SwingSpy examines Swing layouts.
Installation is simple, just add the following lines in your startup code:
try {
Class.forName("jodd.swingspy.SwingSpy").getMethod("install").invoke(null);
} catch (Exception e) {
System.err.println("SwingSpy is not installed... " + e.toString());
}
When SwingSpy is installed, you can invoke it by SHIFT + CTRL + click hot-key combination.