From 2f0f65ebc3172e85684533842a494088b682d4ed Mon Sep 17 00:00:00 2001
From: David Heidelberg <david@ixit.cz>
Date: Fri, 9 Feb 2024 22:57:15 +0100
Subject: [PATCH] basic tablet/phone/watch autodetection

Until we're able to detect touchscreen itself, let's have a detection
based on a form factor of the device.

Tablets and handhelds are usually equiped with touchscreens, so as a
default enable touchscreen GUI there.

 - Windows and Linux supports autodetection.
 - Android is hardcoded as touch-based.
 - MacOS staying same as before without detection.

Heavily "inspired" by systemd way of handling detection.

Signed-off-by: David Heidelberg <david@ixit.cz>
---
 src/defaultsettings.cpp | 96 ++++++++++++++++++++++++++++++-----------
 1 file changed, 71 insertions(+), 25 deletions(-)

diff --git a/src/defaultsettings.cpp b/src/defaultsettings.cpp
index 0907c4c6d..d974530fc 100644
--- a/src/defaultsettings.cpp
+++ b/src/defaultsettings.cpp
@@ -26,9 +26,73 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapgen/mapgen.h" // Mapgen::setDefaultSettings
 #include "util/string.h"
 
+
+/*
+ * inspired by https://github.com/systemd/systemd/blob/7aed43437175623e0f3ae8b071bbc500c13ce893/src/hostname/hostnamed.c#L406
+ * this could be done in future with D-Bus using query:
+ * busctl get-property org.freedesktop.hostname1 /org/freedesktop/hostname1 org.freedesktop.hostname1 Chassis
+ */
+bool detect_touch()
+{
+#if defined(__ANDROID__)
+	return true;
+#else
+	std::string chassis_type;
+#if defined(__linux__)
+
+	// device-tree platforms (non-X86)
+	std::ifstream dtb_file("/proc/device-tree/chassis-type");
+	if (dtb_file.is_open()) {
+		std::getline(dtb_file, chassis_type);
+		chassis_type.pop_back();
+
+		if (chassis_type == "tablet" ||
+		    chassis_type == "handset" ||
+		    chassis_type == "watch")
+			return true;
+
+		if (!chassis_type.empty())
+			return false;
+	}
+	// SMBIOS
+	std::ifstream dmi_file("/sys/class/dmi/id/chassis_type");
+	if (dmi_file.is_open()) {
+		std::getline(dmi_file, chassis_type);
+
+		if (chassis_type == "11" /* Handheld */ ||
+		    chassis_type == "30" /* Tablet */)
+			return true;
+
+		return false;
+	}
+
+	// ACPI-based platforms
+	std::ifstream acpi_file("/sys/firmware/acpi/pm_profile");
+	if (acpi_file.is_open()) {
+		std::getline(acpi_file, chassis_type);
+
+		if (chassis_type == "8" /* Tablet */)
+			return true;
+
+		return false;
+	}
+#elif defined(_WIN32)
+	// 0x01 The device has an integrated touch digitizer
+	// 0x80 The device is ready to receive digitizer input.
+	if ((GetSystemMetrics(SM_DIGITIZER) & 0x81) == 0x81)
+		return true;
+
+	return false;
+#endif
+	// we don't know, return default
+	return false;
+#endif
+}
+
 void set_default_settings()
 {
 	Settings *settings = Settings::createLayer(SL_DEFAULTS);
+	bool has_touch = detect_touch();
 
 	// Client and server
 	settings->setDefault("language", "");
@@ -39,11 +103,7 @@ void set_default_settings()
 	// Client
 	settings->setDefault("address", "");
 	settings->setDefault("enable_sound", "true");
-#if ENABLE_TOUCH
-	settings->setDefault("enable_touch", "true");
-#else
-	settings->setDefault("enable_touch", "false");
-#endif
+	settings->setDefault("enable_touch", bool_to_cstr(has_touch));
 	settings->setDefault("sound_volume", "0.8");
 	settings->setDefault("sound_volume_unfocused", "0.3");
 	settings->setDefault("mute_sound", "false");
@@ -94,12 +154,10 @@ void set_default_settings()
 	settings->setDefault("keymap_cmd_local", ".");
 	settings->setDefault("keymap_minimap", "KEY_KEY_V");
 	settings->setDefault("keymap_console", "KEY_F10");
-#if ENABLE_TOUCH
+
 	// See https://github.com/minetest/minetest/issues/12792
-	settings->setDefault("keymap_rangeselect", "KEY_KEY_R");
-#else
-	settings->setDefault("keymap_rangeselect", "");
-#endif
+	settings->setDefault("keymap_rangeselect", bool_to_cstr(has_touch) ? "KEY_KEY_R" : "");
+
 	settings->setDefault("keymap_freemove", "KEY_KEY_K");
 	settings->setDefault("keymap_pitchmove", "");
 	settings->setDefault("keymap_fastmove", "KEY_KEY_J");
@@ -196,11 +254,7 @@ void set_default_settings()
 	settings->setDefault("screen_h", "600");
 	settings->setDefault("window_maximized", "false");
 	settings->setDefault("autosave_screensize", "true");
-#ifdef ENABLE_TOUCH
-	settings->setDefault("fullscreen", "true");
-#else
-	settings->setDefault("fullscreen", "false");
-#endif
+	settings->setDefault("fullscreen", bool_to_cstr(has_touch));
 	settings->setDefault("vsync", "false");
 	settings->setDefault("fov", "72");
 	settings->setDefault("leaves_style", "fancy");
@@ -307,11 +361,7 @@ void set_default_settings()
 	settings->setDefault("aux1_descends", "false");
 	settings->setDefault("doubletap_jump", "false");
 	settings->setDefault("always_fly_fast", "true");
-#ifdef ENABLE_TOUCH
-	settings->setDefault("autojump", "true");
-#else
-	settings->setDefault("autojump", "false");
-#endif
+	settings->setDefault("autojump", bool_to_cstr(has_touch));
 	settings->setDefault("continuous_forward", "false");
 	settings->setDefault("enable_joysticks", "false");
 	settings->setDefault("joystick_id", "0");
@@ -492,11 +542,7 @@ void set_default_settings()
 	settings->setDefault("fixed_virtual_joystick", "false");
 	settings->setDefault("virtual_joystick_triggers_aux1", "false");
 	settings->setDefault("touch_punch_gesture", "short_tap");
-#ifdef ENABLE_TOUCH
-	settings->setDefault("clickable_chat_weblinks", "false");
-#else
-	settings->setDefault("clickable_chat_weblinks", "true");
-#endif
+	settings->setDefault("clickable_chat_weblinks", bool_to_cstr(!has_touch));
 	// Altered settings for Android
 #ifdef __ANDROID__
 	settings->setDefault("screen_w", "0");