/// <summary>
/// Expect an Acknowledge message from GPS serial device
/// </summary>
/// <param name="classId">Class ID of expected acknowledge message</param>
/// <param name="messageId">Message ID of expected acknowledge message</param>
/// <returns>True if ACK message is received, False if NOT-ACK message is received</returns>
/// <remarks>
/// Use this method to wait acknowledge message (ACK/NOT-ACK) from serial device after transmitting
/// configuration message to the device. This method will wait indefinitely until ACK/NOT-ACK message
/// for specified class and message ID is received.
/// </remarks>
public async Task <bool> ExpectAcknowledgeAsync(byte classId, byte messageId)
{
var expectingDesc = new ExpectingDescription(classId, messageId);
if (expectingList.ContainsKey(expectingDesc))
{
throw new InvalidOperationException(String.Format("Already expecting ACK for Class {0}, MessageID {1}", classId, messageId));
}
var expectingContext = new ExpectingContext();
expectingList.Add(expectingDesc, expectingContext);
await expectingContext.WaitForResponse();
expectingList.Remove(expectingDesc);
var retVal = expectingContext.ResponseReceived;
if (retVal is Acknowledge)
{
return(true);
}
else
{
return(false);
}
}
/// <summary>
/// Expect a message of specific type from GPS serial device.
/// </summary>
/// <typeparam name="T">Type of message which is expected</typeparam>
/// <returns>The message which is expected</returns>
/// <remarks>
/// This method is performed asynchronously and it should be awaited. The method will complete
/// when it receive the <u>first message</u> with required type or if it is aborted by calling
/// <see cref="AbortExpectAsync{T}"/>.
/// </remarks>
public async Task <T> ExpectAsync <T>() where T : UBXModelBase
{
// Create expecting description as key
var expectingDesc = new ExpectingDescription(typeof(T));
// invalid operation if other context already expecting the same type at the same time
if (expectingList.ContainsKey(expectingDesc))
{
throw new InvalidOperationException(String.Format("Already expecting type {0}", typeof(T).FullName));
}
// Create expecting context
var expectingContext = new ExpectingContext();
// Add to expecting list
expectingList.Add(expectingDesc, expectingContext);
// Wait indefinitely until the response of the type is received
await expectingContext.WaitForResponse();
// At this point, the message is received
// Remove from expecting list
expectingList.Remove(expectingDesc);
// Return the message object to the caller
return((T)expectingContext.ResponseReceived);
}
public override bool Equals(object obj)
{
if (base.Equals(obj))
{
return(true);
}
else
{
ExpectingDescription desc = obj as ExpectingDescription;
if (desc != null)
{
if (this.expectedMessageMode == desc.expectedMessageMode)
{
if (this.expectedMessageMode == ExpectingMode.Regular)
{
return(this.expectingType.Equals(desc.expectingType));
}
else
{
return(this.classId == desc.classId && this.messageId == desc.messageId);
}
}
}
}
return(false);
}
/// <summary>
/// Abort the asynchronous ExpectAsync operation.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <remarks>
/// This method is used if you want to implement timeout on <see cref="ExpectAsync{T}"/> execution.
/// The ExpectAsync method will return null if it is awaited.
/// </remarks>
public void AbortExpectAsync <T>()
{
var expectingDesc = new ExpectingDescription(typeof(T));
if (!expectingList.ContainsKey(expectingDesc))
{
return;
}
var expectingContext = expectingList[expectingDesc];
expectingList.Remove(expectingDesc);
expectingContext.Cancel();
}
/// <summary>
/// Notify any party if waits a message of this type
/// </summary>
/// <param name="obj">The message to be notified</param>
/// <returns>True if there is a party that is waiting for this kind of message, false otherwise.</returns>
public bool NotifyIfExpected(UBXModelBase obj)
{
var expectingDesc = new ExpectingDescription(obj);
try
{
var expectingContext = expectingList[expectingDesc];
expectingContext.NotifyResponseReceived(obj);
return(true);
}
catch (KeyNotFoundException)
{
return(false);
}
}