C++ BMediaRoster::GetParameterWebFor方法代码示例

MediaNodeControlApp::MediaNodeControlApp(
	const char* pAppSignature,
	media_node_id nodeID) :
	BApplication(pAppSignature) {

	BMediaRoster* r = BMediaRoster::Roster();
	
	// get the node	
	status_t err = r->GetNodeFor(nodeID, &m_node);
	if(err < B_OK) {
		char buffer[512];
		sprintf(buffer,
			"MediaNodeControlApp: couldn't find node (%ld):\n%s\n",
			nodeID, strerror(err));
		(new BAlert("error", buffer, "OK"))->Go();
		return;
	}
	
	// fetch info (name)
	live_node_info nInfo;
	err = r->GetLiveNodeInfo(m_node, &nInfo);
	if(err < B_OK) {
		char buffer[512];
		sprintf(buffer,
			"MediaNodeControlApp: couldn't get node info (%ld):\n%s\n",
			nodeID, strerror(err));
		(new BAlert("error", buffer, "OK"))->Go();
		return;
	}
	
	BString windowTitle;
	windowTitle << nInfo.name << '(' << nodeID << ") controls";		
	
	// get parameter web
	BParameterWeb* pWeb;
	err = r->GetParameterWebFor(m_node, &pWeb);
	if(err < B_OK) {
		char buffer[512];
		sprintf(buffer,
			"MediaNodeControlApp: no parameters for node (%ld):\n%s\n",
			nodeID, strerror(err));
		(new BAlert("error", buffer, "OK"))->Go();
		return;
	}
	
	// build & show control window
	BView* pView = BMediaTheme::ViewFor(pWeb);
	BWindow* pWnd = new PanelWindow();
	pWnd->AddChild(pView);
	pWnd->ResizeTo(pView->Bounds().Width(), pView->Bounds().Height());
	pWnd->SetTitle(windowTitle.String());
	pWnd->Show();
	
	// release the node
	//r->ReleaseNode(m_node);	
}

void ParameterWindow::_updateParameterView(
    BMediaTheme *theme) {
    D_INTERNAL(("ParameterWindow::_updateParameterView()\n"));

    // clear the old version
    if (m_parameters) {
        ParameterContainerView *view = dynamic_cast<ParameterContainerView *>(FindView("ParameterContainerView"));
        RemoveChild(view);
        delete m_parameters;
        m_parameters = 0;
        delete view;
    }

    // fetch ParameterWeb from the MediaRoster
    BMediaRoster *roster = BMediaRoster::CurrentRoster();
    if (roster) {
        BParameterWeb *web;
        status_t error = roster->GetParameterWebFor(m_node, &web);
        if (!error && (web->CountParameters() || web->CountGroups())) {
            // if no theme was specified, use the preferred theme
            if (!theme) {
                theme = BMediaTheme::PreferredTheme();
            }
            // acquire the view
            m_parameters = BMediaTheme::ViewFor(web, 0, theme);
            if (m_parameters) {
                BMenuBar *menuBar = KeyMenuBar();
                m_idealSize = m_parameters->Bounds();
                m_idealSize.right += B_V_SCROLL_BAR_WIDTH;
                m_idealSize.bottom += B_H_SCROLL_BAR_HEIGHT;
                if (menuBar) {
                    m_parameters->MoveTo(0.0, menuBar->Bounds().bottom + 1.0);
                    m_idealSize.bottom += menuBar->Bounds().bottom + 1.0;
                }
            }
        }
    }

    // limit min size to avoid funny-looking scrollbars
    float hMin = B_V_SCROLL_BAR_WIDTH*6, vMin = B_H_SCROLL_BAR_HEIGHT*3;
    // limit max size to full extents of the parameter view
    float hMax = m_idealSize.Width(), vMax = m_idealSize.Height();
    SetSizeLimits(hMin, hMax, vMin, vMax);

    // adapt the window to the new dimensions
    ResizeTo(m_idealSize.Width(), m_idealSize.Height());
    m_zoomed = true;

    if (m_parameters) {
        BRect paramRect = m_parameters->Bounds();
        AddChild(new ParameterContainerView(paramRect, m_parameters));
    }
}

void
MediaWindow::_MakeParamView()
{
	if (!fCurrentNode.IsSet())
		return;

	fParamWeb = NULL;
	BMediaRoster* roster = BMediaRoster::Roster();
	if (roster->GetParameterWebFor(fCurrentNode, &fParamWeb) == B_OK) {
		BRect hint(fContentLayout->Frame());
		BView* paramView = BMediaTheme::ViewFor(fParamWeb, &hint);
		if (paramView) {
			fContentLayout->AddView(paramView);
			fContentLayout->SetVisibleItem(fContentLayout->CountItems() - 1);
			return;
		}
	}

	_MakeEmptyParamView();
}

void
NodeHarnessWin::MessageReceived(BMessage *msg)
{
	status_t err;

	switch (msg->what)
	{
	case BUTTON_CONNECT:
		mIsConnected = true;

		// set the button states appropriately
		mConnectButton->SetEnabled(false);
		mStartButton->SetEnabled(true);

		// set up the node network
		{
			BMediaRoster* r = BMediaRoster::Roster();

			// find a node that can handle an audio file
#if TEST_WITH_AUDIO
			entry_ref inRef;
			dormant_node_info info;

			::get_ref_for_path("/boot/optional/sound/virtual (void)", &inRef);
			err = r->SniffRef(inRef, B_BUFFER_PRODUCER | B_FILE_INTERFACE, &info);
			ErrorCheck(err, "couldn't find file reader node\n");

			err = r->InstantiateDormantNode(info, &mConnection.producer, B_FLAVOR_IS_LOCAL);
			ErrorCheck(err, "couldn't instantiate file reader node\n");

			bigtime_t dummy_length;			// output = media length; we don't use it
			err = r->SetRefFor(mConnection.producer, inRef, false, &dummy_length);
			ErrorCheck(err, "unable to SetRefFor() to read that sound file!\n");
#else
			r->GetVideoInput(&mConnection.producer);
#endif

			entry_ref logRef;
			::get_ref_for_path("/tmp/node_log", &logRef);

			mLogNode = new LoggingConsumer(logRef);
			err = r->RegisterNode(mLogNode);
			ErrorCheck(err, "unable to register LoggingConsumer node!\n");
			// make sure the Media Roster knows that we're using the node
			r->GetNodeFor(mLogNode->Node().node, &mConnection.consumer);

			// trim down the log's verbosity a touch
			mLogNode->SetEnabled(LOG_HANDLE_EVENT, false);

			// fire off a window with the LoggingConsumer's controls in it
			BParameterWeb* web;
			r->GetParameterWebFor(mConnection.consumer, &web);
			BView* view = BMediaTheme::ViewFor(web);
			BWindow* win = new BWindow(BRect(250, 200, 300, 300), "Controls",
				B_TITLED_WINDOW, B_ASYNCHRONOUS_CONTROLS);
			win->AddChild(view);
			win->ResizeTo(view->Bounds().Width(), view->Bounds().Height());
			win->Show();

			// set the nodes' time sources
			r->GetTimeSource(&mTimeSource);
			r->SetTimeSourceFor(mConnection.consumer.node, mTimeSource.node);
			r->SetTimeSourceFor(mConnection.producer.node, mTimeSource.node);

			// got the nodes; now we find the endpoints of the connection
			media_input logInput;
			media_output soundOutput;
			int32 count;
			err = r->GetFreeOutputsFor(mConnection.producer, &soundOutput, 1, &count);
			ErrorCheck(err, "unable to get a free output from the producer node");
			err = r->GetFreeInputsFor(mConnection.consumer, &logInput, 1, &count);
			ErrorCheck(err, "unable to get a free input to the LoggingConsumer");

			// fill in the rest of the Connection object
			mConnection.source = soundOutput.source;
			mConnection.destination = logInput.destination;

			// got the endpoints; now we connect it!
			media_format format;
#if TEST_WITH_AUDIO
			format.type = B_MEDIA_RAW_AUDIO;			// !!! hmmm.. how to fully wildcard this?
			format.u.raw_audio = media_raw_audio_format::wildcard;
#else
			format.type = B_MEDIA_RAW_VIDEO;			// !!! hmmm.. how to fully wildcard this?
			format.u.raw_video = media_raw_video_format::wildcard;
#endif
			err = r->Connect(mConnection.source, mConnection.destination, &format, &soundOutput, &logInput);
			ErrorCheck(err, "unable to connect nodes");
			mConnection.format = format;

			// for video input, we need to set the downstream latency for record -> playback
			bigtime_t latency;
			r->GetLatencyFor(mConnection.producer, &latency);
			printf("Setting producer run mode latency to %" B_PRIdBIGTIME "\n", latency);
			r->SetProducerRunModeDelay(mConnection.producer, latency + 6000);

			// preroll first, to be a good citizen
			r->PrerollNode(mConnection.consumer);
			r->PrerollNode(mConnection.producer);

//.........这里部分代码省略.........

void
NodeHarnessWin::MessageReceived(BMessage *msg)
{
    status_t err;

    switch (msg->what)
    {
    case BUTTON_CONNECT:
        mIsConnected = true;

        // set the button states appropriately
        mConnectButton->SetEnabled(false);
        mStartButton->SetEnabled(true);

        // set up the node network
        {
            BMediaRoster* r = BMediaRoster::Roster();

            // connect to the mixer
            err = r->GetAudioMixer(&mConnection.consumer);
            ErrorCheck(err, "unable to get the system mixer");

            // fire off a window with the ToneProducer's controls in it
            BParameterWeb* web;
            r->GetParameterWebFor(mConnection.producer, &web);
            BView* view = BMediaTheme::ViewFor(web);
            BWindow* win = new BWindow(BRect(250, 200, 300, 300), "Controls",
                                       B_TITLED_WINDOW, B_ASYNCHRONOUS_CONTROLS);
            win->AddChild(view);
            win->ResizeTo(view->Bounds().Width(), view->Bounds().Height());
            win->Show();

            // set the producer's time source to be the "default" time source, which
            // the Mixer uses too.
            r->GetTimeSource(&mTimeSource);
            r->SetTimeSourceFor(mConnection.producer.node, mTimeSource.node);

            // got the nodes; now we find the endpoints of the connection
            media_input mixerInput;
            media_output soundOutput;
            int32 count = 1;
            err = r->GetFreeOutputsFor(mConnection.producer, &soundOutput, 1, &count);
            ErrorCheck(err, "unable to get a free output from the producer node");
            count = 1;
            err = r->GetFreeInputsFor(mConnection.consumer, &mixerInput, 1, &count);
            ErrorCheck(err, "unable to get a free input to the mixer");

            // got the endpoints; now we connect it!
            media_format format;
            format.type = B_MEDIA_RAW_AUDIO;
            format.u.raw_audio = media_raw_audio_format::wildcard;
            err = r->Connect(soundOutput.source, mixerInput.destination, &format, &soundOutput, &mixerInput);
            ErrorCheck(err, "unable to connect nodes");

            // the inputs and outputs might have been reassigned during the
            // nodes' negotiation of the Connect().  That's why we wait until
            // after Connect() finishes to save their contents.
            mConnection.format = format;
            mConnection.source = soundOutput.source;
            mConnection.destination = mixerInput.destination;

            // Set an appropriate run mode for the producer
            r->SetRunModeNode(mConnection.producer, BMediaNode::B_INCREASE_LATENCY);
        }
        break;

    case BUTTON_START:
        mStartButton->SetEnabled(false);
        mStopButton->SetEnabled(true);

        // start the producer running
        {
            BMediaRoster* r = BMediaRoster::Roster();
            BTimeSource* ts = r->MakeTimeSourceFor(mConnection.producer);
            if (!ts)
            {
                fprintf(stderr, "* ERROR - MakeTimeSourceFor(producer) returned NULL!\n");
                exit(1);
            }

            // make sure we give the producer enough time to run buffers through
            // the node chain, otherwise it'll start up already late
            bigtime_t latency = 0;
            r->GetLatencyFor(mConnection.producer, &latency);
            r->StartNode(mConnection.producer, ts->Now() + latency);
            ts->Release();
            mIsRunning = true;
        }
        break;

    case BUTTON_STOP:
        StopNodes();
        break;

    default:
        BWindow::MessageReceived(msg);
        break;
    }
}