unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs;

type
  TForm1 = class(TForm)
    procedure FormKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
    procedure FormKeyUp(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure FormMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure FormMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;
    strgpressed,keypressed:Boolean ;
  Ortho_korrdinate:Integer ;


implementation

{$R *.dfm}

procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
if strgpressed=False then begin
   strgpressed:= Shift=[ssCtrl] ;
   Ortho_korrdinate:=Mouse.CursorPos.X ;
end ;
end;


procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
if (strgpressed) and (keypressed) then begin SetCursorpos(Ortho_korrdinate,Mouse.CursorPos.Y);
Canvas.LineTo(X, Y); end;
end;


procedure TForm1.FormKeyUp(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
strgpressed:=False ;
end;



procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
if keypressed=False then begin
   keypressed:=True ;
   Ortho_korrdinate:=Mouse.CursorPos.X ;
   Canvas.MoveTo(X, Y);
end ;

end;


procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
keypressed:=False ;
end;


end.