private static void OnValuePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var obj = (IsNullOrEmptyStateTrigger)d;
var val = e.NewValue;
obj.IsActive = IsNullOrEmpty(val);
if (val == null)
{
return;
}
// Try to listen for various notification events
// Starting with INorifyCollectionChanged
var valNotifyCollection = val as INotifyCollectionChanged;
if (valNotifyCollection != null)
{
var weakEvent = new WeakEventListener <INotifyCollectionChanged, object, NotifyCollectionChangedEventArgs>(valNotifyCollection)
{
OnEventAction = (instance, source, args) => obj.IsActive = IsNullOrEmpty(instance),
OnDetachAction = (instance, weakEventListener) => instance.CollectionChanged -= weakEventListener.OnEvent
};
valNotifyCollection.CollectionChanged += weakEvent.OnEvent;
return;
}
// Not INotifyCollectionChanged, try IObservableVector
var valObservableVector = val as IObservableVector <object>;
if (valObservableVector != null)
{
var weakEvent = new WeakEventListener <IObservableVector <object>, object, IVectorChangedEventArgs>(valObservableVector)
{
OnEventAction = (instance, source, args) => obj.IsActive = IsNullOrEmpty(instance),
OnDetachAction = (instance, weakEventListener) => instance.VectorChanged -= weakEventListener.OnEvent
};
valObservableVector.VectorChanged += weakEvent.OnEvent;
return;
}
// Not INotifyCollectionChanged, try IObservableMap
var valObservableMap = val as IObservableMap <object, object>;
if (valObservableMap != null)
{
var weakEvent = new WeakEventListener <IObservableMap <object, object>, object, IMapChangedEventArgs <object> >(valObservableMap)
{
OnEventAction = (instance, source, args) => obj.IsActive = IsNullOrEmpty(instance),
OnDetachAction = (instance, weakEventListener) => instance.MapChanged -= weakEventListener.OnEvent
};
valObservableMap.MapChanged += weakEvent.OnEvent;
}
}
/// <summary>
/// Initializes a new instance of the <see cref="NetworkConnectionStateTrigger"/> class.
/// </summary>
public NetworkConnectionStateTrigger()
{
var weakEvent =
new WeakEventListener <NetworkConnectionStateTrigger, object>(this)
{
OnEventAction = (instance, source) => NetworkInformation_NetworkStatusChanged(source),
OnDetachAction = (instance, weakEventListener) => NetworkInformation.NetworkStatusChanged -= weakEventListener.OnEvent
};
NetworkInformation.NetworkStatusChanged += weakEvent.OnEvent;
UpdateState();
}
/// <summary>
/// Initializes a new instance of the <see cref="OrientationStateTrigger"/> class.
/// </summary>
public OrientationStateTrigger()
{
if (!Windows.ApplicationModel.DesignMode.DesignModeEnabled)
{
var weakEvent =
new WeakEventListener <OrientationStateTrigger, DisplayInformation, object>(this)
{
OnEventAction = OrientationStateTrigger_OrientationChanged,
OnDetachAction = (_, weakEventListener) => DisplayInformation.GetForCurrentView().OrientationChanged -= weakEventListener.OnEvent
};
DisplayInformation.GetForCurrentView().OrientationChanged += weakEvent.OnEvent;
}
}
/// <summary>
/// Initializes a new instance of the <see cref="FullScreenModeTrigger"/> class.
/// </summary>
public FullScreenModeTrigger()
{
if (!Windows.ApplicationModel.DesignMode.DesignModeEnabled)
{
var weakEvent =
new WeakEventListener <FullScreenModeTrigger, ApplicationView, object>(this)
{
OnEventAction = (instance, source, eventArgs) => FullScreenModeTrigger_VisibleBoundsChanged(source, eventArgs),
OnDetachAction = (instance, weakEventListener) => ApplicationView.GetForCurrentView().VisibleBoundsChanged -= weakEventListener.OnEvent
};
ApplicationView.GetForCurrentView().VisibleBoundsChanged += weakEvent.OnEvent;
}
}
/// <summary>
/// Initializes a new instance of the <see cref="UserInteractionModeTrigger"/> class.
/// </summary>
public UserInteractionModeTrigger()
{
if (!Windows.ApplicationModel.DesignMode.DesignModeEnabled)
{
var weakEvent =
new WeakEventListener <UserInteractionModeTrigger, object, WindowSizeChangedEventArgs>(this)
{
OnEventAction = (instance, source, eventArgs) => UserInteractionModeTrigger_SizeChanged(source, eventArgs),
OnDetachAction = (instance, weakEventListener) => Window.Current.SizeChanged -= weakEventListener.OnEvent
};
Window.Current.SizeChanged += weakEvent.OnEvent;
UpdateTrigger(InteractionMode);
}
}
/// <summary>
/// Initializes a new instance of the <see cref="AdaptiveTrigger"/> class.
/// </summary>
public AdaptiveTrigger()
{
this.RegisterPropertyChangedCallback(MinWindowHeightProperty, OnMinWindowHeightPropertyChanged);
this.RegisterPropertyChangedCallback(MinWindowWidthProperty, OnMinWindowWidthPropertyChanged);
var window = CoreApplication.GetCurrentView()?.CoreWindow;
if (window != null)
{
var weakEvent = new WeakEventListener <AdaptiveTrigger, CoreWindow, WindowSizeChangedEventArgs>(this)
{
OnEventAction = (instance, s, e) => OnCoreWindowOnSizeChanged(s, e),
OnDetachAction = (instance, weakEventListener) => window.SizeChanged -= weakEventListener.OnEvent
};
window.SizeChanged += weakEvent.OnEvent;
}
}
