Slider behaving unexpectedly when non-horizontal

Question

For this simple code {Dynamic@Rotate[Slider[Dynamic@x, {0, 2*Pi}], x], Slider[Dynamic@x, {0, 2*Pi}]} At x=0 the slider has an style like this

However if I drag the second slider a little, the style of the first slider change at the moment it started to rotate, like this

Moreover, the first slider isn't working normally. It's supposed to control its own rotation, but dragging doesn't work. The only way to move is to click on the bar, instead of dragging, which is weird for a slider. Why?

Answer 1

To get the slider to rotate itself, do this:

{Rotate[Slider[Dynamic@x, {0, 2*Pi}], Dynamic@x], 
 Slider[Dynamic@x, {0, 2*Pi}]}

Of course, once it rotates, the coordinate system for the slider changes. So using the mouse to set the angle is a bit of a pain, as should be expected.

The reason the OP's code fails (with Dynamic outside Rotate), is that every time the slider is moved, a new instance of a slider is created at rotated to the new angle x. The slider the mouse was controlling disappears, and dragging ceases to have an effect.

You can get a consistent control rendering with the following:

{Rotate[Style[Slider[Dynamic@x, {0., 2*Pi}], 
   ControlsRendering -> "Generic"], Dynamic@x], 
 Slider[Dynamic@x, {0., 2*Pi}]}

Answer 2

The Slider used in mathematica seemed to use microsoft's form. It displayed differently on my mac computer. However there is no sideways slider in windows, so the style changes.