unit UFlowVisionArea;

interface

Uses Windows, Messages;

Type

 TFlowInformation = Record
   ClassName: PWideChar;
   BasicName: PWideChar;
   hIconName: PWideChar;
   dwExStyle: Cardinal;
   dwStyle: Cardinal;
   Style: Cardinal;
   Color: Byte;
   Atom: TAtom;
   WMSG: MSG;
 End;

 TFlowConstructor = Packed Record
   Active: LongBool;
   Handle: HWND;
   Top: Integer;
   Left: Integer;
   Right: Integer;
   Bottom: Integer;
   Width: Integer;
   Height: Integer;
   Diagonal: Integer;
   StartTick: Cardinal;
   WndClassEx: TWndClassEx;
 End;

 TFlowVisionArea = class
 Protected
 var
   FlowInformation: TFlowInformation;
   FlowConstructor: TFlowConstructor;
 Protected
   Procedure IncomeData;
   Procedure ResultData; virtual;
   Procedure InsideData(Key: PInteger); virtual;
   Procedure ActiveData(Key: PInteger); virtual;
   Procedure ChangeName(Name: PWideChar);
 Public
   Constructor Create; virtual;
   Destructor Destroy; override;
 end;

implementation

// Процедура обработки сообщений Windows
function WindowProc(wnd: HWND; MSG: Integer; wparam: wparam; lparam: lparam)
 : LRESULT; STDCALL;
begin
 case MSG of
   WM_DESTROY:
     begin
       PostQuitMessage(0);
       Result := 0;
       Exit;
     end;
 else
   Result := DefWindowProc(wnd, MSG, wparam, lparam);
 end;
end;

{ TFlowVisualizer }

procedure TFlowVisionArea.ActiveData(Key: PInteger);
begin
 With FlowConstructor do
   case Key^ of
     WA_ACTIVE:
       begin
         SetActiveWindow(Handle);
         ShowWindow(Handle, SW_RESTORE);
         SetForegroundWindow(Handle);
         Active := True;
       end;
     WA_CLICKACTIVE:
       begin
         Active := True;
       end;
     WA_INACTIVE:
       begin
         Active := False;
       end;
   end;
end;

procedure TFlowVisionArea.ChangeName(Name: PWideChar);
begin
 if Name = #0 then
   SetWindowText(FlowConstructor.Handle, FlowInformation.BasicName)
 else
   SetWindowText(FlowConstructor.Handle, Name);
end;

constructor TFlowVisionArea.Create;
var
 NoCopy: HWND;
begin
 With FlowConstructor, FlowInformation do
 begin
   StartTick := GetTickCount;

   // Проверяем существование копии программы
   NoCopy := FindWindow(ClassName, nil);
   if (IsIconic(NoCopy)) then
   begin
     ShowWindow(NoCopy, SW_RESTORE);
     SetForegroundWindow(NoCopy);
     StartTick := 0;
     Exit;
   end;

   // Запись параметров
   WndClassEx.cbSize := SizeOf(WndClassEx);
   WndClassEx.Style := Style;
   WndClassEx.lpfnWndProc := @WindowProc;
   WndClassEx.cbClsExtra := 0;
   WndClassEx.cbWndExtra := 0;
   WndClassEx.hInstance := hInstance;
   WndClassEx.hIcon := LoadIcon(hInstance, hIconName);
   WndClassEx.hCursor := LoadCursor(0, MAKEINTRESOURCE(IDC_ARROW));
   WndClassEx.hbrBackground := Color_BtnFace + Color;
   WndClassEx.lpszMenuName := nil;
   WndClassEx.lpszClassName := ClassName;
   WndClassEx.hIconSm := LoadIcon(hInstance, hIconName);

   // Регистрация класса окна
   Atom := RegisterClassEx(WndClassEx);

   // Запись данных о формате экрана
   if Left < 0 then
     Left := GetSystemMetrics(SM_XVIRTUALSCREEN);
   if Top < 0 then
     Top := GetSystemMetrics(SM_YVIRTUALSCREEN);
   if Right = 0 then
     Right := GetSystemMetrics(SM_CXVIRTUALSCREEN);
   if Bottom = 0 then
     Bottom := GetSystemMetrics(SM_CYVIRTUALSCREEN);
   Width := Right - Left;
   Height := Bottom - Top;
   Diagonal := Round(Sqrt(Sqr(Width) + Sqr(Height)));
   Handle := CreateWindowEx(dwExStyle, ClassName, BasicName, dwStyle, Left,
     Top, Right, Bottom, 0, 0, hInstance, nil);
 end;
end;

destructor TFlowVisionArea.Destroy;
begin
 if not FlowInformation.Atom = 0 then
   GlobalDeleteAtom(FlowInformation.Atom);
 PostMessage(FlowConstructor.Handle, WM_CLOSE, 0, 0);
 inherited;
end;

procedure TFlowVisionArea.IncomeData;
begin
 With FlowInformation do
   while GetMessage(WMSG, 0, 0, 0) do
   begin
     TranslateMessage(WMSG);
     DispatchMessage(WMSG);
     Case WMSG.message OF
       WM_KEYDOWN:
         InsideData(@WMSG.wparam);
       WM_ACTIVATE:
         ActiveData(@WMSG.wparam);
     END;
   end;
end;

procedure TFlowVisionArea.InsideData(Key: PInteger);
begin
 if Key = nil then
   Destroy;
end;

procedure TFlowVisionArea.ResultData;
begin
 ShowWindow(FlowConstructor.Handle, SW_SHOWMAXIMIZED);
end;

end.

      WM_ACTIVATE:
        ActiveData(@WMSG.wparam);

 With FlowInformation do
   while GetMessage(WMSG, 0, 0, 0) do
   begin
     If TranslateMessage(WMSG) then
       InsideData(@WMSG.wparam)
     else
       DispatchMessage(WMSG);
     ActiveData(IsIconic(FlowConstructor.Handle));
   end;