Cocoa window dragging - objective-c

Question

I'm using addGlobalMonitorForEventsMatchingMask to listen to events in Cocoa:
[NSEvent addGlobalMonitorForEventsMatchingMask:NSLeftMouseDraggedMask
handler:^(NSEvent *event) {
NSLog(#"Dragged...");
}];
Though I would like to know if I'm dragging/moving a window (and which window that is, I can find the focused window though when holding command and dragging a window it doesn't get focus as far as I know.)
So, can I detect whether or not I'm dragging a window?
Update:
I now have a class: "SATest : NSObject <NSWindowDelegate>" in which I implement the windowDidMove method (and later perhaps windowWillMove too.) Though, now the next step would be attaching this to a window, right? So my question now is: How do I attach the delegate to all windows of all apps?
Update 2:
I now can find a list of all open windows on the screen:
AXUIElementRef _systemWideElement;
_systemWideElement = AXUIElementCreateSystemWide();
CFArrayRef _windows;
AXUIElementCopyAttributeValues(_systemWideElement, kAXWindowsAttribute, 0, 100, &_windows);
Now I have to iterate over the windows, and of each get it's NSWindow so I can add my delegate to it: [window setDelegate:self];
Update 3: To be clear, this question is about detecting the dragging of ALL windows of ALL apps. Not only the windows of my own app.
Also, I'm very new to this event and window management stuff, so no need to keep your answer short I'm happy to read a lot :P
Thanks!
-P

Answer 1

To find out if a window is being dragged you need to have an object that acts as the delegate of the window by responding to the following messages of the NSWindowDelegate protocol:
windowWillMove - this tells the delegate that the window is about to move.
windowDidMove - this tells the delegate that the window has moved.
You can retrieve the NSWindow object in question by sending object to the notification parameter sent to these methods:
e.g.
NSWindow draggedWindow = [notification object];
More information can be found here.
Update:
In response to your request about getting this information for all windows the NSApplication class provides a method which returns an array of all windows owned by the application. The typical way of getting this information is to use one of the NSApplicationDelegate methods to get a reference to your application object.
For example, in your app delegate (pseudocode):
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
NSApplication * app = [aNotification object];
// you now have a reference to your application.
// and can iterate over the collection of windows and call
// [window setDelegate:self]; for each window.
}
Note that you will need to add / remove you delegates as windows are added and removed. The best method for doing this is – applicationDidUpdate:.
This should be enough to get you started solving your problem.

Answer 2

As suggested by Benjamin the answer lies in the accessibility API. I was looking around in this for a while, even before I asked this question, but never got it to do what I wanted. I now have found a pretty nice solution.
At a high-level I do the following:
Listen to the mouse down event and remember both on which window you clicked and it's location.
Listen to the mouse up event and check if the location has changed, if so you know you moved a window
You can do something similar for the size if you also want to know if you resized. There might be a better solution, but after days of trying stuff this is the only way I got it to work the way I wanted.
Hope this helps anyone who was looking for something similar.
-Pablo