unit windowselector;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils,
  ctypes,
  window, windowutil,
  controls,
  graphics,
  forms,
  {$IFNDEF MSWINDOWS}x, xlib
  {$ELSE}
  windows
  {$ENDIF}

  ;

type
    TMWindowSelector = class(TObject)
          constructor Create(aWindow: TMWindow);
          destructor Destroy; override;

          {$IFDEF LINUX}
          function Drag: x.TWindow;
          {$ELSE}
          function Drag: Hwnd;
          {$ENDIF}

    public
          Window: TMWindow;

    end;


implementation


constructor TMWindowSelector.Create(aWindow: TMWindow);
begin
  inherited create;

  Self.Window := aWindow;

end;


destructor TMWindowSelector.Destroy;
begin

  inherited;
end;

{$IFDEF LINUX}
function TMWindowSelector.Drag: x.TWindow;
var
  Tempwindow : x.TWindow;
  root : x.TWindow;
  subwindow : x.TWindow;
  x_root, y_root : cint;
  xmask : cuint;
  x, y : cint;
  Old_Handler : TXErrorHandler;

begin
  Old_Handler := XSetErrorHandler(@MufasaXErrorHandler);

  Result := 0;

  repeat
    XQueryPointer(Window.XDisplay, Window.DesktopWindow, @root,
                @Tempwindow, @x_root, @y_root,
                @x, @y, @xmask);
    subwindow:= Tempwindow;

    while subwindow <> 0 do
    begin
        Tempwindow := subwindow;
        XQueryPointer(Window.XDisplay, Tempwindow, @root,
                 @subwindow, @x_root, @y_root,
                 @x, @y, @xmask);
    end;
    if Result <> Tempwindow then
    begin
      WriteLn('Changing Window to: ' + IntToStr(Tempwindow));
      Result := Tempwindow;
    end;

    Sleep(16);

  until (xmask and Button1Mask) = 0;

  XSetErrorHandler(Old_handler);
end;

{$ELSE}

function TMWindowSelector.Drag: Hwnd;
var
  TargetRect: TRect;
  DC: HDC;
  OldPen, Pen: hPen;
  OldBrush : hBrush;
  BrushHandle : THandle;
  Cursor : TCursor;
  TempHandle : Hwnd;
  Handle : Hwnd;
begin;
  Pen := CreatePen(PS_SOLID, GetSystemMetrics(SM_CXBORDER)*5, clred);
  BrushHandle := GetStockObject(Null_Brush);
  Cursor:= Screen.Cursor;
  Screen.Cursor:= crCross;
  TempHandle := GetDesktopWindow;
  while GetAsyncKeyState(VK_LBUTTON) <> 0 do
  begin;
    Handle:= WindowFromPoint(Mouse.CursorPos);
    if Handle <> TempHandle then
    begin;
      if TempHandle <> 0 then
      begin;
        Invalidaterect(temphandle, nil, true);
        UpdateWindow(temphandle);
        {$IFDEF MSWINDOWS}
        RedrawWindow(TempHandle, nil, 0, RDW_Frame or RDW_Invalidate or RDW_Updatenow or RDW_Allchildren);
        {$ENDIF}
      end;
      if Handle <> 0 then
      begin;
        GetWindowRect(Handle, TargetRect);
        DC := Windows.GetWindowDC(Handle);
        OldPen := SelectObject(DC, Pen);
        OldBrush := SelectObject(DC, BrushHandle);
        Rectangle(DC, 0, 0, TargetRect.Right - TargetRect.Left, TargetRect.Bottom - TargetRect.Top);
        SelectObject(DC, OldBrush);
        SelectObject(DC, OldPen);
        ReleaseDC(Handle, DC);
      end;
      TempHandle  := Handle;
    end;
    Sleep(64);
  end;
  Result := TempHandle;
  Screen.Cursor:= cursor;
  Invalidaterect(temphandle, nil, true);
  UpdateWindow(temphandle);
  RedrawWindow(TempHandle, nil, 0, RDW_Frame or RDW_Invalidate or RDW_Updatenow or RDW_Allchildren);
  DeleteObject(Pen);
end;
{$ENDIF}



end.