reactos/reactos/subsys/csrss/win32csr/desktopbg.c

/* $Id: desktopbg.c,v 1.6 2004/01/17 15:18:25 navaraf Exp $
 *
 * reactos/subsys/csrss/win32csr/desktopbg.c
 *
 * Desktop background window functions
 *
 * ReactOS Operating System
 */

#include <windows.h>
#include <csrss/csrss.h>

#include "api.h"
#include "desktopbg.h"

#define NDEBUG
#include <debug.h>

#define DESKTOP_WINDOW_ATOM 32880

#ifndef WM_APP
#define WM_APP 0x8000
#endif
#define PM_SHOW_DESKTOP (WM_APP + 1)
#define PM_HIDE_DESKTOP (WM_APP + 2)

typedef struct tagDTBG_THREAD_DATA
{
  HDESK Desktop;
  HANDLE Event;
  NTSTATUS Status;
} DTBG_THREAD_DATA, *PDTBG_THREAD_DATA;

static BOOL Initialized = FALSE;
static HWND VisibleDesktopWindow = NULL;

static LRESULT CALLBACK
DtbgWindowProc(HWND Wnd, UINT Msg, WPARAM wParam, LPARAM lParam)
{
  LRESULT Result;

  switch(Msg)
    {
      case WM_NCCREATE:
        Result = (LRESULT) TRUE;
        break;
      case WM_CREATE:
        Result = 0;
        break;
      case WM_PAINT:
        {
          PAINTSTRUCT PS;
          BeginPaint(Wnd, &PS);
          /* No need to paint, already done in WM_ERASEBKGND. */
          EndPaint(Wnd, &PS);
          Result = 0;
        }
        break;
      case WM_ERASEBKGND:
        {
          PaintDesktop((HDC)wParam);
          Result = 1;
        }
        break;
      case PM_SHOW_DESKTOP:
        Result = ! SetWindowPos(Wnd,
                                NULL, 0, 0,
                                (int)(short) LOWORD(lParam),
                                (int)(short) HIWORD(lParam),
                                SWP_NOACTIVATE | SWP_NOZORDER | SWP_SHOWWINDOW | SWP_NOREDRAW);
        UpdateWindow(Wnd);
        VisibleDesktopWindow = Wnd;
        break;
      case PM_HIDE_DESKTOP:
        Result = ! SetWindowPos(Wnd,
                                NULL, 0, 0, 0, 0,
                                SWP_NOACTIVATE | SWP_NOZORDER | SWP_NOMOVE | SWP_NOSIZE |
                                SWP_HIDEWINDOW);
        UpdateWindow(Wnd);
        VisibleDesktopWindow = NULL;
        break;
      default:
        Result = 0;
        break;
    }

  return Result;
}

static BOOL FASTCALL
DtbgInit()
{
  WNDCLASSEXW Class;
  HWINSTA WindowStation;
  ATOM ClassAtom;

  /* Attach to window station */
  WindowStation = OpenWindowStationW(L"WinSta0", FALSE, GENERIC_ALL);
  if (NULL == WindowStation)
    {
      DPRINT1("Failed to open window station\n");
      return FALSE;
    }
  if (! SetProcessWindowStation(WindowStation))
    {
      DPRINT1("Failed to set process window station\n");
      return FALSE;
    }

  /* 
   * Create the desktop window class
   */
  Class.cbSize = sizeof(WNDCLASSEXW);
  Class.style = 0;
  Class.lpfnWndProc = DtbgWindowProc;
  Class.cbClsExtra = 0;
  Class.cbWndExtra = 0;
  Class.hInstance = (HINSTANCE) GetModuleHandleW(NULL);
  Class.hIcon = NULL;
  Class.hCursor = NULL;
  Class.hbrBackground = GetSysColorBrush(COLOR_BACKGROUND);
  Class.lpszMenuName = NULL;
  Class.lpszClassName = (LPCWSTR) DESKTOP_WINDOW_ATOM;
  ClassAtom = RegisterClassExW(&Class);
  if ((ATOM) 0 == ClassAtom)
    {
      DPRINT1("Unable to register desktop background class (error %d)\n",
              GetLastError());
      return FALSE;
    }
  VisibleDesktopWindow = NULL;

  return TRUE;
}

static DWORD STDCALL
DtbgDesktopThread(PVOID Data)
{
  HWND BackgroundWnd;
  MSG msg;
  PDTBG_THREAD_DATA ThreadData = (PDTBG_THREAD_DATA) Data;

  if (! SetThreadDesktop(ThreadData->Desktop))
    {
      DPRINT1("Failed to set thread desktop\n");
      ThreadData->Status = STATUS_UNSUCCESSFUL;
      SetEvent(ThreadData->Event);
      return 1;
    }
  BackgroundWnd = CreateWindowW((LPCWSTR) DESKTOP_WINDOW_ATOM,
                                L"",
                                WS_POPUP | WS_CLIPCHILDREN,
                                0,
                                0,
                                0,
                                0,
                                NULL,
                                NULL,
                                (HINSTANCE) GetModuleHandleW(NULL),
                                NULL);
  if (NULL == BackgroundWnd)
    {
      DPRINT1("Failed to create desktop background window\n");
      ThreadData->Status = STATUS_UNSUCCESSFUL;
      SetEvent(ThreadData->Event);
      return 1;
    }

  ThreadData->Status = STATUS_SUCCESS;
  SetEvent(ThreadData->Event);

  while (GetMessageW(&msg, NULL, 0, 0))
    {
      TranslateMessage(&msg);
      DispatchMessageW(&msg);
    }

  return 1;
}

CSR_API(CsrCreateDesktop)
{
  HDESK Desktop;
  DTBG_THREAD_DATA ThreadData;
  HANDLE ThreadHandle;

  DPRINT("CsrCreateDesktop\n");

  Reply->Header.MessageSize = sizeof(CSRSS_API_REPLY);
  Reply->Header.DataSize = sizeof(CSRSS_API_REPLY) - sizeof(LPC_MESSAGE);

  if (! Initialized)
    {
      Initialized = TRUE;
      if (! DtbgInit())
        {
          return Reply->Status = STATUS_UNSUCCESSFUL;
        }
    }

  Desktop = OpenDesktopW(Request->Data.CreateDesktopRequest.DesktopName,
                         0, FALSE, GENERIC_ALL);
  if (NULL == Desktop)
    {
      DPRINT1("Failed to open desktop %S\n",
              Request->Data.CreateDesktopRequest.DesktopName);
      return Reply->Status = STATUS_UNSUCCESSFUL;
    }

  ThreadData.Desktop = Desktop;
  ThreadData.Event = CreateEventW(NULL, FALSE, FALSE, NULL);
  if (NULL == ThreadData.Event)
    {
      DPRINT1("Failed to create event (error %d)\n", GetLastError());
      return Reply->Status = STATUS_UNSUCCESSFUL;
    }
  ThreadHandle = CreateThread(NULL,
                              0,
                              DtbgDesktopThread,
                              (PVOID) &ThreadData,
                              0,
                              NULL);
  if (NULL == ThreadHandle)
    {
      CloseHandle(ThreadData.Event);
      DPRINT1("Failed to create desktop window thread.\n");
      return Reply->Status = STATUS_UNSUCCESSFUL;
    }
  CloseHandle(ThreadHandle);

  WaitForSingleObject(ThreadData.Event, INFINITE);
  CloseHandle(ThreadData.Event);

  Reply->Status = ThreadData.Status;

  return Reply->Status;
}

CSR_API(CsrShowDesktop)
{
  DPRINT("CsrShowDesktop\n");

  Reply->Header.MessageSize = sizeof(CSRSS_API_REPLY);
  Reply->Header.DataSize = sizeof(CSRSS_API_REPLY) - sizeof(LPC_MESSAGE);

  Reply->Status = SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
                               PM_SHOW_DESKTOP,
                               0,
                               MAKELONG(Request->Data.ShowDesktopRequest.Width,
                                        Request->Data.ShowDesktopRequest.Height))
                  ? STATUS_UNSUCCESSFUL : STATUS_SUCCESS;

  return Reply->Status;
}

CSR_API(CsrHideDesktop)
{
  DPRINT("CsrHideDesktop\n");

  Reply->Header.MessageSize = sizeof(CSRSS_API_REPLY);
  Reply->Header.DataSize = sizeof(CSRSS_API_REPLY) - sizeof(LPC_MESSAGE);

  Reply->Status = SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
                               PM_HIDE_DESKTOP, 0, 0)
                  ? STATUS_UNSUCCESSFUL : STATUS_SUCCESS;

  return Reply->Status;
}

BOOL FASTCALL
DtbgIsDesktopVisible(VOID)
{
  if (NULL != VisibleDesktopWindow && ! IsWindowVisible(VisibleDesktopWindow))
    {
      VisibleDesktopWindow = NULL;
    }

  return NULL != VisibleDesktopWindow;
}

/* EOF */