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authorE.Z. Hart <hartez@users.noreply.github.com>2017-01-31 06:10:28 -0700
committerRui Marinho <me@ruimarinho.net>2017-01-31 13:10:28 +0000
commitb4fe4e0c902177ff7c175f691a5304d7c7ef518d (patch)
tree50bbf0a4c2ff4fef7492f3ba0dee9f7d0c445d67 /Xamarin.Forms.Core/MessagingCenter.cs
parentd80be6fdb228567cc372e6c242052a6ba5853681 (diff)
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Make MessagingCenter testable (#723)
* Make MessagingCenter testable * Eagerly create MessagingCenter instancef * More succinct version
Diffstat (limited to 'Xamarin.Forms.Core/MessagingCenter.cs')
-rw-r--r--Xamarin.Forms.Core/MessagingCenter.cs89
1 files changed, 69 insertions, 20 deletions
diff --git a/Xamarin.Forms.Core/MessagingCenter.cs b/Xamarin.Forms.Core/MessagingCenter.cs
index b6a167da..d5753e1d 100644
--- a/Xamarin.Forms.Core/MessagingCenter.cs
+++ b/Xamarin.Forms.Core/MessagingCenter.cs
@@ -2,12 +2,28 @@ using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
-using System.Runtime.CompilerServices;
namespace Xamarin.Forms
{
- public static class MessagingCenter
+ public interface IMessagingCenter
{
+ void Send<TSender, TArgs>(TSender sender, string message, TArgs args) where TSender : class;
+
+ void Send<TSender>(TSender sender, string message) where TSender : class;
+
+ void Subscribe<TSender, TArgs>(object subscriber, string message, Action<TSender, TArgs> callback, TSender source = null) where TSender : class;
+
+ void Subscribe<TSender>(object subscriber, string message, Action<TSender> callback, TSender source = null) where TSender : class;
+
+ void Unsubscribe<TSender, TArgs>(object subscriber, string message) where TSender : class;
+
+ void Unsubscribe<TSender>(object subscriber, string message) where TSender : class;
+ }
+
+ public class MessagingCenter : IMessagingCenter
+ {
+ public static IMessagingCenter Instance { get; } = new MessagingCenter();
+
class Sender : Tuple<string, Type, Type>
{
public Sender(string message, Type senderType, Type argType) : base(message, senderType, argType)
@@ -19,8 +35,8 @@ namespace Xamarin.Forms
class MaybeWeakReference
{
- WeakReference DelegateWeakReference { get; set; }
- object DelegateStrongReference { get; set; }
+ WeakReference DelegateWeakReference { get; }
+ object DelegateStrongReference { get; }
readonly bool _isStrongReference;
@@ -84,11 +100,16 @@ namespace Xamarin.Forms
}
}
- static readonly Dictionary<Sender, List<Subscription>> s_subscriptions =
+ readonly Dictionary<Sender, List<Subscription>> _subscriptions =
new Dictionary<Sender, List<Subscription>>();
public static void Send<TSender, TArgs>(TSender sender, string message, TArgs args) where TSender : class
{
+ Instance.Send(sender, message, args);
+ }
+
+ void IMessagingCenter.Send<TSender, TArgs>(TSender sender, string message, TArgs args)
+ {
if (sender == null)
throw new ArgumentNullException(nameof(sender));
InnerSend(message, typeof(TSender), typeof(TArgs), sender, args);
@@ -96,6 +117,11 @@ namespace Xamarin.Forms
public static void Send<TSender>(TSender sender, string message) where TSender : class
{
+ Instance.Send(sender, message);
+ }
+
+ void IMessagingCenter.Send<TSender>(TSender sender, string message)
+ {
if (sender == null)
throw new ArgumentNullException(nameof(sender));
InnerSend(message, typeof(TSender), null, sender, null);
@@ -103,6 +129,11 @@ namespace Xamarin.Forms
public static void Subscribe<TSender, TArgs>(object subscriber, string message, Action<TSender, TArgs> callback, TSender source = null) where TSender : class
{
+ Instance.Subscribe(subscriber, message, callback, source);
+ }
+
+ void IMessagingCenter.Subscribe<TSender, TArgs>(object subscriber, string message, Action<TSender, TArgs> callback, TSender source)
+ {
if (subscriber == null)
throw new ArgumentNullException(nameof(subscriber));
if (callback == null)
@@ -121,6 +152,11 @@ namespace Xamarin.Forms
public static void Subscribe<TSender>(object subscriber, string message, Action<TSender> callback, TSender source = null) where TSender : class
{
+ Instance.Subscribe(subscriber, message, callback, source);
+ }
+
+ void IMessagingCenter.Subscribe<TSender>(object subscriber, string message, Action<TSender> callback, TSender source)
+ {
if (subscriber == null)
throw new ArgumentNullException(nameof(subscriber));
if (callback == null)
@@ -139,27 +175,32 @@ namespace Xamarin.Forms
public static void Unsubscribe<TSender, TArgs>(object subscriber, string message) where TSender : class
{
+ Instance.Unsubscribe<TSender, TArgs>(subscriber, message);
+ }
+
+ void IMessagingCenter.Unsubscribe<TSender, TArgs>(object subscriber, string message)
+ {
InnerUnsubscribe(message, typeof(TSender), typeof(TArgs), subscriber);
}
public static void Unsubscribe<TSender>(object subscriber, string message) where TSender : class
{
- InnerUnsubscribe(message, typeof(TSender), null, subscriber);
+ Instance.Unsubscribe<TSender>(subscriber, message);
}
- internal static void ClearSubscribers()
+ void IMessagingCenter.Unsubscribe<TSender>(object subscriber, string message)
{
- s_subscriptions.Clear();
+ InnerUnsubscribe(message, typeof(TSender), null, subscriber);
}
- static void InnerSend(string message, Type senderType, Type argType, object sender, object args)
+ void InnerSend(string message, Type senderType, Type argType, object sender, object args)
{
if (message == null)
throw new ArgumentNullException(nameof(message));
var key = new Sender(message, senderType, argType);
- if (!s_subscriptions.ContainsKey(key))
+ if (!_subscriptions.ContainsKey(key))
return;
- List<Subscription> subcriptions = s_subscriptions[key];
+ List<Subscription> subcriptions = _subscriptions[key];
if (subcriptions == null || !subcriptions.Any())
return; // should not be reachable
@@ -178,24 +219,24 @@ namespace Xamarin.Forms
}
}
- static void InnerSubscribe(object subscriber, string message, Type senderType, Type argType, object target, MethodInfo methodInfo, Filter filter)
+ void InnerSubscribe(object subscriber, string message, Type senderType, Type argType, object target, MethodInfo methodInfo, Filter filter)
{
if (message == null)
throw new ArgumentNullException(nameof(message));
var key = new Sender(message, senderType, argType);
var value = new Subscription(subscriber, target, methodInfo, filter);
- if (s_subscriptions.ContainsKey(key))
+ if (_subscriptions.ContainsKey(key))
{
- s_subscriptions[key].Add(value);
+ _subscriptions[key].Add(value);
}
else
{
var list = new List<Subscription> { value };
- s_subscriptions[key] = list;
+ _subscriptions[key] = list;
}
}
- static void InnerUnsubscribe(string message, Type senderType, Type argType, object subscriber)
+ void InnerUnsubscribe(string message, Type senderType, Type argType, object subscriber)
{
if (subscriber == null)
throw new ArgumentNullException(nameof(subscriber));
@@ -203,11 +244,19 @@ namespace Xamarin.Forms
throw new ArgumentNullException(nameof(message));
var key = new Sender(message, senderType, argType);
- if (!s_subscriptions.ContainsKey(key))
+ if (!_subscriptions.ContainsKey(key))
return;
- s_subscriptions[key].RemoveAll(sub => sub.CanBeRemoved() || sub.Subscriber.Target == subscriber);
- if (!s_subscriptions[key].Any())
- s_subscriptions.Remove(key);
+ _subscriptions[key].RemoveAll(sub => sub.CanBeRemoved() || sub.Subscriber.Target == subscriber);
+ if (!_subscriptions[key].Any())
+ _subscriptions.Remove(key);
+ }
+
+ // This is a bit gross; it only exists to support the unit tests in PageTests
+ // because the implementations of ActionSheet, Alert, and IsBusy are all very
+ // tightly coupled to the MessagingCenter singleton
+ internal static void ClearSubscribers()
+ {
+ (Instance as MessagingCenter)?._subscriptions.Clear();
}
}
} \ No newline at end of file