Light the screen (dimmed) while a Notification's Toast shows

An Off screen turns on dimmed for the Toast's duration so the user can
see what beeped. It isn't user activity: the timeouts aren't restarted,
and a key pressed meanwhile reaches the App.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

lib/services/src/power_policy.cpp

@@ -12,6 +12,12 @@ bool PowerPolicy::activity(uint32_t nowMs) {
 ScreenState PowerPolicy::update(uint32_t nowMs) {
     uint32_t idle = nowMs - lastActivityMs_;
     state_ = idle >= offMs_ ? ScreenState::Off : idle >= dimMs_ ? ScreenState::Dimmed : ScreenState::On;
+    if (notifying_) {
+        if (static_cast<int32_t>(nowMs - notifyUntilMs_) >= 0)
+            notifying_ = false;
+        else if (state_ == ScreenState::Off)
+            state_ = ScreenState::Dimmed;
+    }
     return state_;
 }
 

lib/services/src/power_policy.h

@@ -19,6 +19,14 @@ class PowerPolicy {
     // Records a key press. Returns true if the key only woke an Off screen and must not reach the App.
     bool activity(uint32_t nowMs);
 
+    // A Notification is showing until untilMs: an Off screen lights up Dimmed meanwhile. It's not
+    // user activity, so it doesn't restart the timeouts.
+    void notify(uint32_t nowMs, uint32_t untilMs) {
+        (void)nowMs;
+        notifyUntilMs_ = untilMs;
+        notifying_ = true;
+    }
+
     ScreenState update(uint32_t nowMs);
     ScreenState state() const { return state_; }
 
@@ -26,6 +34,8 @@ class PowerPolicy {
     uint32_t dimMs_;
     uint32_t offMs_;
     uint32_t lastActivityMs_ = 0;
+    uint32_t notifyUntilMs_ = 0;
+    bool notifying_ = false;
     ScreenState state_ = ScreenState::On;
 };