If you are a plugin developer for Eclipse, you may use Alt+Shift+F1 to trigger Eclipse Plug-in Spy. But you can't find some thing like that in Intellij IDEA. So this is for Intellij IDEA plugin developers to see implementation of gui elements.
Just install the swing-spy.jar
as a plugin and restart and double click Ctrl
key to trigger spy action , it will show a popup which inculdes all components that contain current mouse position.