Source8


unit PrimeForm;

interface

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

type
TPrimeFrm = class(TForm)
NumEdit: TEdit;
SpawnButton: TButton;
ResultsMemo: TMemo;
procedure SpawnButtonClick(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
private
{ Private declarations }
FThreadRefCount: integer;
procedure HandleTerminate(Sender: TObject);
public
{ Public declarations }
end;

var
PrimeFrm: TPrimeFrm;

implementation

uses PrimeThread;

{$R *.DFM}

procedure TPrimeFrm.SpawnButtonClick(Sender: TObject);

var
NewThread: TPrimeThrd;

begin
NewThread := TPrimeThrd.Create(True);
NewThread.FreeOnTerminate := True;
try
with NewThread do
begin
TestNumber := StrToInt(NumEdit.Text);
Inc(FThreadRefCount);
OnTerminate := HandleTerminate;
Resume;
end;
except on EConvertError do
begin
NewThread.Free;
ShowMessage('That is not a valid number!');
end;
end;
end;

procedure TPrimeFrm.FormCreate(Sender: TObject);
begin
FThreadRefCount := 0;
end;

procedure TPrimeFrm.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
CanClose := true;
if FThreadRefCount > 0 then
begin
if MessageDlg('Threads active. Do you still want to quit?',
mtWarning, [mbYes, mbNo], 0) = mrNo then
CanClose := false;
end;
end;

procedure TPrimeFrm.HandleTerminate(Sender: TObject);
begin
Dec(FThreadRefCount);
end;

end.