/// <summary>
/// Compares two <see cref="ObservableBluetoothLEDevice"/> and returns a value indicating
/// whether one is less than, equal to, or greater than the other.
/// </summary>
/// <param name="x">First object to compare</param>
/// <param name="y">Second object to compare</param>
/// <returns>Returns 0 if equal</returns>
public int Compare(object x, object y)
{
ObservableBluetoothLEDevice a = x as ObservableBluetoothLEDevice;
ObservableBluetoothLEDevice b = y as ObservableBluetoothLEDevice;
if (a == null || b == null)
{
throw new InvalidOperationException("Compared objects are not ObservableBluetoothLEDevice");
}
// If they're equal
if (a.RSSI == b.RSSI)
{
return(0);
}
// RSSI == 0 means we don't know it. Always make that the end.
if (b.RSSI == 0)
{
return(-1);
}
if (a.RSSI < b.RSSI || a.RSSI == 0)
{
return(1);
}
else
{
return(-1);
}
}
/// <summary>
/// Executes when a device is updated
/// </summary>
/// <param name="sender">The device watcher.</param>
/// <param name="deviceInfoUpdate">The update device information.</param>
private async void DeviceWatcher_Updated(DeviceWatcher sender, DeviceInformationUpdate deviceInfoUpdate)
{
ObservableBluetoothLEDevice device = null;
device = BluetoothLeDevices.FirstOrDefault(i => i.DeviceInfo.Id == deviceInfoUpdate.Id);
if (device != null)
{
await device.UpdateAsync(deviceInfoUpdate);
}
if (device == null)
{
if (_readerWriterLockSlim.TryEnterWriteLock(TimeSpan.FromSeconds(2)))
{
var unusedDevice = _unusedDevices.FirstOrDefault(i => i.Id == deviceInfoUpdate.Id);
if (unusedDevice != null)
{
_unusedDevices.Remove(unusedDevice);
unusedDevice.Update(deviceInfoUpdate);
}
_readerWriterLockSlim.ExitWriteLock();
// The update to the unknown device means we should move it to the Bluetooth LE Device collection.
await AddDeviceToList(unusedDevice);
}
}
}
/// <summary>
/// Adds the new or updated device to the displayed or unused list
/// </summary>
/// <param name="deviceInfo">The device to add</param>
/// <returns>The task being used to add a device to a list</returns>
private async Task AddDeviceToList(DeviceInformation deviceInfo)
{
// Make sure device name isn't blank or already present in the list.
if (!string.IsNullOrEmpty(deviceInfo?.Name))
{
var device = new ObservableBluetoothLEDevice(deviceInfo);
var connectable = true;
if (device.DeviceInfo.Properties.Keys.Contains("System.Devices.Aep.Bluetooth.Le.IsConnectable"))
{
connectable = (bool)device.DeviceInfo.Properties["System.Devices.Aep.Bluetooth.Le.IsConnectable"];
}
if (connectable)
{
await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
CoreDispatcherPriority.Normal,
() =>
{
if (_readerWriterLockSlim.TryEnterWriteLock(TimeSpan.FromSeconds(1)))
{
if (!BluetoothLeDevices.Contains(device))
{
BluetoothLeDevices.Add(device);
}
_readerWriterLockSlim.ExitWriteLock();
}
});
return;
}
}
if (_readerWriterLockSlim.TryEnterWriteLock(TimeSpan.FromSeconds(1)))
{
_unusedDevices.Add(deviceInfo);
_readerWriterLockSlim.ExitWriteLock();
}
}
/// <summary>
/// Adds the new or updated device to the displayed or unused list
/// </summary>
/// <param name="deviceInfo">The device to add</param>
/// <returns>The task being used to add a device to a list</returns>
private async Task AddDeviceToList(DeviceInformation deviceInfo)
{
// Make sure device name isn't blank or already present in the list.
if (!string.IsNullOrEmpty(deviceInfo?.Name))
{
var device = new ObservableBluetoothLEDevice(deviceInfo, DispatcherQueue);
var connectable = (device.DeviceInfo.Properties.Keys.Contains("System.Devices.Aep.Bluetooth.Le.IsConnectable") &&
(bool)device.DeviceInfo.Properties["System.Devices.Aep.Bluetooth.Le.IsConnectable"]) ||
(device.DeviceInfo.Properties.Keys.Contains("System.Devices.Aep.IsConnected") &&
(bool)device.DeviceInfo.Properties["System.Devices.Aep.IsConnected"]);
if (connectable)
{
await DispatcherQueue.ExecuteOnUIThreadAsync(
() =>
{
if (_readerWriterLockSlim.TryEnterWriteLock(TimeSpan.FromSeconds(1)))
{
if (!BluetoothLeDevices.Contains(device))
{
BluetoothLeDevices.Add(device);
}
_readerWriterLockSlim.ExitWriteLock();
}
}, DispatcherQueuePriority.Normal);
return;
}
}
if (_readerWriterLockSlim.TryEnterWriteLock(TimeSpan.FromSeconds(1)))
{
_unusedDevices.Add(deviceInfo);
_readerWriterLockSlim.ExitWriteLock();
}
}
