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// **************************************************************************
// * This file is part of the FreeFileSync project. It is distributed under *
// * GNU General Public License: http://www.gnu.org/licenses/gpl.html *
// * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved *
// **************************************************************************
#include "notify_removal.h"
#include <set>
#include <algorithm>
#include <dbt.h>
#include "scope_guard.h"
using namespace zen;
namespace
{
bool messageProviderConstructed = false;
}
class MessageProvider //administrates a single dummy window to receive messages
{
public:
static MessageProvider& instance() //throw (FileError)
{
static MessageProvider inst;
messageProviderConstructed = true;
return inst;
}
class Listener
{
public:
virtual ~Listener() {}
virtual void onMessage(UINT message, WPARAM wParam, LPARAM lParam) = 0; //throw()!
};
void registerListener(Listener& l) { listener.insert(&l); }
void unregisterListener(Listener& l) { listener.erase(&l); } //don't unregister objects with static lifetime
HWND getWnd() const { return windowHandle; } //get handle in order to register additional notifications
private:
MessageProvider();
~MessageProvider();
MessageProvider(const MessageProvider&);
MessageProvider& operator=(const MessageProvider&);
static const wchar_t dummyWindowName[];
friend LRESULT CALLBACK topWndProc(HWND, UINT, WPARAM, LPARAM);
void processMessage(UINT message, WPARAM wParam, LPARAM lParam);
const HINSTANCE hMainModule;
HWND windowHandle;
std::set<Listener*> listener;
};
const wchar_t MessageProvider::dummyWindowName[] = L"E6AD5EB1-527B-4EEF-AC75-27883B233380"; //random name
LRESULT CALLBACK topWndProc(HWND hwnd, //handle to window
UINT uMsg, //message identifier
WPARAM wParam, //first message parameter
LPARAM lParam) //second message parameter
{
if (messageProviderConstructed) //attention: this callback is triggered in the middle of singleton construction! It is a bad idea to to call back at this time!
try
{
MessageProvider::instance().processMessage(uMsg, wParam, lParam); //not supposed to throw
}
catch (...) { assert(false); }
return ::DefWindowProc(hwnd, uMsg, wParam, lParam);
}
MessageProvider::MessageProvider() :
hMainModule(::GetModuleHandle(nullptr)), //get program's module handle
windowHandle(nullptr)
{
if (!hMainModule)
throw FileError(_("Unable to register to receive system messages."), formatSystemError(L"GetModuleHandle", getLastError()));
//register the main window class
WNDCLASS wc = {};
wc.lpfnWndProc = topWndProc;
wc.hInstance = hMainModule;
wc.lpszClassName = dummyWindowName;
if (::RegisterClass(&wc) == 0)
throw FileError(_("Unable to register to receive system messages."), formatSystemError(L"RegisterClass", getLastError()));
ScopeGuard guardClass = makeGuard([&] { ::UnregisterClass(dummyWindowName, hMainModule); });
//create dummy-window
windowHandle = ::CreateWindow(dummyWindowName, //LPCTSTR lpClassName OR ATOM in low-order word!
nullptr, //LPCTSTR lpWindowName,
0, //DWORD dwStyle,
0, //int x,
0, //int y,
0, //int nWidth,
0, //int nHeight,
0, //note: we need a toplevel window to receive device arrival events, not a message-window (HWND_MESSAGE)!
nullptr, //HMENU hMenu,
hMainModule, //HINSTANCE hInstance,
nullptr); //LPVOID lpParam
if (!windowHandle)
throw FileError(_("Unable to register to receive system messages."), formatSystemError(L"CreateWindow", getLastError()));
guardClass.dismiss();
}
MessageProvider::~MessageProvider()
{
//clean-up in reverse order
::DestroyWindow(windowHandle);
::UnregisterClass(dummyWindowName, //LPCTSTR lpClassName OR ATOM in low-order word!
hMainModule); //HINSTANCE hInstance
}
void MessageProvider::processMessage(UINT message, WPARAM wParam, LPARAM lParam)
{
std::for_each(listener.begin(), listener.end(),
[&](Listener* ls) { ls->onMessage(message, wParam, lParam); });
}
//####################################################################################################
class NotifyRequestDeviceRemoval::Pimpl : private MessageProvider::Listener
{
public:
Pimpl(NotifyRequestDeviceRemoval& parent, HANDLE hDir) : //throw FileError
parent_(parent)
{
MessageProvider::instance().registerListener(*this); //throw FileError
ScopeGuard guardProvider = makeGuard([&] { MessageProvider::instance().unregisterListener(*this); });
//register handles to receive notifications
DEV_BROADCAST_HANDLE filter = {};
filter.dbch_size = sizeof(filter);
filter.dbch_devicetype = DBT_DEVTYP_HANDLE;
filter.dbch_handle = hDir;
hNotification = ::RegisterDeviceNotification(MessageProvider::instance().getWnd(), //__in HANDLE hRecipient,
&filter, //__in LPVOID NotificationFilter,
DEVICE_NOTIFY_WINDOW_HANDLE); //__in DWORD Flags
if (!hNotification)
{
const DWORD lastError = ::GetLastError();
if (lastError != ERROR_CALL_NOT_IMPLEMENTED && //fail on SAMBA share: this shouldn't be a showstopper!
lastError != ERROR_SERVICE_SPECIFIC_ERROR && //neither should be fail for "Pogoplug" mapped network drives
lastError != ERROR_INVALID_DATA) //this seems to happen for a NetDrive-mapped FTP server
throw zen::FileError(_("Unable to register to receive system messages."), formatSystemError(L"RegisterDeviceNotification", lastError));
}
guardProvider.dismiss();
}
~Pimpl()
{
if (hNotification)
::UnregisterDeviceNotification(hNotification);
MessageProvider::instance().unregisterListener(*this);
}
private:
Pimpl(Pimpl&);
Pimpl& operator=(Pimpl&);
virtual void onMessage(UINT message, WPARAM wParam, LPARAM lParam) //throw()!
{
//DBT_DEVICEQUERYREMOVE example: http://msdn.microsoft.com/en-us/library/aa363427(v=VS.85).aspx
if (message == WM_DEVICECHANGE)
if (wParam == DBT_DEVICEQUERYREMOVE ||
wParam == DBT_DEVICEQUERYREMOVEFAILED ||
wParam == DBT_DEVICEREMOVECOMPLETE)
{
PDEV_BROADCAST_HDR header = reinterpret_cast<PDEV_BROADCAST_HDR>(lParam);
if (header->dbch_devicetype == DBT_DEVTYP_HANDLE)
{
PDEV_BROADCAST_HANDLE body = reinterpret_cast<PDEV_BROADCAST_HANDLE>(lParam);
if (body->dbch_hdevnotify == hNotification) //is it for the notification we registered?
switch (wParam)
{
case DBT_DEVICEQUERYREMOVE:
parent_.onRequestRemoval(body->dbch_handle);
break;
case DBT_DEVICEQUERYREMOVEFAILED:
parent_.onRemovalFinished(body->dbch_handle, false);
break;
case DBT_DEVICEREMOVECOMPLETE:
parent_.onRemovalFinished(body->dbch_handle, true);
break;
}
}
}
}
NotifyRequestDeviceRemoval& parent_;
HDEVNOTIFY hNotification;
};
//####################################################################################################
NotifyRequestDeviceRemoval::NotifyRequestDeviceRemoval(HANDLE hDir)
{
pimpl.reset(new Pimpl(*this, hDir));
}
NotifyRequestDeviceRemoval::~NotifyRequestDeviceRemoval() {} //make sure ~unique_ptr() works with complete type
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