Switch camera on webview video call - xamarin.forms

I have app in xamarin form where i am accessing webview for video call. Everything is working fine just i need to know how i can switch back/front camera during call? as when video call start front camera open by default.
Code for initializing video call
function initializeLocalMedia(options, callback) {
if(options) {
options['audio'] = true;
if(options['video'])
options['video'] = true;
} else {
options['audio'] = true;
options['video'] = false;
}
// Get audio/video stream
navigator.getUserMedia(options, function(stream) {
// Set your video displays
window.localStream = stream;
myapp.setMyVideo(window.localStream)
if(callback)
callback();
}, function(err) {
console.log("The following error occurred: " + err.name);
alert('Unable to call ' + err.name)
});
}

Going straight to code then it should look like:
Camera.CameraInfo camInfo = new Camera.CameraInfo ();
for (int i = 0; i < Camera.NumberOfCameras; i++) {
Camera.GetCameraInfo (i, camInfo);
if (camInfo.Facing == CameraFacing.Front){
try {
return Camera.Open(i);
} catch (Exception e) {
// log or something
}
}
}
return null;
What we are doing is iterating over the hardware and then check to match the front camera, if it match then do the things. Same is true for back camera too

Related

How to enable Platform.runlater within method

I am creating a Javafx chat app which also allows for file transfer. My issue is I open a FileOutputStream for the received file within the below method. I can see my listener.statusTransferring() updating the UI only if I enable Platform.runLater. I think I now need to enable the same on the fos.write(b, 0, tmpTransferred) within the while loop but don't know how to do this. I have tried unsuccessfully wrapping the whole method within Platform runlater. Note: If I don't use platform runlater I don't get any errors however the UI does not update until the file transfer is complete eg listener.statusCompleted() is called;. The error I get now as a result of the fos being in Platform runlater. is below.. Line 185 is fos.write(b, 0, tmpTransferred); The other listener calls appear to work fine. Just not listener.statusTransferring(); or listener.transferUpdate(); which utilise the fos. Any help will be greatly appreciated. Also for your own sanity I am a self taught google programmer. Yep the worst kind I am sure. Thanks in advance.
Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at net.thebowdens.net.FileReceiver.transfer(FileReceiver.java:185)
at net.thebowdens.net.DefaultMessageResponder.fileSend(DefaultMessageResponder.java:543)
public boolean transfer() {
listener.statusConnecting();
received = false;
cancel = false;
try {
if (sSock != null) {
sock = sSock.accept();
listener.statusTransferring();
Platform.runLater(() ->{
try {
fos = new FileOutputStream(file);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
});
is = sock.getInputStream();
final byte[] b = new byte[1024];
transferred = 0;
percent = 0;
int tmpTransferred = 0;
int tmpPercent = 0;
int transCounter = 0;
bCounter.prepare();
while (!cancel && (tmpTransferred = is.read(b)) != -1) {
fos.write(b, 0, tmpTransferred);
transferred += tmpTransferred;
percent = (int) ((transferred * 100) / size);
bCounter.addBytes(tmpTransferred);
transCounter++;
if (percent > tmpPercent || transCounter >= 250) {
transCounter = 0;
tmpPercent = percent;
listener.transferUpdate();
}
}
if (!cancel && transferred == size) {
received = true;
listener.statusCompleted();
}
else {
listener.statusFailed();
}
}
}
catch (final IOException e) {
LOG.log(Level.SEVERE, e.toString());
listener.statusFailed();
}
finally {
stopReceiver();
cleanupConnections();
}
return received;
}
Keep in mind that you should use Platform.runLater only for updating the UI, everything else should be outside it otherwhise the UI will become unresponsive.
I suggest you to to refactor your code according to this.
Well after much discussion over the correct language and other issues I solved my problem of the UI updating. I had two issues. My choice selector and Filechooser methods were not on the Javafx application thread (hope this is the right terminology) so I had to do the following:
private ExecutorService executorService = Executors.newCachedThreadPool();
executorService.execute(new Runnable() {
#Override
public void run() {
Platform.runLater(() -> {
try {
receiveRequest(tmpUser, fileRes, user, fileName, size, fileHash);
} catch (IOException | ServerException | CommandException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
});
}
});
I then had to do the same within the Filechooser and file accept method for the transfer class UI to update
executorService.execute(new Runnable() {
#Override public void run() {
if (fileRes.transfer()) {
ui.showSystemMessage("Successfully received " + fileName +
" from " + user + ", and saved as " + fileRes.getFile().getName());
}
else {
ui.showSystemMessage("Failed to receive " + fileName + " from " + user);
fileRes.cancel();
}
}
});
}

How to get source and target of edge after any change on cell connect?

I'm programming a web application that use workflow. I used jgraph(Mxgraph) for designing workflow.
I will save workflow parts in database (activities, notifications, transitions).
I need to get source and target of transitions. So how should I catch any changes on transitions in client?
I used before from these three events but don't work always. For example when I change connection target.
Editor.graph.connectionHandler.addListener(mxEvent.CONNECT, function (sender, evt) {
console.log('connect');
});
Editor.graph.connectionHandler.addListener(mxEvent.START, function (sender, evt) {
console.log('start');
});
Editor.graph.connectionHandler.addListener(mxEvent.RESET, function (sender, evt) {
console.log('reset');
});
I found it.
We can use mxEvent.Change event for getting any change on graph model.
editor.graph.getModel().addListener(mxEvent.CHANGE, function (sender, evt) {
editor.graph.validateGraph();
var xml = getEditorXml(Editor);
$("#BpmnXml").val(xml);
//console.log(getCells_ByType("Start"));
// /console.log(getCells_ByType("Task"));
let connectors = getCells_ByType("Connector");
if (connectors != null && connectors.length > 0) {
connectors.forEach(element => {
var source = Editor.graph.getModel().getTerminal(element, true);
var target = Editor.graph.getModel().getTerminal(element, false);
setData(element, { FromActivityClientId: source.getId(), ToActivityClientId: target.getId() });
});
}
});
function getCells_ByType(TypeCell) { // dar report estafede mishavad
var AllCells = Editor.graph.getChildCells(Editor.graph.getDefaultParent(), true, true);
var result = $.grep(AllCells, function (s) { return s.getValue().localName == TypeCell; });
if (result.length != 0)
return result;
else
return null;
}

Xamarin.Android - How to continue a process while app is minimized or screen is locked

I've created a Xamarin app that checks the users current location every couple minutes. My problem is it doesn't work when I minimize the app or the screen locks. Is there a way for me to continue the process while minimized or when the phone is locked?
This function checks to see if the user is at the destination location.
public bool atLocation(decimal currentLat, decimal currentLong, decimal destLat, decimal destLong)
{
decimal GPSLatitudePadding = 0.001M;
decimal GPSLongitudePadding = 0.001M;
var totalLowerLatitude = Convert.ToDecimal((destLat - GPSLatitudePadding).ToString("#.####"));
var totalLowerLongitude = Convert.ToDecimal((destLong + GPSLongitudePadding).ToString("#.####"));
var totalUpperLatitude = Convert.ToDecimal((destLat + GPSLatitudePadding).ToString("#.####"));
var totalUpperLongitude = Convert.ToDecimal((destLong - GPSLongitudePadding).ToString("#.####"));
if ((Convert.ToDecimal(destLat) >= totalLowerLatitude) &&
(Convert.ToDecimal(destLat) <= totalUpperLatitude) &&
(Convert.ToDecimal(destLong) <= totalLowerLongitude) &&
(Convert.ToDecimal(destLong) >= totalUpperLongitude))
{
return true;
}
return false;
}
If the user is at the destination for 2 instances of 2 minutes the process is ended. This is where you could start a new process or update a database.
int intNumberOfTimesFoundAtLocation = 0;
void OnLocationResult(object sender, Android.Locations.Location location)
{
decimal currentLatitude = Convert.ToDecimal(location.Latitude);
decimal currentLongitude = Convert.ToDecimal(location.Longitude);
decimal destLatitude = Convert.ToDecimal(this.dblDestLatitude);
decimal destLongitude = Convert.ToDecimal(this.dblDestLongitude);
var atLocation = locationQ.atLocation(currentLatitude, currentLongitude, destLatitude, destLongitude);
if (ayLocation == true)
{
intNumberOfTimesFoundAtLocation = intNumberOfTimesFoundAtLocation + 1;
if(intNumberOfTimesFoundAtLocation == 2)
{
client.RemoveLocationUpdates(locationCallback);
}
}
}
I call this function to start the process
MyLocationCallback locationCallback;
FusedLocationProviderClient client;
public async void StartLocationUpdatesAsync()
{
// Create a callback that will get the location updates
if (locationCallback == null)
{
locationCallback = new MyLocationCallback();
locationCallback.LocationUpdated += OnLocationResult;
}
// Get the current client
if (client == null)
client = LocationServices.GetFusedLocationProviderClient(this);
try
{
locationRequest = new LocationRequest()
.SetInterval(120000)
.SetFastestInterval(120000)
.SetPriority(LocationRequest.PriorityHighAccuracy);
await client.RequestLocationUpdatesAsync(locationRequest, locationCallback);
}
catch (Exception ex)
{
//Handle exception here if failed to register
}
}
}
class MyLocationCallback : LocationCallback
{
public EventHandler<Android.Locations.Location> LocationUpdated;
public override void OnLocationResult(LocationResult result)
{
base.OnLocationResult(result);
LocationUpdated?.Invoke(this, result.LastLocation);
}
}
Create a foreground service.
Inside service call the following code to start the request updates.
locationLogger = new LocationLogger();
locationLogger.LogInterval = _currentInterval;
locationLogger.StopUpdates();
locationLogger.StartRequestionUpdates();
Check here for the code
Let me know if you need more help.

WebAPI call hangs when return a large amount of data

I have a web api call that I recently added to my app. I returns a complete list of all countries, states and cities in the app (currently 486 rows) I perform this call when all of the reference data for my application loads (I have a base loading page and call the function in my startup class to load all the data there). The challenge is that the call to get all my countries.... hangs and eventually I get "The operation was canceled" error. If I modify my stored procedure that selects the data from the database on the server to only return say 20 rows, it runs fine. Any suggestions?
Below is the code from the startup class:
using System;
using System.Diagnostics;
using System.Threading.Tasks;
namespace GBarScene
{
class StartUpClass
{
public event GeneralDataLoad BaseDataLoadComplete;
public async Task<GBSStartUpEventArgs> ProcessStartup()
{
GBSStartUpEventArgs lobj_EventArgs;
lobj_EventArgs = new GBSStartUpEventArgs();
App.InStartUpDataLoad = true;
try
{
if (!App.IsGeolocationEnabled)
{
lobj_EventArgs.ErrorOccurred = true;
lobj_EventArgs.ShowRetry = true;
lobj_EventArgs.ShowWebSite = false;
lobj_EventArgs.ErrorMessage = resourcestrings.GetValue("NoLocationServicesMessage");
}
else if (!App.InternetIsAvailable)
{
lobj_EventArgs.ErrorOccurred = true;
lobj_EventArgs.ErrorMessage = resourcestrings.GetValue("NoInternetConnectionFound");
lobj_EventArgs.ShowRetry = true;
lobj_EventArgs.ShowWebSite = false;
}
else
{
Debug.WriteLine("Process StartUp");
await Task.Delay(500);
//Reset values
ViewModelObjects.DayOfWeek.DataLoadProcessed = false;
ViewModelObjects.Languages.DataLoadProcessed = false;
if (await ViewModelObjects.DayOfWeek.LoadData() == false)
// //try it once more
await ViewModelObjects.DayOfWeek.LoadData();
Debug.WriteLine("GBar After DayofWeek Load");
await ViewModelObjects.Languages.LoadData();
Debug.WriteLine("GBar After Languages Load");
if ((ge_AppMode)ViewModelObjects.AppSettings.AppMode == ge_AppMode.CitySelected)
{
//We need to reload the NearbyCities and set the selected one
await ViewModelObjects.NearbyCities.LoadData();
}
Debug.WriteLine("Before load of coutries");
await ViewModelObjects.CountryStateCity.LoadData();
Debug.WriteLine("After load of coutries");
Debug.WriteLine("Count: " + ViewModelObjects.CountryStateCity.CountryItems_ForList.Count.ToString());
ViewModelObjects.NumberOfResults.LoadData();
ViewModelObjects.Perspectives.LoadData();
ViewModelObjects.SearchRadiuses.LoadData();
ViewModelObjects.UseMetric.LoadData();
while (!ViewModelObjects.DayOfWeek.DataLoadProcessed && !ViewModelObjects.Languages.DataLoadProcessed && !App.IsGeolocationEnabled)
{
await Task.Delay(100);
}
if (App.BaseDataLoadError)
{
lobj_EventArgs.ErrorOccurred = true;
lobj_EventArgs.ShowRetry = true;
lobj_EventArgs.ShowWebSite = true;
lobj_EventArgs.ErrorMessage = resourcestrings.GetValue("ErrorLoadingReferenceData");
}
}
Debug.WriteLine("StartUp Process Ended");
BaseDataLoadComplete(this, lobj_EventArgs);
}
catch (Exception ex)
{
App.ProcessException(ex);
}
App.InStartUpDataLoad = false;
return lobj_EventArgs;
}
}
}
This is the helper class that makes all the WebAPI calls:
using Newtonsoft.Json;
using System;
using System.Diagnostics;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
using Xamarin.Forms;
namespace GBarScene
{
public class WebAPICaller: IDisposable
{
HttpClient iobj_HTTPClient = null;
public void Dispose()
{
if (iobj_HTTPClient != null)
iobj_HTTPClient.Dispose();
}
public async Task<string> HTTPGetWebServiceAsync(string ps_URI)
{
string ls_Response = "";
string ls_JSONData = "";
string ls_Prefix = "";
try
{
iobj_HTTPClient = await GetClient();
switch (Device.RuntimePlatform)
{
case Device.Android:
ls_Prefix = App.APIStandardPrefix;
break;
//case Device.Android:
// ls_Prefix = App.APISecurePrefix;
// break;
//case Device.Windows:
//case Device.WinPhone:
// ls_Prefix = App.APISecurePrefix;
// break;
default:
ls_Prefix = App.APISecurePrefix;
break;
}
Debug.WriteLine("before api call");
iobj_HTTPClient.BaseAddress = new Uri(ls_Prefix);
ls_JSONData = await iobj_HTTPClient.GetStringAsync(ps_URI);
Debug.WriteLine("after api call");
ls_Response = System.Net.WebUtility.HtmlDecode(ls_JSONData);
}
catch (Exception ex)
{
Debug.WriteLine("api call error");
App.ProcessException(ex);
}
return ls_Response;
}
public async Task<bool> HTTPPostWebService(string ps_URI, object pobj_BodyObject)
{
HttpResponseMessage lobj_HTTPResponse = null;
bool lb_Response = false;
HttpContent lobj_Content = null;
try
{
if (iobj_HTTPClient != null)
iobj_HTTPClient = await GetClient();
iobj_HTTPClient.BaseAddress = new Uri(App.APISecurePrefix);
lobj_Content = new StringContent(JsonConvert.SerializeObject(pobj_BodyObject == null ? "" : pobj_BodyObject));
lobj_Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
lobj_HTTPResponse = await iobj_HTTPClient.PostAsync(ps_URI, lobj_Content);
if (!lobj_HTTPResponse.IsSuccessStatusCode)
{
Exception lobj_Exception = new Exception(lobj_HTTPResponse.ToString());
lobj_Exception.Source = "HTTPGetWebService for: " + ps_URI;
App.ProcessException(lobj_Exception);
}
else
{
lb_Response = true;
}
}
catch (Exception ex)
{
App.ProcessException(ex);
}
finally
{
if (lobj_HTTPResponse != null)
{
lobj_HTTPResponse.Dispose();
}
//Debug.WriteLine("WebAPICaller-CallWebService-1: Done");
}
return lb_Response;
}
private async Task<HttpClient> GetClient()
{
HttpClient lobj_HTTPClient = null;
if (lobj_HTTPClient == null)
{
lobj_HTTPClient = new HttpClient();
lobj_HTTPClient.DefaultRequestHeaders.Add("Accept", "application/json");
lobj_HTTPClient.MaxResponseContentBufferSize = 2147483647;
lobj_HTTPClient.Timeout = new TimeSpan(0,0,0,0,60000);
}
return lobj_HTTPClient;
}
}
}
Sorry I forget to include the method in the CountryStateCity view model that calls the webapi helper class.
public async Task<bool> LoadData()
{
string ls_Response = "";
string ls_WorkURI = "";
WebAPICaller lobj_WebAPICaller = null;
bool lb_DataLoaded = false;
try
{
IsDataLoaded = false;
//Debug.WriteLine("City Data Load");
lobj_WebAPICaller = new WebAPICaller();
ls_WorkURI = ic_CoutryStateCityAPIUrl.Replace("{Language}", "EN");
ls_Response = await lobj_WebAPICaller.HTTPGetWebServiceAsync(ls_WorkURI);
if (ls_Response.Trim().Length == 0)
{
AddErrorEntry();
}
else
{
CountryItems_ForList = new ObservableCollection<GBSCountry_ForList>();
StateItems_ForList = new ObservableCollection<GBSState_ForList>();
CityItems_ForList = new ObservableCollection<GBSCity_ForList>();
iobj_CountryStateCity = JsonConvert.DeserializeObject<ObservableCollection<GBSCountryStateCity>>(ls_Response);
//Now load the display lists
CountryItems_ForList = new ObservableCollection<GBSCountry_ForList>(
(from lobj_Country in iobj_CountryStateCity
select new GBSCountry_ForList()
{
ID = lobj_Country.Country_Code,
Value = lobj_Country.Country_Name_Text
}).Distinct().ToList());
CountryItems_ForList.Insert(0, new GBSCountry_ForList
{
ID = "XX",
Value = "Base Value"
});
lb_DataLoaded = true;
}
}
catch (Exception ex)
{
AddErrorEntry();
App.ProcessException(ex);
}
finally
{
IsDataLoaded = true;
if (lobj_WebAPICaller != null)
lobj_WebAPICaller.Dispose();
}
return lb_DataLoaded;
}
So after much time, I believe I figured out what the problem is. The problem started to manifest itself again with smaller amounts of data and I could not figure out why. The problem appeared. The issue appears to be the IP address I was using. (I was using the IP address of the actual laptop I was hosting both the App and WebAPIs on.) It appears you have to use one of the other network adaptors for the emulator to have this work reliably.
Here are the steps I used to resolved this:
I launched my Windows 10 mobile emulator.
Click on the >> (Tools) icon in the tool bar of the emulator.
Click on the Network tab of the Additional Tools window.
Look in the list for the network adaptor labeled Desktop Adaptor #1 and copy the IP address.
Edit the Applicationhost.config file in the folder of the WebAPI project.
Find the entry in the file for site name="XXXXX" where XXXXX is the name of the Visual Studio project you are hosting your WebAPIs in.
Within the section of the entry for your WebAPI project, add a binding for the IP address you copied from in step 4. It should look something like this:
<binding protocol="http" bindingInformation="*:56952:169.254.69.220" />
Where 56952 is the port my IIS Express is hosting the WebAPIs on and 169.254.69.220 is the IP address I copied from step 4. After adding this, I was able to connect to locally hosted WebAPIs in IIS Express.
Hope this helps.

Older asynchronous messages overwriting newer ones

We are developing a document collaboration tool in SignalR where multiple users can update one single WYSIWYG form.
We are struggling getting the app to work using the KeyUp method to send the changes back to the server. This causes the system to overwrite what the user wrote after his first key stroke when it sends the message back.
Is there anyway to work around this problem?
For the moment I tried to set up a 2 seconds timeout but this delays all updates not only the "writer" page.
public class ChatHub : Hub
{
public ChatHub()
{
}
public void Send(int id,string message)
{
// Call the broadcastMessage method to update clients.
Clients.All.broadcastMessage(id,message); //id is for the document id where to update the content
}
}
and the client:
$(function () {
// Declare a proxy to reference the hub.
var chat = $.connection.chatHub;
//console.log("Declare a proxy to reference the hub.");
// Create a function that the hub can call to broadcast messages.
chat.client.broadcastMessage = function (id, message) {
var encodedValue = $('<div />').text(id).html();
// Add the message to the page.
if (encodedValue == $('#hdnDocId').val()) {
$('#DiaplayMsg').text(message);
tinyMCE.activeEditor.setContent("");
tinyMCE.get('txtContent').execCommand('insertHTML', false, message); //!!!
}
};
// Start the connection.
$.connection.hub.start().done(function (e) {
//console.log("Start the connection.");
if ($('#hdnDocId').val() != '') {
tinyMCE.activeEditor.onKeyUp.add(function (ed, e) {
var elelist = $(tinyMCE.activeEditor.getBody()).text();
var content = tinyMCE.get('txtContent').getContent();
function Chat() {
var content = tinyMCE.get('txtContent').getContent();
chat.server.send($('#hdnDocId').val(), content); //send a push to server
}
typewatch(Chat, 2000);
});
}
});
});
var typewatch = function () {
var timer = 0;
return function (Chat, ms) {
clearTimeout(timer);
timer = setTimeout(Chat, ms);
}
} ();
</script>
Hello, here is an update of the client KeyUp code. It seems to be working but I would like your opinion. I've used a global variable to store the timeout, see below:
<script type="text/javascript">
$(function () {
// Declare a proxy to reference the hub.
var chat = $.connection.chatHub;
//console.log("Declare a proxy to reference the hub.");
// Create a function that the hub can call to broadcast messages.
chat.client.broadcastMessage = function (id, message) {
var encodedValue = $('<div />').text(id).html();
var currenttime = new Date().getTime() / 1000 - 2
if (typeof window.istyping == 'undefined') {
window.istyping = 0;
}
if (encodedValue == $('#hdnDocId').val() && window.istyping == 0 && window.istyping < currenttime) {
function Update() {
$('#DiaplayMsg').text(message);
tinyMCE.activeEditor.setContent("");
tinyMCE.get('txtContent').execCommand('insertHTML', false, message); //!!!
// tinyMCE.get('txtContent').setContent(message);
window.istyping = 0
}
Update();
}
};
// Start the connection.
$.connection.hub.start().done(function (e) {
//console.log("Start the connection.");
if ($('#hdnDocId').val() != '') {
tinyMCE.activeEditor.onKeyUp.add(function (ed, e) {
var elelist = $(tinyMCE.activeEditor.getBody()).text();
var content = tinyMCE.get('txtContent').getContent();
function Chat() {
//alert("Call");
var content = tinyMCE.get('txtContent').getContent();
chat.server.send($('#hdnDocId').val(), content);
window.istyping = new Date().getTime() / 1000;
}
Chat();
});
}
});
});
var typewatch = function () {
var timer = 0;
return function (Chat, ms) {
clearTimeout(timer);
timer = setTimeout(Chat, ms);
}
} ();
Thanks,
Roberto.
Is there anyway to work around this problem?
Yes, by not sending the entire document to the server, but document elements like paragraphs, table cells, and so on. You can synchronize these after the user has stopped typing for a period, or when focus is lost for example.
Otherwise add some incrementing counter to the messages, so older return values don't overwrite newer ones arriving earlier.
But you're basically asking us to solve a non-trivial problem regarding collaborated document editing. What have you tried?
"This causes the system to overwrite what the user wrote"
that's because this code isn't making any effort to merge changes. it is just blindly overwriting whatever is there.
tinyMCE.activeEditor.setContent("");
tinyMCE.get('txtContent').execCommand('insertHTML', false, message);
as #CodeCaster hinted, you need to be more precise in the messages you send - pass specific changes back and forth rather re-sending the entire document - so that changes can be carefully merged on the receiving side

Resources