monitor crimes

hosts/flubber-machine/default.nix

@@ -85,10 +85,13 @@
 
       # monitors, see `modules/desktop/monitors`
       monitors.enable = true;
-      monitors.monitors = [
+      monitors.monitors = let
-        { name = "DP-2"; scale = 1.0; }
+        p1080 = { width = 1920; height = 1080; };
-        { name = "DP-3"; scale = 2.0; vrr = true; }
+        p2160 = { width = 3840; height = 2160; };
-        { name = "HDMI-A-1"; scale = 1.0; }
+      in [
+        { name = "HDMI-A-1"; scale = 1.0; resolution = p1080; position = { x = -p1080.width; y = 0; }; }
+        { name = "DP-2"; scale = 1.0; primary = true; resolution = p1080; position = { x = 0; y = 0; }; }
+        { name = "DP-3"; scale = 2.0; vrr = true; resolution = p2160; position = { x = p1080.width; y = 0; }; }
       ];
     };
     software = {

modules/desktop/monitors.nix

@@ -1,33 +1,64 @@
 { lib, config, pkgs, ... }:
 
 with lib;
+with lib.my;
 let
   cfg = config.modules.desktop.monitors;
 in {
   options.modules.desktop.monitors = {
     enable = mkEnableOption "manually configure monitor settings, use if manual configuration is needed";
     monitors = mkOption {
-      type = types.listOf types.attrs;
+      type = types.listOf (types.submodule {
-      description = ''
+        options = {
-        a list of monitor configurations. each entry should be an attribute set with the following keys:
+          name = mkOption {
-        - `name`: The name of the monitor to configure
+            type = types.str;
-        - `scale`: The scale factor to apply to the monitor
+            description = "the monitor name to configure. easily fetchable from `niri msg outputs`";
-        - `vrr`?: Whether or not the display supports variable refresh rate. Defaults to false
+            example = "eDP-1";
-        note: the first monitor in the list will be considered the "primary" monitor
+          };
-      '';
+          scale = mkOpt (types.nullOr types.float) 1.0;
+          vrr = mkEnableOption "whether or not to enable VRR (variable refresh rate)";
+          primary = mkEnableOption "whether or not the monitor is the primary monitor";
+          resolution = mkOpt (types.nullOr (types.submodule {
+            options = {
+              width = mkOption { type = types.int; };
+              height = mkOption { type = types.int; };
+            };
+          })) null;
+          position = mkOpt (types.nullOr (types.submodule {
+            options = {
+              x = mkOption { type = types.int; };
+              y = mkOption { type = types.int; };
+            };
+          })) null;
+        };
+      });
       example = [
-        { name = "eDP-1"; scale = 2.0; }
+        { name = "eDP-1"; scale = 2.0; primary = true; }
-        { name = "HDMI-1"; scale = 1.0; }
+        { name = "HDMI-1"; scale = 1.0; vrr = true; }
       ];
     };
   };
 
   config = mkIf cfg.enable {
+    assertions = [
+      {
+        assertion = builtins.length (builtins.filter (m: m.primary) cfg.monitors) <= 1;
+        message = "only one monitor should be marked as primary";
+      }
+    ];
+
     hm.programs.niri.settings.outputs = builtins.listToAttrs (builtins.map (monitor: {
       name = monitor.name;
       value = {
         scale = monitor.scale;
-        variable-refresh-rate = monitor.vrr or false;
+        variable-refresh-rate = monitor.vrr;
+        focus-at-startup = monitor.primary;
+        position = monitor.position;
+      } // optionalAttrs (monitor.resolution != null) {
+        mode = {
+          width = monitor.resolution.width;
+          height = monitor.resolution.height;
+        };
       };
     }) cfg.monitors);
   };