Question

In Cocoa, I get the array of windows of an app using the following code:

CFArrayRef windows;
AXError gettingWindowsResult = AXUIElementCopyAttributeValues(app, (CFStringRef)NSAccessibilityWindowsAttribute, 0, 999, &windows);

Then I check some values of those windows and keep the AXUIElementRef of one of them in a variable of my class. At the end of the method, I release the CFArrayRef to make sure I don’t have any memory leaks:

if (windows != nil)
{
    CFRelease(windows);
}

Though this makes it so that when I try to use the window I kept, I get a bad access error. So my question: is it necessary that I release the array? And if so, how do I prevent the bad access error?

Answer 1

Why not make a retained copy of the “AXUIElementRef” of the one element you want to keep?

To do this, figure out the index of the element you want to keep, and then make another call to the “AXUIElementCopyAttributeValues” function, only this time just pass the index for the element you desire and a “maxValue” of 1. For example, for the element at position 26:

AXError gettingWindowsResult = AXUIElementCopyAttributeValues(app, (CFStringRef)NSAccessibilityWindowsAttribute, 26, 1, &arrayOfOne);

Then you can safely call “CFRelease” on the “windows” array.