime;
 
         p = newStatus->p;
 

src/gps/GPS.cpp

@@ -1446,7 +1446,7 @@ void GPS::publishUpdate()
         LOG_DEBUG("Publish pos@%x:2, hasVal=%d, Sats=%d, GPSlock=%d", p.timestamp, hasValidLocation, p.sats_in_view, hasLock());
 
         // Notify any status instances that are observing us
-        const meshtastic::GPSStatus status = meshtastic::GPSStatus(hasValidLocation, isConnected(), isPowerSaving(), p);
+        const meshtastic::GPSStatus status = meshtastic::GPSStatus(hasValidLocation, isConnected(), isPowerSaving(), p, gotTime);
         newStatus.notifyObservers(&status);
         if (config.position.gps_mode == meshtastic_Config_PositionConfig_GpsMode_ENABLED) {
             positionModule->handleNewPosition();
@@ -1502,7 +1502,7 @@ int32_t GPS::runOnce()
     // gps_update_interval is faster than the position broadcast interval so there's a
     // fresh position ready when the device wants to broadcast one on the mesh.
     //
-    // 1. Got a time for the first time --> set the time, don't publish.
+    // 1. Got a time for the first time --> set the time, publish so the UI can show the time-only state.
     // 2. Got a lock for the first time
     //   --> If gps_update_interval is <= 10s --> publishUpdate
     //   --> Otherwise, hold for MIN(gps_update_interval - GPS_UPDATE_ALWAYS_ON_THRESHOLD_MS, 20s)
@@ -1536,6 +1536,11 @@ int32_t GPS::runOnce()
         // 1. Got a time for the first time this cycle
         if (!gotTime && lookForTime()) { // Note: we count on this && short-circuiting and not resetting the RTC time
             gotTime = true;
+            // Publish immediately (rather than via the block below, which would clear fixHoldEnds) so the
+            // time-only state reaches the UI without waiting for a location. Safe without a valid location:
+            // PositionModule::handleNewPosition ignores invalid positions.
+            shouldPublish = true;
+            publishUpdate();
         }
 
         // 2. Got a lock for the first time, or 3. Got a lock after turning back on

src/graphics/draw/UIRenderer.cpp

@@ -582,7 +582,7 @@ void UIRenderer::drawGpsCoordinates(OLEDDisplay *display, int16_t x, int16_t y,
         }
     } else if (!gps->getHasLock() && !config.position.fixed_position) {
         if (strcmp(mode, "line1") == 0) {
-            strcpy(displayLine, "No GPS Lock");
+            strcpy(displayLine, gps->getHasTime() ? "GPS Time Only" : "No GPS Lock");
             display->drawString(x, y, displayLine);
         }
     } else {