sculpt: screensaver infrastructure

This patch enhances Sculpt with the ability to detect user inactivity
for driving a screensaver by combining nitpicker's hover and focus
reports with a timer.

Issue #4950

repos/gems/run/sculpt.run

@@ -273,6 +273,8 @@ install_config {
 			<policy label="runtime -> capslock" report="global_keys_handler -> capslock"/>
 			<policy label="drivers -> numlock"  report="global_keys_handler -> numlock"/>
 			<policy label="runtime -> clicked"  report="nitpicker -> clicked"/>
+			<policy label="leitzentrale -> manager -> nitpicker_focus" report="nitpicker -> focus"/>
+			<policy label="leitzentrale -> manager -> nitpicker_hover" report="nitpicker -> hover"/>
 			<policy label="nit_focus -> leitzentrale"
 			        report="global_keys_handler -> leitzentrale"/>
 			<policy label="nit_focus -> slides"
@@ -577,6 +579,8 @@ install_config {
 				<child name="config_fs_rom"/> </service>
 			<service name="ROM" label_prefix="config -> ">
 				<child name="config_fs_rom"/> </service>
+			<service name="ROM" label="manager -> nitpicker_focus">
+				<child name="report_rom"/> </service>
 			<service name="ROM" label="manager -> nitpicker_hover">
 				<child name="report_rom"/> </service>
 			<service name="ROM" label="manager -> leitzentrale">

repos/gems/sculpt/leitzentrale/default

@@ -254,6 +254,8 @@
 						<child name="config_fs_report" label="managed -> depot_query"/> </service>
 					<service name="Report"> <child name="report_rom"/> </service>
 					<service name="ROM" label_prefix="report ->"> <parent/> </service>
+					<service name="ROM" label="nitpicker_focus">  <parent/> </service>
+					<service name="ROM" label="nitpicker_hover">  <parent/> </service>
 					<service name="ROM" label_suffix="_hover">     <child name="report_rom"/> </service>
 					<service name="ROM" label="window_list">       <child name="report_rom"/> </service>
 					<service name="ROM" label="decorator_margins"> <child name="report_rom"/> </service>

repos/gems/src/app/sculpt_manager/main.cc

@@ -36,6 +36,7 @@
 #include <model/file_operation_queue.h>
 #include <model/settings.h>
 #include <model/presets.h>
+#include <model/screensaver.h>
 #include <view/download_status.h>
 #include <view/popup_dialog.h>
 #include <view/panel_dialog.h>
@@ -71,7 +72,8 @@ struct Sculpt::Main : Input_event_handler,
                       Panel_dialog::State,
                       Dialog,
                       Popup_dialog::Refresh,
-                      Menu_view::Hover_update_handler
+                      Menu_view::Hover_update_handler,
+                      Screensaver::Action
 {
 	Env &_env;
 
@@ -114,6 +116,16 @@ struct Sculpt::Main : Input_event_handler,
 
 	void _handle_gui_mode();
 
+	Screensaver _screensaver { _env, *this };
+
+	/**
+	 * Screensaver::Action interface
+	 */
+	void screensaver_changed() override
+	{
+		/* hook for driving the lifetime of the display driver */
+	}
+
 	Managed_config<Main> _fonts_config {
 		_env, "config", "fonts", *this, &Main::_handle_fonts_config };
 

repos/gems/src/app/sculpt_manager/model/screensaver.h

@@ -0,0 +1,140 @@
+/*
+ * \brief  Logic for activating/deactivating the screensaver
+ * \author Norman Feske
+ * \date   2023-06-27
+ */
+
+/*
+ * Copyright (C) 2023 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU Affero General Public License version 3.
+ */
+
+#ifndef _MODEL__SCREENSAVER_H_
+#define _MODEL__SCREENSAVER_H_
+
+#include <types.h>
+
+namespace Sculpt { class Screensaver; }
+
+
+class Sculpt::Screensaver : Noncopyable
+{
+	public:
+
+		struct Action : Interface
+		{
+			virtual void screensaver_changed() = 0;
+		};
+
+	private:
+
+		Env    &_env;
+		Action &_action;
+
+		/* config */
+		unsigned _max_seconds_of_inactivity = 10;
+		bool     _blank_after_some_time = true;
+
+		/* state */
+		uint64_t _last_activity_ms = 0;
+		bool     _recent_user_activity = true;
+		bool     _forced_blanked = false;
+
+		Timer::Connection _timer { _env };
+
+		Signal_handler<Screensaver> _timer_handler {
+			_env.ep(), *this, &Screensaver::_handle_timer };
+
+		void _handle_timer()
+		{
+			uint64_t const now = _timer.elapsed_ms();
+
+			if (now - _last_activity_ms > _max_seconds_of_inactivity*1000) {
+				if (_recent_user_activity) {
+					_recent_user_activity = false;
+					_action.screensaver_changed();
+				}
+			}
+		}
+
+		void _wake_up()
+		{
+			_last_activity_ms = _timer.elapsed_ms();
+			_timer.trigger_once(_max_seconds_of_inactivity*1024*1024);
+			if (!_recent_user_activity) {
+				_recent_user_activity = true;
+				_action.screensaver_changed();
+			}
+		}
+
+		/**
+		 * Utility for watching the 'active' attribute of a ROM module
+		 */
+		struct Watched_rom : Noncopyable
+		{
+			Screensaver &_screensaver;
+
+			Attached_rom_dataspace _rom;
+
+			Signal_handler<Watched_rom> _handler {
+				_screensaver._env.ep(), *this, &Watched_rom::_handle };
+
+			Watched_rom(Screensaver &screensaver, char const *label)
+			:
+				_screensaver(screensaver), _rom(screensaver._env, label)
+			{
+				_rom.sigh(_handler);
+			}
+
+			void _handle()
+			{
+				_rom.update();
+				if (_rom.xml().attribute_value("active", false))
+					_screensaver._wake_up();
+			}
+		};
+
+		Watched_rom _nitpicker_focus { *this, "nitpicker_focus" };
+		Watched_rom _nitpicker_hover { *this, "nitpicker_hover" };
+
+	public:
+
+		Screensaver(Env &env, Action &action) : _env(env), _action(action)
+		{
+			_timer.sigh(_timer_handler);
+		}
+
+		bool display_enabled() const
+		{
+			if (_forced_blanked)
+				return false;
+
+			if (_blank_after_some_time && !_recent_user_activity)
+				return false;
+
+			return true;
+		}
+
+		void blank_after_some_time(bool blank_after_some_time)
+		{
+			_blank_after_some_time = blank_after_some_time;
+			_wake_up();
+		}
+
+		/**
+		 * User enforces the enabling or disabling of the display (power button)
+		 */
+		void force_toggle()
+		{
+			if (display_enabled())
+				_forced_blanked = true;
+			else
+				_forced_blanked = false;
+
+			_action.screensaver_changed();
+		}
+};
+
+#endif /* _MODEL__SCREENSAVER_H_ */