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