vscode: add options for keybindings

Adds a new `keybindings` option to the `vscode` configuration.

It contains a list of key bindings, which will be written to
`%vscode-dir%/User/keybindings.json`.

PR #1351

modules/programs/vscode.nix

@@ -20,11 +20,14 @@ let
     "vscodium" = "vscode-oss";
   }.${vscodePname};
 
-  configFilePath =
+  userDir =
     if pkgs.stdenv.hostPlatform.isDarwin then
-      "Library/Application Support/${configDir}/User/settings.json"
+      "Library/Application Support/${configDir}/User"
     else
-      "${config.xdg.configHome}/${configDir}/User/settings.json";
+      "${config.xdg.configHome}/${configDir}/User";
+
+  configFilePath = "${userDir}/settings.json";
+  keybindingsFilePath = "${userDir}/keybindings.json";
 
   # TODO: On Darwin where are the extensions?
   extensionPath = ".${extensionDir}/extensions";
@@ -59,6 +62,45 @@ in
         '';
       };
 
+      keybindings = mkOption {
+        type = types.listOf (types.submodule {
+          options = {
+            key = mkOption {
+              type = types.str;
+              example = "ctrl+c";
+              description = "The key or key-combination to bind.";
+            };
+
+            command = mkOption {
+              type = types.str;
+              example = "editor.action.clipboardCopyAction";
+              description = "The VS Code command to execute.";
+            };
+
+            when = mkOption {
+              type = types.str;
+              default = "";
+              example = "textInputFocus";
+              description = "Optional context filter.";
+            };
+          };
+        });
+        default = [];
+        example = literalExample ''
+          [
+            {
+              key = "ctrl+c";
+              command = "editor.action.clipboardCopyAction";
+              when = "textInputFocus";
+            }
+          ]
+        '';
+        description = ''
+          Keybindings written to Visual Studio Code's
+          <filename>keybindings.json</filename>.
+        '';
+      };
+
       extensions = mkOption {
         type = types.listOf types.package;
         default = [];
@@ -93,6 +135,10 @@ in
               mkIf (cfg.userSettings != {}) {
                 text = builtins.toJSON cfg.userSettings;
               };
+            "${keybindingsFilePath}" =
+              mkIf (cfg.keybindings != []) {
+                text = builtins.toJSON cfg.keybindings;
+              };
           }
           toSymlink;
   };