I want to create two different applications. In first application user should be able to access the camera of other devices and in the second application, user type in one device via keyboard and it should be displayed in other device.
For this purpose, it is mandatory to access other mobile's application via bluetooth or Wi-fi?
How does it be possible?
It is not mandatory. You can also implement this as a server client solution, where the data transfer between the clients takes through the server. If you didn't try it yet, that will be a tedious task for the particular solution. Both side should keep services to monitor and transfer data.
But if you intent a real time solution, I'll prefer Bluetooth for faster response.
Related
I want to use an USB HID from a website. The website will only be accessed by Chrome browsers. The solution should require a minimum amount of extra software and setup for the website user to work.
The USB device presents itself as USB HID to the OS and I need to write and read byte arrays to and from it in order to implement the manufacturers specification for some of the device's features.
My current solution consists of two parts:
A Chrome App that uses the chrome.hid API to talk to the device. This App exposes a Chrome Cross-Extension messaging port to provide and interface for "service calls".
JavaScript code on the website that sends requests to the Chrome App, which then talks to the USB device to process the request.
In order to make it easier for the user I want to get rid of the App, so the user can just surf to the website, grant access to the device if necessary and then be able to use the device.
To be clear, I want the user to be able to use the website without installing any dependency first.
I already tried using the WebUSB navigator.usb API but Chrome blocks access to USB HID devices. Is there another way to accomplish this?
WebHID is being developed for this use case. It has been available behind a feature flag since Chrome 78, with an original trial expected in Chrome 84 (probably later due to current Covid-19 situation), estimated stable August 2020 .
For more details: https://github.com/robatwilliams/awesome-webhid
I've written a simple web app to factory-reset bluetooth devices that were accidentally turned on during shipping. The app scans for a class of bluetooth devices (those made by the company I work for), renders a list of devices found, and, when I click a button next to a device in the list, sends a reset message to the device.
This is a very manual process and I'd like to automate it. The problem is the Chrome dialog that asks for permissions to pair with a device. I am trying automate the app with Puppeteer, but I can't find a way to either (a) programmatically grant permissions to pair with a device or (b) to select the device in the dialog and click the "pair" button via Puppeteer. Anyone know if what I'm trying to do is possible, or if there's a better way to achieve the goal? Thanks!
This is not possible in Chrome. (I work on chrome.) The automation that does exist for Chrome's testing is layered such that actual Bluetooth connections aren't made.
Eventually we would like to enable this workflow via Enterprise configuration controls. But that is not started yet and there is no date commitment.
One alternative is to use node.js, though you lose the easy interface. You might build the reset backend in a node server and have it serve a web page interface.
Does WP8 have any OS hook or callback (sync mechanism) I can implement to get a notification when a contact changes?
For example I'm running an application as a background agent, and a user randomly changes a contact's details. I want to get notified in my background engine so that I can do various operations.
I could always implement a periodic check (say every minute I read all contacts and check to see if there are any modifications - assuming I'm remembering the last configuration somehow). But this solution is not efficient for a large number of contacts, especially when I want the application to run on the low end phones.
Windows Phone does not support any built in way for applications to be notified of contact changes.
As you've noted, the only way to do this would be to track the details and periodically look for differences. Yes, you'd have to do this with the app running (rather than a background agent) if you want to support WP7 devices with one 256MB of memory.
As an alternative and assuming that the user is syncing their contacts with their live.Windows account you could create an external service that periodically polls their live account (via http://msdn.microsoft.com/en-us/live/ff519582.aspx) for changes and then send a notification to the device/app regarding the change.
I am wondering if someone knows the best method for storing data in a global DB against a mobile device (iOS and Android)?
I am building an app that writes/retrieves information based on a query however I need to know if any of the records returned were sent from that device.
Basically the idea is that if a user submits some information (which is stored in the DB) they gain access to additional features of the app. When the app is launched, I will check the DB to see if they submitted information in the past and allow access to other areas.
I use local storage for the information they submitted but also store remotely so if the local storage becomes corrupted for any reason there is still a record of the information the user submitted.
The ID needs to be unique to the device as there could be 100 of users (hoping for millions) so the ID needs to be unique enough that it will never conflict with another device. Any information submitted will be available for retrieval by all other users.
Thanks :)
There are three options as I see it:
1. User
You can create a typical username + password user scheme and use this to verify the user. A possible advantage of this method would be that the user can log in from any of their devices (for instance, under your method a user using the app from their iPhone and iPad would have two different views - which you may not want). Of course, this means forcing every user of the app to register within your system, which is not ideal.
2. App Install
You can uniquely identify an app install by having your app generate a UUID the first time that the app is run (you can use an AS3 helper library to generate the UUID). You can store this UUID locally and send it along with every request the app makes. The downside to this approach is that it doesn't uniquely identify the device - only a specific app install. For instance, if the user deletes the app and then reinstalls it at a later point, it will now count as a new unique device, even though the user is on the same device.
3. Device
AIR does not have a built-in way of reading device identifying info. However, you can retrieve device info through AIR Native Extensions, for example this one can get the MAC address and some other things. There are privacy concerns and other issues involved in reading and storing device info such as these, so you are probably best served trying to implement the OpenUDID project as an AIR Native Extension, since they have already dealt with all such issues. Unfortunately, I have never looked too far into developing ANE's so I am not sure how complicated or feasible it will be to turn OpenUDID into an ANE.
Summary: I would recommend the app install method due to the ease of implementation. If you really need the unique device and are worried about the multiple app installs case, you will have to work out how to use native extensions to get the info you need. If you decide that you would rather identify by user rather than device, use the user method.
As of now I don't think its possible to get the hardware devices guid using air mobile. However you do have a couple of options.
If the MAC address is good enough for you there is an ANE that will let you grab it on both iOS and Android.
http://www.adobe.com/devnet/air/native-extensions-for-air/extensions/networkinfo.html
and an example of how to use it
http://cookbooks.adobe.com/post_Getting_NetworkInfo_from_both_Android_and_iOS-19473.html
You could also write your own ANE, it should be pretty simple to wrap both Android and iOS implementations.
Objective-c: [[UIDevice currentDevice] uniqueIdentifier]
Android: TelephonyManager.getDeviceId()
If your app requires any kind of user account or login the best option would be to store this setting in the remote db.
Let's say I have two applications which have to work together to a certain extent.
A web application (PHP, Ruby on Rails, ...)
A desktop application (Java, C++, ...)
The desktop application has to be notified from the web application and the delay between sending and receiving the notification must be short. (< 10 seconds)
What are possible ways to do this? I can think of polling in a 10 second interval, but that would produce much traffic if many desktop applications have to be notified. On a LAN I'd use an UDP broadcast, but unfortunately that's not possible here...
I appreciate any ideas you could give me.
I think the "best practice" here will depend on the number of desktop clients you expect to serve. If there's just one desktop to be notified, then polling may well be a fine approach -- yes, polling is much more overhead than an event-based notification, but it'll certainly be the easiest solution to implement.
If the overhead of polling is truly unacceptable, then I see two basic alternatives:
Keep a persistent connection open between the desktop and web-server (could be a "comet"-style web request, or a raw socket connection)
Expose a service from within the desktop app, and register the address of the service with the web-server. This way, the web-server can call out to the desktop as needed.
Be warned, though -- both alternatives are chock full of gotchas. A few highlights:
Keeping a connection open can be tricky, since you want your web-servers to be hot-swappable
Calling out to an external service (eg, your desktop) from a web-server is dangerous, because this request could hang. You'd want move this notification onto a separate thread to avoid tying up the webserver.
To mitigate some of the concerns, you might decouple the unreliable desktop from the web-server by introducing an intermediary notification server -- the web-server could post an update somewhere, and the desktop could poll/connect/register there to be notified. To avoid reinventing the wheel here, this could involve some sort of MessageQueue system... This, of course, adds the complexity of needing to maintain the new intermediary.
Again, all of these approaches are probably quite complex, so I'd say polling is probably the best bet.
I can see two ways:
Your desktop application polls the web app
Your web app notifies the desktop application
Your web app could publish an RSS feed, but your desktop app will still have to poll the feed every 10 s.
The traffic need not be huge: if you use an HTTP HEAD request, you'll get a small packet with the date of the last modification (conveniently named Last-Modified).
I don't know exactly what to do to achieve your task but I can suggest to create a windows service at the desktop application PC.
This service checks the web application every interval of time for new changes and if changes occurred it can run the desktop application with notification that there is a change in the web application and in the web application when any change occurrs you can response with acknowledgment
I hope that this may be useful I didn't try it exactly but I am suggesting using like this idea.
A layer of syndication would help to scale out the system.
The desktop app can register itself with a "publisher" service (running on one of several/many machines) This publisher service receives the "notice" from your web app that something has changed, and immediately starts notifying all of its registered subscribers.
The number of publishers you need will increase with the number of users.
Edit: Forgot to mention that the desktop app will need to listen on a socket.