static void BindEvents(NavigationPage page)
{
page.Popped += (s, args) =>
{
TinyPubSub.Unsubscribe(args.Page);
TinyPubSub.Unsubscribe(args.Page.BindingContext);
if (args.Page is MultiPage <Page> multipage)
{
foreach (var child in multipage.Children)
{
TinyPubSub.Unsubscribe(child);
TinyPubSub.Unsubscribe(child.BindingContext);
}
}
};
page.PoppedToRoot += (s, args) =>
{
var poppedToRootEventArgs = args as PoppedToRootEventArgs;
foreach (var poppedPage in poppedToRootEventArgs.PoppedPages)
{
TinyPubSub.Unsubscribe(poppedPage);
TinyPubSub.Unsubscribe(poppedPage?.BindingContext);
}
};
}
/// <summary>
/// Scans an object after attributes to hook up to TinyPubSub
/// </summary>
/// <param name="obj">The object to scan</param>
public static void Register(object obj)
{
//// TODO: EB: Move the reflection code to a separate type, for performance - add a cache (ConcurrentDictionary) to scanned objects and use expressions to invoke the subscriber methods instead of method.Invoke()..
var typeInfo = IntrospectionExtensions.GetTypeInfo(obj.GetType());
foreach (var method in typeInfo.DeclaredMethods)
{
var attributes = method.GetCustomAttributes(typeof(TinySubscribeAttribute)).OfType <TinySubscribeAttribute>();
foreach (var attribute in attributes)
{
var channel = attribute.Channel;
var methodParameters = method.GetParameters();
if (methodParameters.Length > 0)
{
// Concept code for subscriptions
var firstParam = methodParameters.First();
var paramType = firstParam.ParameterType; // EB: Not used
TinyPubSub.Subscribe <object>(obj, channel, (data) => method.Invoke(obj, new object[] { data }));
}
else
{
// Register without parameters since the target method has none
TinyPubSub.Subscribe(obj, channel, () => method.Invoke(obj, null));
}
}
}
}
public static void SubscribeOnMainThread <T>(object owner, string channel, Action <T> action)
{
TinyPubSub.Subscribe <T>(owner, channel, (obj) => {
Device.BeginInvokeOnMainThread(() => action(obj));
});
}
public static void Init(Application app)
{
TinyPubSub.Clear();
app.PropertyChanged += App_PropertyChanged;
}
public static void Deregister(object obj)
{
TinyPubSub.Unsubscribe(obj);
}