Hidden metrics are draggable
In the glyph window, when metrics are hidden you can still drag the side bearings (even though they are invisible). This probably shouldn't happen, if something isn't visible, I shouldn't be able to move it.
but you first have to click to be able to drag some metrics and when a glyph is clicked a rectangle is been drawn the size of the width
but I don't want to accidentally move side bearings that aren't visible.