public void PropertyObserver_Getter_Observes_instance_IntProperty()
{
var instance = new NotifyPropertyChangedClass1()
{
Class2 = null
};
var callCount = 0;
using var observes = PropertyValueObserver.ObservesAndGet(instance, i => i.Class2.IntProperty, () => callCount++);
Assert.AreEqual(0, callCount);
Assert.AreEqual(null, observes.Value);
instance.Class2 = new NotifyPropertyChangedClass2 {
IntProperty = 1
};
Assert.AreEqual(0, callCount);
Assert.AreEqual(1, observes.Value);
observes.Activate();
Assert.AreEqual(1, callCount);
Assert.AreEqual(1, observes.Value);
instance.Class2.IntProperty = 2;
Assert.AreEqual(2, callCount);
Assert.AreEqual(2, observes.Value);
observes.Deactivate();
Assert.AreEqual(2, callCount);
Assert.AreEqual(2, observes.Value);
instance.Class2.IntProperty = 3;
Assert.AreEqual(2, callCount);
Assert.AreEqual(3, observes.Value);
instance.Class2 = null;
Assert.AreEqual(2, callCount);
Assert.AreEqual(null, observes.Value);
}
/// <summary>
/// Initializes a new instance of the <see cref="CanExecuteObserver{TOwner}" /> class.
/// </summary>
/// <param name="parameter">The owner.</param>
/// <param name="canExecuteExpression">The can execute expression.</param>
/// <exception cref="ArgumentNullException">
/// parameter
/// or
/// canExecuteExpression is null.
/// </exception>
public CanExecuteObserver(
[NotNull] TParameter1 parameter,
[NotNull] Expression <Func <TParameter1, bool> > canExecuteExpression)
{
if (parameter == null)
{
throw new ArgumentNullException(nameof(parameter));
}
if (canExecuteExpression == null)
{
throw new ArgumentNullException(nameof(canExecuteExpression));
}
this.Parameter = parameter;
var observesAndGet = PropertyValueObserver.ObservesAndGet(
parameter,
canExecuteExpression,
() => this.Update.Raise(),
false);
this.Observer = observesAndGet;
this.CanExecute = () => observesAndGet.GetValue();
}
public void PropertyObserver_OnNotifyProperyChanged_Observes_instance_IntProperty_Cashed_TaskSchedulerCurrent_AutoActivateTrue()
{
var instance = new NotifyPropertyChangedClass1()
{
Class2 = null
};
var callCount = 0;
using var observes = PropertyValueObserver.ObservesOnNotifyProperyChanged <int>(() => instance.Class2.IntProperty, true, LazyThreadSafetyMode.None, TaskScheduler.Current, true);
observes.PropertyChanged += (sender, args) => callCount++;
Assert.AreEqual(0, callCount);
Assert.AreEqual(null, observes.Value);
instance.Class2 = new NotifyPropertyChangedClass2 {
IntProperty = 1
};
Assert.AreEqual(1, callCount);
Assert.AreEqual(1, observes.Value);
instance.Class2.IntProperty = 2;
Assert.AreEqual(2, callCount);
Assert.AreEqual(2, observes.Value);
instance.Class2.IntProperty = 2;
Assert.AreEqual(2, callCount);
Assert.AreEqual(2, observes.Value);
observes.Deactivate();
Assert.AreEqual(2, callCount);
Assert.AreEqual(2, observes.Value);
instance.Class2.IntProperty = 3;
Assert.AreEqual(2, callCount);
Assert.AreEqual(2, observes.Value);
}
public void PropertyObserver_OnValueChanged_Observes_instance_IntProperty_AutoActivateTrue()
{
var instance = new NotifyPropertyChangedClass1()
{
Class2 = null
};
var callCount = 0;
using var observes = PropertyValueObserver.ObservesOnValueChanged <int>(() => instance.Class2.IntProperty, true);
observes.PropertyChanged += (sender, args) => callCount++;
Assert.AreEqual(0, callCount);
Assert.AreEqual(null, observes.Value);
instance.Class2 = new NotifyPropertyChangedClass2 {
IntProperty = 1
};
Assert.AreEqual(1, callCount);
Assert.AreEqual(1, observes.Value);
instance.Class2.IntProperty = 2;
Assert.AreEqual(2, callCount);
Assert.AreEqual(2, observes.Value);
instance.Class2.IntProperty = 2;
Assert.AreEqual(2, callCount);
Assert.AreEqual(2, observes.Value);
observes.Deactivate();
Assert.AreEqual(2, callCount);
Assert.AreEqual(2, observes.Value);
instance.Class2.IntProperty = 3;
Assert.AreEqual(2, callCount);
Assert.AreEqual(2, observes.Value);
}
