bool MidiDriver::checkDevice(MidiDriver::DeviceHandle handle) {
	const MusicPlugin::List p = MusicMan.getPlugins();
	for (MusicPlugin::List::const_iterator m = p.begin(); m != p.end(); m++) {
		if (getDeviceString(handle, MidiDriver::kDriverId).equals((**m)->getId()))
			return (**m)->checkDevice(handle);
	}

	return false;
}

MidiDriver *MidiDriver::createMidi(MidiDriver::DeviceHandle handle) {
	MidiDriver *driver = 0;
	const MusicPlugin::List p = MusicMan.getPlugins();
	for (MusicPlugin::List::const_iterator m = p.begin(); m != p.end(); m++) {
		if (getDeviceString(handle, MidiDriver::kDriverId).equals((**m)->getId()))
			(**m)->createInstance(&driver, handle);
	}

	return driver;
}

MusicType MidiDriver::getMusicType(MidiDriver::DeviceHandle handle) {
	if (_forceTypeMT32)
		return MT_MT32;

	if (handle) {
		const MusicPlugin::List p = MusicMan.getPlugins();
		for (MusicPlugin::List::const_iterator m = p.begin(); m != p.end(); m++) {
			MusicDevices i = (**m)->getDevices();
			for (MusicDevices::iterator d = i.begin(); d != i.end(); d++) {
				if (handle == d->getHandle())
					return d->getMusicType();
			}
		}
	}

	return MT_INVALID;
}

MidiDriver::DeviceHandle MidiDriver::getDeviceHandle(const Common::String &identifier) {
	const MusicPlugin::List p = MusicMan.getPlugins();

	if (p.begin() == p.end())
		error("MidiDriver::getDeviceHandle: Music plugins must be loaded prior to calling this method");

	for (MusicPlugin::List::const_iterator m = p.begin(); m != p.end(); m++) {
		MusicDevices i = (**m)->getDevices();
		for (MusicDevices::iterator d = i.begin(); d != i.end(); d++) {
			// The music driver id isn't unique, but it will match
			// driver's first device. This is useful when selecting
			// the driver from the command line.
			if (identifier.equals(d->getMusicDriverId()) || identifier.equals(d->getCompleteId()) || identifier.equals(d->getCompleteName())) {
				return d->getHandle();
			}
		}
	}

	return 0;
}

Common::String MidiDriver::getDeviceString(DeviceHandle handle, DeviceStringType type) {
	if (handle) {
		const MusicPlugin::List p = MusicMan.getPlugins();
		for (MusicPlugin::List::const_iterator m = p.begin(); m != p.end(); m++) {
			MusicDevices i = (**m)->getDevices();
			for (MusicDevices::iterator d = i.begin(); d != i.end(); d++) {
				if (handle == d->getHandle()) {
					if (type == kDriverName)
						return d->getMusicDriverName();
					else if (type == kDriverId)
						return d->getMusicDriverId();
					else if (type == kDeviceId)
						return d->getCompleteId();
					else
						return Common::String("auto");
				}
			}
		}
	}

	return Common::String("auto");
}

MidiDriver::DeviceHandle MidiDriver::detectDevice(int flags) {
	// Query the selected music device (defaults to MT_AUTO device).
	Common::String selDevStr = ConfMan.hasKey("music_driver") ? ConfMan.get("music_driver") : Common::String("auto");
	DeviceHandle hdl = getDeviceHandle(selDevStr.empty() ? Common::String("auto") : selDevStr);
	DeviceHandle reslt = 0;

	_forceTypeMT32 = false;

	// Check whether the selected music driver is compatible with the
	// given flags.
	switch (getMusicType(hdl)) {
	case MT_PCSPK:
		if (flags & MDT_PCSPK)
			reslt = hdl;
		break;

	case MT_PCJR:
		if (flags & MDT_PCJR)
			reslt = hdl;
		break;

	case MT_CMS:
		if (flags & MDT_CMS)
			reslt = hdl;
		break;

	case MT_ADLIB:
		if (flags & MDT_ADLIB)
			reslt = hdl;
		break;

	case MT_C64:
		if (flags & MDT_C64)
			reslt = hdl;
		break;

	case MT_AMIGA:
		if (flags & MDT_AMIGA)
			reslt = hdl;
		break;

	case MT_APPLEIIGS:
		if (flags & MDT_APPLEIIGS)
			reslt = hdl;
		break;

	case MT_TOWNS:
		if (flags & MDT_TOWNS)
			reslt = hdl;
		break;

	case MT_PC98:
		if (flags & MDT_PC98)
			reslt = hdl;
		break;

	case MT_GM:
	case MT_GS:
	case MT_MT32:
		if (flags & MDT_MIDI)
			reslt = hdl;
		break;

	case MT_NULL:
		reslt = hdl;
		break;

	default:
		break;
	}

	Common::String failedDevStr;
	if (getMusicType(hdl) == MT_INVALID) {
		// If the expressly selected driver or device cannot be found (no longer compiled in, turned off, etc.)
		// we display a warning and continue.
		failedDevStr = selDevStr;
		Common::String warningMsg = Common::String::format(_("The selected audio device '%s' was not found (e.g. might be turned off or disconnected)."), failedDevStr.c_str()) + " " + _("Attempting to fall back to the next available device...");
		GUI::MessageDialog dialog(warningMsg);
		dialog.runModal();
	}

	MusicType tp = getMusicType(reslt);
	if (tp != MT_INVALID && tp != MT_AUTO) {
		if (checkDevice(reslt)) {
			return reslt;
		} else {
			// If the expressly selected device cannot be used we display a warning and continue.
			failedDevStr = getDeviceString(hdl, MidiDriver::kDeviceName);
			Common::String warningMsg = Common::String::format(_("The selected audio device '%s' cannot be used. See log file for more information."), failedDevStr.c_str()) + " " + _("Attempting to fall back to the next available device...");
			GUI::MessageDialog dialog(warningMsg);
			dialog.runModal();
		}
	}

	// If the selected driver did not match the flags setting,
	// we try to determine a suitable and "optimal" music driver.
	const MusicPlugin::List p = MusicMan.getPlugins();
	// If only MDT_MIDI but not MDT_PREFER_MT32 or MDT_PREFER_GM is set we prefer the other devices (which will always be
	// detected since they are hard coded and cannot be disabled).
	bool skipMidi = !(flags & (MDT_PREFER_GM | MDT_PREFER_MT32));
//.........这里部分代码省略.........

MidiDriver::DeviceHandle MidiDriver::detectDevice(int flags) {
	// Query the selected music device (defaults to MT_AUTO device).
	DeviceHandle hdl = getDeviceHandle(ConfMan.get("music_driver"));

	_forceTypeMT32 = false;

	// Check whether the selected music driver is compatible with the
	// given flags.
	switch (getMusicType(hdl)) {
	case MT_PCSPK:
		if (flags & MDT_PCSPK)
			return hdl;
		break;

	case MT_PCJR:
		if (flags & MDT_PCJR)
			return hdl;
		break;

	case MT_CMS:
		if (flags & MDT_CMS)
			return hdl;
		break;

	case MT_ADLIB:
		if (flags & MDT_ADLIB)
			return hdl;
		break;

	case MT_C64:
		if (flags & MDT_C64)
			return hdl;
		break;

	case MT_AMIGA:
		if (flags & MDT_AMIGA)
			return hdl;
		break;

	case MT_APPLEIIGS:
		if (flags & MDT_APPLEIIGS)
			return hdl;
		break;

	case MT_TOWNS:
		if (flags & MDT_TOWNS)
			return hdl;
		break;

	case MT_PC98:
		if (flags & MDT_PC98)
			return hdl;
		break;

	case MT_GM:
	case MT_GS:
	case MT_MT32:
		if (flags & MDT_MIDI)
			return hdl;
		break;

	case MT_NULL:
		return hdl;

	default:
		break;
	}

	// If the selected driver did not match the flags setting,
	// we try to determine a suitable and "optimal" music driver.
	const MusicPlugin::List p = MusicMan.getPlugins();
	// If only MDT_MIDI but not MDT_PREFER_MT32 or MDT_PREFER_GM is set we prefer the other devices (which will always be
	// detected since they are hard coded and cannot be disabled.
	for (int l = (flags & (MDT_PREFER_GM | MDT_PREFER_MT32)) ? 1 : 0; l < 2; ++l) {
		if ((flags & MDT_MIDI) && (l == 1)) {
			// If a preferred MT32 or GM device has been selected that device gets returned.
			if (flags & MDT_PREFER_MT32)
				hdl = getDeviceHandle(ConfMan.get("mt32_device"));
			else if (flags & MDT_PREFER_GM)
				hdl = getDeviceHandle(ConfMan.get("gm_device"));
			else
				hdl = getDeviceHandle("auto");

			const MusicType type = getMusicType(hdl);

			// If we have a "Don't use GM/MT-32" setting we skip this part and jump
			// to AdLib, PC Speaker etc. detection right away.
			if (type != MT_NULL) {
				if (type != MT_AUTO && type != MT_INVALID) {
					if (flags & MDT_PREFER_MT32)
						// If we have a preferred MT32 device we disable the gm/mt32 mapping (more about this in mididrv.h).
						_forceTypeMT32 = true;

					return hdl;
				}

				// If no specific device is selected (neither in the scummvm nor in the game domain)
				// and there is no preferred MT32 or GM device selected either we arrive here.
				// If MT32 is preferred we try for the first available device with music type 'MT_MT32' (usually the mt32 emulator).
				if (flags & MDT_PREFER_MT32) {
//.........这里部分代码省略.........