Gallery slideshow - setting navigation button hiding timeout

Many times, in the gallery slideshow view, when the user looks at the image more than 5 seconds, the next/prev navigation buttons are sliding away unnoticed. Then the user clicks on the place where he kept the mouse pointer above the button to go to the next image, but when clicking, the slideshow view is suddenly closed, revealing the file list. The controls come back if the user moves the pointer before clicking, but if he doesn’t, it can be very annoying, re-opening the images all the time.

Is there a way to set or disable this timeout? It’s fine if it’s in the source somewhere but I was unable to find it. Any help is appreciated.