Устанавливаем события на TGauge

unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Gauges;
 
type
  TGauge = class(Gauges.TGauge)
    public
      property OnMouseDown;
  end;
 
  TForm1 = class(TForm)
    Gauge1: TGauge;
    Gauge2: TGauge;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    procedure GaugeVertMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
    procedure GaugeHorzMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.dfm}
 
procedure TForm1.FormCreate(Sender: TObject);
begin
  Gauge1.OnMouseDown:=GaugeHorzMouseDown;
  Gauge2.OnMouseDown:=GaugeVertMouseDown;
end;
 
procedure TForm1.GaugeHorzMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  // горизонтальный
  if Button = mbLeft then begin
    with TGauge(Sender) do Progress:=(round(((MaxValue-MinValue)/Width)*X)+MinValue);
  end;
end;
 
procedure TForm1.GaugeVertMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  // вертикальный
  if Button = mbLeft then begin
    with TGauge(Sender) do Progress:=-1*(round((MaxValue-MinValue)/Height*Y)+MinValue-MaxValue);
  end;
end;
 
end.