This is a list of properties available when creating Custom Render Controls:
PROPERTY: gxIsFreestyle, TYPE: boolean
PROPERTY: gxWidth, TYPE: number
PROPERTY: gxWidthUnit, TYPE: string
PROPERTY: gxHeight, TYPE: number
PROPERTY: gxAllowSelection, TYPE: boolean
PROPERTY: gxAllowHovering, TYPE: boolean
PROPERTY: gxAllowCollapsing, TYPE: boolean
PROPERTY: gxCollapsed, TYPE: boolean
PROPERTY: gxSortable, TYPE: boolean
PROPERTY: gxSelectionColor, TYPE: object
PROPERTY: gxHoverColor, TYPE: object
PROPERTY: gxVisible, TYPE: boolean
PROPERTY: gxGridCols, TYPE: number
PROPERTY: gxIsMasterPageGrid, TYPE: boolean
PROPERTY: gxDragable, TYPE: boolean
PROPERTY: gxHasAddlines, TYPE: boolean
PROPERTY: gxHasForEachLine, TYPE: boolean
PROPERTY: gxOnLineActivate, TYPE: object
PROPERTY: gxNewRowText, TYPE: string
PROPERTY: gxCssClass, TYPE: string
PROPERTY: gxTitleClass, TYPE: string
PROPERTY: gxFooterClass, TYPE: string
PROPERTY: gxOddLlinesClass, TYPE: string
PROPERTY: gxEvenLinesClass, TYPE: string
PROPERTY: gxBackColor, TYPE: string
PROPERTY: gxTitleBackColor, TYPE: string
PROPERTY: gxTitleForeColor, TYPE: string
PROPERTY: gxTitleBackstyle, TYPE: string
PROPERTY: gxTitleFont, TYPE: string
PROPERTY: gxLinesFont, TYPE: string
PROPERTY: gxBackground, TYPE: string
PROPERTY: gxLinesBackcolorOdd, TYPE: string
PROPERTY: gxLinesBackcolorEven, TYPE: string
PROPERTY: gxBorderWidth, TYPE: string
PROPERTY: gxBordercolor, TYPE: string
PROPERTY: gxToolTipText, TYPE: string