From 25b3734e0a2710f7e34d5c88e7f87d05a7194e15 Mon Sep 17 00:00:00 2001
From: Sindre Sorhus <sindresorhus@gmail.com>
Date: Wed, 13 Nov 2019 16:35:04 +0700
Subject: [PATCH] Improve #59

---
 Sources/active-win/main.swift | 19 ++++++++++++++-----
 index.test-d.ts               |  4 ++--
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/Sources/active-win/main.swift b/Sources/active-win/main.swift
index 49b4b95..ef9100b 100644
--- a/Sources/active-win/main.swift
+++ b/Sources/active-win/main.swift
@@ -1,5 +1,18 @@
 import AppKit
 
+// This shows the system prompt if there's no permission.
+func hasScreenRecordingPermission() -> Bool {
+	CGDisplayStream(
+		dispatchQueueDisplay: CGMainDisplayID(),
+		outputWidth: 1,
+		outputHeight: 1,
+		pixelFormat: Int32(kCVPixelFormatType_32BGRA),
+		properties: nil,
+		queue: DispatchQueue.global(),
+		handler: { _, _, _, _ in }
+	) != nil
+}
+
 func toJson<T>(_ data: T) throws -> String {
 	let json = try JSONSerialization.data(withJSONObject: data)
 	return String(data: json, encoding: .utf8)!
@@ -15,11 +28,7 @@ let frontmostAppPID = NSWorkspace.shared.frontmostApplication!.processIdentifier
 let windows = CGWindowListCopyWindowInfo([.optionOnScreenOnly, .excludeDesktopElements], kCGNullWindowID) as! [[String: Any]]
 
 // Show screen recording permission prompt if needed. Required to get the complete window title.
-if
-	let firstWindow = windows.first,
-	let windowNumber = firstWindow[kCGWindowNumber as String] as? CGWindowID,
-	CGWindowListCreateImage(.null, .optionIncludingWindow, windowNumber, [.boundsIgnoreFraming, .bestResolution]) == nil
-{
+if !hasScreenRecordingPermission() {
 	print("active-win requires the screen recording permission in “System Preferences › Security & Privacy › Privacy › Screen Recording”.")
 	exit(1)
 }
diff --git a/index.test-d.ts b/index.test-d.ts
index 5371565..9fa9f47 100644
--- a/index.test-d.ts
+++ b/index.test-d.ts
@@ -1,6 +1,6 @@
 import {expectType, expectError} from 'tsd';
 import activeWin = require('.');
-import { Result, LinuxResult, MacOSResult, WindowsResult } from '.';
+import {Result, LinuxResult, MacOSResult, WindowsResult} from '.';
 
 expectType<Promise<Result | undefined>>(activeWin());
 
@@ -9,7 +9,7 @@ const result = activeWin.sync();
 expectType<Result | undefined>(result);
 
 if (result) {
-	expectType<string>(result.platform);
+	expectType<'macos' | 'linux' | 'windows'>(result.platform);
 	expectType<string>(result.title);
 	expectType<number>(result.id);
 	expectType<number>(result.bounds.x);