For controls that support scrolls, we need to know the max ctrl width and max ctrl height for scrolls values to make sense, since they are percentages.
`ctrlPosition _ctrl`
returns
`[x, y, w, h, maxW, maxH]`
Alternatively, add a new command that does this, since I'm not sure if this will break backward compatibility.
New command syntax:
```
getCtrlViewPort _ctrl
```
returns the visible part of the control, based on scroll values:
```
[x1, y1, x2, y2]
/*
[x1, y1]
______________
| |
|_____________|
[x2, y2]
*/
```
For controls that don't have sliders,The coordinate values are relative to the control itself. it returns `[x,E.g. yif scroll values are 0, x + wthe top `[x1, y + w]`
The coordinate values are relative to the control itself. E.g.y1]` is `[0, 0]`
For controls that don't have sliders, if scroll values are 0it returns `[0, the top `[x10, y1]` is `[0w, 0]`h]`