gecko-dev/xpfe/bootstrap/nsNativeAppSupportWin.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Netscape Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code is Mozilla Communicator client code.
 *
 * The Initial Developer of the Original Code is Netscape Communications
 * Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s): 
 *   Bill Law       law@netscape.com
 */
#include "nsNativeAppSupportBase.h"
#include "nsNativeAppSupportWin.h"
#include "nsString.h"
#include "nsICmdLineService.h"
#include "nsCOMPtr.h"
#include "nsXPIDLString.h"
#include "nsIComponentManager.h"
#include "nsIServiceManager.h"
#include "nsICmdLineHandler.h"
#include "nsIDOMWindow.h"
#include "nsISupportsPrimitives.h"
#include "nsIWindowWatcher.h"
#include <windows.h>
#include <ddeml.h>
#include <stdlib.h>
#include <stdio.h>
#include <io.h>
#include <fcntl.h>

// Define this macro to 1 to get DDE debugging output.
#define MOZ_DEBUG_DDE 0

#ifdef DEBUG_law
#undef MOZ_DEBUG_DDE
#define MOZ_DEBUG_DDE 1
#endif

class nsSplashScreenWin : public nsISplashScreen {
public:
    nsSplashScreenWin();
    ~nsSplashScreenWin();

    NS_IMETHOD Show();
    NS_IMETHOD Hide();

    // nsISupports methods
    NS_IMETHOD_(nsrefcnt) AddRef() {
        mRefCnt++;
        return mRefCnt;
    }
    NS_IMETHOD_(nsrefcnt) Release() {
        --mRefCnt;
        if ( !mRefCnt ) {
            delete this;
            return 0;
        }
        return mRefCnt;
    }
    NS_IMETHOD QueryInterface( const nsIID &iid, void**p ) {
        nsresult rv = NS_OK;
        if ( p ) {
            *p = 0;
            if ( iid.Equals( NS_GET_IID( nsISplashScreen ) ) ) {
                nsISplashScreen *result = this;
                *p = result;
                NS_ADDREF( result );
            } else if ( iid.Equals( NS_GET_IID( nsISupports ) ) ) {
                nsISupports *result = NS_STATIC_CAST( nsISupports*, this );
                *p = result;
                NS_ADDREF( result );
            } else {
                rv = NS_NOINTERFACE;
            }
        } else {
            rv = NS_ERROR_NULL_POINTER;
        }
        return rv;
    }

    void SetDialog( HWND dlg );
    void LoadBitmap();
    static nsSplashScreenWin* GetPointer( HWND dlg );

    static BOOL CALLBACK DialogProc( HWND dlg, UINT msg, WPARAM wp, LPARAM lp );
    static BOOL CALLBACK PhantomDialogProc( HWND dlg, UINT msg, WPARAM wp, LPARAM lp );
    static DWORD WINAPI ThreadProc( LPVOID );

    HWND mDlg;
    HBITMAP mBitmap;
    nsrefcnt mRefCnt;
}; // class nsSplashScreenWin

// Simple Win32 mutex wrapper.
struct Mutex {
    Mutex( const char *name )
        : mName( name ),
          mHandle( 0 ),
          mState( -1 ) {
        mHandle = CreateMutex( 0, FALSE, mName.get() );
        #if MOZ_DEBUG_DDE
        printf( "CreateMutex error = 0x%08X\n", (int)GetLastError() );
        #endif
    }
    ~Mutex() {
        if ( mHandle ) {
            // Make sure we release it if we own it.
            Unlock();

            BOOL rc = CloseHandle( mHandle );
            #if MOZ_DEBUG_DDE
            if ( !rc ) {
                printf( "CloseHandle error = 0x%08X\n", (int)GetLastError() );
            }
            #endif
        }
    }
    BOOL Lock( DWORD timeout ) {
        if ( mHandle ) {
            #if MOZ_DEBUG_DDE
            printf( "Waiting (%d msec) for DDE mutex...\n", (int)timeout );
            #endif
            mState = WaitForSingleObject( mHandle, timeout );
            #if MOZ_DEBUG_DDE
            printf( "...wait complete, result = 0x%08X\n", (int)mState );
            #endif
            return mState == WAIT_OBJECT_0;
        } else {
            return FALSE;
        }
    }
    void Unlock() {
        if ( mHandle && mState == WAIT_OBJECT_0 ) {
            #if MOZ_DEBUG_DDE
            printf( "Releasing DDE mutex\n" );
            #endif
            ReleaseMutex( mHandle );
            mState = -1;
        }
    }
private:
    nsCString mName;
    HANDLE    mHandle;
    DWORD     mState;
};

/* DDE Notes
 *
 * This section describes the Win32 DDE service implementation for
 * Mozilla.  DDE is used on Win32 platforms to communicate between
 * separate instances of mozilla.exe (or other Mozilla-based
 * executables), or, between the Win32 desktop shell and Mozilla.
 *
 * The first instance of Mozilla will become the "server" and
 * subsequent executables (and the shell) will use DDE to send
 * requests to that process.  The requests are DDE "execute" requests
 * that pass the command line arguments.
 *
 * Mozilla registers the DDE application "Mozilla" and currently
 * supports only the "WWW_OpenURL" topic.  This should be reasonably
 * compatible with applications that interfaced with Netscape
 * Communicator (and its predecessors?).  Note that even that topic
 * may not be supported in a compatible fashion as the command-line
 * options for Mozilla are different than for Communiator.
 *
 * It is imperative that at most one instance of Mozilla execute in
 * "server mode" at any one time.  The "native app support" in Mozilla
 * on Win32 ensures that only the server process performs XPCOM
 * initialization (that is not required for subsequent client processes
 * to communicate with the server process).
 *
 * To guarantee that only one server starts up, a Win32 "mutex" is used
 * to ensure only one process executes the server-detection code.  That
 * code consists of initializing DDE and doing a DdeConnect to Mozilla's
 * application/topic.  If that connection succeeds, then a server process
 * must be running already.
 * 
 * Otherwise, no server has started.  In that case, the current process
 * calls DdeNameService to register that application/topic.  Only at that
 * point does the mutex get released.
 *
 * There are a couple of subtleties that one should be aware of:
 * 
 * 1. It is imperative that DdeInitialize be called only after the mutex
 *    lock has been obtained.  The reason is that at shutdown, DDE
 *    notifications go out to all initialized DDE processes.  Thus, if
 *    the mutex is owned by a terminating intance of Mozilla, then
 *    calling DdeInitialize and then WaitForSingleObject will cause the
 *    DdeUninitialize from the terminating process to "hang" until the
 *    process waiting for the mutex times out (and can then service the
 *    notification that the DDE server is terminating).  So, don't mess
 *    with the sequence of things in the startup/shutdown logic.
 *
 * 2. All mutex requests are made with a reasonably long timeout value and
 *    are designed to "fail safe" (i.e., a timeout is treated as failure).
 * 
 * 3. An attempt has been made to minimize the degree to which the main
 *    Mozilla application logic needs to be aware of the DDE mechanisms
 *    implemented herein.  As a result, this module surfaces a very
 *    large-grained interface, consisting of simple start/stop methods.
 *    As a consequence, details of certain scenarios can be "lost."
 *    Particularly, incoming DDE requests can arrive after this module
 *    initiates the DDE server, but before Mozilla is initialized to the
 *    point where those requests can be serviced (e.g., open a browser
 *    window to a particular URL).  Since the client process sends the
 *    request early on, it may not be prepared to respond to that error.
 *    Thus, such situations may fail silently.  The design goal is that
 *    they fail harmlessly.  Refinements on this point will be made as
 *    details emerge (and time permits).
 */

/* Update 2001 March
 *
 * A significant DDE bug in Windows is causing Mozilla to get wedged at
 * startup.  This is detailed in Bugzill bug 53952
 * (http://bugzilla.mozilla.org/show_bug.cgi?id=53952).
 *
 * To resolve this, we are using a new strategy:
 *   o Use a "message window" to detect that Mozilla is already running and
 *     to pass requests from a second instance back to the first;
 *   o Run only as a "DDE server" (not as DDE client); this avoids the
 *     problematic call to DDEConnect().
 *
 * We still use the mutex semaphore to protect the code that detects
 * whether Mozilla is already running.
 */

class nsNativeAppSupportWin : public nsNativeAppSupportBase {
public:
    // Overrides of base implementation.
    NS_IMETHOD Start( PRBool *aResult );
    NS_IMETHOD Stop( PRBool *aResult );
    NS_IMETHOD Quit();

    // The "old" Start method (renamed).
    NS_IMETHOD StartDDE();

    // Utility function to handle a Win32-specific command line
    // option: "-console", which dynamically creates a Windows
    // console.
    static void CheckConsole();

private:
    static HDDEDATA CALLBACK HandleDDENotification( UINT     uType,
                                                    UINT     uFmt,
                                                    HCONV    hconv,
                                                    HSZ      hsz1,
                                                    HSZ      hsz2,
                                                    HDDEDATA hdata,
                                                    ULONG    dwData1,
                                                    ULONG    dwData2 );
    static void HandleRequest( LPBYTE request );
    static nsresult GetCmdLineArgs( LPBYTE request, nsICmdLineService **aResult );
    static nsresult OpenWindow( const char *urlstr, const char *args );
    static int   mConversations;
    static HSZ   mApplication, mTopic;
    static DWORD mInstance;
    static char *mAppName;
    friend struct MessageWindow;
}; // nsNativeAppSupportWin

nsSplashScreenWin::nsSplashScreenWin()
    : mDlg( 0 ), mBitmap( 0 ), mRefCnt( 0 ) {
}

nsSplashScreenWin::~nsSplashScreenWin() {
#if MOZ_DEBUG_DDE
    printf( "splash screen dtor called\n" );
#endif
    // Make sure dialog is gone.
    Hide();
}

NS_IMETHODIMP
nsSplashScreenWin::Show() {
    /*
     * A hack for http://bugzilla.mozilla.org/show_bug.cgi?id=26581
     *
     * Windows NT seems to think that the first thread to show a window must 
     * therefore be our main UI thread. It then seems to want to put the first 
     * window that shows up on other threads in our application behind the main 
     * windows of other applications. Since we want to show our splash screen 
     * on a 'non-main' thread, our browser windows start showing up later on a 
     * thread that Windows thinks is not our main UI thread. So, (I believe) it 
     * pushes the first one of our browser windows to the back until the user 
     * pulls it forward. That is not what we want!
     * 
     * This hack attempts to trick Windows by very briefly showing an 
     * offscreen window on the main thread. This happens before the splash 
     * screen thread creates its window (which it sets as topmost). So when our
     * browser windows start showing up on the main thread Windows will see that 
     * they are on the "first thread with a window" and it will (hopefully!) not
     * push them to the back.
     */
    DialogBox( GetModuleHandle( 0 ),
               MAKEINTRESOURCE( IDD_SPLASH ),
               HWND_DESKTOP,
               (DLGPROC)PhantomDialogProc );

    // Spawn new thread to display real splash screen.
    DWORD threadID = 0;
    HANDLE handle = CreateThread( 0, 0, (LPTHREAD_START_ROUTINE)ThreadProc, this, 0, &threadID );
    CloseHandle(handle);

    return NS_OK;
}

NS_IMETHODIMP
nsSplashScreenWin::Hide() {
    if ( mDlg ) {
        // Dismiss the dialog.
        EndDialog( mDlg, 0 );
        // Release custom bitmap (if there is one).
        if ( mBitmap ) {
            BOOL ok = DeleteObject( mBitmap );
        }
        mBitmap = 0;
        mDlg = 0;
    }
    return NS_OK;
}

BOOL CALLBACK
nsSplashScreenWin::PhantomDialogProc( HWND dlg, UINT msg, WPARAM wp, LPARAM lp ) {
    if ( msg == WM_INITDIALOG ) {
        // Show window for an instant to make this the active thread.
        ShowWindow( dlg, SW_SHOW );
        EndDialog( dlg, 0 );
        return 1;
    } 
    return 0;
}

void
nsSplashScreenWin::LoadBitmap() {
    // Check for '<program-name>.bmp" in same directory as executable.
    char fileName[ _MAX_PATH ];
    int fileNameLen = ::GetModuleFileName( NULL, fileName, sizeof fileName );
    if ( fileNameLen >= 3 ) {
        fileName[ fileNameLen - 3 ] = 0;
        strcat( fileName, "bmp" );
        // Try to load bitmap from that file.
        HBITMAP bitmap = (HBITMAP)::LoadImage( NULL,
                                               fileName,
                                               IMAGE_BITMAP,
                                               0,
                                               0,
                                               LR_LOADFROMFILE );
        if ( bitmap ) {
            HWND bitmapControl = GetDlgItem( mDlg, IDB_SPLASH );
            if ( bitmapControl ) {
                HBITMAP old = (HBITMAP)SendMessage( bitmapControl,
                                                    STM_SETIMAGE,
                                                    IMAGE_BITMAP,
                                                    (LPARAM)bitmap );
                // Remember bitmap so we can delete it later.
                mBitmap = bitmap;
                // Delete old bitmap.
                if ( old ) {
                    BOOL ok = DeleteObject( old );
                }
            } else {
                // Delete bitmap since it isn't going to be used.
                DeleteObject( bitmap );
            }
        }
    }
}

BOOL CALLBACK
nsSplashScreenWin::DialogProc( HWND dlg, UINT msg, WPARAM wp, LPARAM lp ) {
    if ( msg == WM_INITDIALOG ) {
        // Store dialog handle.
        nsSplashScreenWin *splashScreen = (nsSplashScreenWin*)lp;
        if ( lp ) {
            splashScreen->SetDialog( dlg );

            // Try to load customized bitmap.
            splashScreen->LoadBitmap();
        }

        /* Size and center the splash screen correctly. The flags in the 
         * dialog template do not do the right thing if the user's 
         * machine is using large fonts.
         */ 
        HWND bitmapControl = GetDlgItem( dlg, IDB_SPLASH );
        if ( bitmapControl ) {
            HBITMAP hbitmap = (HBITMAP)SendMessage( bitmapControl,
                                                    STM_GETIMAGE,
                                                    IMAGE_BITMAP,
                                                    0 );
            if ( hbitmap ) {
                BITMAP bitmap;
                if ( GetObject( hbitmap, sizeof bitmap, &bitmap ) ) {
                    SetWindowPos( dlg,
                                  NULL,
                                  GetSystemMetrics(SM_CXSCREEN)/2 - bitmap.bmWidth/2,
                                  GetSystemMetrics(SM_CYSCREEN)/2 - bitmap.bmHeight/2,
                                  bitmap.bmWidth,
                                  bitmap.bmHeight,
                                  SWP_NOZORDER );
                    ShowWindow( dlg, SW_SHOW );
                }
            }
        }
        return 1;
    }
    return 0;
}

void nsSplashScreenWin::SetDialog( HWND dlg ) {
    // Save dialog handle.
    mDlg = dlg;
    // Store this pointer in the dialog.
    SetWindowLong( mDlg, DWL_USER, (LONG)(void*)this );
}

nsSplashScreenWin *nsSplashScreenWin::GetPointer( HWND dlg ) {
    // Get result from dialog user data.
    LONG data = GetWindowLong( dlg, DWL_USER );
    return (nsSplashScreenWin*)(void*)data;
}

DWORD WINAPI nsSplashScreenWin::ThreadProc( LPVOID splashScreen ) {
    DialogBoxParam( GetModuleHandle( 0 ),
                    MAKEINTRESOURCE( IDD_SPLASH ),
                    HWND_DESKTOP,
                    (DLGPROC)DialogProc,
                    (LPARAM)splashScreen );
    return 0;
}

void
nsNativeAppSupportWin::CheckConsole() {
    for ( int i = 1; i < __argc; i++ ) {
        if ( strcmp( "-console", __argv[i] ) == 0
             ||
             strcmp( "/console", __argv[i] ) == 0 ) {
            // Users wants to make sure we have a console.
            // Try to allocate one.
            BOOL rc = ::AllocConsole();
            if ( rc ) {
                // Console allocated.  Fix it up so that output works in
                // all cases.  See http://support.microsoft.com/support/kb/articles/q105/3/05.asp.

                // stdout
                int hCrt = ::_open_osfhandle( (long)GetStdHandle( STD_OUTPUT_HANDLE ),
                                            _O_TEXT );
                if ( hCrt != -1 ) {
                    FILE *hf = ::_fdopen( hCrt, "w" );
                    if ( hf ) {
                        *stdout = *hf;
                        ::fprintf( stdout, "stdout directed to dynamic console\n" );
                    }
                }

                // stderr
                hCrt = ::_open_osfhandle( (long)::GetStdHandle( STD_ERROR_HANDLE ),
                                          _O_TEXT );
                if ( hCrt != -1 ) {
                    FILE *hf = ::_fdopen( hCrt, "w" );
                    if ( hf ) {
                        *stderr = *hf;
                        ::fprintf( stderr, "stderr directed to dynamic console\n" );
                    }
                }

                // stdin?
                /* Don't bother for now.
                hCrt = ::_open_osfhandle( (long)::GetStdHandle( STD_INPUT_HANDLE ),
                                          _O_TEXT );
                if ( hCrt != -1 ) {
                    FILE *hf = ::_fdopen( hCrt, "r" );
                    if ( hf ) {
                        *stdin = *hf;
                    }
                }
                */
            } else {
                // Failed.  Probably because there already is one.
                // There's little we can do, in any case.
            }
            // Don't bother doing this more than once.
            break;
        }
    }
    return;
}


// Create and return an instance of class nsNativeAppSupportWin.
nsresult
NS_CreateNativeAppSupport( nsINativeAppSupport **aResult ) {
    if ( aResult ) {
        *aResult = new nsNativeAppSupportWin;
        if ( *aResult ) {
            NS_ADDREF( *aResult );
        } else {
            return NS_ERROR_OUT_OF_MEMORY;
        }
    } else {
        return NS_ERROR_NULL_POINTER;
    }

    // Check for dynamic console creation request.
    nsNativeAppSupportWin::CheckConsole();
    return NS_OK;
}

// Create instance of Windows splash screen object.
nsresult
NS_CreateSplashScreen( nsISplashScreen **aResult ) {
    if ( aResult ) {
        *aResult = 0;
        for ( int i = 1; i < __argc; i++ ) {
            if ( strcmp( "-quiet", __argv[i] ) == 0
                 ||
                 strcmp( "/quiet", __argv[i] ) == 0 ) {
                // No splash screen, please.
                return NS_OK;
            }
        }
        *aResult = new nsSplashScreenWin;
        if ( *aResult ) {
            NS_ADDREF( *aResult );
        } else {
            return NS_ERROR_OUT_OF_MEMORY;
        }
    } else {
        return NS_ERROR_NULL_POINTER;
    }

    return NS_OK;
}

// Constants
#define MOZ_DDE_APPLICATION   "Mozilla"
#define MOZ_DDE_TOPIC         "WWW_OpenURL"
#define MOZ_STARTUP_MUTEX_NAME "StartupMutex"
#define MOZ_DDE_START_TIMEOUT 30000
#define MOZ_DDE_STOP_TIMEOUT  15000
#define MOZ_DDE_EXEC_TIMEOUT  15000

// Static member definitions.
int   nsNativeAppSupportWin::mConversations = 0;
HSZ   nsNativeAppSupportWin::mApplication   = 0;
HSZ   nsNativeAppSupportWin::mTopic         = 0;
DWORD nsNativeAppSupportWin::mInstance      = 0;

// Message window encapsulation.
struct MessageWindow {
    // ctor/dtor are simplistic
    MessageWindow() {
        // Try to find window.
        mHandle = ::FindWindow( className(), 0 ); 
    }

    // Act like an HWND.
    operator HWND() {
        return mHandle;
    }

    // Class name: appName + "MessageWindow"
    static const char *className() {
        static char classNameBuffer[128];
        static char *mClassName = 0;
        if ( !mClassName ) { 
            ::_snprintf( classNameBuffer,
                         sizeof classNameBuffer,
                         "%s%s",
                         nsNativeAppSupportWin::mAppName,
                         "MessageWindow" );
            mClassName = classNameBuffer;
        }
        return mClassName;
    }

    // Create: Register class and create window.
    NS_IMETHOD Create() {
        WNDCLASS classStruct = { 0,                          // style
                                 &MessageWindow::WindowProc, // lpfnWndProc
                                 0,                          // cbClsExtra
                                 0,                          // cbWndExtra
                                 0,                          // hInstance
                                 0,                          // hIcon
                                 0,                          // hCursor
                                 0,                          // hbrBackground
                                 0,                          // lpszMenuName
                                 className() };              // lpszClassName

        // Register the window class.
        NS_ENSURE_TRUE( ::RegisterClass( &classStruct ), NS_ERROR_FAILURE );

        // Create the window.
        NS_ENSURE_TRUE( ( mHandle = ::CreateWindow( className(),
                                                    0,          // title
                                                    WS_CAPTION, // style
                                                    0,0,0,0,    // x, y, cx, cy
                                                    0,          // parent
                                                    0,          // menu
                                                    0,          // instance
                                                    0 ) ),      // create struct
                        NS_ERROR_FAILURE );

        #ifdef MOZ_DEBUG_DDE
        printf( "Message window = 0x%08X\n", (int)mHandle );
        #endif

        return NS_OK;
    }

    // SendRequest: Pass string via WM_COPYDATA to message window.
    NS_IMETHOD SendRequest( const char *cmd ) {
        COPYDATASTRUCT cds = { 0, ::strlen( cmd ) + 1, (void*)cmd };
        ::SendMessage( mHandle, WM_COPYDATA, 0, (LPARAM)&cds );
        return NS_OK;
    }

    // Window proc.
    static long CALLBACK WindowProc( HWND msgWindow, UINT msg, WPARAM wp, LPARAM lp ) {
        if ( msg == WM_COPYDATA ) {
            // This is an incoming request.
            COPYDATASTRUCT *cds = (COPYDATASTRUCT*)lp;
            #ifdef MOZ_DEBUG_DDE
            printf( "Incoming request: %s\n", (const char*)cds->lpData );
            #endif
            (void)nsNativeAppSupportWin::HandleRequest( (LPBYTE)cds->lpData );
        }
        return TRUE;
    }

private:
    HWND mHandle;
}; // struct MessageWindow

static char nameBuffer[128] = { 0 };
char *nsNativeAppSupportWin::mAppName = nameBuffer;

/* Start: Tries to find the "message window" to determine if it
 *        exists.  If so, then Mozilla is already running.  In that
 *        case, we use the handle to the "message" window and send
 *        a request corresponding to this process's command line
 *        options.
 *        
 *        If not, then this is the first instance of Mozilla.  In
 *        that case, we create and set up the message window.
 *
 *        The checking for existance of the message window must
 *        be protected by use of a mutex semaphore.
 */
NS_IMETHODIMP
nsNativeAppSupportWin::Start( PRBool *aResult ) {
    NS_ENSURE_ARG( aResult );
    NS_ENSURE_TRUE( mInstance == 0, NS_ERROR_NOT_INITIALIZED );

    nsresult rv = NS_ERROR_FAILURE;
    *aResult = PR_FALSE;

    // Grab mutex first.
    int retval;
    UINT id = ID_DDE_APPLICATION_NAME;
    retval = LoadString( (HINSTANCE) NULL, id, (LPTSTR) nameBuffer, sizeof(nameBuffer) );
    if ( retval == 0 ) {
        // No app name; just keep running.
        *aResult = PR_TRUE;
        return NS_OK;
    }

    // Build mutex name from app name.
    char mutexName[128];
    ::_snprintf( mutexName, sizeof mutexName, "%s%s", nameBuffer, MOZ_STARTUP_MUTEX_NAME );
    Mutex startupLock = Mutex( mutexName );

    NS_ENSURE_TRUE( startupLock.Lock( MOZ_DDE_START_TIMEOUT ), NS_ERROR_FAILURE );

    // Search for existing message window.
    MessageWindow msgWindow;
    if ( (HWND)msgWindow ) {
        // We are a client process.  Pass request to message window.
        LPTSTR cmd = ::GetCommandLine();
        rv = msgWindow.SendRequest( cmd );
    } else {
        // We will be server.
        rv = msgWindow.Create();
        if ( NS_SUCCEEDED( rv ) ) {
            // Start up DDE server.
            this->StartDDE();
            // Tell caller to spin message loop.
            *aResult = PR_TRUE;
        }
    }

    startupLock.Unlock();

    return rv;
}

// Start DDE server.
//
// This used to be the Start() method when we were using DDE as the
// primary IPC mechanism between secondary Mozilla processes and the
// initial "server" process.
//
// Now, it simply initializes the DDE server.  The caller must check
// that this process is to be the server, and, must acquire the DDE
// startup mutex semaphore prior to calling this routine.  See ::Start(),
// above.
NS_IMETHODIMP
nsNativeAppSupportWin::StartDDE() {
    NS_ENSURE_TRUE( mInstance == 0, NS_ERROR_NOT_INITIALIZED );

    // Initialize DDE.
    NS_ENSURE_TRUE( DMLERR_NO_ERROR == DdeInitialize( &mInstance,
                                                      nsNativeAppSupportWin::HandleDDENotification,
                                                      APPCLASS_STANDARD,
                                                      0 ),
                    NS_ERROR_FAILURE );     
    
    // Allocate DDE strings.
    NS_ENSURE_TRUE( ( mApplication = DdeCreateStringHandle( mInstance, mAppName, CP_WINANSI ) ) &&
                    ( mTopic       = DdeCreateStringHandle( mInstance, MOZ_DDE_TOPIC, CP_WINANSI ) ),
                    NS_ERROR_FAILURE );

    // Next step is to register a DDE service.
    NS_ENSURE_TRUE( DdeNameService( mInstance, mApplication, 0, DNS_REGISTER ), NS_ERROR_FAILURE );

    #if MOZ_DEBUG_DDE
    printf( "DDE server started\n" );
    #endif

    return NS_OK;
}

// If no DDE conversations are pending, terminate DDE.
NS_IMETHODIMP
nsNativeAppSupportWin::Stop( PRBool *aResult ) {
    NS_ENSURE_ARG( aResult );
    NS_ENSURE_TRUE( mInstance, NS_ERROR_NOT_INITIALIZED );

    nsresult rv = NS_OK;
    *aResult = PR_TRUE;

    Mutex ddeLock( MOZ_STARTUP_MUTEX_NAME );

    if ( ddeLock.Lock( MOZ_DDE_STOP_TIMEOUT ) ) {
        if ( mConversations == 0 ) {
            this->Quit();
        } else {
            *aResult = PR_FALSE;
        }

        ddeLock.Unlock();
    }

    return rv;
}

// Terminate DDE regardless.
NS_IMETHODIMP
nsNativeAppSupportWin::Quit() {
    if ( mInstance ) {
        // Unregister application name.
        DdeNameService( mInstance, mApplication, 0, DNS_UNREGISTER );
        // Clean up strings.
        if ( mApplication ) {
            DdeFreeStringHandle( mInstance, mApplication );
            mApplication = 0;
        }
        if ( mTopic ) {
            DdeFreeStringHandle( mInstance, mTopic );
            mTopic = 0;
        }
        DdeUninitialize( mInstance );
        mInstance = 0;
    }

    return NS_OK;
}

PRBool NS_CanRun()
{
      return PR_TRUE;
}

#if MOZ_DEBUG_DDE
// Macro to generate case statement for a given XTYP value.
#define XTYP_CASE(t) \
    case t: result = #t; break

static nsCString uTypeDesc( UINT uType ) {
    nsCString result;
    switch ( uType ) {
    XTYP_CASE(XTYP_ADVSTART);
    XTYP_CASE(XTYP_CONNECT);
    XTYP_CASE(XTYP_ADVREQ);
    XTYP_CASE(XTYP_REQUEST);
    XTYP_CASE(XTYP_WILDCONNECT);
    XTYP_CASE(XTYP_ADVDATA);
    XTYP_CASE(XTYP_EXECUTE);
    XTYP_CASE(XTYP_POKE);
    XTYP_CASE(XTYP_ADVSTOP);
    XTYP_CASE(XTYP_CONNECT_CONFIRM);
    XTYP_CASE(XTYP_DISCONNECT);
    XTYP_CASE(XTYP_ERROR);
    XTYP_CASE(XTYP_MONITOR);
    XTYP_CASE(XTYP_REGISTER);
    XTYP_CASE(XTYP_XACT_COMPLETE);
    XTYP_CASE(XTYP_UNREGISTER);
    default: result = "XTYP_?????";
    }
    return result;
}

static nsCString hszValue( DWORD instance, HSZ hsz ) {
    // Extract string from HSZ.
    nsCString result("[");
    DWORD len = DdeQueryString( instance, hsz, NULL, NULL, CP_WINANSI );
    if ( len ) {
        char buffer[ 256 ];
        DdeQueryString( instance, hsz, buffer, sizeof buffer, CP_WINANSI );
        result += buffer;
    }
    result += "]";
    return result;
}
#else
// These are purely a safety measure to avoid the infamous "won't
// build non-debug" type Tinderbox flames.
static nsCString uTypeDesc( UINT ) {
    return nsCString( "?" );
}
static nsCString hszValue( DWORD, HSZ ) {
    return nsCString( "?" );
}
#endif


HDDEDATA CALLBACK
nsNativeAppSupportWin::HandleDDENotification( UINT uType,       // transaction type
                                              UINT uFmt,        // clipboard data format
                                              HCONV hconv,      // handle to the conversation
                                              HSZ hsz1,         // handle to a string
                                              HSZ hsz2,         // handle to a string
                                              HDDEDATA hdata,   // handle to a global memory object
                                              ULONG dwData1,    // transaction-specific data
                                              ULONG dwData2 ) { // transaction-specific data

    #if MOZ_DEBUG_DDE
    printf( "DDE: uType  =%s\n",      uTypeDesc( uType ).get() );
    printf( "     uFmt   =%u\n",      (unsigned)uFmt );
    printf( "     hconv  =%08x\n",    (int)hconv );
    printf( "     hsz1   =%08x:%s\n", (int)hsz1, hszValue( mInstance, hsz1 ).get() );
    printf( "     hsz2   =%08x:%s\n", (int)hsz2, hszValue( mInstance, hsz2 ).get() );
    printf( "     hdata  =%08x\n",    (int)hdata );
    printf( "     dwData1=%08x\n",    (int)dwData1 );
    printf( "     dwData2=%08x\n",    (int)dwData2 );
    #endif

    HDDEDATA result = 0;
    if ( uType & XCLASS_BOOL ) {
        switch ( uType ) {
        case XTYP_CONNECT:
        case XTYP_CONNECT_CONFIRM:
            // Make sure its for our service/topic.
            if ( DdeCmpStringHandles( hsz1, mTopic ) == 0
                 &&
                 DdeCmpStringHandles( hsz2, mApplication ) == 0 ) {
                // We support this connection.
                result = (HDDEDATA)1;
            }
        }
    } else if ( uType & XCLASS_DATA ) {
    } else if ( uType & XCLASS_FLAGS ) {
        if ( uType == XTYP_EXECUTE ) {
            // Prove that we received the request.
            DWORD bytes;
            LPBYTE request = DdeAccessData( hdata, &bytes );
            #if MOZ_DEBUG_DDE
            printf( "Handling dde request: [%s]...\n", (char*)request );
            #endif
            HandleRequest( request );
            result = (HDDEDATA)DDE_FACK;
        } else {
            result = (HDDEDATA)DDE_FNOTPROCESSED;
        }
    } else if ( uType & XCLASS_NOTIFICATION ) {
    }
    return result;
}

// Handle DDE request.  The argument is the command line received by the
// DDE client process.  We convert that string to an nsICmdLineService
// object via GetCmdLineArgs.  Then, we look for certain well-known cmd
// arguments.  This replicates code elsewhere, to some extent,
// unfortunately (if you can fix that, please do).
void
nsNativeAppSupportWin::HandleRequest( LPBYTE request ) {
    // Parse command line.
    nsCOMPtr<nsICmdLineService> args;
    nsresult rv = GetCmdLineArgs( request, getter_AddRefs( args ) );
    if ( NS_SUCCEEDED( rv ) ) {
        nsXPIDLCString arg;
        if (NS_SUCCEEDED(args->GetURLToLoad(getter_Copies(arg) ) ) &&
            (const char*)arg ) {
            // Launch browser.
            #if MOZ_DEBUG_DDE
            printf( "Launching browser on url [%s]...\n", (const char*)arg );
            #endif
            (void)OpenWindow( "chrome://navigator/content/", arg );
        }
        else if (NS_SUCCEEDED(args->GetCmdLineValue("-chrome", getter_Copies(arg))) &&
                 (const char*)arg ) {
            // Launch chrome.
            #if MOZ_DEBUG_DDE
            printf( "Launching chrome url [%s]...\n", (const char*)arg );
            #endif
            (void)OpenWindow( arg, "" );
        }
        else if (NS_SUCCEEDED(args->GetCmdLineValue("-edit", getter_Copies(arg))) &&
                 (const char*)arg ) {
            // Launch composer.
            #if MOZ_DEBUG_DDE
            printf( "Launching editor on url [%s]...\n", arg );
            #endif
            (void)OpenWindow( "chrome://editor/content/", arg );
        } else if ( NS_SUCCEEDED( args->GetCmdLineValue( "-mail", getter_Copies(arg))) &&
                    (const char*)arg ) {
            // Launch composer.
            #if MOZ_DEBUG_DDE
            printf( "Launching mail...\n" );
            #endif
            (void)OpenWindow( "chrome://messenger/content/", "" );
        } else {
            #if MOZ_DEBUG_DDE
            printf( "Unknown request [%s]\n", (char*) request );
            #endif
            // if all else fails, open a browser window
            const char * const contractID = "@mozilla.org/commandlinehandler/general-startup;1?type=browser";
            nsCOMPtr<nsICmdLineHandler> handler(do_GetService(contractID, &rv));

            nsXPIDLString defaultArgs;
            if (handler) {
                handler->GetDefaultArgs(getter_Copies(defaultArgs));
            }

            if (defaultArgs) {
                nsCString url;
                url.AssignWithConversion( defaultArgs );
                OpenWindow("chrome://navigator/content/", (const char*)url);
            } else {
                OpenWindow("chrome://navigator/content/", "about:blank");
            }
        }
    
    }
}

// Parse command line args according to MS spec
// (see "Parsing C++ Command-Line Arguments" at
// http://msdn.microsoft.com/library/devprods/vs6/visualc/vclang/_pluslang_parsing_c.2b2b_.command.2d.line_arguments.htm).
nsresult
nsNativeAppSupportWin::GetCmdLineArgs( LPBYTE request, nsICmdLineService **aResult ) {
    nsresult rv = NS_OK;

    int justCounting = 1;
    char **argv = 0;
    // Flags, etc.
    int init = 1;
    int between, quoted, bSlashCount;
    int argc;
    char *p;
    nsCString arg;
    // We loop if we've not finished the second pass through.
    while ( 1 ) {
        // Initialize if required.
        if ( init ) {
            p = (char*)request;
            between = 1;
            argc = quoted = bSlashCount = 0;

            init = 0;
        }
        if ( between ) {
            // We are traversing whitespace between args.
            // Check for start of next arg.
            if (  *p != 0 && !isspace( *p ) ) {
                // Start of another arg.
                between = 0;
                arg = "";
                switch ( *p ) {
                    case '\\':
                        // Count the backslash.
                        bSlashCount = 1;
                        break;
                    case '"':
                        // Remember we're inside quotes.
                        quoted = 1;
                        break;
                    default:
                        // Add character to arg.
                        arg += *p;
                        break;
                }
            } else {
                // Another space between args, ignore it.
            }
        } else {
            // We are processing the contents of an argument.
            // Check for whitespace or end.
            if ( *p == 0 || ( !quoted && isspace( *p ) ) ) {
                // Process pending backslashes (interpret them 
                // literally since they're not followed by a ").
                while( bSlashCount ) {
                    arg += '\\';
                    bSlashCount--;
                }
                // End current arg.
                if ( !justCounting ) {
                    argv[argc] = new char[ arg.Length() + 1 ];
                    strcpy( argv[argc], arg.get() ); 
                }
                argc++;
                // We're now between args.
                between = 1;
            } else {
                // Still inside argument, process the character.
                switch ( *p ) {
                    case '"':
                        // First, digest preceding backslashes (if any).
                        while ( bSlashCount > 1 ) {
                            // Put one backsplash in arg for each pair.
                            arg += '\\';
                            bSlashCount -= 2;
                        }
                        if ( bSlashCount ) {
                            // Quote is literal.
                            arg += '"';
                            bSlashCount = 0;
                        } else {
                            // Quote starts or ends a quoted section.
                            if ( quoted ) {
                                // Check for special case of consecutive double
                                // quotes inside a quoted section.
                                if ( *(p+1) == '"' ) {
                                    // This implies a literal double-quote.  Fake that
                                    // out by causing next double-quote to look as
                                    // if it was preceded by a backslash.
                                    bSlashCount = 1;
                                } else {
                                    quoted = 0;
                                }
                            } else {
                                quoted = 1;
                            }
                        }
                        break;
                    case '\\':
                        // Add to count.
                        bSlashCount++;
                        break;
                    default:
                        // Accept any preceding backslashes literally.
                        while ( bSlashCount ) {
                            arg += '\\';
                            bSlashCount--;
                        }
                        // Just add next char to the current arg.
                        arg += *p;
                        break;
                }
            }
        }
        // Check for end of input.
        if ( *p ) {
            // Go to next character.
            p++;
        } else {
            // If on first pass, go on to second.
            if ( justCounting ) {
                // Allocate argv array.
                argv = new char*[ argc ];
    
                // Start second pass
                justCounting = 0;
                init = 1;
            } else {
                // Quit.
                break;
            }
        }
    }

    // OK, now create nsICmdLineService object from argc/argv.
    static NS_DEFINE_CID( kCmdLineServiceCID,    NS_COMMANDLINE_SERVICE_CID );
    rv = nsComponentManager::CreateInstance( kCmdLineServiceCID,
                                             0,
                                             NS_GET_IID( nsICmdLineService ),
                                             (void**)aResult );
    if ( NS_FAILED( rv ) || NS_FAILED( ( rv = (*aResult)->Initialize( argc, argv ) ) ) ) {
        #if MOZ_DEBUG_DDE
        printf( "Error creating command line service = 0x%08X (argc=%d, argv=0x%08X)\n", (int)rv, (int)argc, (void*)argv );
        #endif
    }

    // Cleanup.
    while ( argc ) {
        delete [] argv[ --argc ];
    }
    delete [] argv;

    return rv;
}

nsresult
nsNativeAppSupportWin::OpenWindow( const char*urlstr, const char *args ) {

  nsresult rv = NS_ERROR_FAILURE;

  nsCOMPtr<nsIWindowWatcher> wwatch(do_GetService("@mozilla.org/embedcomp/window-watcher;1"));
  nsCOMPtr<nsISupportsString> sarg(do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID));
  if (sarg)
    sarg->SetData(args);

  if (wwatch && sarg) {
    nsCOMPtr<nsIDOMWindow> newWindow;
    rv = wwatch->OpenWindow(0, urlstr, "_blank", "chrome,dialog=no,all",
                   sarg, getter_AddRefs(newWindow));
#ifdef MOZ_DEBUG_DDE
  } else {
      printf("Get WindowWatcher (or create string) failed\n");
#endif
  }
  return rv;
}