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
  12 #include "w32csr.h"
  13 #include <debug.h>
  14
  15 #define DESKTOP_WINDOW_ATOM 32769
  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     struct /* PM_SHOW_DESKTOP */
  31     {
  32         int Width;
  33         int Height;
  34     } ShowDesktop;
  35 } PRIVATE_NOTIFY_DESKTOP, *PPRIVATE_NOTIFY_DESKTOP;
  36
  37 static BOOL BgInitialized = FALSE;
  38 static HWND VisibleDesktopWindow = NULL;
  39
  40 static
  41 LRESULT
  42 CALLBACK
  43 DtbgWindowProc(HWND Wnd,
  44                UINT Msg,
  45                WPARAM wParam,
  46                LPARAM lParam)
  47 {
  48     PAINTSTRUCT PS;
  49
  50     switch (Msg)
  51     {
  52         case WM_ERASEBKGND:
  53             PaintDesktop((HDC)wParam);
  54             return 1;
  55
  56         case WM_PAINT:
  57             if (BeginPaint(Wnd, &PS))
  58                 EndPaint(Wnd, &PS);
  59             return 0;
  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         case WM_CLOSE:
  69             return 0;
  70
  71         case WM_NOTIFY:
  72         {
  73             PPRIVATE_NOTIFY_DESKTOP nmh = (PPRIVATE_NOTIFY_DESKTOP)lParam;
  74
  75             /* Use WM_NOTIFY for private messages since
  76              * it can't be sent between processes!
  77              */
  78             switch (nmh->hdr.code)
  79             {
  80                 case PM_SHOW_DESKTOP:
  81                 {
  82                     LRESULT Result;
  83
  84                     Result = !SetWindowPos(Wnd, NULL, 0, 0,
  85                                            nmh->ShowDesktop.Width,
  86                                            nmh->ShowDesktop.Height,
  87                                            SWP_NOACTIVATE | SWP_NOZORDER |
  88                                            SWP_SHOWWINDOW);
  89
  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, NULL, 0, 0, 0, 0,
 100                                            SWP_NOACTIVATE | SWP_NOZORDER |
 101                                            SWP_NOMOVE | SWP_NOSIZE | SWP_HIDEWINDOW);
 102
 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",
 110                            nmh->hdr.code);
 111                     return 0;
 112             }
 113         }
 114
 115         default:
 116             return DefWindowProcW(Wnd, Msg, wParam, lParam);
 117     }
 118
 119     return 0;
 120 }
 121
 122 static
 123 BOOL
 124 FASTCALL
 125 DtbgInit(VOID)
 126 {
 127     WNDCLASSEXW Class;
 128     ATOM ClassAtom;
 129
 130     /*
 131      * Create the desktop window class
 132      */
 133     Class.cbSize = sizeof(WNDCLASSEXW);
 134     Class.style = CS_GLOBALCLASS;
 135     Class.lpfnWndProc = DtbgWindowProc;
 136     Class.cbClsExtra = 0;
 137     Class.cbWndExtra = 0;
 138     Class.hInstance = (HINSTANCE)GetModuleHandleW(NULL);
 139     Class.hIcon = NULL;
 140     Class.hCursor = NULL;
 141     Class.hbrBackground = GetSysColorBrush(COLOR_BACKGROUND);
 142     Class.lpszMenuName = NULL;
 143     Class.lpszClassName = (LPCWSTR)DESKTOP_WINDOW_ATOM;
 144     ClassAtom = RegisterClassExW(&Class);
 145
 146     if (ClassAtom == INVALID_ATOM)
 147     {
 148         DPRINT1("Unable to register desktop background class (error %d)\n",
 149                 GetLastError());
 150
 151         return FALSE;
 152     }
 153
 154     VisibleDesktopWindow = NULL;
 155
 156     return TRUE;
 157 }
 158
 159 static
 160 DWORD
 161 WINAPI
 162 DtbgDesktopThread(PVOID Data)
 163 {
 164     HWND BackgroundWnd;
 165     MSG msg;
 166     PDTBG_THREAD_DATA ThreadData = (PDTBG_THREAD_DATA)Data;
 167
 168     if (!SetThreadDesktop(ThreadData->Desktop))
 169     {
 170         DPRINT1("Failed to set thread desktop\n");
 171         ThreadData->Status = STATUS_UNSUCCESSFUL;
 172         SetEvent(ThreadData->Event);
 173         return 1;
 174     }
 175
 176     BackgroundWnd = CreateWindowW((LPCWSTR)DESKTOP_WINDOW_ATOM,
 177                                   L"",
 178                                   WS_POPUP | WS_CLIPCHILDREN,
 179                                   0, 0, 0, 0,
 180                                   NULL, NULL,
 181                                   (HINSTANCE)GetModuleHandleW(NULL),
 182                                   NULL);
 183
 184     if (NULL == BackgroundWnd)
 185     {
 186         DPRINT1("Failed to create desktop background window\n");
 187         ThreadData->Status = STATUS_UNSUCCESSFUL;
 188         SetEvent(ThreadData->Event);
 189         return 1;
 190     }
 191
 192     ThreadData->Status = STATUS_SUCCESS;
 193     SetEvent(ThreadData->Event);
 194
 195     while (GetMessageW(&msg, NULL, 0, 0))
 196     {
 197         TranslateMessage(&msg);
 198         DispatchMessageW(&msg);
 199     }
 200
 201     return 1;
 202 }
 203
 204 CSR_API(CsrCreateDesktop)
 205 {
 206     DTBG_THREAD_DATA ThreadData;
 207     HANDLE ThreadHandle;
 208
 209     DPRINT("CsrCreateDesktop\n");
 210
 211     Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
 212     Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
 213
 214     if (!BgInitialized)
 215     {
 216         BgInitialized = TRUE;
 217
 218         if (!DtbgInit())
 219             return STATUS_UNSUCCESSFUL;
 220     }
 221
 222     /*
 223      * The desktop handle we got from win32k is in
 224      * the scope of CSRSS so we can just use it.
 225      */
 226     ThreadData.Desktop = Request->Data.CreateDesktopRequest.DesktopHandle;
 227
 228     ThreadData.Event = CreateEventW(NULL, FALSE, FALSE, NULL);
 229
 230     if (NULL == ThreadData.Event)
 231     {
 232         DPRINT1("Failed to create event (error %d)\n", GetLastError());
 233         return STATUS_UNSUCCESSFUL;
 234     }
 235
 236     ThreadHandle = CreateThread(NULL,
 237                                 0,
 238                                 DtbgDesktopThread,
 239                                 (PVOID)&ThreadData,
 240                                 0,
 241                                 NULL);
 242
 243     if (NULL == ThreadHandle)
 244     {
 245         CloseHandle(ThreadData.Event);
 246         DPRINT1("Failed to create desktop window thread.\n");
 247         return STATUS_UNSUCCESSFUL;
 248     }
 249
 250     CloseHandle(ThreadHandle);
 251
 252     WaitForSingleObject(ThreadData.Event, INFINITE);
 253     CloseHandle(ThreadData.Event);
 254
 255     return ThreadData.Status;
 256 }
 257
 258 CSR_API(CsrShowDesktop)
 259 {
 260     PRIVATE_NOTIFY_DESKTOP nmh;
 261     DPRINT("CsrShowDesktop\n");
 262
 263     Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
 264     Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
 265
 266     nmh.hdr.hwndFrom = Request->Data.ShowDesktopRequest.DesktopWindow;
 267     nmh.hdr.idFrom = 0;
 268     nmh.hdr.code = PM_SHOW_DESKTOP;
 269
 270     nmh.ShowDesktop.Width = (int)Request->Data.ShowDesktopRequest.Width;
 271     nmh.ShowDesktop.Height = (int)Request->Data.ShowDesktopRequest.Height;
 272
 273     if (SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
 274                      WM_NOTIFY,
 275                      (WPARAM)nmh.hdr.hwndFrom,
 276                      (LPARAM)&nmh))
 277     {
 278         return STATUS_UNSUCCESSFUL;
 279     }
 280
 281     return STATUS_SUCCESS;
 282 }
 283
 284 CSR_API(CsrHideDesktop)
 285 {
 286     PRIVATE_NOTIFY_DESKTOP nmh;
 287     DPRINT("CsrHideDesktop\n");
 288
 289     Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
 290     Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
 291
 292     nmh.hdr.hwndFrom = Request->Data.ShowDesktopRequest.DesktopWindow;
 293     nmh.hdr.idFrom = 0;
 294     nmh.hdr.code = PM_HIDE_DESKTOP;
 295
 296     if (SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
 297                      WM_NOTIFY,
 298                      (WPARAM)nmh.hdr.hwndFrom,
 299                      (LPARAM)&nmh))
 300     {
 301         return STATUS_UNSUCCESSFUL;
 302     }
 303
 304     return STATUS_SUCCESS;
 305 }
 306
 307 BOOL
 308 FASTCALL
 309 DtbgIsDesktopVisible(VOID)
 310 {
 311     if (VisibleDesktopWindow != NULL &&
 312         !IsWindowVisible(VisibleDesktopWindow))
 313     {
 314         VisibleDesktopWindow = NULL;
 315     }
 316
 317     return VisibleDesktopWindow != NULL;
 318 }
 319
 320 /* EOF */