| GridLayout |
| AutoColumns | Should we update Columns automatically? |
| Columns | How many columns should we have? |
| ItemHeight | The fixed height of each item. |
| ItemWidth | The fixed width of each item. If it is lower than 0 then we'll stretch to fill the size. |
| Justify | How columns should be justified |
| Rect | The Rect of this layout. Set via Update. |
| ScrollOffset | Where the top of the visible space is |
| GetHeight | Get the full height if we have this many items |
| GetPosition | Get the position of this cell |
| GetVisibleRange | Get the range of cells that are visible |
| Position | Move this panel into the position. This will set the Left/Top/Width/Height on the panel |
| Update | Update specifics of this layout. Returns true if we're dirty. |