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 32769
  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   PAINTSTRUCT PS;
  46   HDC hDC;
  47
  48     switch(Msg)
  49     {
  50       case WM_ERASEBKGND:
  51         PaintDesktop((HDC)wParam);
  52         return 1;
  53
  54       case WM_PAINT:
  55       {
  56         if((hDC = BeginPaint(Wnd, &PS)))
  57           EndPaint(Wnd, &PS);
  58         return 0;
  59       }
  60
  61       case WM_SETCURSOR:
  62         return (LRESULT) SetCursor(LoadCursorW(0, (LPCWSTR)IDC_ARROW));
  63
  64       case WM_NCCREATE:
  65         return (LRESULT) TRUE;
  66
  67       case WM_CREATE:
  68         return 0;
  69
  70       case WM_CLOSE:
  71         return 0;
  72
  73       case WM_NOTIFY:
  74       {
  75         PPRIVATE_NOTIFY_DESKTOP nmh = (PPRIVATE_NOTIFY_DESKTOP)lParam;
  76
  77         /* Use WM_NOTIFY for private messages since it can't be sent between
  78            processes! */
  79         switch(nmh->hdr.code)
  80         {
  81           case PM_SHOW_DESKTOP:
  82           {
  83             LRESULT Result;
  84
  85             Result = ! SetWindowPos(Wnd,
  86                                     NULL, 0, 0,
  87                                     nmh->ShowDesktop.Width,
  88                                     nmh->ShowDesktop.Height,
  89                                     SWP_NOACTIVATE | SWP_NOZORDER | SWP_SHOWWINDOW);
  90             UpdateWindow(Wnd);
  91             VisibleDesktopWindow = Wnd;
  92             return Result;
  93           }
  94
  95           case PM_HIDE_DESKTOP:
  96           {
  97             LRESULT Result;
  98
  99             Result = ! SetWindowPos(Wnd,
 100                                     NULL, 0, 0, 0, 0,
 101                                     SWP_NOACTIVATE | SWP_NOZORDER | SWP_NOMOVE | SWP_NOSIZE |
 102                                     SWP_HIDEWINDOW);
 103             UpdateWindow(Wnd);
 104             VisibleDesktopWindow = NULL;
 105             return Result;
 106           }
 107
 108           default:
 109             DPRINT("Unknown notification code 0x%x sent to the desktop window!\n", nmh->hdr.code);
 110             return 0;
 111         }
 112       }
 113     }
 114
 115   return 0;
 116 }
 117
 118 static BOOL FASTCALL
 119 DtbgInit()
 120 {
 121   WNDCLASSEXW Class;
 122   ATOM ClassAtom;
 123
 124   /*
 125    * Create the desktop window class
 126    */
 127   Class.cbSize = sizeof(WNDCLASSEXW);
 128   Class.style = CS_GLOBALCLASS;
 129   Class.lpfnWndProc = DtbgWindowProc;
 130   Class.cbClsExtra = 0;
 131   Class.cbWndExtra = 0;
 132   Class.hInstance = (HINSTANCE) GetModuleHandleW(NULL);
 133   Class.hIcon = NULL;
 134   Class.hCursor = NULL;
 135   Class.hbrBackground = GetSysColorBrush(COLOR_BACKGROUND);
 136   Class.lpszMenuName = NULL;
 137   Class.lpszClassName = (LPCWSTR) DESKTOP_WINDOW_ATOM;
 138   ClassAtom = RegisterClassExW(&Class);
 139   if ((ATOM) 0 == ClassAtom)
 140     {
 141       DPRINT1("Unable to register desktop background class (error %d)\n",
 142               GetLastError());
 143       return FALSE;
 144     }
 145   VisibleDesktopWindow = NULL;
 146
 147   return TRUE;
 148 }
 149
 150 static DWORD WINAPI
 151 DtbgDesktopThread(PVOID Data)
 152 {
 153   HWND BackgroundWnd;
 154   MSG msg;
 155   PDTBG_THREAD_DATA ThreadData = (PDTBG_THREAD_DATA) Data;
 156
 157   if (! SetThreadDesktop(ThreadData->Desktop))
 158     {
 159       DPRINT1("Failed to set thread desktop\n");
 160       ThreadData->Status = STATUS_UNSUCCESSFUL;
 161       SetEvent(ThreadData->Event);
 162       return 1;
 163     }
 164   BackgroundWnd = CreateWindowW((LPCWSTR) DESKTOP_WINDOW_ATOM,
 165                                 L"",
 166                                 WS_POPUP | WS_CLIPCHILDREN,
 167                                 0,
 168                                 0,
 169                                 0,
 170                                 0,
 171                                 NULL,
 172                                 NULL,
 173                                 (HINSTANCE) GetModuleHandleW(NULL),
 174                                 NULL);
 175   if (NULL == BackgroundWnd)
 176     {
 177       DPRINT1("Failed to create desktop background window\n");
 178       ThreadData->Status = STATUS_UNSUCCESSFUL;
 179       SetEvent(ThreadData->Event);
 180       return 1;
 181     }
 182
 183   ThreadData->Status = STATUS_SUCCESS;
 184   SetEvent(ThreadData->Event);
 185
 186   while (GetMessageW(&msg, NULL, 0, 0))
 187     {
 188       TranslateMessage(&msg);
 189       DispatchMessageW(&msg);
 190     }
 191
 192   return 1;
 193 }
 194
 195 CSR_API(CsrCreateDesktop)
 196 {
 197   DTBG_THREAD_DATA ThreadData;
 198   HANDLE ThreadHandle;
 199
 200   DPRINT("CsrCreateDesktop\n");
 201
 202   Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
 203   Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
 204
 205   if (! BgInitialized)
 206     {
 207       BgInitialized = TRUE;
 208       if (! DtbgInit())
 209         {
 210           return STATUS_UNSUCCESSFUL;
 211         }
 212     }
 213
 214   /*
 215    * the desktop handle we got from win32k is in the scope of CSRSS so we can just use it
 216    */
 217   ThreadData.Desktop = Request->Data.CreateDesktopRequest.DesktopHandle;
 218
 219   ThreadData.Event = CreateEventW(NULL, FALSE, FALSE, NULL);
 220   if (NULL == ThreadData.Event)
 221     {
 222       DPRINT1("Failed to create event (error %d)\n", GetLastError());
 223       return STATUS_UNSUCCESSFUL;
 224     }
 225   ThreadHandle = CreateThread(NULL,
 226                               0,
 227                               DtbgDesktopThread,
 228                               (PVOID) &ThreadData,
 229                               0,
 230                               NULL);
 231   if (NULL == ThreadHandle)
 232     {
 233       CloseHandle(ThreadData.Event);
 234       DPRINT1("Failed to create desktop window thread.\n");
 235       return STATUS_UNSUCCESSFUL;
 236     }
 237   CloseHandle(ThreadHandle);
 238
 239   WaitForSingleObject(ThreadData.Event, INFINITE);
 240   CloseHandle(ThreadData.Event);
 241
 242   return ThreadData.Status;
 243 }
 244
 245 CSR_API(CsrShowDesktop)
 246 {
 247   PRIVATE_NOTIFY_DESKTOP nmh;
 248   DPRINT("CsrShowDesktop\n");
 249
 250   Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
 251   Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
 252
 253   nmh.hdr.hwndFrom = Request->Data.ShowDesktopRequest.DesktopWindow;
 254   nmh.hdr.idFrom = 0;
 255   nmh.hdr.code = PM_SHOW_DESKTOP;
 256
 257   nmh.ShowDesktop.Width = (int)Request->Data.ShowDesktopRequest.Width;
 258   nmh.ShowDesktop.Height = (int)Request->Data.ShowDesktopRequest.Height;
 259
 260   return SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
 261                       WM_NOTIFY,
 262                       (WPARAM)nmh.hdr.hwndFrom,
 263                       (LPARAM)&nmh)
 264          ? STATUS_UNSUCCESSFUL : STATUS_SUCCESS;
 265 }
 266
 267 CSR_API(CsrHideDesktop)
 268 {
 269   PRIVATE_NOTIFY_DESKTOP nmh;
 270   DPRINT("CsrHideDesktop\n");
 271
 272   Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
 273   Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
 274
 275   nmh.hdr.hwndFrom = Request->Data.ShowDesktopRequest.DesktopWindow;
 276   nmh.hdr.idFrom = 0;
 277   nmh.hdr.code = PM_HIDE_DESKTOP;
 278
 279   return SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
 280                       WM_NOTIFY,
 281                       (WPARAM)nmh.hdr.hwndFrom,
 282                       (LPARAM)&nmh)
 283          ? STATUS_UNSUCCESSFUL : STATUS_SUCCESS;
 284 }
 285
 286 BOOL FASTCALL
 287 DtbgIsDesktopVisible(VOID)
 288 {
 289   if (NULL != VisibleDesktopWindow && ! IsWindowVisible(VisibleDesktopWindow))
 290     {
 291       VisibleDesktopWindow = NULL;
 292     }
 293
 294   return NULL != VisibleDesktopWindow;
 295 }
 296
 297 /* EOF */