reactos/subsystems/win32/csrss/win32csr/desktopbg.c

   1 /* $Id$
   2  *
   3  * reactos/subsys/csrss/win32csr/desktopbg.c
   4  *
   5  * Desktop background window functions
   6  *
   7  * ReactOS Operating System
   8  */
   9
  10 #define NDEBUG
  11 #include "w32csr.h"
  12 #include <debug.h>
  13
  14 #define DESKTOP_WINDOW_ATOM 32880
  15
  16 #define PM_SHOW_DESKTOP 1
  17 #define PM_HIDE_DESKTOP 2
  18
  19 typedef struct tagDTBG_THREAD_DATA
  20 {
  21   HDESK Desktop;
  22   HANDLE Event;
  23   NTSTATUS Status;
  24 } DTBG_THREAD_DATA, *PDTBG_THREAD_DATA;
  25
  26 typedef struct tagPRIVATE_NOTIFY_DESKTOP
  27 {
  28   NMHDR hdr;
  29   union
  30   {
  31     struct /* PM_SHOW_DESKTOP */
  32     {
  33       int Width;
  34       int Height;
  35     } ShowDesktop;
  36   };
  37 } PRIVATE_NOTIFY_DESKTOP, *PPRIVATE_NOTIFY_DESKTOP;
  38
  39 static BOOL BgInitialized = FALSE;
  40 static HWND VisibleDesktopWindow = NULL;
  41
  42 static LRESULT CALLBACK
  43 DtbgWindowProc(HWND Wnd, UINT Msg, WPARAM wParam, LPARAM lParam)
  44 {
  45   switch(Msg)
  46     {
  47       case WM_ERASEBKGND:
  48         return 1;
  49
  50       case WM_PAINT:
  51       {
  52         PAINTSTRUCT PS;
  53         RECT rc;
  54         HDC hDC;
  55
  56         if(GetUpdateRect(Wnd, &rc, FALSE) &&
  57            (hDC = BeginPaint(Wnd, &PS)))
  58         {
  59           PaintDesktop(hDC);
  60           EndPaint(Wnd, &PS);
  61         }
  62         return 0;
  63       }
  64
  65       case WM_SETCURSOR:
  66         return (LRESULT) SetCursor(LoadCursorW(0, (LPCWSTR)IDC_ARROW));
  67
  68       case WM_NCCREATE:
  69         return (LRESULT) TRUE;
  70
  71       case WM_CREATE:
  72         return 0;
  73
  74       case WM_NOTIFY:
  75       {
  76         PPRIVATE_NOTIFY_DESKTOP nmh = (PPRIVATE_NOTIFY_DESKTOP)lParam;
  77
  78         /* Use WM_NOTIFY for private messages since it can't be sent between
  79            processes! */
  80         switch(nmh->hdr.code)
  81         {
  82           case PM_SHOW_DESKTOP:
  83           {
  84             LRESULT Result;
  85
  86             Result = ! SetWindowPos(Wnd,
  87                                     NULL, 0, 0,
  88                                     nmh->ShowDesktop.Width,
  89                                     nmh->ShowDesktop.Height,
  90                                     SWP_NOACTIVATE | SWP_NOZORDER | SWP_SHOWWINDOW);
  91             UpdateWindow(Wnd);
  92             VisibleDesktopWindow = Wnd;
  93             return Result;
  94           }
  95
  96           case PM_HIDE_DESKTOP:
  97           {
  98             LRESULT Result;
  99
 100             Result = ! SetWindowPos(Wnd,
 101                                     NULL, 0, 0, 0, 0,
 102                                     SWP_NOACTIVATE | SWP_NOZORDER | SWP_NOMOVE | SWP_NOSIZE |
 103                                     SWP_HIDEWINDOW);
 104             UpdateWindow(Wnd);
 105             VisibleDesktopWindow = NULL;
 106             return Result;
 107           }
 108
 109           default:
 110             DPRINT("Unknown notification code 0x%x sent to the desktop window!\n", nmh->hdr.code);
 111             return 0;
 112         }
 113       }
 114     }
 115
 116   return 0;
 117 }
 118
 119 static BOOL FASTCALL
 120 DtbgInit()
 121 {
 122   WNDCLASSEXW Class;
 123   ATOM ClassAtom;
 124
 125   /*
 126    * Create the desktop window class
 127    */
 128   Class.cbSize = sizeof(WNDCLASSEXW);
 129   Class.style = 0;
 130   Class.lpfnWndProc = DtbgWindowProc;
 131   Class.cbClsExtra = 0;
 132   Class.cbWndExtra = 0;
 133   Class.hInstance = (HINSTANCE) GetModuleHandleW(NULL);
 134   Class.hIcon = NULL;
 135   Class.hCursor = NULL;
 136   Class.hbrBackground = GetSysColorBrush(COLOR_BACKGROUND);
 137   Class.lpszMenuName = NULL;
 138   Class.lpszClassName = (LPCWSTR) DESKTOP_WINDOW_ATOM;
 139   ClassAtom = RegisterClassExW(&Class);
 140   if ((ATOM) 0 == ClassAtom)
 141     {
 142       DPRINT1("Unable to register desktop background class (error %d)\n",
 143               GetLastError());
 144       return FALSE;
 145     }
 146   VisibleDesktopWindow = NULL;
 147
 148   return TRUE;
 149 }
 150
 151 static DWORD WINAPI
 152 DtbgDesktopThread(PVOID Data)
 153 {
 154   HWND BackgroundWnd;
 155   MSG msg;
 156   PDTBG_THREAD_DATA ThreadData = (PDTBG_THREAD_DATA) Data;
 157
 158   if (! SetThreadDesktop(ThreadData->Desktop))
 159     {
 160       DPRINT1("Failed to set thread desktop\n");
 161       ThreadData->Status = STATUS_UNSUCCESSFUL;
 162       SetEvent(ThreadData->Event);
 163       return 1;
 164     }
 165   BackgroundWnd = CreateWindowW((LPCWSTR) DESKTOP_WINDOW_ATOM,
 166                                 L"",
 167                                 WS_POPUP | WS_CLIPCHILDREN,
 168                                 0,
 169                                 0,
 170                                 0,
 171                                 0,
 172                                 NULL,
 173                                 NULL,
 174                                 (HINSTANCE) GetModuleHandleW(NULL),
 175                                 NULL);
 176   if (NULL == BackgroundWnd)
 177     {
 178       DPRINT1("Failed to create desktop background window\n");
 179       ThreadData->Status = STATUS_UNSUCCESSFUL;
 180       SetEvent(ThreadData->Event);
 181       return 1;
 182     }
 183
 184   ThreadData->Status = STATUS_SUCCESS;
 185   SetEvent(ThreadData->Event);
 186
 187   while (GetMessageW(&msg, NULL, 0, 0))
 188     {
 189       TranslateMessage(&msg);
 190       DispatchMessageW(&msg);
 191     }
 192
 193   return 1;
 194 }
 195
 196 CSR_API(CsrCreateDesktop)
 197 {
 198   DTBG_THREAD_DATA ThreadData;
 199   HANDLE ThreadHandle;
 200
 201   DPRINT("CsrCreateDesktop\n");
 202
 203   Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
 204   Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
 205
 206   if (! BgInitialized)
 207     {
 208       BgInitialized = TRUE;
 209       if (! DtbgInit())
 210         {
 211           return STATUS_UNSUCCESSFUL;
 212         }
 213     }
 214
 215   /*
 216    * the desktop handle we got from win32k is in the scope of CSRSS so we can just use it
 217    */
 218   ThreadData.Desktop = Request->Data.CreateDesktopRequest.DesktopHandle;
 219
 220   ThreadData.Event = CreateEventW(NULL, FALSE, FALSE, NULL);
 221   if (NULL == ThreadData.Event)
 222     {
 223       DPRINT1("Failed to create event (error %d)\n", GetLastError());
 224       return STATUS_UNSUCCESSFUL;
 225     }
 226   ThreadHandle = CreateThread(NULL,
 227                               0,
 228                               DtbgDesktopThread,
 229                               (PVOID) &ThreadData,
 230                               0,
 231                               NULL);
 232   if (NULL == ThreadHandle)
 233     {
 234       CloseHandle(ThreadData.Event);
 235       DPRINT1("Failed to create desktop window thread.\n");
 236       return STATUS_UNSUCCESSFUL;
 237     }
 238   CloseHandle(ThreadHandle);
 239
 240   WaitForSingleObject(ThreadData.Event, INFINITE);
 241   CloseHandle(ThreadData.Event);
 242
 243   return ThreadData.Status;
 244 }
 245
 246 CSR_API(CsrShowDesktop)
 247 {
 248   PRIVATE_NOTIFY_DESKTOP nmh;
 249   DPRINT("CsrShowDesktop\n");
 250
 251   Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
 252   Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
 253
 254   nmh.hdr.hwndFrom = Request->Data.ShowDesktopRequest.DesktopWindow;
 255   nmh.hdr.idFrom = 0;
 256   nmh.hdr.code = PM_SHOW_DESKTOP;
 257
 258   nmh.ShowDesktop.Width = (int)Request->Data.ShowDesktopRequest.Width;
 259   nmh.ShowDesktop.Height = (int)Request->Data.ShowDesktopRequest.Height;
 260
 261   return SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
 262                       WM_NOTIFY,
 263                       (WPARAM)nmh.hdr.hwndFrom,
 264                       (LPARAM)&nmh)
 265          ? STATUS_UNSUCCESSFUL : STATUS_SUCCESS;
 266 }
 267
 268 CSR_API(CsrHideDesktop)
 269 {
 270   PRIVATE_NOTIFY_DESKTOP nmh;
 271   DPRINT("CsrHideDesktop\n");
 272
 273   Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
 274   Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
 275
 276   nmh.hdr.hwndFrom = Request->Data.ShowDesktopRequest.DesktopWindow;
 277   nmh.hdr.idFrom = 0;
 278   nmh.hdr.code = PM_HIDE_DESKTOP;
 279
 280   return SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
 281                       WM_NOTIFY,
 282                       (WPARAM)nmh.hdr.hwndFrom,
 283                       (LPARAM)&nmh)
 284          ? STATUS_UNSUCCESSFUL : STATUS_SUCCESS;
 285 }
 286
 287 BOOL FASTCALL
 288 DtbgIsDesktopVisible(VOID)
 289 {
 290   if (NULL != VisibleDesktopWindow && ! IsWindowVisible(VisibleDesktopWindow))
 291     {
 292       VisibleDesktopWindow = NULL;
 293     }
 294
 295   return NULL != VisibleDesktopWindow;
 296 }
 297
 298 /* EOF */