public void CollectionAndContextAreHeldWeaklyClosingOverCollection()
{
WeakReference weakCollection = null, weakContext = null;
int i = 0;
Action create = null;
create = () =>
{
if (i++ < 1024)
{
create();
return;
}
string[] collection = new[] { "foo", "bar" };
weakCollection = new WeakReference(collection);
object context = new object();
weakContext = new WeakReference(context);
BindingBase.EnableCollectionSynchronization(collection, context, (enumerable, o, method, access) =>
{
collection[0] = "baz";
});
};
create();
GC.Collect();
GC.WaitForPendingFinalizers();
Assert.IsFalse(weakCollection.IsAlive);
Assert.IsFalse(weakContext.IsAlive);
}
public void SynchronizedCollectionAccess()
{
var collection = new ObservableCollection <string> {
"foo"
};
var context = new object();
var list = new ListProxy(collection);
bool executed = false;
BindingBase.EnableCollectionSynchronization(collection, context, (enumerable, o, method, access) =>
{
executed = true;
Assert.AreSame(collection, enumerable);
Assert.AreSame(context, o);
Assert.IsNotNull(method);
Assert.IsFalse(access);
lock (enumerable)
method();
});
object value = list[0];
Assert.IsTrue(executed, "Callback was not executed");
}
public ContactsViewModel(INavigation navigation) : base(navigation)
{
Contacts = new ObservableCollection <ContactModel>();
BindingBase.EnableCollectionSynchronization(Contacts, null, ObservableCollectionCallback);
App.ContactsService.OnContactLoaded += OnContactLoaded;
LoadContacts();
}
public LogViewerModel()
{
Logs = new ObservableCollection <LogMsg>();
Log.LogsSink.OnLogEmit = new AsyncCommand <LogMsg>(OnLogEmit);
MaxLogs = 500;
BindingBase.EnableCollectionSynchronization(Logs, _syncLock, ObservableCollectionCallback);
}
public CollectionViewModel()
{
Title = "Browse";
Items = new RangeObservableCollection <T>();
BindingBase.EnableCollectionSynchronization(Items, null, ObservableCollectionCallback);
LoadItemsCommand = new Command(async() => await ExecuteLoadItemsCommand());
AddItemCommand = new AsyncCommand <T>(async(item) => await ExecuteAddItemCommand(item));
}
public void EnableCollectionSynchronizationInvalid()
{
Assert.That(() => BindingBase.EnableCollectionSynchronization(null, new object(),
(collection, context, method, access) => { }), Throws.InstanceOf <ArgumentNullException>());
Assert.That(() => BindingBase.EnableCollectionSynchronization(new string[0], new object(),
null), Throws.InstanceOf <ArgumentNullException>());
Assert.That(() => BindingBase.EnableCollectionSynchronization(new string[0], null,
(collection, context, method, access) => { }), Throws.Nothing);
}
public Task SynchronizedCollectionAdd() => DispatcherTest.Run(() =>
{
bool invoked = false;
DispatcherProviderStubOptions.IsInvokeRequired = () => true;
DispatcherProviderStubOptions.InvokeOnMainThread = action =>
{
invoked = true;
action();
};
var collection = new ObservableCollection <string> {
"foo"
};
var context = new object();
var list = new ListProxy(collection);
Assert.IsFalse(invoked, "An invoke shouldn't be executed just setting up ListProxy");
bool executed = false;
BindingBase.EnableCollectionSynchronization(collection, context, (enumerable, o, method, access) =>
{
executed = true;
Assert.AreSame(collection, enumerable);
Assert.AreSame(context, o);
Assert.IsNotNull(method);
Assert.IsFalse(access);
lock (enumerable)
method();
});
var mre = new ManualResetEvent(false);
Task.Factory.StartNew(() =>
{
DispatcherProviderStubOptions.IsInvokeRequired = () => true;
DispatcherProviderStubOptions.InvokeOnMainThread = action =>
{
invoked = true;
action();
};
lock (collection)
collection.Add("foo");
mre.Set();
}, CancellationToken.None, TaskCreationOptions.None, TaskScheduler.Default);
mre.WaitOne(5000);
Assert.IsTrue(executed, "Callback was not executed");
Assert.IsTrue(invoked, "Callback was not executed on the UI thread");
});
public void DisableCollectionSynchronization()
{
string[] stuff = new[] { "foo", "bar" };
object context = new object();
CollectionSynchronizationCallback callback = (collection, o, method, access) => { };
BindingBase.EnableCollectionSynchronization(stuff, context, callback);
BindingBase.DisableCollectionSynchronization(stuff);
CollectionSynchronizationContext syncContext;
Assert.IsFalse(BindingBase.TryGetSynchronizedCollection(stuff, out syncContext));
Assert.IsNull(syncContext);
}
public void EnableCollectionSynchronization()
{
string[] stuff = new[] { "foo", "bar" };
object context = new object();
CollectionSynchronizationCallback callback = (collection, o, method, access) => { };
BindingBase.EnableCollectionSynchronization(stuff, context, callback);
CollectionSynchronizationContext syncContext;
Assert.IsTrue(BindingBase.TryGetSynchronizedCollection(stuff, out syncContext));
Assert.That(syncContext, Is.Not.Null);
Assert.AreSame(syncContext.Callback, callback);
Assert.That(syncContext.ContextReference, Is.Not.Null);
Assert.That(syncContext.ContextReference.Target, Is.SameAs(context));
}
public NewsViewModel()
{
//Ensure Observable Collection is thread-safe https://codetraveler.io/2019/09/11/using-observablecollection-in-a-multi-threaded-xamarin-forms-application/
BindingBase.EnableCollectionSynchronization(TopStoryCollection, null, ObservableCollectionCallback);
}
public OpportunitiesViewModel()
{
//https://codetraveler.io/2019/09/11/using-observablecollection-in-a-multi-threaded-xamarin-forms-application/
BindingBase.EnableCollectionSynchronization(VisibleOpportunitiesCollection, null, ObservableCollectionCallback);
}
public PhotoListViewModel()
{
//https://codetraveler.io/2019/09/11/using-observablecollection-in-a-multi-threaded-xamarin-forms-application/
BindingBase.EnableCollectionSynchronization(AllPhotosList, null, ObservableCollectionCallback);
}
public OpportunitiesViewModel()
{
BindingBase.EnableCollectionSynchronization(VisibleOpportunitiesCollection, null, ObservableCollectionCallback);
}
public FileBrowserDirectoryAdapter(params IFileSystemDiscovery[] fileSystemDiscoverers)
{
_fileSystemDiscoverers = fileSystemDiscoverers;
BindingBase.EnableCollectionSynchronization(_items, null, ObservableCollectionCallback);
NavigateToFileSystemItemAsync(CreateRootItem(_fileSystemDiscoverers));
}
