How can we get cobalt page loading state from starboard ?
We want to exit Cobalt application If network error message received in star board during app launch So for this we want to know Cobalt app state in starboard.
Cobalt will call SbSystemRaisePlatformError() if it encounters an unrecoverable connection error (the call is made here: https://cobalt.googlesource.com/cobalt/+/master/src/cobalt/browser/h5vcc_url_handler.cc#104 ). You can implement on your platform to react appropriately, will that work for you?
In general, we do not support having the Starboard layer depend on the Cobalt layer in any way (otherwise there would be a cyclical dependency).
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My team has been struggling with a pretty strange issue while using the WinRT/C++ APIs for Windows to connect to both a MIDI port and receive BLE notifications through a proprietary service on the same device.
The WinRT/C++ library itself is really nice and provides easy and modern C++ interfaces to access the managed Windows runtime classes.
I've pushed a sample repo to Github where we've replicated the issue with a minimal example.
The repo's readme goes over the problem in detail, but I'll post the relevant bits here for completeness.
The sample program is performing roughly these steps:
Check for available MIDI devices using a DeviceWatcher.
Check for available Bluetooth LE devices using another instance of a DeviceWatcher.
Match discovered MIDI and BluetoothLE devices on their ContainerId property (see DeviceInfo for details). This is the method JUCE employs in the native WinRT code for their library, and works as expected.
Open the MIDI port and attach a handler to the MessageReceived event (see the code).
This causes the system to create a connection to the Bluetooth LE device. The program detects this state change, creates a BluetoothLEDevice, we perform GATT service discovery and attach a handler to the ValueChanged event for the characteristic we're interested in notifications from (see the code).
The program then counts how many MIDI messages are received on each port and how many BLE notifications are received from the corresponding device.
The behaviour we notice is that data from the most recently connected device streams just fine, while the throughput for the others is severly limited. We are at quite a standstill regarding this issue, and are not sure where the problem may lie.
We are at quite a standstill here. I'd be more willing to accept it if all the devices would exhibit this behaviour, but that's not the case. Is there any reason that creating both a MidiInPort and an BluetoothLEDevice from the same peripheral should cause this issue?
A BLE radio can only receive or send at any given time. And therefore only communicate with one device at any given time. It uses a scheduler to allocate radio time for every device when you have many devices. That way a second connection can "interrupt" a connection event from another device, decreasing the throughput for that device. See https://infocenter.nordicsemi.com/topic/sds_s132/SDS/s1xx/multilink_scheduling/central_connection_timing.html
I'm new to electron and I want to make sure I understand the distinction between code that is appropriate for the main process vs the renderer process. The app is essentially a React app hosted inside a single electron page. So, as I understand it, I have one main process and one render process.
If I want to make REST calls as part of the React app (using axios for example), I assume I can do it inside the React code within the renderer process, right? No need to go to the main process for that is there?
I also have to create a socket connection to an outside server. This is not an HTTP REST interface, it's a raw TCP/IP socket. Can this also be done within the renderer process or do I need to go to the main for that?
I tried putting the socket calls using node's net library and it seems to work okay. The very first time I got some kind of connection error but subsequent tries seem to be working. That one error is making me wonder if using net inside the renderer is a good idea though.
I have been using Windows APIs for NFC communication. I am successful in getting and sending NFC messages from Windows PC, using a local console app. However, I want the communication to be done using a Windows service. Here is what I have:
A C# plugin (DLL), which makes the API calls.
C++/CLI Wrapper that allows unmanaged C++ code, to use the above plugin.
A C++ plugin, that the service will load (this is a requirement, it has to be a plugin)
If I load the C++ plugin into a local console app, and run, it can catch all NFC events (NFC device arrives in proximity, departs from proximity, can read and write to it). But, when I use the same plugin with a service, it is not able to catch those events. I can clearly hear the ping sound that comes when an NFC device comes close to Windows PC, however, none of the event handlers are called (For device arrival, device departure, read or write).
I also tried impersonation thinking that perhaps the context of who calls the method might result in blocking of the events. I could impersonate local user on the service, but the results were the same, no events could be identified.
Is there a reason why I cannot see any NFC events from a service, where as a local console app can get all of them? Again, I am able to hear the ping sound signifying that NFC device is close to Windows PC, but there is no handler getting called for it, suggesting there is blockage of something. Any ideas of what is going on?
Appreciate your time guys!
I am trying to collect GPS location every 5 seconds from a smart phone by using socket.io.
I notice that when users pick up a phone call, socket.io will stop emitting messages. When users switching tabs in the browser, socket.io will stop emitting messages too.
Does anyone know how to solve this problem?
Thanks very much!
Your best bet would be to package the website in a native app. Use a service such as http://build.phonegap.com or Intel XDK. There are configuration options to keep your app alive in the background. As for it disconnecting during phone calls, this is a carrier limitation. If the user was connected to WIFI, most phones will that for data while simultaneously on a call.
Some networks (such as Verizon) do not have the capability to do voice and data at the same time. Thus, when a call is made, data is suspended until the call is finished. AT&T does not have this limitation.
The operation of background tabs will vary by mobile browser and is likely done for battery conservation reasons. It is unlikely there is a work-around to keep the background tab running (because that would defeat the whole battery management purpose).
I would like to notify my main application (if it is still running) when the ScheduledAgent has finished its background task.
Is it actually possible? I couldn't figure out how I could reference my App or MainPage
For simply protecting shared data access between main app and background agent using Mutexes have a look at this question. Maybe this already gives you a hint in the right direction.
But if you want to react to events like "the background agent just finished" (in main app) or "the main app starts up" (in background agent) then you might be out of luck. There is no simple direct communication available, let alone direct data access. You could use Sockets or Raw Notifications.
A method based on polling and Mutexes is discussed in this question.