/// <summary>
/// Handles connecting to and disconnecting from a set of potential devices by their definition
/// </summary>
/// <param name="filterDeviceDefinitions">Device definitions to connect to and disconnect from</param>
/// <param name="pollMilliseconds">Poll interval in milliseconds, or null if checking is called externally</param>
public DeviceListener(IEnumerable <FilterDeviceDefinition> filterDeviceDefinitions, int?pollMilliseconds)
{
FilterDeviceDefinitions.AddRange(filterDeviceDefinitions);
if (pollMilliseconds.HasValue)
{
_PollTimer = new timer(pollMilliseconds.Value);
_PollTimer.Elapsed += _PollTimer_Elapsed;
}
}
/// <summary>
/// Handles connecting to and disconnecting from a set of potential devices by their definition
/// </summary>
/// <param name="filterDeviceDefinitions">Device definitions to connect to and disconnect from</param>
/// <param name="pollMilliseconds">Poll interval in milliseconds, or null if checking is called externally</param>
public DeviceListener(IEnumerable <FilterDeviceDefinition> filterDeviceDefinitions, int?pollMilliseconds)
{
FilterDeviceDefinitions.AddRange(filterDeviceDefinitions);
_ListenSemaphoreSlim = new SemaphoreSlim(1, 1);
if (!pollMilliseconds.HasValue)
{
return;
}
_PollTimer = new timer(pollMilliseconds.Value);
_PollTimer.Elapsed += _PollTimer_Elapsed;
}
public async Task CheckForDevicesAsync()
{
try
{
if (_IsDisposed)
{
return;
}
await _ListenSemaphoreSlim.WaitAsync();
var connectedDeviceDefinitions = new List <ConnectedDeviceDefinition>();
foreach (var deviceDefinition in FilterDeviceDefinitions)
{
connectedDeviceDefinitions.AddRange(await DeviceManager.Current.GetConnectedDeviceDefinitionsAsync(deviceDefinition));
}
//Iterate through connected devices
foreach (var connectedDeviceDefinition in connectedDeviceDefinitions)
{
var deviceDefinition = FilterDeviceDefinitions.FirstOrDefault(d => DeviceManager.IsDefinitionMatch(d, connectedDeviceDefinition));
if (deviceDefinition == null)
{
continue;
}
//TODO: What to do if there are multiple?
IDevice device = null;
if (_CreatedDevicesByDefinition.ContainsKey(deviceDefinition))
{
device = _CreatedDevicesByDefinition[deviceDefinition];
}
if (device == null)
{
//Need to use the connected device def here instead of the filter version because the filter version won't have the id or any details
device = DeviceManager.Current.GetDevice(connectedDeviceDefinition);
_CreatedDevicesByDefinition.Add(deviceDefinition, device);
}
if (device.IsInitialized)
{
continue;
}
Log($"Attempting to initialize with DeviceId of {device.DeviceId}", null);
//The device is not initialized so initialize it
await device.InitializeAsync();
//Let listeners know a registered device was initialized
DeviceInitialized?.Invoke(this, new DeviceEventArgs(device));
Log(Messages.InformationMessageDeviceConnected, null);
}
var removeDefs = new List <FilterDeviceDefinition>();
//Iterate through registered devices
foreach (var filteredDeviceDefinitionKey in _CreatedDevicesByDefinition.Keys)
{
var device = _CreatedDevicesByDefinition[filteredDeviceDefinitionKey];
if (connectedDeviceDefinitions.Any(cdd =>
DeviceManager.IsDefinitionMatch(filteredDeviceDefinitionKey, cdd)))
{
continue;
}
if (!device.IsInitialized)
{
continue;
}
//Let listeners know a registered device was disconnected
//NOTE: let the rest of the app know before disposal so that the app can stop doing whatever it's doing.
DeviceDisconnected?.Invoke(this, new DeviceEventArgs(device));
//The device is no longer connected so close it
device.Close();
removeDefs.Add(filteredDeviceDefinitionKey);
Log(Messages.InformationMessageDeviceListenerDisconnected, null);
}
foreach (var removeDef in removeDefs)
{
_CreatedDevicesByDefinition.Remove(removeDef);
}
Log(Messages.InformationMessageDeviceListenerPollingComplete, null);
}
catch (Exception ex)
{
Log(Messages.ErrorMessagePollingError, ex);
//TODO: What else to do here?
}
finally
{
if (!_IsDisposed)
{
_ListenSemaphoreSlim.Release();
}
}
}