0

Is there a way to determine what's being dragged during an onMouseDrag event? Specifically, I'd like to know if a window is being dragged.

I've tried the following: Accessibility API: Store the initial location of the active window, query window location again during drag and compare values. The problem with this method is that Accessibility API does not update the position of a window until mouse stopped moving (with primary mouse button still depressed). It gives updated position when mouse starts dragging again after a brief stop.

Attach an NSWindowDelegate to the active window: I'm fairly new to this so I'm unaware of a way to find the focused/active window's NSWindow.

Thanks in advance!

UPDATE: I used the Accessibility API to get the active window and attached an AXObserverRef to get a kAXMovedNotification. I added this observer to the run loop using CFRunLoopAddSource. The result is that the callback to the notification gets queued and fires multiple calls to it only when I stop dragging the window. Is there a way to get the callback to fire right away without being queued like this so that I get to run some code WHILE the window is being dragged and not when dragging stops?

theNotSoPro
  • 308
  • 3
  • 16

1 Answers1

0

Window's status isn't updated while you are moving it but you're able to know when it starts being dragged and when it stop being dragged.

If you set a delegate to your window that conforms to NSWindowDelegate protocol you'll be able to be notified when window is being dragged with windowWillMove: and also notified when you stop dragging or release mouse button with windowDidMove:.

If you want to know which window is dragged both method receive an NSNotification object named notification, you can retrieve the window using [notification object] or notification.object.

Pyroh
  • 216
  • 2
  • 13
  • 1
    Thanks for your response. The NSWindowDelegate method would work great if I could set the delegate to the active/focused window. As far as I know, in order for NSWindowDelegate to receive notifications, I'd need to obtain the active/focused window (note that the program I'm writing needs to work on all windows of all apps, not just the windows that belong to my app) and this is where I'm stuck. I can't find a way to get the focused/active window's NSWindow to attach my delegate to. – theNotSoPro Jan 29 '13 at 18:28
  • It seams to be a huge system hack. You cannot set a delegate for a window that doesn't belong to your app. You have to 1. get the whole system's windows list 2. check which window is active 3. ????? 4. profit. I'm affraid I won't be helpful in this case. Sorry – Pyroh Jan 29 '13 at 20:50