feat: flashlight - the whole screen white at full brightness

L2: a Flashlight app on Home (a lightbulb icon added to the fonts): a
white layer over everything, the backlight at 100 %, no auto-off; a tap,
the side or the top button puts it away and the brightness back.
L1: Tools > System > Flashlight, the whole OLED lit at full contrast
until a key. Not on e-ink.

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

examples/companion_radio/ui-new/FlashlightScreen.h

@@ -0,0 +1,26 @@
+#pragma once
+// Tools › Flashlight: the whole panel lit at full brightness, kept on (no
+// auto-off) until a key. Not on e-ink, which gives no light. Leaving it, by
+// a key or anything that changes the screen, puts the brightness back
+// (UITask::setCurrScreen).
+// Included by UITask.cpp.
+
+class FlashlightScreen : public UIScreen {
+  UITask* _task;
+
+public:
+  FlashlightScreen(UITask* task) : _task(task) {}
+
+  int render(DisplayDriver& display) override {
+    display.setBrightness(4);
+    display.setColor(DisplayDriver::LIGHT);
+    display.fillRect(0, 0, display.width(), display.height());
+    return 1000;
+  }
+
+  bool handleInput(char c) override {
+    (void)c;
+    _task->leaveTool();
+    return true;
+  }
+};

examples/companion_radio/ui-new/ToolsScreen.h

@@ -14,7 +14,7 @@ public:
   enum Action {
     ACT_NEARBY, ACT_LIVESHARE, ACT_TRAIL, ACT_LOCATOR, ACT_COMPASS,
     ACT_BOT, ACT_AUTOADVERT, ACT_REPEATER, ACT_ADMIN,
-    ACT_CLOCK, ACT_RINGTONE
+    ACT_CLOCK, ACT_RINGTONE, ACT_FLASHLIGHT
 #if defined(PIN_GPIO1)
     , ACT_GPIO
 #endif
@@ -51,6 +51,7 @@ public:
       case ACT_ADMIN:       task->pickAdminTarget();       break;  // Admin is remote-only: pick a node first
       case ACT_CLOCK:       task->gotoClockTools();        break;
       case ACT_RINGTONE:    task->gotoRingtoneEditor();    break;
+      case ACT_FLASHLIGHT:  task->gotoFlashlight();        break;
 #if defined(PIN_GPIO1)
       case ACT_GPIO:        task->gotoGpioScreen();        break;
 #endif
@@ -135,6 +136,9 @@ const ToolsScreen::Tool ToolsScreen::COMMS_TOOLS[] = {
 const ToolsScreen::Tool ToolsScreen::SYSTEM_TOOLS[] = {
   { "Clock Tools",     ACT_CLOCK },
   { "Ringtone Editor", ACT_RINGTONE },
+#if !defined(EINK_DISPLAY_MODEL)   // Features::IS_EINK: no light to give
+  { "Flashlight",      ACT_FLASHLIGHT },
+#endif
 #if defined(PIN_GPIO1)
   { "GPIO",            ACT_GPIO },
 #endif

examples/companion_radio/ui-new/UITask.cpp

@@ -105,6 +105,7 @@ static const telemetry::Style L1_INFO      = { "\xc2\xb0", true,  false, 5 };
 #if defined(PIN_GPIO1)
 #include "GpioScreen.h"
 #endif
+#include "FlashlightScreen.h"
 #include "ToolsScreen.h"
 #include "CalendarView.h"       // the month under a tall clock, Clock tools › Calendar
 #include "ClockToolsScreen.h"   // Alarm / Timer / Stopwatch / Calendar (Clock page › Enter)
@@ -226,6 +227,7 @@ void UITask::begin(DisplayDriver* display, SensorManager* sensors, NodePrefs* no
   status_screen      = new StatusScreen(this);
   repeater_screen    = new RepeaterScreen(this);
   clock_tools        = new ClockToolsScreen(this, node_prefs);
+  if (!Features::IS_EINK) flashlight = new FlashlightScreen(this);
 #if defined(PIN_GPIO1)
   gpio_screen        = new GpioScreen(this, node_prefs);
 #endif
@@ -273,6 +275,7 @@ void UITask::gotoStatusScreen(uint8_t tab) {
 }
 void UITask::gotoRepeaterScreen()  { setCurrScreen(repeater_screen); }
 void UITask::gotoClockTools()      { setCurrScreen(clock_tools); }
+void UITask::gotoFlashlight()      { setCurrScreen(flashlight); }
 void UITask::gotoGpioScreen() {
 #if defined(PIN_GPIO1)
   setCurrScreen(gpio_screen);
@@ -729,6 +732,7 @@ void UITask::setCurrScreen(UIScreen* c) {
   // begin()) stays nullptr thanks to the in-class initialisers. Bail here so
   // that mistake is an inert no-op instead of a null deref in render()/poll().
   if (!c) return;
+  if (flashlight && curr == flashlight && c != flashlight) applyBrightness();   // its full brightness goes with it
   curr = c;
   c->onShow();          // central per-visit reset hook (see UIScreen::onShow)
   _next_refresh = 0;
@@ -1440,6 +1444,10 @@ void UITask::loop() {
       _auto_off = millis() + AUTO_OFF_MILLIS;
     }
 #endif
+    if (flashlight && curr == flashlight) {   // a torch stays lit; after it, the usual timeout
+      uint32_t aoff = autoOffMillis();
+      _auto_off = millis() + (aoff > 0 ? aoff : AUTO_OFF_MILLIS);
+    }
     if (!_locked && autoOffMillis() > 0 && (int32_t)(millis() - _auto_off) >= 0 && !isRinging()) {
       _display->turnOff();
 #ifdef PIN_LED

examples/companion_radio/ui-new/UITask.h

@@ -131,6 +131,7 @@ class UITask : public UITaskBase, public UiCoreHost {
   UIScreen* status_screen = nullptr;   // Home › Status (radio, GPS, sky, power, mesh, system)
   UIScreen* repeater_screen = nullptr;
   UIScreen* clock_tools = nullptr;
+  UIScreen* flashlight = nullptr;   // not on e-ink (Features::IS_EINK)
 #if defined(PIN_GPIO1)
   UIScreen* gpio_screen = nullptr;
 #endif
@@ -386,6 +387,7 @@ public:
   void gotoRepeaterScreen();
   void gotoGpioScreen();   // no-op on boards without user GPIO pins (see PIN_GPIO1)
   void gotoClockTools();   // Alarm / Timer / Stopwatch (from the home Clock page)
+  void gotoFlashlight();
   // Wake the display for an alarm/timer ring (force an immediate refresh).
   void wakeForAlarm();
   // Clear any active alert overlay early (alarm dismiss).