Graphics Programs Reference
In-Depth Information
Adding this value to this setting says, “When you are building the
TouchTracker
target
with the debug configuration, a preprocessor macro
VIEW_DEBUG
is defined.”
Let's add some debugging code to
TouchTracker
that will only be compiled when the tar-
get is built with the debug configuration.
UIView
has a private method
recursiveDe-
scription
that prints out the entire view hierarchy of an application. However, you
cannot call this method in an application that you deploy to the App Store, so you will
only allow it to be called if
VIEW_DEBUG
is defined.
In
AppDelegate.m
, add the following code to
applica-
tion:didFinishLaunchingWithOptions:
.
[self.window makeKeyAndVisible];
#ifdef VIEW_DEBUG
NSLog(@"%@", [[self window] performSelector:@selector(recursiveDescription)]);
#endif
return YES;
}
This code will send the message
recursiveDescription
to the window. (Notice the
use of
performSelector:
.
recursiveDescription
is a private method, so we
have to dispatch it in this way.)
recursiveDescription
will print a view's descrip-
