Mac / Cocoa - Getting a list of windows using Accessibility API

Question

I want to use the Accessibility API to get a list of all windows for a given application (external).

The goal is to check if a certain window is open. First I chec

Answer 1

You can use windowNumbersWithOptions:. It lists all the windows from all the applications by their number. But I can't find how to get a NSWindow from a window number...

Answer 2

I don't know a way to get window ID and PID from the Accessibility API.
The NSWindow method Laurent mentioned only provides Window IDs but not the PID of the window owning application.
I would use the CGWindowList methods that are available since 10.5.
To get a list of window IDs and the PID of the owner you can try the following:

CFArrayRef windowList = CGWindowListCopyWindowInfo(kCGWindowListOptionOnScreenOnly, kCGNullWindowID);
for (NSMutableDictionary* entry in (NSArray*)windowList) 
{
    NSString* ownerName = [entry objectForKey:(id)kCGWindowOwnerName];
    NSInteger ownerPID = [[entry objectForKey:(id)kCGWindowOwnerPID] integerValue];
    NSLog(@"%@:%d", ownerName, ownerPID);
}
CFRelease(windowList);  

You can control if you want all windows (including offscreen, ...) with the option paramter.
Also the entry objects contain a lot more information. Documentation link

Answer 3

Use AXUIElementCopyAttributeValues to copy the value for kAXWindowsAttribute, which should be an array of AXUIElement objects representing the application's windows.

As you can guess from its function name, it follows the copy rule.

Answer 4

This works for me in Swift 5.1:

let windowList: CFArray? = CGWindowListCopyWindowInfo(.optionOnScreenOnly, kCGNullWindowID)

for entry in windowList! as Array {

    let ownerName: String = entry.object(forKey: kCGWindowName) as? String ?? "N/A"
    let ownerPID: Int = entry.object(forKey: kCGWindowOwnerPID) as? Int ?? 0
    print("ownerName: \(ownerName), ownerPID:\(ownerPID)")
}