i3,sway: workspace output assignment (#2003)

(cherry picked from commit ea3ff797c87313e71f2ed2fd2b932a18a4b4400b)

modules/services/window-managers/i3-sway/i3.nix

@@ -17,7 +17,7 @@ let
       inherit (commonOptions)
         fonts window floating focus assigns modifier workspaceLayout
         workspaceAutoBackAndForth keycodebindings colors bars startup gaps menu
-        terminal defaultWorkspace;
+        terminal defaultWorkspace workspaceOutputAssign;
 
       keybindings = mkOption {
         type = types.attrsOf (types.nullOr types.str);
@@ -141,7 +141,7 @@ let
   inherit (commonFunctions)
     keybindingsStr keycodebindingsStr modeStr assignStr barStr gapsStr
     floatingCriteriaStr windowCommandsStr colorSetStr windowBorderString
-    fontConfigStr keybindingDefaultWorkspace keybindingsRest;
+    fontConfigStr keybindingDefaultWorkspace keybindingsRest workspaceOutputStr;
 
   startupEntryStr = { command, always, notification, workspace, ... }: ''
     ${if always then "exec_always" else "exec"} ${
@@ -186,6 +186,7 @@ let
       ${concatStringsSep "\n" (map floatingCriteriaStr floating.criteria)}
       ${concatStringsSep "\n" (map windowCommandsStr window.commands)}
       ${concatStringsSep "\n" (map startupEntryStr startup)}
+      ${concatStringsSep "\n" (map workspaceOutputStr workspaceOutputAssign)}
     ''
   else
     "") + "\n" + cfg.extraConfig);

modules/services/window-managers/i3-sway/lib/functions.nix

@@ -155,4 +155,6 @@ rec {
     "for_window ${criteriaStr criteria} floating enable";
   windowCommandsStr = { command, criteria, ... }:
     "for_window ${criteriaStr criteria} ${command}";
+  workspaceOutputStr = item:
+    ''workspace "${item.workspace}" output ${item.output}'';
 }

modules/services/window-managers/i3-sway/lib/options.nix

@@ -831,4 +831,35 @@ in {
     '';
     example = "workspace number 9";
   };
+
+  workspaceOutputAssign = mkOption {
+    type = with types;
+      let
+        workspaceOutputOpts = submodule {
+          options = {
+            workspace = mkOption {
+              type = str;
+              default = "";
+              example = "Web";
+              description = ''
+                Name of the workspace to assign.
+              '';
+            };
+
+            output = mkOption {
+              type = str;
+              default = "";
+              example = "eDP";
+              description = ''
+                Name of the output from <command>
+                  ${if isSway then "swaymsg" else "i3-msg"} -t get_outputs
+                </command>.
+              '';
+            };
+          };
+        };
+      in listOf workspaceOutputOpts;
+    default = [ ];
+    description = "Assign workspaces to outputs.";
+  };
 }

modules/services/window-managers/i3-sway/sway.nix

@@ -17,7 +17,7 @@ let
       inherit (commonOptions)
         fonts window floating focus assigns workspaceLayout
         workspaceAutoBackAndForth modifier keycodebindings colors bars startup
-        gaps menu terminal defaultWorkspace;
+        gaps menu terminal defaultWorkspace workspaceOutputAssign;
 
       left = mkOption {
         type = types.str;
@@ -246,7 +246,7 @@ let
   inherit (commonFunctions)
     keybindingsStr keycodebindingsStr modeStr assignStr barStr gapsStr
     floatingCriteriaStr windowCommandsStr colorSetStr windowBorderString
-    fontConfigStr keybindingDefaultWorkspace keybindingsRest;
+    fontConfigStr keybindingDefaultWorkspace keybindingsRest workspaceOutputStr;
 
   startupEntryStr = { command, always, ... }: ''
     ${if always then "exec_always" else "exec"} ${command}
@@ -307,6 +307,7 @@ let
         ++ map floatingCriteriaStr floating.criteria # floating
         ++ map windowCommandsStr window.commands # window commands
         ++ map startupEntryStr startup # startup
+        ++ map workspaceOutputStr workspaceOutputAssign # custom mapping
       )}
     ''
   else