feat: Add password input for screen unlock

docs/solo_features/screen_lock/screen_lock.md

@@ -63,3 +63,15 @@ Fully autonomous, independent of Auto-lock and of any key combo:
 
 - **Magnet near (cover closed)** — locks and blanks the display immediately, no wake grace.
 - **Magnet away (cover opened)** — unlocks and wakes the display right away.
+
+---
+
+### Lock-screen password
+
+Enable **LockPass** in **Settings › Display** to require a password when unlocking the device.  
+
+Upon enabling the setting the keyboard will show, requiring you to submit a new password.  
+Attempting to unlock the device will then require the same password to be typed and submitted to reach the home screen.  
+Submitting an incorrect password clears the keyboard input.
+
+Disabling the setting clears the stored password and allows an instant unlock again.

examples/companion_radio/ui-new/UITask.cpp

@@ -2212,6 +2212,73 @@ void UITask::syncLockToHome() {
   if (home) static_cast<HomeScreen*>(home)->setLocked(_locked);
 }
 
+bool UITask::passwordLockEnabled() const {
+  // Is lock_screen_password setting not empty?
+  return _node_prefs && _node_prefs->lock_screen_password[0] != '\0';
+}
+
+void UITask::beginUnlockPrompt() {
+  _unlock_kb = true; // Track that keyboard is visible and is waiting for input
+  int max_len = _node_prefs ? (int)sizeof(_node_prefs->lock_screen_password) - 1 : 32;
+  _kb.begin("", max_len);
+  _kb.clearPlaceholders();
+  _lock_wake_until = millis() + 5000; // keep the display on while typing
+  _next_refresh = 0;
+}
+
+void UITask::cancelUnlockPrompt() {
+  _unlock_kb = false;
+  _next_refresh = 100;
+}
+
+void UITask::handleUnlockKey(char c) {
+  auto res = _kb.handleInput(c);
+  if (res == KeyboardWidget::DONE) { // Process input on submit
+    if (_node_prefs && strcmp(_kb.buf, _node_prefs->lock_screen_password) == 0) {
+      // Match: Unlock
+      _unlock_kb = false;
+      _locked = false;
+      if (_display && !_display->isOn()) _display->turnOn();
+      uint32_t aoff = autoOffMillis();
+      if (aoff > 0) _auto_off = millis() + aoff;
+      syncLockToHome();
+    } else {
+      // Invalid: Clear input and reset keyboard
+      _kb.len = 0;
+      _kb.buf[0] = '\0';
+      _kb.cursor_pos = 0;
+      _kb.page = _kb.row = _kb.col = 0;
+      _kb.caps = _kb.caps_lock = false;
+      _next_refresh = 0;
+    }
+  } else if (res == KeyboardWidget::CANCELLED) {
+    cancelUnlockPrompt();
+  }
+  _lock_wake_until = millis() + 5000; // keep the display on while typing
+}
+
+void UITask::toggleLock() {
+  if (_unlock_kb) {
+    cancelUnlockPrompt();
+    return;
+  }
+  if (_locked) {
+    if (passwordLockEnabled()) { // Prompt for password
+      beginUnlockPrompt();
+    } else {                     // ...or unlock instantly
+      _locked = false;
+      if (_display && !_display->isOn()) _display->turnOn();
+      uint32_t aoff = autoOffMillis();
+      if (aoff > 0) _auto_off = millis() + aoff;
+    }
+  } else { // Device is currently unlocked -> lock it
+    _locked = true;
+    _lock_wake_until = millis() + 2000; // Briefly show lockscreen before blanking
+  }
+  syncLockToHome();
+  _next_refresh = 0;
+}
+
 bool UITask::savePrefsIfDirty(bool& dirty) {
   if (!dirty) return false;
   the_mesh.savePrefs();
@@ -2561,15 +2628,7 @@ void UITask::pollCardKB() {
     // two-key combo, so it doesn't need the physical combo's extra 3x
     // repetition to guard against accidental triggering.
     if (_display && !_display->isOn()) _display->turnOn();
-    _locked = !_locked;
+    toggleLock();
-    if (_locked) {
-      _lock_wake_until = millis() + 2000;
-    } else {
-      uint32_t aoff = autoOffMillis();
-      if (aoff > 0) _auto_off = millis() + aoff;
-    }
-    syncLockToHome();
-    _next_refresh = 0;
     return;
   } else if (raw >= 0x80 && raw <= 0xAF) {   // Fn+<letter> -- open its accent popup
     char base = CARDKB_FN_BASE[raw - 0x80];
@@ -2623,6 +2682,7 @@ void UITask::pollHallSensor() {
   _hall_magnet_present = present;
 
   if (present) {   // cover closed
+    cancelUnlockPrompt();   // a cover can't be over the password prompt
     _locked = true;
     syncLockToHome();
     _lock_wake_until = 0;
@@ -2663,15 +2723,7 @@ void UITask::loop() {
       if (_lock_seq_count >= 3) {
         _lock_seq_count = 0;
         _lock_seq_used = true;  // suppress Back release click
-        _locked = !_locked;
+        toggleLock();
-        if (_locked) {
-          _lock_wake_until = millis() + 2000;
-        } else {
-          if (_display && !_display->isOn()) _display->turnOn();
-          uint32_t aoff = autoOffMillis();
-          if (aoff > 0) _auto_off = millis() + aoff;
-        }
-        syncLockToHome();
       }
       // eat the Enter — don't pass to curr
     } else {
@@ -2864,7 +2916,12 @@ void UITask::loop() {
   }
 
   if (_kq_head != _kq_tail) {
-    if (!_locked && curr) {
+    if (_unlock_kb) {
+      // Lock-screen password keyboard: Consume every key press
+      char k;
+      while (dequeueKey(k)) handleUnlockKey(k);
+      _next_refresh = 100;  // redraw immediately after key press
+    } else if (!_locked && curr) {
       // Apply the whole queued burst, then redraw once — N taps captured during
       // a blocking refresh become N navigation steps at the cost of one refresh.
       char k;
@@ -2901,8 +2958,22 @@ void UITask::loop() {
   tickClockTools();
 
   if (_display != NULL && _display->isOn()) {
-    if (_locked && (int32_t)(millis() - _lock_wake_until) >= 0) {
+    // Lock-screen password prompt
+    if (_locked && _unlock_kb && (int32_t)(millis() - _lock_wake_until) >= 0) {
+      cancelUnlockPrompt(); // Cancel unlock attempt on idle
+      _next_refresh = 0;
+    }
+    if (_locked && !_unlock_kb && (int32_t)(millis() - _lock_wake_until) >= 0) {
       _display->turnOff();
+    } else if (_locked && _unlock_kb && millis() >= _next_refresh) {
+      // While the prompt is up the password keyboard replaces the lockscreen view
+      _display->startFrame();
+      _kb.beginFrame();
+      int delay_millis = _kb.render(*_display);
+      // Alert overlay on top // TODO: Is this necessary here?
+      // if (millis() < _alert_expiry) renderAlertOverlay();
+      _display->endFrame();
+      _next_refresh = millis() + delay_millis;
     } else if (_locked && millis() >= _next_refresh && home) {
       _display->startFrame();
       home->render(*_display);
@@ -2950,6 +3021,7 @@ void UITask::loop() {
       digitalWrite(PIN_LED, LOW);  // turn off status LED with display to save power
 #endif
       if (_node_prefs && _node_prefs->auto_lock) {
+        cancelUnlockPrompt();   // idle-lock isn't a password prompt
         _locked = true;
         _lock_wake_until = 0;
         syncLockToHome();

examples/companion_radio/ui-new/UITask.h

@@ -58,6 +58,8 @@ class UITask : public AbstractUITask {
   int  _lock_seq_count;            // Enter presses while Back held (lock/unlock sequence)
   unsigned long _lock_seq_ms;      // millis() of last lock-sequence press (for timeout)
   bool _lock_seq_used;             // true = suppress next back_btn CLICK (post-sequence release)
+  // True while the lock screen shows the on-screen keyboard and waits for submission
+  bool _unlock_kb = false;
   char _alert[80];
   char _notif_mel_buf[220];  // persistent RTTTL buffer for custom notification melodies
   // Persistent RTTTL buffer for the bot !buzz command (see botBuzz()) -- sized
@@ -288,6 +290,15 @@ private:
   // dedicated lock-screen code path in loop().
   void syncLockToHome();
 
+  // Whether a lockscreen password is set
+  bool passwordLockEnabled() const;
+  // Handles (un)locking and requesting password input when one is set
+  void toggleLock();
+  void beginUnlockPrompt();
+  void cancelUnlockPrompt();
+  // Handles shortcuts during lockscreen password input
+  void handleUnlockKey(char c);
+
   // Centred alert overlay (the showAlert() box). Wraps long text to up to
   // three lines inside the box instead of letting it overflow the border.
   // Shared by the normal render path and the lock screen (so a ringing
@@ -566,7 +577,7 @@ public:
 #endif
   }
 
-  bool isBuzzerQuiet() { 
+  bool isBuzzerQuiet() {
 #ifdef PIN_BUZZER
     return buzzer.isQuiet();
 #else