Reference TSurfaceGraphicControl

  TSurfaceGraphicControl = class(TGraphicControl, IFloatPropertyNotify)
  protected
    { Allow controls direct access to draw state }
    FDrawState: TDrawState;
    { Areas are clickable regions of a control, such as the arrow of a drop down
      button. AreaClick is invoked when an area is clicked. }
    procedure AreaClick(Area: Integer); virtual;
    { Return the number of areas }
    function GetAreaCount: Integer; virtual;
    { Return the bounds of an area }
    function GetAreaRect(Index: Integer): TRectI; virtual;
    { Return the draw state of an area }
    function GetAreaState(Index: Integer): TDrawState;
    procedure MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer); override;
    procedure MouseUp(Button: TMouseButton; Shift: TShiftState; X, Y: Integer); override;
    procedure MouseMove(Shift: TShiftState; X, Y: Integer); override;
    procedure MouseEnter; override;
    procedure MouseLeave; override;
    { Add an item to the draw state }
    procedure IncludeStateItem(Item: TDrawStateItem); virtual;
    { Remove an item from the draw state }
    procedure ExcludeStateItem(Item: TDrawStateItem); virtual;
    { Float property change notification }
    procedure PropChange(Prop: PFloat); virtual;
    procedure SetParent(NewParent: TWinControl); override;
    { Create a default size }
    class function GetControlClassDefaultSize: TSize; override;
    { Update draw state when enabled is changed }
    procedure EnabledChanged; override;
    { 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;
    { The point where the mouse was pressed inside the control }
    property MousePoint: TPointI read FMousePoint;
  public
    { Create a new control }
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
  end;