/// <summary>
/// Subscribes to the given MessageType during the livetime of the given control.
/// Events OnHandleCreated and OnHandleDestroyed are used for subscribing / unsubscribing.
/// </summary>
/// <typeparam name="MessageType">Type of the message.</typeparam>
/// <param name="actionOnMessage">Action to perform on incoming message.</param>
/// <param name="target">The target control.</param>
public void SubscribeOnControl <MessageType>(System.Windows.Forms.Control target, Action <MessageType> actionOnMessage)
where MessageType : SeeingSharpMessage
{
target.EnsureNotNull(nameof(target));
actionOnMessage.EnsureNotNull(nameof(actionOnMessage));
MessageSubscription subscription = null;
//Create handler delegates
EventHandler onHandleCreated = (sender, eArgs) =>
{
if (subscription == null)
{
subscription = Subscribe(actionOnMessage);
}
};
EventHandler onHandleDestroyed = (inner, eArgs) =>
{
if (subscription != null)
{
Unsubscribe(subscription);
subscription = null;
}
};
//Attach to events and subscribe on message, if handle is already created
target.HandleCreated += onHandleCreated;
target.HandleDestroyed += onHandleDestroyed;
if (target.IsHandleCreated)
{
subscription = Subscribe(actionOnMessage);
}
}
/// <summary>
/// Subscribes all receiver-methods of the given target object to this Messenger.
/// Subscribe and unsubscribe is automatically called when the control is created/destroyed.
/// </summary>
/// <param name="target">The target win.forms control.</param>
public void SubscribeAllOnControl(System.Windows.Forms.Control target)
{
target.EnsureNotNull(nameof(target));
IEnumerable <MessageSubscription> generatedSubscriptions = null;
// Create handler delegates
EventHandler onHandleCreated = (sender, eArgs) =>
{
if (generatedSubscriptions == null)
{
generatedSubscriptions = SubscribeAll(target);
}
};
EventHandler onHandleDestroyed = (inner, eArgs) =>
{
if (generatedSubscriptions != null)
{
foreach (MessageSubscription actSubscription in generatedSubscriptions)
{
actSubscription.Unsubscribe();
}
generatedSubscriptions = null;
}
};
// Attach to events and subscribe on message, if handle is already created
target.HandleCreated += onHandleCreated;
target.HandleDestroyed += onHandleDestroyed;
if (target.IsHandleCreated)
{
generatedSubscriptions = SubscribeAll(target);
}
}
