add maps app (doesn't do much yet)

I don't know why this works, but modemmanager-small needs to be
in environment.systemPackages

Makefile

@@ -9,6 +9,10 @@ default toplevel:
 android-bootimg android-recovery:
 	nix-build  $(NFLAGS) -A outputs.android.$@ -o $@
 
+lk2nd:
+	nix-build  $(NFLAGS) ../mobile-nixos --argstr device motorola-harpia  -A pkgs.pkgsBuildBuild.lk2nd.msm8916 -o lk2nd
+
+
 update: toplevel
 	nix-copy-closure --to $(DEVICE) -v --include-outputs ./toplevel
 	ssh $(DEVICE) "nix-env --profile /nix/var/nix/profiles/system --set `readlink toplevel`  && /nix/var/nix/profiles/system/bin/switch-to-configuration switch"

README

@@ -1,5 +1,5 @@
 
-Config for my moto potter to turn it into a bike computer. We will
+Config for my moto harpia to turn it into a bike computer. We will
 need
 
 - working gps
@@ -19,19 +19,43 @@ write the app in fennel. I want it to
 - show where I am on a map
 - record trail of where I've been (note: indoor counts too)
 
-we can use l"ove2d instead of dragging in that gtk stuff
 
-   SDL2
 
-   To run an SDL2 application on Wayland, set
-   SDL_VIDEODRIVER=wayland. 
-
-can we do bluetooth not through dbus? dbus seems to make it flakey
+can we somehow do non-flakey bluetooth (is it dbus?)
 
 
 
 cool extras
 ===========
 
-adjust screen brightness (go dark when not moving)
+adjust screen brightness 
+
+* turn off backlight when stopped after a minute
+* dim the screen when following a route and the next
+ navigation instruction is still some way off
+* tap to wake screen
+
+note that IPS LCD requires as much battery for dark pixels
+as light ones, so we get no power saving by colouring only part
+of the screen
+
+
+------
+
+random notes follow ...
+
+1) Satellite requires these commands to be run before
+it will work. 
+
+  mmcli -m 0 --enable
+  mmcli -m 0 --location-enable-gps-raw
+  mmcli -m 0 --location-enable-gps-nmea 
+  mmcli -m 0 --location-status
+
+
+2) we should make saturn give visual feedback while it's loading an
+app. How does it know when the app has finished loading?  Maybe it
+could get told when its window is obscured
+
+
 

configuration.nix

@@ -12,6 +12,8 @@ let
     makeFlags = ["prefix=${placeholder "out"}"];
   };
 
+  saturn = pkgs.callPackage ./pkgs/saturn {};
+
   drm-framebuffer =  pkgs.stdenv.mkDerivation {
     name = "drm-framebuffer";
     src = pkgs.fetchFromGitHub {
@@ -38,12 +40,21 @@ in {
   ];
 
   config = {
+    nixpkgs.overlays = [
+      (final: prev:
+        let mm = pkgs.callPackage ./pkgs/modem-manager {};
+        in {
+          wlr-randr = prev.wlr-randr.overrideAttrs(o: {
+            depsBuildBuild = [ final.pkgsBuildBuild.pkg-config ];
+          });
+          modemmanager-small = mm;
+          satellite  = prev.satellite.override { modemmanager = mm; };
+          maps = final.callPackage ./pkgs/maps {};
+        })
+    ];
+
     mobile = {
       adbd.enable = true;
-      # boot.stage-1.gui.enable = false;
-      # beautification.splash = false;
-      # quirks.fb-refresher.enable = lib.mkForce false;
-      # quirks.qualcomm.msm8953-modem.enable = true;
       boot.stage-1.firmware = [
         modemFirmware
         pkgs.wireless-regdb
@@ -56,28 +67,142 @@ in {
     system.stateVersion = "23.11";
 
     boot.kernelParams = [
-      "dyndbg=\"file drivers/base/firmware_loader/main.c +fmp\""
+      # "dyndbg=\"file drivers/base/firmware_loader/main.c +fmp\""
       # "dyndbg=\"file drivers/gpu/drm/panel/msm8953-generated/panel-boe-bs052fhm-a00-6c01.c  +fmp\""
       # "dyndbg=\"file drivers/video/backlight/qcom-wled.c +fmp\""
     ];
 
+    # according to fdisk, /dev/mmcblk0p41 is 30469887-7471104=22998783
+    # blocks, and if we let it get resized by whatever magic this is
+    # (I'm assuming systemd-growfs), on the subsequent boot we'll get
+    # an error
+
+    # EXT4-fs (mmcblk0p41): bad geometry: block count 2883067 exceeds size of device (2874848 blocks)
+
+    # in which neither number matches the reported size (they're both
+    # about 10% of it). cool.
+
+    boot.growPartition = lib.mkForce false;
+    fileSystems."/" = lib.mkDefault {
+      autoResize = lib.mkForce false;
+    };
+    services.udev.extraRules = ''
+ACTION!="add|change|move|bind", GOTO="mm_qcom_soc_end"
+
+# Process only known wwan, net and rpmsg ports
+SUBSYSTEM=="net",   DRIVERS=="bam-dmux",      GOTO="mm_qcom_soc_process"
+# SUBSYSTEM=="platform",   DRIVERS=="bam-dmux",      GOTO="mm_qcom_soc_process"
+SUBSYSTEM=="net",   DRIVERS=="ipa",           GOTO="mm_qcom_soc_process"
+SUBSYSTEM=="wwan",  DRIVERS=="qcom-q6v5-mss", GOTO="mm_qcom_soc_process"
+SUBSYSTEM=="rpmsg", DRIVERS=="qcom-q6v5-mss", GOTO="mm_qcom_soc_process"
+GOTO="mm_qcom_soc_end"
+
+LABEL="mm_qcom_soc_process"
+
+# Flag the port as being part of the SoC
+ENV{ID_MM_QCOM_SOC}="1"
+
+# #
+# # Add a common physdev UID to all ports in the Qualcomm SoC, so that they
+# # are all bound together to the same modem object.
+# #
+# # The MSM8916, MSM8974, .... Qualcomm SoCs use the combination of RPMSG/WWAN
+# # based control ports plus BAM-DMUX based network ports.
+# #
+ENV{ID_MM_PHYSDEV_UID}="qcom-soc"
+
+# port type hints for the rpmsgexport-ed ports
+SUBSYSTEM=="rpmsg", ATTR{name}=="DATA*", ATTR{name}=="*_CNTL", ENV{ID_MM_PORT_TYPE_QMI}="1"
+SUBSYSTEM=="rpmsg", ATTR{name}=="DATA*", ATTR{name}!="*_CNTL", ENV{ID_MM_PORT_TYPE_AT_SECONDARY}="1"
+
+# ignore every other port without explicit hints
+SUBSYSTEM=="rpmsg", ENV{ID_MM_PORT_TYPE_QMI}!="1", ENV{ID_MM_PORT_TYPE_AT_SECONDARY}!="1", ENV{ID_MM_PORT_IGNORE}="1"
+
+# explicitly ignore ports intended for USB tethering (DATA40, DATA40_CNTL)
+SUBSYSTEM=="rpmsg", ATTR{name}=="DATA40*", ENV{ID_MM_PORT_IGNORE}="1"
+KERNEL=="rmnet_usb*", ENV{ID_MM_PORT_IGNORE}="1"
+
+# flag all rpmsg ports under this plugin as candidate
+# KERNEL=="rpmsg*", SUBSYSTEM=="rpmsg", ENV{ID_MM_CANDIDATE}="1"
+KERNEL=="rpmsg*", SUBSYSTEM=="rpmsg", ENV{ID_MM_CANDIDATE}="1"
+
+LABEL="mm_qcom_soc_end"
+
+
+
+ACTION!="add|change|move|bind", GOTO="mm_candidate_end"
+
+# # Opening bound but disconnected Bluetooth RFCOMM ttys would initiate the
+# # connection. Don't do that.
+
+KERNEL=="rfcomm*", DEVPATH=="*/virtual/*", GOTO="mm_candidate_end" # */
+
+SUBSYSTEM=="net", ENV{ID_MM_CANDIDATE}="1"
+
+# WWAN subsystem port handling
+#  - All USB devices ignored for now, only PCI devices expected
+#  - Only "wwan_port" device types processed (single ports); we fully ignore
+#    the "wwan_dev" device type (full device, not just one port)
+
+SUBSYSTEMS=="usb", GOTO="mm_candidate_end"
+SUBSYSTEM=="wwan", ENV{DEVTYPE}=="wwan_dev", GOTO="mm_candidate_end"
+SUBSYSTEM=="wwan", ENV{ID_MM_CANDIDATE}="1"
+
+LABEL="mm_candidate_end"
+
+# unlock the gps engine
+SUBSYSTEM=="wwan", ENV{DEVNAME}=="/dev/wwan0qmi0", ENV{DEVTYPE}=="wwan_port", \
+  RUN+="${pkgs.libqmi}/bin/qmicli -pd $env{DEVNAME} --loc-set-engine-lock=none"
+
+    '';
+
+    systemd.services.ModemManager = {
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig =
+        let script = pkgs.writeScript "start-modem-manager" ''
+          #!${pkgs.bash}/bin/bash
+          source ${config.system.build.setEnvironment}
+          ${pkgs.modemmanager-small}/bin/ModemManager
+        '';
+        in  {
+          StandardInput = "journal";
+          StandardError = "journal";
+          StandardOutput = "journal";
+          SyslogIdentifier = "ModemManager";
+          ExecStart = script;
+          Restart = "always";
+          BindsTo = ["dbus.service"];
+        };
+    };
     networking = {
       useDHCP = true;
       hostName = "biscuit";
       networkmanager = { enable = false; };
+      useNetworkd = true;
       inherit (secrets) wireless;
     };
 
     services.openssh.enable = true;
 
-#    environment.systemPackages = [ qrtr tqftpserv ];
-    services.udev.extraRules = ''
-      # copied from https://github.com/andersson/rpmsgexport
-      ACTION=="add", SUBSYSTEM=="rpmsg", KERNEL=="rpmsg_ctrl[0-9]*", ATTRS{rpmsg_name}=="pronto", RUN+="${rpmsgexport}/bin/rpmsgexport /dev/$name APPS_RIVA_CTRL"
-      SUBSYSTEM=="rpmsg", KERNEL=="rpmsg_ctrl[0-9]*", ATTRS{rpmsg_name}=="?*", SYMLINK+="rpmsg/$attr{rpmsg_name}/ctrl"
-      SUBSYSTEM=="rpmsg", KERNEL=="rpmsg[0-9]*", ATTR{name}=="?*", ATTRS{rpmsg_name}=="?*", SYMLINK+="rpmsg/$attr{rpmsg_name}/$attr{name}"
-    '';
-    environment.systemPackages = with pkgs; [ drm-framebuffer];
+    services.cage =
+      let wlinit = pkgs.writeScript "wlinit" ''
+        ${pkgs.wlr-randr}/bin/wlr-randr --output DSI-1 --scale 2
+        exec ${saturn}/bin/saturn
+      '';
+      in {
+        enable = true;
+        program = wlinit;
+        user = "dan";
+      };
+
+    environment.systemPackages = with pkgs; [
+      drm-framebuffer
+      saturn
+      satellite
+      wlr-randr
+      modemmanager-small
+      maps
+    ];
 
     users.users.dan = {
       isNormalUser = true;
@@ -95,5 +220,30 @@ in {
     hardware.opengl = {
       enable = true; driSupport = true;
     };
+
+    systemd.services = {
+      rmtfs =
+        # the four files in here are partition images:
+        #  partlabel => filename
+        #  modemst1  => modem_fs1
+        #  modemst2  => modem_fs2
+        #  fsc       => modem_fsc
+        #  fsg       => modem_fsg
+
+        let files = pkgs.runCommand "rmtfs" {} ''
+          mkdir -p $out/lib/firmware
+          cp ${./local/uncompressed-firmware/rmtfs}/* $out/lib/firmware
+        '';
+        in {
+          wantedBy = [ "multi-user.target" ];
+          serviceConfig = {
+            # https://github.com/andersson/rmtfs/blob/7a5ae7e0a57be3e09e0256b51b9075ee6b860322/rmtfs.c#L507-L541
+            ExecStart = "${pkgs.rmtfs}/bin/rmtfs -s -r -o ${files}/lib/firmware";
+            Restart = "always";
+            RestartSec = "10";
+          };
+        };
+    };
+
   };
 }

pkgs/maps/Makefile

@@ -0,0 +1,16 @@
+FENNEL?=fennel
+PREFIX?=/usr/local
+NAME?=maps
+
+MODULES=main.fnl
+
+%.lua : %.fnl
+	$(FENNEL) --compile $< > $@
+
+$(NAME): $(patsubst %.fnl,%.lua,$(MODULES)) Makefile
+	(echo -e "#!/usr/bin/env lua\n" ; cat main.lua ) > $@
+	chmod +x $@
+
+install:
+	mkdir -p $(PREFIX)/bin $(PREFIX)/
+	cp $(NAME) $(PREFIX)/bin

pkgs/maps/default.nix

@@ -0,0 +1,85 @@
+{ stdenv
+, pkg-config
+, buildPackages
+, callPackage
+, clutter
+, fetchFromGitHub
+, fetchurl
+, gobject-introspection
+, gtk3
+, lib
+, lua53Packages
+, lua5_3
+, makeDesktopItem
+, makeWrapper
+, wrapGAppsHook3
+, writeText
+, osm-gps-map
+, glib-networking
+, copyDesktopItems
+}:
+let
+  luaPackages = lua53Packages;
+  fennel = luaPackages.fennel;
+  lgi = luaPackages.buildLuaPackage {
+    pname = "lgi";
+    version = "0.9.2-2";
+    buildInputs = [ gobject-introspection ];
+    nativeBuildInputs = [ pkg-config ];
+
+    src = fetchFromGitHub {
+      owner = "lgi-devs";
+      repo = "lgi";
+      rev = "e06ad94c8a1c84e3cdb80cee293450a280dfcbc7";
+      hash = "sha256-VYr/DV1FAyzPe6p6Quc1nmsHup23IAMfz532rL167Q4=";
+    };
+  };
+  lua = lua5_3.withPackages (ps: with ps; [
+    lgi
+    luafilesystem
+    luaposix
+    readline
+  ]);
+  pname = "maps";
+in stdenv.mkDerivation {
+  inherit pname;
+  version = "0.1";
+  src =./.;
+
+  buildInputs = [
+    lua
+    gtk3.dev
+    gobject-introspection # .dev
+    osm-gps-map
+    glib-networking
+#    gdk-pixbuf
+    #    glib
+#    libchamplain
+  ];
+  nativeBuildInputs = [
+    buildPackages.lua
+    gobject-introspection
+    makeWrapper
+    fennel
+    wrapGAppsHook3
+    copyDesktopItems
+  ];
+  GIO_EXTRA_MODULES = [ "${glib-networking.out}/lib/gio/modules" ];
+
+  makeFlags = [ "PREFIX=${placeholder "out"}" "NAME=${pname}" ];
+
+  postInstall = ''
+    mkdir -p $out/share/icons/
+    cp icon.svg  $out/share/icons/${pname}.svg
+  '';
+
+  desktopItems = [
+    (makeDesktopItem {
+      name = pname;
+      desktopName = "Maps";
+      exec = pname;
+      type = "Application";
+      icon = "nix-snowflake"; # "${placeholder "out"}/share/icons/${pname}.svg";
+    })
+  ];
+}

pkgs/maps/main.fnl

@@ -0,0 +1,71 @@
+; (local { : view } (require :fennel))
+
+(local {
+        : Gtk
+        : OsmGpsMap
+        : Gdk
+        }
+       (require :lgi))
+
+(local CSS "
+label.readout {
+    font: 48px \"Noto Sans\";
+    margin: 10px;
+    padding: 5px;
+    background-color: rgba(0, 0, 0, 0.2);
+}
+")
+
+(fn styles []
+  (let [style_provider (Gtk.CssProvider)]
+    (Gtk.StyleContext.add_provider_for_screen
+     (Gdk.Screen.get_default)
+     style_provider
+     Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION
+     )
+    (style_provider:load_from_data CSS)))
+
+(local window (Gtk.Window {
+                           :title "Map"
+                           :name "toplevel"
+                           :default_width 720
+                           :default_height 800
+
+                           :on_destroy Gtk.main_quit
+                           }))
+
+(fn osm-widget []
+  (doto (OsmGpsMap.Map {})
+    (tset :map-source  OsmGpsMap.MapSource_t.OPENSTREETMAP)
+    (: :set_center_and_zoom 52.595 -0.1 14)
+    (: :layer_add (OsmGpsMap.MapOsd {
+                                     :show_copyright true
+                                     ; :show_coordinates true
+                                     :show_scale true
+                                     }))
+    ))
+
+(fn readout [text]
+  (doto (Gtk.Label {:label text})
+    (-> (: :get_style_context) (: :add_class :readout))))
+
+(fn readouts []
+  (doto (Gtk.Box
+         {
+          :orientation Gtk.Orientation.VERTICAL
+          :halign Gtk.Align.END
+          })
+    (-> (: :get_style_context) (: :add_class :readouts))
+    (: :add (readout "21:05:00"))
+    (: :add (readout "00:00"))
+    (: :add (readout "25 km/h"))))
+
+(window:add
+ (doto (Gtk.Overlay {})
+   (: :add (osm-widget))
+   (: :add_overlay (readouts))
+   ))
+
+(window:show_all)
+(styles)
+(Gtk:main)

pkgs/maps/shell.nix

@@ -0,0 +1,9 @@
+with import <nixpkgs> {};
+let package = pkgs.callPackage ./. {};
+in
+package.overrideAttrs(o: {
+  shellHook = ''
+    export LUA_CPATH=$(lua -e "print(package.cpath)")
+    export LUA_PATH=$(lua -e "print(package.path)")
+  '';
+})

pkgs/modem-manager/default.nix

@@ -0,0 +1,84 @@
+{
+  stdenv,
+  fetchFromGitLab,
+  libxslt,
+  bash, # shebangs in share/ModemManager/fcc-unlock.available.d/,
+  bash-completion,
+  dbus,
+  gettext,
+  glib,
+  libgudev,
+  libqmi,
+  meson,
+  ninja,
+  cmake,
+  pkg-config,
+  python3,
+  systemd,
+  gobject-introspection,
+  pkgsBuildBuild,
+  buildPackages
+}: stdenv.mkDerivation rec {
+  pname = "modemmanager";
+  version = "1.22.0";
+
+  src = fetchFromGitLab {
+    domain = "gitlab.freedesktop.org";
+    owner = "mobile-broadband";
+    repo = "ModemManager";
+    rev = version;
+    hash = "sha256-/D9b2rCCUhpDCUfSNAWR65+3EyUywzFdH1R17eSKRDo=";
+  };
+  patches = [
+    /home/dan/src/nixpkgs/pkgs/tools/networking/modemmanager/no-dummy-dirs-in-sysconfdir.patch
+  ];
+  nativeBuildInputs = [
+    meson
+    ninja
+    gobject-introspection
+    gettext
+    pkg-config
+    libxslt
+    python3
+    cmake
+    glib # for gdbus-codegen
+  ];
+
+  buildInputs = [
+    glib
+    libgudev
+    # polkit
+     pkg-config
+    # ppp
+    # libmbim
+    libqmi
+    systemd
+    bash-completion
+    dbus
+#    cmake
+    bash # shebangs in share/ModemManager/fcc-unlock.available.d/
+  ];
+
+  depsBuildBuild = [
+    pkg-config
+  ];
+
+  mesonFlags = [
+    "-Dudevdir=${placeholder "out"}/lib/udev"
+    "-Ddbus_policy_dir=${placeholder "out"}/share/dbus-1/system.d"
+    "--sysconfdir=/etc"
+    "--localstatedir=/var"
+    "-Dvapi=false"
+    "-Dmbim=false"
+    "-Dqmi=true"
+    "-Dqrtr=false"
+    "-Dpolkit=no"
+    "-Dplugin_foxconn=disabled"
+    "-Dplugin_quectel=disabled"
+    "-Dman=false"
+    "-Dexamples=false"
+    "-Dtests=false"
+#    "-Dintrospection=false"
+  ];
+
+}

pkgs/saturn/Makefile

@@ -0,0 +1,15 @@
+FENNEL?=fennel
+PREFIX?=/usr/local
+
+MODULES=main.fnl
+
+%.lua : %.fnl
+	$(FENNEL) --compile $< > $@
+
+saturn: $(patsubst %.fnl,%.lua,$(MODULES)) Makefile
+	(echo -e "#!/usr/bin/env lua\n" ; cat main.lua ) > $@
+	chmod +x $@
+
+install:
+	mkdir -p $(PREFIX)/bin
+	cp saturn $(PREFIX)/bin

pkgs/saturn/README.md

@@ -0,0 +1,9 @@
+# Saturn
+
+>  Saturn 5, you really were the greatest sight
+
+A very simple launcher app for the Pinephone, written using Fennel and
+the LGI bindings to gobject-introspection.
+
+I may someday separate this from the rest of Slab but for the moment
+it's more convenient to keep it all together

pkgs/saturn/default.nix

@@ -0,0 +1,99 @@
+{ stdenv
+, pkg-config
+, buildPackages
+, callPackage
+, fennel
+, fetchFromGitHub
+, fetchurl
+, gdk-pixbuf
+, glib
+, gobject-introspection
+, gtk3
+, harfbuzz
+, lib
+, librsvg
+, lua53Packages
+, lua5_3
+, makeWrapper
+, pango
+, wrapGAppsHook3
+, writeText
+}:
+let
+  luaPackages = lua53Packages;
+  lgi = luaPackages.buildLuaPackage {
+    pname = "lgi";
+    version = "0.9.2-2";
+    buildInputs = [ gobject-introspection ];
+    nativeBuildInputs = [ pkg-config ];
+
+    src = fetchFromGitHub {
+      owner = "lgi-devs";
+      repo = "lgi";
+      rev = "e06ad94c8a1c84e3cdb80cee293450a280dfcbc7";
+      hash = "sha256-VYr/DV1FAyzPe6p6Quc1nmsHup23IAMfz532rL167Q4=";
+    };
+  };
+  luaDbusProxy = callPackage ./lua-dbus-proxy.nix {
+    inherit (luaPackages) buildLuaPackage;
+    inherit lgi;
+    lua = lua5_3;
+  };
+  inifile = luaPackages.buildLuaPackage rec {
+    pname = "inifile";
+    name = "${pname}-${version}";
+    version  = "1.0.2";
+    src = fetchFromGitHub {
+      owner = "bartbes";
+      repo = "inifile";
+      rev = "f0b41a8a927f3413310510121c5767021957a4e0";
+      sha256 = "1ry0q238vbp8wxwy4qp1aychh687lvbckcf647pmc03rwkakxm4r";
+    };
+    buildPhase = ":";
+    installPhase = ''
+        mkdir -p "$out/share/lua/${lua.luaversion}"
+        cp inifile.lua "$out/share/lua/${lua.luaversion}/"
+      '';
+  };
+  lua = lua5_3.withPackages (ps: with ps; [
+    luaDbusProxy
+    inifile
+    inspect
+    lgi
+    luafilesystem
+    luaposix
+    penlight
+    readline
+  ]);
+in stdenv.mkDerivation {
+  pname = "saturn";
+  version = "0.4.9";            # nearly Saturn 0.5
+  src =./.;
+
+  buildInputs = [
+    lua
+    gtk3.dev
+    gobject-introspection # .dev
+    gdk-pixbuf
+    glib
+  ];
+  nativeBuildInputs = [
+    buildPackages.lua
+    gobject-introspection
+    makeWrapper
+    fennel
+    wrapGAppsHook3
+  ];
+
+  makeFlags = [ "PREFIX=${placeholder "out"}" ];
+
+  postInstall = ''
+    mkdir -p $out/share/dbus-1/services
+
+    cat <<SERVICE > $out/share/dbus-1/services/net.telent.saturn.service
+    [D-BUS Service]
+    Name=net.telent.saturn
+    Exec=$out/bin/saturn
+    SERVICE
+  '';
+}

pkgs/saturn/lua-dbus-proxy.nix

@@ -0,0 +1,25 @@
+{ lua, lgi, pkg-config, buildLuaPackage, fetchFromGitHub }:
+let
+  simpleName = "dbus_proxy";
+in buildLuaPackage rec {
+  version = "0.10.2";
+  pname = simpleName;
+  nativeBuildInputs = [ pkg-config ];
+
+  src = fetchFromGitHub {
+    owner = "stefano-m";
+    repo = "lua-${simpleName}";
+    rev = "v${version}";
+    sha256 = "0kl8ff1g1kpmslzzf53cbzfl1bmb5cb91w431hbz0z0vdrramh6l";
+  };
+
+  propagatedBuildInputs = [ lgi ];
+
+  buildPhase = ":";
+
+  installPhase = ''
+    mkdir -p "$out/share/lua/${lua.luaversion}"
+    cp -r src/${pname} "$out/share/lua/${lua.luaversion}/"
+  '';
+
+}

pkgs/saturn/main.fnl

@@ -0,0 +1,301 @@
+(local {: Gio
+        : GLib
+        : GObject
+        : Gtk
+        : GdkPixbuf
+        : Gdk
+        : Pango}
+       (require :lgi))
+
+(local {: List
+        : stringx
+        : tablex
+        }
+       ((require :pl.import_into)))
+
+(local dbus (require :dbus_proxy))
+(local inspect (require :inspect))
+(local lfs (require :lfs))
+(local inifile (require :inifile))
+(local posix (require :posix))
+
+(local ICON_SIZE 64)
+
+(local CSS "
+    * {
+      color: rgb(255, 255, 255);
+      text-shadow:
+           0px  1px rgba(0, 0, 0, 255)
+        ,  1px  0px rgba(0, 0, 0, 255)
+        ,  0px -1px rgba(0, 0, 0, 255)
+        , -1px  0px rgba(0, 0, 0, 255)
+        ,  1px  1px rgba(0, 0, 0, 255)
+        ,  1px -1px rgba(0, 0, 0, 255)
+        , -1px  1px rgba(0, 0, 0, 255)
+        , -1px -1px rgba(0, 0, 0, 255)
+      ;
+    }
+    button.appbutton {
+        padding: 0px;
+    }
+    #toplevel {
+      background-color: rgba(0.2, 0.2, 0.4, 1.0);
+    }
+  ")
+
+(local dbus-service-attrs
+       {
+        :bus dbus.Bus.SESSION
+        :name "net.telent.saturn"
+        :interface "net.telent.saturn"
+        :path "/net/telent/saturn"
+        })
+
+(local bus (dbus.Proxy:new
+            {
+             :bus dbus.Bus.SESSION
+             :name "org.freedesktop.DBus"
+             :interface "org.freedesktop.DBus"
+             :path "/org/freedesktop/DBus"
+             }))
+
+(local interface-info
+       (let [xml
+             "<node>
+                <interface name='net.telent.saturn'>
+                  <method name='SetVisible'>
+                    <arg type='b' name='visible' direction='in'/>
+                    <doc:doc><doc:description>
+                      Switch visibility of launcher window
+                    </doc:description></doc:doc>
+                  </method>
+                  <method name='ToggleVisible'>
+                    <doc:doc><doc:description>
+                      Toggle launcher window visible/invisible
+                    </doc:description></doc:doc>
+                  </method>
+                  <property name='Visible' type='b' access='read'>
+                  </property>
+                </interface>
+              </node>"
+             node-info (Gio.DBusNodeInfo.new_for_xml xml)]
+         (. node-info.interfaces 1)))
+
+;; these values don't seem to be available through introspection
+(local DBUS_NAME_FLAG_DO_NOT_QUEUE 4)
+(local DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER 1)
+(local DBUS_REQUEST_NAME_REPLY_IN_QUEUE 2)
+(local DBUS_REQUEST_NAME_REPLY_EXISTS 3)
+(local DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER 4)
+
+(let [ret (bus:RequestName dbus-service-attrs.name
+                           DBUS_NAME_FLAG_DO_NOT_QUEUE)]
+  (match ret
+    DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER
+    true
+
+    DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER
+    true
+
+    DBUS_REQUEST_NAME_REPLY_IN_QUEUE
+    (error "unexpected DBUS_REQUEST_NAME_REPLY_IN_QUEUE")
+
+    DBUS_REQUEST_NAME_REPLY_EXISTS
+    ;; Show the currently running instance
+    (let [saturn (dbus.Proxy:new dbus-service-attrs)]
+      (saturn:SetVisible true)
+      (os.exit 0))))
+
+
+(local path {
+             :absolute? (fn [str] (= (str:sub 1 1) "/"))
+             :concat (fn [...] (table.concat [...] "/"))
+             })
+(local search-path {
+                    :concat (fn [...] (table.concat [...] ":"))
+                    })
+
+
+(local icon-theme (Gtk.IconTheme.get_default))
+
+;; Use the declared CSS for this app
+(let [style_provider (Gtk.CssProvider)]
+  (style_provider:load_from_data CSS)
+  (Gtk.StyleContext.add_provider_for_screen
+    (Gdk.Screen.get_default)
+    style_provider
+    Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION
+    ))
+
+(local window (Gtk.Window {
+                           :title "Saturn"
+                           :name "toplevel"
+                           :default_width 720
+                           :default_height 800
+                           :on_destroy Gtk.main_quit
+                           }))
+
+;; Using RGBA visual for semi-transparent backgrounds
+;; Requires compositing (e.g. a compositor on X11)
+(let [screen (window:get_screen)
+      visual (screen:get_rgba_visual)]
+  (window:set_visual visual))
+
+(fn find-icon [name]
+  (var found false)
+  (if (path.absolute? name)
+    ;; From a direct path
+    (set found (GdkPixbuf.Pixbuf.new_from_file_at_size name ICON_SIZE ICON_SIZE))
+    ;; From icon theme
+    (let [sizes (icon-theme:get_icon_sizes name)]
+      ;; Uses a list of "safe fallback" values
+      ;; Try the desired size first
+      (each [_ res (pairs [ICON_SIZE 128 64 48]) :until found]
+        (set found
+             (-?> (icon-theme:load_icon
+                   name res
+                   (+ Gtk.IconLookupFlags.FORCE_SVG Gtk.IconLookupFlags.USE_BUILTIN))
+                 (: :scale_simple ICON_SIZE ICON_SIZE GdkPixbuf.InterpType.BILINEAR))))
+      ))
+  (Gtk.Image.new_from_pixbuf found))
+
+(fn read-desktop-file [f]
+  (let [parsed (inifile.parse f)
+        vals (. parsed "Desktop Entry")]
+    (tset vals "IconImage"
+          (find-icon (or vals.Icon "application-x-executable")))
+    (tset vals "ID" (f:sub 0 -9))
+    vals))
+
+(fn current-user-home []
+  "Returns current user's home directory."
+  (-> (posix.unistd.getuid)
+      (posix.pwd.getpwuid)
+      (. :pw_dir)))
+
+(fn xdg-data-home []
+  "Provides XDG_DATA_HOME or its default fallback value"
+  (or (os.getenv "XDG_DATA_HOME")
+      (path.concat (current-user-home) ".local/share/")))
+
+(fn xdg-data-dirs []
+  "Provides all data-dirs as a List. Most important first."
+  ;; Expected to be used with gmatch as a generator.
+  (let [dirs (List)]
+  (dirs:append (xdg-data-home))
+  (dirs:extend (stringx.split (os.getenv "XDG_DATA_DIRS") ":"))
+  dirs
+  ))
+
+(fn all-apps []
+  ;; Each desktop entry representing an application is identified
+  ;; by its desktop file ID, which is based on its filename.
+  ;;  — https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html#desktop-file-id
+  "Provides apps in a List, sorted by name"
+  (var apps-table {})
+  ;; Reversing the data dirs gives priority to the first elements.
+  ;; This means conflicting `.desktop` files (or: desktop file ID) are given
+  ;; priority to the first elements by "simply" reading it last.
+  (each [path (List.iter (List.reverse (xdg-data-dirs)))]
+    (let [apps-dir (..  path "/applications/")]
+      (when (lfs.attributes apps-dir)
+        (each [f (lfs.dir apps-dir)]
+          (when (= (f:sub -8) ".desktop")
+            (let [attrs (read-desktop-file (.. apps-dir  f))]
+              (when (not attrs.NoDisplay)
+                (tset apps-table attrs.ID attrs))))))))
+  ;; We have a table indexed by IDs, we don't care about the indexing.
+  ;; Make a List and sort it by name.
+  (List.sort (List (tablex.values apps-table))
+    (fn [a b] (< (string.upper a.Name) (string.upper b.Name)))))
+
+;; Exec entries in desktop files may contain %u %f and other characters
+;; in which the launcher is supposed to interpolate filenames/urls etc.
+;; We don't afford the user any way to pick filenames, but we do need
+;; to remove the placeholders.
+(fn parse-percents [str]
+  (str:gsub "%%(.)" (fn [c] (if (= c "%") "%" ""))))
+
+(fn spawn-async [vec]
+  (let [pid (posix.unistd.fork)]
+    (if (> pid 0) true
+        (< pid 0) (assert (= "can't fork" nil))
+        (do
+          (for [f 3 255] (posix.unistd.close f))
+          (posix.execp "/usr/bin/env" vec)))))
+
+(fn launch [app]
+  ;; FIXME check app.DBusActivatable and do DBus launch if true
+  (let [cmd (parse-percents app.Exec)]
+    (if app.Terminal
+        (spawn-async ["kitty" cmd])
+        (spawn-async ["sh" "-c" cmd]))
+    ; (window:hide)
+    ))
+
+(fn button-for [app]
+  (doto (Gtk.Button
+         {
+          :image-position Gtk.PositionType.TOP
+          :relief Gtk.ReliefStyle.NONE
+          :on_clicked #(launch app)
+          })
+    (-> (: :get_style_context) (: :add_class "appbutton"))
+    (: :add
+       (doto (Gtk.Box {:orientation Gtk.Orientation.VERTICAL})
+         (: :pack_start app.IconImage false false 0)
+         (: :pack_start
+            (doto
+                (Gtk.Label {
+                            ;; https://stackoverflow.com/questions/27462926/how-to-set-max-width-of-gtklabel-properly
+                            :label app.Name
+                            :justify Gtk.Justification.CENTER
+                            :ellipsize Pango.EllipsizeMode.END
+                            :hexpand true
+                            })
+              (: :set_max_width_chars 1))
+            true true 0)
+         ))))
+
+(fn handle-dbus-method-call [conn sender path interface method params invocation]
+  (when (and (= path dbus-service-attrs.path)
+             (= interface dbus-service-attrs.interface))
+    (match method
+      "SetVisible"
+      (let [[value] (dbus.variant.strip params)]
+        (if value (window:show_all) (window:hide))
+        (invocation:return_value nil))
+      "ToggleVisible"
+      (let [v window.visible]
+        (if v (window:hide) (window:show_all))
+        (invocation:return_value nil)))))
+
+(fn handle-dbus-get [conn sender path interface name]
+  (when (and (= path dbus-service-attrs.path)
+             (= interface dbus-service-attrs.interface)
+             (= name "Visible"))
+    (GLib.Variant "b" window.visible)))
+
+(Gio.DBusConnection.register_object
+ bus.connection
+ dbus-service-attrs.path
+ interface-info
+ (GObject.Closure handle-dbus-method-call)
+ (GObject.Closure handle-dbus-get)
+ (GObject.Closure (fn [a] (print "set"))))
+
+(let [grid (Gtk.FlowBox {
+                         :orientation Gtk.Orientation.HORIZONTAL
+                         :valign Gtk.Align.START
+                         :column_spacing 2
+                         :row_spacing 5
+                         :homogeneous true
+                         })
+      scrolled-window (Gtk.ScrolledWindow {})]
+  (each [app (List.iter (all-apps))]
+    (grid:insert (button-for app) -1))
+  (scrolled-window:add grid)
+  (window:add scrolled-window))
+
+(window:show_all)
+(Gtk:main)

pkgs/saturn/shell.nix

@@ -0,0 +1,7 @@
+with import <nixpkgs> { overlays = [ (import ../../overlay.nix) ];  } ;
+(callPackage ./. {
+}).overrideAttrs(o: {
+  GDK_PIXBUF_MODULE_FILE = "${pkgs.librsvg.out}/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache";
+  nativeBuildInputs = o.nativeBuildInputs ++
+                      [  ] ;
+})