How to measure the spacing between controls of a NSRunAlertPanel

Question

How can I find out the number of pixel position between the controls of a NSRunAlertPanel. In Interface Builder we can use the Option+Mouse to find the pixel length.Please help.

Answer 1

Just to share the answer,If really need to measure the AlertPanel spacing there is an easy way.

When the Alert is running,press Cmd+Shft+4,drag between the controls,cursor will display the length and width in pixels.