Finding From Where A Method Is Being Called  

The linked SO post has a nice method for logging where an Objective-C method is being called from. Simple but helpful.

    NSString *sourceString = [[NSThread callStackSymbols] objectAtIndex:1];
    // Example: 1   UIKit                               0x00540c89 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1163
    NSCharacterSet *separatorSet = [NSCharacterSet characterSetWithCharactersInString:@" -[]+?.,"];
    NSMutableArray *array = [NSMutableArray arrayWithArray:[sourceString  componentsSeparatedByCharactersInSet:separatorSet]];
    [array removeObject:@""];

    NSLog(@"Stack = %@", [array objectAtIndex:0]);
    NSLog(@"Framework = %@", [array objectAtIndex:1]);
    NSLog(@"Memory address = %@", [array objectAtIndex:2]);
    NSLog(@"Class caller = %@", [array objectAtIndex:3]);
    NSLog(@"Function caller = %@", [array objectAtIndex:4]);

Now read this

Finally (?) Understanding Bounds, Frames, and Positions Thanks to Misunderstanding CAShapeLayers, CGPaths and Lines

I will try to keep this short so that I can get this post out. TL;DR CAShapeLayer is a canvas upon which you can draw CGPath. It’s bounds, and position must be set manually. The easiest way to do that is CGPathGetBoundingBox(path);... Continue →