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_DISPLAYCHANGE:
  72         MoveWindow(Wnd, 0, 0, LOWORD(lParam), HIWORD(lParam), TRUE);
  73         break;
  74
  75     case WM_NOTIFY:
  76     {
  77         PPRIVATE_NOTIFY_DESKTOP nmh = (PPRIVATE_NOTIFY_DESKTOP)lParam;
  78
  79         /* Use WM_NOTIFY for private messages since
  80          * it can't be sent between processes!
  81          */
  82         switch (nmh->hdr.code)
  83         {
  84         case PM_SHOW_DESKTOP:
  85         {
  86             LRESULT Result;
  87
  88             Result = !SetWindowPos(Wnd, NULL, 0, 0,
  89                                    nmh->ShowDesktop.Width,
  90                                    nmh->ShowDesktop.Height,
  91                                    SWP_NOACTIVATE | SWP_NOZORDER |
  92                                    SWP_SHOWWINDOW);
  93
  94             UpdateWindow(Wnd);
  95             VisibleDesktopWindow = Wnd;
  96             return Result;
  97         }
  98
  99         case PM_HIDE_DESKTOP:
 100         {
 101             LRESULT Result;
 102
 103             Result = !SetWindowPos(Wnd, NULL, 0, 0, 0, 0,
 104                                    SWP_NOACTIVATE | SWP_NOZORDER |
 105                                    SWP_NOMOVE | SWP_NOSIZE | SWP_HIDEWINDOW);
 106
 107             UpdateWindow(Wnd);
 108             VisibleDesktopWindow = NULL;
 109             return Result;
 110         }
 111
 112         default:
 113             DPRINT("Unknown notification code 0x%x sent to the desktop window!\n",
 114                    nmh->hdr.code);
 115             return 0;
 116         }
 117     }
 118
 119     default:
 120         return DefWindowProcW(Wnd, Msg, wParam, lParam);
 121     }
 122
 123     return 0;
 124 }
 125
 126 static
 127 BOOL
 128 FASTCALL
 129 DtbgInit(VOID)
 130 {
 131     WNDCLASSEXW Class;
 132     ATOM ClassAtom;
 133
 134     /*
 135      * Create the desktop window class
 136      */
 137     Class.cbSize = sizeof(WNDCLASSEXW);
 138     Class.style = CS_GLOBALCLASS;
 139     Class.lpfnWndProc = DtbgWindowProc;
 140     Class.cbClsExtra = 0;
 141     Class.cbWndExtra = 0;
 142     Class.hInstance = (HINSTANCE)GetModuleHandleW(NULL);
 143     Class.hIcon = NULL;
 144     Class.hCursor = NULL;
 145     Class.hbrBackground = GetSysColorBrush(COLOR_BACKGROUND);
 146     Class.lpszMenuName = NULL;
 147     Class.lpszClassName = (LPCWSTR)DESKTOP_WINDOW_ATOM;
 148     ClassAtom = RegisterClassExW(&Class);
 149
 150     if (ClassAtom == INVALID_ATOM)
 151     {
 152         DPRINT1("Unable to register desktop background class (error %d)\n",
 153                 GetLastError());
 154
 155         return FALSE;
 156     }
 157
 158     VisibleDesktopWindow = NULL;
 159
 160     return TRUE;
 161 }
 162
 163 static
 164 DWORD
 165 WINAPI
 166 DtbgDesktopThread(PVOID Data)
 167 {
 168     HWND BackgroundWnd;
 169     MSG msg;
 170     PDTBG_THREAD_DATA ThreadData = (PDTBG_THREAD_DATA)Data;
 171
 172     if (!SetThreadDesktop(ThreadData->Desktop))
 173     {
 174         DPRINT1("Failed to set thread desktop\n");
 175         ThreadData->Status = STATUS_UNSUCCESSFUL;
 176         SetEvent(ThreadData->Event);
 177         return 1;
 178     }
 179
 180     BackgroundWnd = CreateWindowW((LPCWSTR)DESKTOP_WINDOW_ATOM,
 181                                   L"",
 182                                   WS_POPUP | WS_CLIPCHILDREN,
 183                                   0, 0, 0, 0,
 184                                   NULL, NULL,
 185                                   (HINSTANCE)GetModuleHandleW(NULL),
 186                                   NULL);
 187
 188     if (NULL == BackgroundWnd)
 189     {
 190         DPRINT1("Failed to create desktop background window\n");
 191         ThreadData->Status = STATUS_UNSUCCESSFUL;
 192         SetEvent(ThreadData->Event);
 193         return 1;
 194     }
 195
 196     ThreadData->Status = STATUS_SUCCESS;
 197     SetEvent(ThreadData->Event);
 198
 199     while (GetMessageW(&msg, NULL, 0, 0))
 200     {
 201         TranslateMessage(&msg);
 202         DispatchMessageW(&msg);
 203     }
 204
 205     return 1;
 206 }
 207
 208 CSR_API(CsrCreateDesktop)
 209 {
 210     DTBG_THREAD_DATA ThreadData;
 211     HANDLE ThreadHandle;
 212
 213     DPRINT("CsrCreateDesktop\n");
 214
 215     Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
 216     Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
 217
 218     if (!BgInitialized)
 219     {
 220         BgInitialized = TRUE;
 221
 222         if (!DtbgInit())
 223             return STATUS_UNSUCCESSFUL;
 224     }
 225
 226     /*
 227      * The desktop handle we got from win32k is in
 228      * the scope of CSRSS so we can just use it.
 229      */
 230     ThreadData.Desktop = Request->Data.CreateDesktopRequest.DesktopHandle;
 231
 232     ThreadData.Event = CreateEventW(NULL, FALSE, FALSE, NULL);
 233
 234     if (NULL == ThreadData.Event)
 235     {
 236         DPRINT1("Failed to create event (error %d)\n", GetLastError());
 237         return STATUS_UNSUCCESSFUL;
 238     }
 239
 240     ThreadHandle = CreateThread(NULL,
 241                                 0,
 242                                 DtbgDesktopThread,
 243                                 (PVOID)&ThreadData,
 244                                 0,
 245                                 NULL);
 246
 247     if (NULL == ThreadHandle)
 248     {
 249         CloseHandle(ThreadData.Event);
 250         DPRINT1("Failed to create desktop window thread.\n");
 251         return STATUS_UNSUCCESSFUL;
 252     }
 253
 254     CloseHandle(ThreadHandle);
 255
 256     WaitForSingleObject(ThreadData.Event, INFINITE);
 257     CloseHandle(ThreadData.Event);
 258
 259     return ThreadData.Status;
 260 }
 261
 262 CSR_API(CsrShowDesktop)
 263 {
 264     PRIVATE_NOTIFY_DESKTOP nmh;
 265     DPRINT("CsrShowDesktop\n");
 266
 267     Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
 268     Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
 269
 270     nmh.hdr.hwndFrom = Request->Data.ShowDesktopRequest.DesktopWindow;
 271     nmh.hdr.idFrom = 0;
 272     nmh.hdr.code = PM_SHOW_DESKTOP;
 273
 274     nmh.ShowDesktop.Width = (int)Request->Data.ShowDesktopRequest.Width;
 275     nmh.ShowDesktop.Height = (int)Request->Data.ShowDesktopRequest.Height;
 276
 277     if (SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
 278                      WM_NOTIFY,
 279                      (WPARAM)nmh.hdr.hwndFrom,
 280                      (LPARAM)&nmh))
 281     {
 282         return STATUS_UNSUCCESSFUL;
 283     }
 284
 285     return STATUS_SUCCESS;
 286 }
 287
 288 CSR_API(CsrHideDesktop)
 289 {
 290     PRIVATE_NOTIFY_DESKTOP nmh;
 291     DPRINT("CsrHideDesktop\n");
 292
 293     Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
 294     Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
 295
 296     nmh.hdr.hwndFrom = Request->Data.ShowDesktopRequest.DesktopWindow;
 297     nmh.hdr.idFrom = 0;
 298     nmh.hdr.code = PM_HIDE_DESKTOP;
 299
 300     if (SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
 301                      WM_NOTIFY,
 302                      (WPARAM)nmh.hdr.hwndFrom,
 303                      (LPARAM)&nmh))
 304     {
 305         return STATUS_UNSUCCESSFUL;
 306     }
 307
 308     return STATUS_SUCCESS;
 309 }
 310
 311 BOOL
 312 FASTCALL
 313 DtbgIsDesktopVisible(VOID)
 314 {
 315     if (VisibleDesktopWindow != NULL &&
 316             !IsWindowVisible(VisibleDesktopWindow))
 317     {
 318         VisibleDesktopWindow = NULL;
 319     }
 320
 321     return VisibleDesktopWindow != NULL;
 322 }
 323
 324 /* EOF */