feat: allow macOS apps to set activation policies

docs/api/app.md

@@ -994,6 +994,17 @@ Updates the current activity if its type matches `type`, merging the entries fro
 
 Changes the [Application User Model ID][app-user-model-id] to `id`.
 
+### `app.setActivationPolicy(policy)` _macOS_
+
+* `policy` String - Can be 'regular', 'accessory', or 'prohibited'.
+
+Sets the activation policy for a given app.
+
+Activation policy types:
+* 'regular' - The application is an ordinary app that appears in the Dock and may have a user interface.
+* 'accessory' - The application doesn’t appear in the Dock and doesn’t have a menu bar, but it may be activated programmatically or by clicking on one of its windows.
+* 'prohibited' - The application doesn’t appear in the Dock and may not create windows or be activated.
+
 ### `app.importCertificate(options, callback)` _Linux_
 
 * `options` Object

shell/browser/api/electron_api_app.cc

@@ -1459,6 +1459,7 @@ void App::BuildPrototype(v8::Isolate* isolate,
                  base::BindRepeating(&Browser::UpdateCurrentActivity, browser))
       .SetMethod("moveToApplicationsFolder", &App::MoveToApplicationsFolder)
       .SetMethod("isInApplicationsFolder", &App::IsInApplicationsFolder)
+      .SetMethod("setActivationPolicy", &App::SetActivationPolicy)
 #endif
       .SetMethod("setAboutPanelOptions",
                  base::BindRepeating(&Browser::SetAboutPanelOptions, browser))

shell/browser/api/electron_api_app.h

@@ -201,6 +201,8 @@ class App : public ElectronBrowserClient::Delegate,
   bool CanBrowserClientUseCustomSiteInstance();
 
 #if defined(OS_MACOSX)
+  void SetActivationPolicy(gin_helper::ErrorThrower thrower,
+                           const std::string& policy);
   bool MoveToApplicationsFolder(gin_helper::ErrorThrower, gin::Arguments* args);
   bool IsInApplicationsFolder();
   v8::Local<v8::Value> GetDockAPI(v8::Isolate* isolate);

shell/browser/api/electron_api_app_mac.mm

@@ -2,6 +2,8 @@
 // Use of this source code is governed by the MIT license that can be
 // found in the LICENSE file.
 
+#include <string>
+
 #include "base/path_service.h"
 #include "shell/browser/api/electron_api_app.h"
 #include "shell/browser/electron_paths.h"
@@ -32,6 +34,24 @@
   }
 }
 
+void App::SetActivationPolicy(gin_helper::ErrorThrower thrower,
+                              const std::string& policy) {
+  NSApplicationActivationPolicy activation_policy;
+  if (policy == "accessory") {
+    activation_policy = NSApplicationActivationPolicyAccessory;
+  } else if (policy == "prohibited") {
+    activation_policy = NSApplicationActivationPolicyProhibited;
+  } else if (policy == "regular") {
+    activation_policy = NSApplicationActivationPolicyRegular;
+  } else {
+    thrower.ThrowError("Invalid activation policy: must be one of 'regular', "
+                       "'accessory', or 'prohibited'");
+    return;
+  }
+
+  [NSApp setActivationPolicy:activation_policy];
+}
+
 }  // namespace api
 
 }  // namespace electron

spec-main/api-app-spec.ts

@@ -202,6 +202,14 @@ describe('app module', () => {
     })
   })
 
+  ifdescribe(process.platform === 'darwin')('app.setActivationPolicy', () => {
+    it('throws an error on invalid application policies', () => {
+      expect(() => {
+        app.setActivationPolicy('terrible' as any)
+      }).to.throw(/Invalid activation policy: must be one of 'regular', 'accessory', or 'prohibited'/)
+    })
+  })
+
   describe('app.requestSingleInstanceLock', () => {
     it('prevents the second launch of app', function (done) {
       this.timeout(120000)