public MagickImageControl()
{
InitializeComponent();
BusyStack = new BusyStack();
BusyStack.OnChanged = (hasItems) => IsBusy = hasItems;
}
// TODO fiure out a way to call this async and still maintain order
// maybe blocking collection + cancellationtokensource
private void UpdateDataContext()
{
if (Content == null || !IsSelected || GetDataContext == null)
{
return;
}
// while fetching the dataconext, we will switch IsBusy accordingly
using (var token = BusyStack.GetToken())
{
var currentContext = Content.DataContext as ObservableObject;
var newContext = GetDataContext.Invoke();
if (currentContext == null && newContext == null)
{
return;
}
if (EqualityComparer <ObservableObject> .Default.Equals(currentContext, newContext))
{
return;
}
Content.DataContext = newContext;
}
}
public Scene()
{
BusyStack = new BusyStack();
BusyStack.OnChanged = (hasItems) =>
{
IsBusy = hasItems;
};
}
public void RemoveRange(IList items)
{
if (items == null)
{
throw new ArgumentNullException(nameof(items));
}
using (BusyStack.GetToken())
Items.RemoveRange(items);
}
public void AddRange(IEnumerable <T> items)
{
if (items == null)
{
throw new ArgumentNullException(nameof(items));
}
using (BusyStack.GetToken())
Items.AddRange(items);
}
public void Add(T item)
{
if (item == null)
{
throw new ArgumentNullException(nameof(item));
}
using (BusyStack.GetToken())
Items.Add(item);
}
private void InitializeProperties()
{
_itemsLock = new object();
Items = new RangeObservableCollection <T>();
Items.CollectionChanged += ItemsCollectionChanged;
BusyStack = new BusyStack();
BusyStack.OnChanged = (hasItems) => IsBusy = hasItems;
View = CollectionViewSource.GetDefaultView(Items);
// initial Notification, so that UI recognizes the value
OnPropertyChanged(nameof(Count));
}
private async void MagickImageControl_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if (IsBusy)
{
return;
}
using (BusyStack.GetToken())
{
try
{
Image = await AnalyzeContext(e);
}
catch (UnauthorizedAccessException)
{
Image = default(BitmapSource);
// this exception should be logged, instead of being ignored
}
}
}
public BusyToken(BusyStack stack) : base(stack)
{
stack.Push(this);
}
public void Clear()
{
using (BusyStack.GetToken())
Items.Clear();
}
public void Remove(T item)
{
using (BusyStack.GetToken())
Items.Remove(item);
}