Reference TSurfaceCustomControl

  TSurfaceCustomControl = class(TCustomControl, IFloatPropertyNotify)
  protected
    { Allow controls direct access to draw state }
    FDrawState: TDrawState;
    { Float property change notification }
    procedure PropChange(Prop: PFloat); virtual;
    { Override ThemeAware and return true to subscribe to global theme changes }
    function ThemeAware: Boolean; virtual;
    { Invoked when the theme is changed }
    procedure ThemeChanged; virtual;
    { Paint is now final, so use Draw to access Surface }
    procedure Paint; override; final;
    { While Draw is executing Surface refers to a valid ISurface }
    procedure Draw; virtual;
    { Surface is only valid while Draw is executing }
    property Surface: ISurface read GetSurface;
    { Visual representation of the control. Is it pressed, hot, checked, etc }
    property DrawState: TDrawState read FDrawState write SetDrawState;
    { Theme name determines the styling for a control }
    property ThemeName: string read FThemeName write SetThemeName;
    { Draw event handler }
    property OnDraw: TDrawEvent read FOnDraw write FOnDraw;
  public
    { Create a new control }
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
  end;