Extending Microsoft's Terminal Services Client To Provide Seamless Windows

//*********************************************************************************
//
//Title: Terminal Services Window Clipper
//
//Author: Martin Wickett
//
//Date: 2004
//
//*********************************************************************************

#include <windows.h>

#include "resource.h"
#include "hookdll/hook.h"

//
// some global data
//
HWND				ghWnd;
NOTIFYICONDATA		nid;
HINSTANCE			hAppInstance;

static const UINT WM_TRAY_NOTIFY	= (WM_APP + 1000);
static const char szAppName[]		= "Terminal Services Window Clipper";

//
// spawn a message box
//
void Message(const char* message)
{
	MessageBox(GetDesktopWindow(),message,"TS Window Clipper", MB_OK);
}

//
// manage the tray icon
//
bool InitTrayIcon()
{
	nid.cbSize				= sizeof(NOTIFYICONDATA) ;
	nid.hWnd				= ghWnd;
	nid.uID					= 0 ;
	nid.uFlags				= NIF_MESSAGE | NIF_ICON | NIF_TIP ;	
	nid.uCallbackMessage	= WM_TRAY_NOTIFY;  
	strcpy(nid.szTip,szAppName);
	nid.hIcon				= ::LoadIcon(hAppInstance,MAKEINTRESOURCE(IDI_TRAY)); 
	
	if (Shell_NotifyIcon (NIM_ADD,&nid) != TRUE)
	{
		Message("Unable to create tray icon.");
		return false;
	}

	return true;
}

//
// Remove tray icon
//
bool RemoveTrayIcon()
{
	if (Shell_NotifyIcon (NIM_DELETE,&nid) != TRUE)
	{
		Message("Unable to remove tray icon.");
		return false;
	}

	return true;

}

//
// manage the about dialog box
//
BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam )
{
	if (uMsg == WM_COMMAND)
	{
		WORD wID		 = LOWORD(wParam);
		if (wID == IDOK) DestroyWindow(hwndDlg);
	}

	return 0;
}

void AboutDlg()
{
	DialogBox(hAppInstance,MAKEINTRESOURCE(IDD_ABOUT),NULL,DialogProc);
}

//
// manage the context menu
//
void DoContextMenu()
{
	HMENU hMenu =LoadMenu(hAppInstance,MAKEINTRESOURCE(IDR_TRAY));
	if (hMenu == NULL)
	{
		Message("Unable to load menu ressource.");
		return;
	}

	HMENU hSubMenu = GetSubMenu(hMenu,0);
	if (hSubMenu == NULL)
	{
		Message("Unable to find popup mennu.");
		return;
	}

	// get the cursor position
	POINT pt;
	GetCursorPos (&pt) ;

	SetForegroundWindow(ghWnd);
	int cmd = TrackPopupMenu(hSubMenu,TPM_RETURNCMD|TPM_LEFTALIGN|TPM_RIGHTBUTTON,
							pt.x,pt.y,0,ghWnd,NULL);				
	DeleteObject(hMenu);

	switch (cmd)
	{
		case ID_WMEXIT :
		{
			PostQuitMessage(0);
			break;						
		}
		case ID_WMABOUT :
		{
			AboutDlg();
			break;
		}
	}
}

//
// manage the main window
//
LONG WINAPI MainWndProc ( HWND    hWnd, UINT    uMsg, WPARAM  wParam, LPARAM  lParam) 
{ 
	switch (uMsg)
	{
		case WM_DESTROY :
		{
			PostQuitMessage (0);
			return 0;
		}
		case WM_TRAY_NOTIFY :
		{
			if (lParam == WM_RBUTTONDOWN) 
				DoContextMenu();
			return 0;
		}
	}
	
	return DefWindowProc (hWnd, uMsg, wParam, lParam); 
} 

//
//Init window
//
bool InitWindow()
{
	// register the frame class
	WNDCLASS wndclass;
    wndclass.style         = 0; 
    wndclass.lpfnWndProc   = (WNDPROC)MainWndProc; 
    wndclass.cbClsExtra    = 0; 
    wndclass.cbWndExtra    = 0; 
    wndclass.hInstance     = hAppInstance; 
    wndclass.hIcon         = 0; 
    wndclass.hCursor       = LoadCursor (NULL,IDC_ARROW); 
    wndclass.hbrBackground = (HBRUSH)(COLOR_WINDOW+1); 
    wndclass.lpszMenuName  = NULL; 
    wndclass.lpszClassName = szAppName;
 
    if (!RegisterClass (&wndclass))
	{
		Message("Unable to register the window class.");
		return false;
	}
 
    // create the frame 
    ghWnd = CreateWindow (szAppName, szAppName, 
         WS_OVERLAPPEDWINDOW | WS_CLIPSIBLINGS | WS_CLIPCHILDREN, 
             CW_USEDEFAULT, 
             CW_USEDEFAULT, 
             640, 
             480, 
             NULL, 
             NULL, 
             hAppInstance, 
             NULL); 
 
    // make sure window was created
    if (!ghWnd) 
	{
		Message("Unable to create the window.");
		return false; 
	}

	return true;
}

//
// init
//
bool Init(LPSTR lpCmdLine)
{
	// try to load WTSWinClipper.dll
	if (!WTSWinClipper::Init())
	{
		Message("Application not installed correctly: Unable to init hookdll.dll.");
		return false;
	}

	// check number of instances
	if (WTSWinClipper::GetInstanceCount() == 1)
	{
		// hook in
		WTSWinClipper::SetCbtHook();	
		return true;
	} else 
	{
		// already hooked
		return false;
	}
}

// 
// our main loop
//
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) 
{
	hAppInstance = hInstance;
	if (!Init(lpCmdLine)) 
	{
		return 0;
	}

	// if we have been specified an app to launch, we will wait until the app has closed and use that for
	// our cue to exit
	if (strlen(lpCmdLine)> 0)
	{
		// Because we do not have a explorer.exe we need to make this application the replacement
		// shell. We do this by calling SystemParametersInfo. If we don't do this, we won't get the WH_SHELL notifications.
		
		// From MSDN:
		// Note that custom shell applications do not receive WH_SHELL messages. Therefore, any application that 
		// registers itself as the default shell must call the SystemParametersInfo function with SPI_SETMINIMIZEDMETRICS 
		// before it (or any other application) can receive WH_SHELL messages.

		MINIMIZEDMETRICS mmm;
		mmm.cbSize = sizeof( MINIMIZEDMETRICS);
		SystemParametersInfo(SPI_SETMINIMIZEDMETRICS ,sizeof( MINIMIZEDMETRICS),&mmm,0);

		//set the current directory to that of the requested app .exe location
		//tokenise lpCmdLine. first is the exe path. second (if exists) is the current directory to set.
		//SetCurrentDirectory ();

		//start process specified from command line arg.
		PROCESS_INFORMATION procInfo;
		STARTUPINFO startupInfo = {0}; 
		startupInfo.cb = sizeof(STARTUPINFO);
		char attr[] = "";
		LPTSTR process= lpCmdLine;
		DWORD dwExitCode;

		BOOL m_create  = CreateProcess( NULL,process,NULL, NULL, FALSE, 0, NULL, NULL, &startupInfo, &procInfo);
		
		if (m_create != false)
		{		 
			// A loop to watch the process. 
			GetExitCodeProcess(procInfo.hProcess, &dwExitCode);

			while (dwExitCode == STILL_ACTIVE )
			{
				GetExitCodeProcess(procInfo.hProcess, &dwExitCode);
				Sleep(1000);
			}

			// Release handles
			CloseHandle(procInfo.hProcess);
			CloseHandle(procInfo.hThread);
		}
		else
		{
			// CreateProcess failed.
			Message("Unable to launch the requested application");
		}
	}
	else
	// we are launching without an app, therefore we will show the system tray app and wait for the user to close it
	{
		// create a dummy window to receive WM_QUIT message
		InitWindow();

		// create the tray icon
		InitTrayIcon();

		// just get and dispatch messages until we're killed
		MSG msg;
		while (GetMessage(&msg,0,0,0))
		{
			TranslateMessage(&msg);
			DispatchMessage(&msg);
		};

		// remove our tray icon
		RemoveTrayIcon();
	}


	// remove hook before saying goodbye
	WTSWinClipper::RemoveCbtHook();
	
	WTSWinClipper::Done();

	return 1;
}