/// <summary>
/// Append a contact to the list of contacts in this report. Note you cannot call this more than 'MaxContactsPerReport' per report.
/// </summary>
/// <param name="pContact">The contact to add.</param>
public void addContact(HidContactInfo pContact)
{
// If we have reached the maximum number of contacts - throw an error.
if (lContacts.Count == MaxContactsPerReport)
{
throw new InvalidOperationException("Cannot add more than " + MaxContactsPerReport + " to a MultiTouchReport.");
}
// All is well so add it.
lContacts.Add(pContact);
}
/// <summary>
/// This is called to enqueue a HID contact onto the list to send out.
/// </summary>
/// <param name="contactInfo"></param>
private void enqueueContact(HidContactInfo pContact)
{
// Obtain mutual exclusion over the queue.
this.pContactLock.WaitOne();
// Add it to the queue.
this.lCurrentContacts.Enqueue(pContact);
// Release exclusion.
this.pContactLock.ReleaseMutex();
}
/// <summary>
/// Calling this will send all the currently queued contacts off to the HID driver.
/// </summary>
public void sendContacts()
{
// Build the list of contacts to send.
List <HidContactInfo> lContacts = new List <HidContactInfo>();
// Get mutual exclusion over the queue.
this.pContactLock.WaitOne();
// While there are still contacts to deal with...
while (this.lCurrentContacts.Count > 0)
{
// Pop the one off the start of the queue.
HidContactInfo pContact = this.lCurrentContacts.Dequeue();
// If there is a previous contact it had a remove signal then we want to ignore the event.
HidContactInfo pPreviousContact;
if (this.dLastContacts.TryGetValue(pContact.Id, out pPreviousContact))
{
// If we got an update for the new contact and a remove in the previous state then drop the contact.
if (pContact.State == HidContactState.Updated && pPreviousContact.State == HidContactState.Removing)
{
continue;
}
}
// Update the contact list to contain the latest reference.
this.dLastContacts[pContact.Id] = pContact;
// Append it to the list of contacts we want to ship out.
lContacts.Add(pContact);
}
// Release access to the queue.
this.pContactLock.ReleaseMutex();
// Add all existing contacts in the table to the send-list which are not already in there and set to update.
lContacts.AddRange(this.dLastContacts.Values.Except(lContacts, this.pComparer).Where(c => c.State == HidContactState.Updated).ToList());
// If we have more than one contact after all that...
if (lContacts.Count > 0)
{
this.sendContacts(lContacts);
}
// Remove all active contacts which are flagged as removed from the table.
// TODO: Perhaps put a watchdog do to this but with a timeout?
foreach (ushort id in this.dLastContacts.Values.Where(c => c.State == HidContactState.Removed).Select(c => c.Id).ToList())
{
this.dLastContacts.Remove(id);
}
// Queue up all contacts which are flagged as removing and send a remove event.
foreach (HidContactInfo pContact in this.dLastContacts.Values.Where(c => c.State == HidContactState.Removing).ToList())
{
this.enqueueContact(new HidContactInfo(HidContactState.Removed, pContact.Contact));
}
// Queue up all contacts which are flagged as added and send an updated event.
foreach (HidContactInfo pContact in this.dLastContacts.Values.Where(c => c.State == HidContactState.Adding).ToList())
{
this.enqueueContact(new HidContactInfo(HidContactState.Updated, pContact.Contact));
}
}