[dgorbachev] 44474: Cleanup in desktopbg.c, inspired by BeastL (slyhome|AT|ipnet|DOT|ua), bug #4985.

Author: dgorbachev
Date: Tue Dec  8 22:57:27 2009
New Revision: 44474

URL: http://svn.reactos.org/svn/reactos?rev=44474&view=rev
Log:
Cleanup in desktopbg.c, inspired by BeastL (slyhome|AT|ipnet|DOT|ua), bug #4985.

Modified:
    trunk/reactos/subsystems/win32/csrss/win32csr/desktopbg.c

Modified: trunk/reactos/subsystems/win32/csrss/win32csr/desktopbg.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/win32/csrss/win…
==============================================================================
--- trunk/reactos/subsystems/win32/csrss/win32csr/desktopbg.c [iso-8859-1] (original)
+++ trunk/reactos/subsystems/win32/csrss/win32csr/desktopbg.c [iso-8859-1] Tue Dec  8
22:57:27 2009
@@ -8,6 +8,7 @@
  */
 
 #define NDEBUG
+
 #include "w32csr.h"
 #include <debug.h>
 
@@ -18,283 +19,302 @@
 
 typedef struct tagDTBG_THREAD_DATA
 {
-  HDESK Desktop;
-  HANDLE Event;
-  NTSTATUS Status;
+    HDESK Desktop;
+    HANDLE Event;
+    NTSTATUS Status;
 } DTBG_THREAD_DATA, *PDTBG_THREAD_DATA;
 
 typedef struct tagPRIVATE_NOTIFY_DESKTOP
 {
-  NMHDR hdr;
-  union
-  {
+    NMHDR hdr;
     struct /* PM_SHOW_DESKTOP */
     {
-      int Width;
-      int Height;
+        int Width;
+        int Height;
     } ShowDesktop;
-  };
 } PRIVATE_NOTIFY_DESKTOP, *PPRIVATE_NOTIFY_DESKTOP;
 
 static BOOL BgInitialized = FALSE;
 static HWND VisibleDesktopWindow = NULL;
 
-static LRESULT CALLBACK
-DtbgWindowProc(HWND Wnd, UINT Msg, WPARAM wParam, LPARAM lParam)
-{
-  PAINTSTRUCT PS;
-  HDC hDC;
-
-    switch(Msg)
-    {
-      case WM_ERASEBKGND:
-        PaintDesktop((HDC)wParam);
+static
+LRESULT
+CALLBACK
+DtbgWindowProc(HWND Wnd,
+               UINT Msg,
+               WPARAM wParam,
+               LPARAM lParam)
+{
+    PAINTSTRUCT PS;
+
+    switch (Msg)
+    {
+        case WM_ERASEBKGND:
+            PaintDesktop((HDC)wParam);
+            return 1;
+
+        case WM_PAINT:
+            if (BeginPaint(Wnd, &PS))
+                EndPaint(Wnd, &PS);
+            return 0;
+
+        case WM_SETCURSOR:
+            return (LRESULT)SetCursor(LoadCursorW(0, (LPCWSTR)IDC_ARROW));
+
+        case WM_NCCREATE:
+            return (LRESULT)TRUE;
+
+        case WM_CREATE:
+        case WM_CLOSE:
+            return 0;
+
+        case WM_NOTIFY:
+        {
+            PPRIVATE_NOTIFY_DESKTOP nmh = (PPRIVATE_NOTIFY_DESKTOP)lParam;
+
+            /* Use WM_NOTIFY for private messages since
+             * it can't be sent between processes!
+             */
+            switch (nmh->hdr.code)
+            {
+                case PM_SHOW_DESKTOP:
+                {
+                    LRESULT Result;
+
+                    Result = !SetWindowPos(Wnd, NULL, 0, 0,
+                                           nmh->ShowDesktop.Width,
+                                           nmh->ShowDesktop.Height,
+                                           SWP_NOACTIVATE | SWP_NOZORDER |
+                                           SWP_SHOWWINDOW);
+
+                    UpdateWindow(Wnd);
+                    VisibleDesktopWindow = Wnd;
+                    return Result;
+                }
+
+                case PM_HIDE_DESKTOP:
+                {
+                    LRESULT Result;
+
+                    Result = !SetWindowPos(Wnd, NULL, 0, 0, 0, 0,
+                                           SWP_NOACTIVATE | SWP_NOZORDER |
+                                           SWP_NOMOVE | SWP_NOSIZE | SWP_HIDEWINDOW);
+
+                    UpdateWindow(Wnd);
+                    VisibleDesktopWindow = NULL;
+                    return Result;
+                }
+
+                default:
+                    DPRINT("Unknown notification code 0x%x sent to the desktop
window!\n",
+                           nmh->hdr.code);
+                    return 0;
+            }
+        }
+
+        default:
+            return DefWindowProcW(Wnd, Msg, wParam, lParam);
+    }
+
+    return 0;
+}
+
+static
+BOOL
+FASTCALL
+DtbgInit(VOID)
+{
+    WNDCLASSEXW Class;
+    ATOM ClassAtom;
+
+    /*
+     * Create the desktop window class
+     */
+    Class.cbSize = sizeof(WNDCLASSEXW);
+    Class.style = CS_GLOBALCLASS;
+    Class.lpfnWndProc = DtbgWindowProc;
+    Class.cbClsExtra = 0;
+    Class.cbWndExtra = 0;
+    Class.hInstance = (HINSTANCE)GetModuleHandleW(NULL);
+    Class.hIcon = NULL;
+    Class.hCursor = NULL;
+    Class.hbrBackground = GetSysColorBrush(COLOR_BACKGROUND);
+    Class.lpszMenuName = NULL;
+    Class.lpszClassName = (LPCWSTR)DESKTOP_WINDOW_ATOM;
+    ClassAtom = RegisterClassExW(&Class);
+
+    if (ClassAtom == INVALID_ATOM)
+    {
+        DPRINT1("Unable to register desktop background class (error %d)\n",
+                GetLastError());
+
+        return FALSE;
+    }
+
+    VisibleDesktopWindow = NULL;
+
+    return TRUE;
+}
+
+static
+DWORD
+WINAPI
+DtbgDesktopThread(PVOID Data)
+{
+    HWND BackgroundWnd;
+    MSG msg;
+    PDTBG_THREAD_DATA ThreadData = (PDTBG_THREAD_DATA)Data;
+
+    if (!SetThreadDesktop(ThreadData->Desktop))
+    {
+        DPRINT1("Failed to set thread desktop\n");
+        ThreadData->Status = STATUS_UNSUCCESSFUL;
+        SetEvent(ThreadData->Event);
         return 1;
-
-      case WM_PAINT:
-      {
-        if((hDC = BeginPaint(Wnd, &PS)))
-          EndPaint(Wnd, &PS);
-        return 0;
-      }
-
-      case WM_SETCURSOR:
-	return (LRESULT) SetCursor(LoadCursorW(0, (LPCWSTR)IDC_ARROW));
-
-      case WM_NCCREATE:
-        return (LRESULT) TRUE;
-
-      case WM_CREATE:
-        return 0;
-
-      case WM_CLOSE:
-        return 0;
-
-      case WM_NOTIFY:
-      {
-        PPRIVATE_NOTIFY_DESKTOP nmh = (PPRIVATE_NOTIFY_DESKTOP)lParam;
-
-        /* Use WM_NOTIFY for private messages since it can't be sent between
-           processes! */
-        switch(nmh->hdr.code)
-        {
-          case PM_SHOW_DESKTOP:
-          {
-            LRESULT Result;
-
-            Result = ! SetWindowPos(Wnd,
-                                    NULL, 0, 0,
-                                    nmh->ShowDesktop.Width,
-                                    nmh->ShowDesktop.Height,
-                                    SWP_NOACTIVATE | SWP_NOZORDER | SWP_SHOWWINDOW);
-            UpdateWindow(Wnd);
-            VisibleDesktopWindow = Wnd;
-            return Result;
-          }
-
-          case PM_HIDE_DESKTOP:
-          {
-            LRESULT Result;
-
-            Result = ! SetWindowPos(Wnd,
-                                    NULL, 0, 0, 0, 0,
-                                    SWP_NOACTIVATE | SWP_NOZORDER | SWP_NOMOVE |
SWP_NOSIZE |
-                                    SWP_HIDEWINDOW);
-            UpdateWindow(Wnd);
-            VisibleDesktopWindow = NULL;
-            return Result;
-          }
-
-          default:
-            DPRINT("Unknown notification code 0x%x sent to the desktop
window!\n", nmh->hdr.code);
-            return 0;
-        }
-      }
-
-      default:
-        return DefWindowProcW(Wnd, Msg, wParam, lParam);
-    }
-
-  return 0;
-}
-
-static BOOL FASTCALL
-DtbgInit()
-{
-  WNDCLASSEXW Class;
-  ATOM ClassAtom;
-
-  /*
-   * Create the desktop window class
-   */
-  Class.cbSize = sizeof(WNDCLASSEXW);
-  Class.style = CS_GLOBALCLASS;
-  Class.lpfnWndProc = DtbgWindowProc;
-  Class.cbClsExtra = 0;
-  Class.cbWndExtra = 0;
-  Class.hInstance = (HINSTANCE) GetModuleHandleW(NULL);
-  Class.hIcon = NULL;
-  Class.hCursor = NULL;
-  Class.hbrBackground = GetSysColorBrush(COLOR_BACKGROUND);
-  Class.lpszMenuName = NULL;
-  Class.lpszClassName = (LPCWSTR) DESKTOP_WINDOW_ATOM;
-  ClassAtom = RegisterClassExW(&Class);
-  if ((ATOM) 0 == ClassAtom)
-    {
-      DPRINT1("Unable to register desktop background class (error %d)\n",
-              GetLastError());
-      return FALSE;
-    }
-  VisibleDesktopWindow = NULL;
-
-  return TRUE;
-}
-
-static DWORD WINAPI
-DtbgDesktopThread(PVOID Data)
-{
-  HWND BackgroundWnd;
-  MSG msg;
-  PDTBG_THREAD_DATA ThreadData = (PDTBG_THREAD_DATA) Data;
-
-  if (! SetThreadDesktop(ThreadData->Desktop))
-    {
-      DPRINT1("Failed to set thread desktop\n");
-      ThreadData->Status = STATUS_UNSUCCESSFUL;
-      SetEvent(ThreadData->Event);
-      return 1;
-    }
-  BackgroundWnd = CreateWindowW((LPCWSTR) DESKTOP_WINDOW_ATOM,
-                                L"",
-                                WS_POPUP | WS_CLIPCHILDREN,
+    }
+
+    BackgroundWnd = CreateWindowW((LPCWSTR)DESKTOP_WINDOW_ATOM,
+                                  L"",
+                                  WS_POPUP | WS_CLIPCHILDREN,
+                                  0, 0, 0, 0,
+                                  NULL, NULL,
+                                  (HINSTANCE)GetModuleHandleW(NULL),
+                                  NULL);
+
+    if (NULL == BackgroundWnd)
+    {
+        DPRINT1("Failed to create desktop background window\n");
+        ThreadData->Status = STATUS_UNSUCCESSFUL;
+        SetEvent(ThreadData->Event);
+        return 1;
+    }
+
+    ThreadData->Status = STATUS_SUCCESS;
+    SetEvent(ThreadData->Event);
+
+    while (GetMessageW(&msg, NULL, 0, 0))
+    {
+        TranslateMessage(&msg);
+        DispatchMessageW(&msg);
+    }
+
+    return 1;
+}
+
+CSR_API(CsrCreateDesktop)
+{
+    DTBG_THREAD_DATA ThreadData;
+    HANDLE ThreadHandle;
+
+    DPRINT("CsrCreateDesktop\n");
+
+    Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
+    Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) -
sizeof(PORT_MESSAGE);
+
+    if (!BgInitialized)
+    {
+        BgInitialized = TRUE;
+
+        if (!DtbgInit())
+            return STATUS_UNSUCCESSFUL;
+    }
+
+    /*
+     * The desktop handle we got from win32k is in
+     * the scope of CSRSS so we can just use it.
+     */
+    ThreadData.Desktop = Request->Data.CreateDesktopRequest.DesktopHandle;
+
+    ThreadData.Event = CreateEventW(NULL, FALSE, FALSE, NULL);
+
+    if (NULL == ThreadData.Event)
+    {
+        DPRINT1("Failed to create event (error %d)\n", GetLastError());
+        return STATUS_UNSUCCESSFUL;
+    }
+
+    ThreadHandle = CreateThread(NULL,
                                 0,
+                                DtbgDesktopThread,
+                                (PVOID)&ThreadData,
                                 0,
-                                0,
-                                0,
-                                NULL,
-                                NULL,
-                                (HINSTANCE) GetModuleHandleW(NULL),
                                 NULL);
-  if (NULL == BackgroundWnd)
-    {
-      DPRINT1("Failed to create desktop background window\n");
-      ThreadData->Status = STATUS_UNSUCCESSFUL;
-      SetEvent(ThreadData->Event);
-      return 1;
-    }
-
-  ThreadData->Status = STATUS_SUCCESS;
-  SetEvent(ThreadData->Event);
-
-  while (GetMessageW(&msg, NULL, 0, 0))
-    {
-      TranslateMessage(&msg);
-      DispatchMessageW(&msg);
-    }
-
-  return 1;
-}
-
-CSR_API(CsrCreateDesktop)
-{
-  DTBG_THREAD_DATA ThreadData;
-  HANDLE ThreadHandle;
-
-  DPRINT("CsrCreateDesktop\n");
-
-  Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
-  Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
-
-  if (! BgInitialized)
-    {
-      BgInitialized = TRUE;
-      if (! DtbgInit())
-        {
-          return STATUS_UNSUCCESSFUL;
-        }
-    }
-
-  /*
-   * the desktop handle we got from win32k is in the scope of CSRSS so we can just use
it
-   */
-  ThreadData.Desktop = Request->Data.CreateDesktopRequest.DesktopHandle;
-
-  ThreadData.Event = CreateEventW(NULL, FALSE, FALSE, NULL);
-  if (NULL == ThreadData.Event)
-    {
-      DPRINT1("Failed to create event (error %d)\n", GetLastError());
-      return STATUS_UNSUCCESSFUL;
-    }
-  ThreadHandle = CreateThread(NULL,
-                              0,
-                              DtbgDesktopThread,
-                              (PVOID) &ThreadData,
-                              0,
-                              NULL);
-  if (NULL == ThreadHandle)
-    {
-      CloseHandle(ThreadData.Event);
-      DPRINT1("Failed to create desktop window thread.\n");
-      return STATUS_UNSUCCESSFUL;
-    }
-  CloseHandle(ThreadHandle);
-
-  WaitForSingleObject(ThreadData.Event, INFINITE);
-  CloseHandle(ThreadData.Event);
-
-  return ThreadData.Status;
+
+    if (NULL == ThreadHandle)
+    {
+        CloseHandle(ThreadData.Event);
+        DPRINT1("Failed to create desktop window thread.\n");
+        return STATUS_UNSUCCESSFUL;
+    }
+
+    CloseHandle(ThreadHandle);
+
+    WaitForSingleObject(ThreadData.Event, INFINITE);
+    CloseHandle(ThreadData.Event);
+
+    return ThreadData.Status;
 }
 
 CSR_API(CsrShowDesktop)
 {
-  PRIVATE_NOTIFY_DESKTOP nmh;
-  DPRINT("CsrShowDesktop\n");
-
-  Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
-  Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
-
-  nmh.hdr.hwndFrom = Request->Data.ShowDesktopRequest.DesktopWindow;
-  nmh.hdr.idFrom = 0;
-  nmh.hdr.code = PM_SHOW_DESKTOP;
-
-  nmh.ShowDesktop.Width = (int)Request->Data.ShowDesktopRequest.Width;
-  nmh.ShowDesktop.Height = (int)Request->Data.ShowDesktopRequest.Height;
-
-  return SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
-                      WM_NOTIFY,
-                      (WPARAM)nmh.hdr.hwndFrom,
-                      (LPARAM)&nmh)
-         ? STATUS_UNSUCCESSFUL : STATUS_SUCCESS;
+    PRIVATE_NOTIFY_DESKTOP nmh;
+    DPRINT("CsrShowDesktop\n");
+
+    Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
+    Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) -
sizeof(PORT_MESSAGE);
+
+    nmh.hdr.hwndFrom = Request->Data.ShowDesktopRequest.DesktopWindow;
+    nmh.hdr.idFrom = 0;
+    nmh.hdr.code = PM_SHOW_DESKTOP;
+
+    nmh.ShowDesktop.Width = (int)Request->Data.ShowDesktopRequest.Width;
+    nmh.ShowDesktop.Height = (int)Request->Data.ShowDesktopRequest.Height;
+
+    if (SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
+                     WM_NOTIFY,
+                     (WPARAM)nmh.hdr.hwndFrom,
+                     (LPARAM)&nmh))
+    {
+        return STATUS_UNSUCCESSFUL;
+    }
+
+    return STATUS_SUCCESS;
 }
 
 CSR_API(CsrHideDesktop)
 {
-  PRIVATE_NOTIFY_DESKTOP nmh;
-  DPRINT("CsrHideDesktop\n");
-
-  Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
-  Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) - sizeof(PORT_MESSAGE);
-
-  nmh.hdr.hwndFrom = Request->Data.ShowDesktopRequest.DesktopWindow;
-  nmh.hdr.idFrom = 0;
-  nmh.hdr.code = PM_HIDE_DESKTOP;
-
-  return SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
-                      WM_NOTIFY,
-                      (WPARAM)nmh.hdr.hwndFrom,
-                      (LPARAM)&nmh)
-         ? STATUS_UNSUCCESSFUL : STATUS_SUCCESS;
-}
-
-BOOL FASTCALL
+    PRIVATE_NOTIFY_DESKTOP nmh;
+    DPRINT("CsrHideDesktop\n");
+
+    Request->Header.u1.s1.TotalLength = sizeof(CSR_API_MESSAGE);
+    Request->Header.u1.s1.DataLength = sizeof(CSR_API_MESSAGE) -
sizeof(PORT_MESSAGE);
+
+    nmh.hdr.hwndFrom = Request->Data.ShowDesktopRequest.DesktopWindow;
+    nmh.hdr.idFrom = 0;
+    nmh.hdr.code = PM_HIDE_DESKTOP;
+
+    if (SendMessageW(Request->Data.ShowDesktopRequest.DesktopWindow,
+                     WM_NOTIFY,
+                     (WPARAM)nmh.hdr.hwndFrom,
+                     (LPARAM)&nmh))
+    {
+        return STATUS_UNSUCCESSFUL;
+    }
+
+    return STATUS_SUCCESS;
+}
+
+BOOL
+FASTCALL
 DtbgIsDesktopVisible(VOID)
 {
-  if (NULL != VisibleDesktopWindow && ! IsWindowVisible(VisibleDesktopWindow))
-    {
-      VisibleDesktopWindow = NULL;
-    }
-
-  return NULL != VisibleDesktopWindow;
+    if (VisibleDesktopWindow != NULL &&
+        !IsWindowVisible(VisibleDesktopWindow))
+    {
+        VisibleDesktopWindow = NULL;
+    }
+
+    return VisibleDesktopWindow != NULL;
 }
 
 /* EOF */