/// <summary>
/// Binds to the specified child <paramref name="binding"/> of this binding.
/// </summary>
/// <remarks>
/// This can be used to bind to child objects of your view model, for example
/// <code>model.SomeProperty.ChildProperty</code>.
/// </remarks>
/// <example>
/// Use this like so:
/// <code>
/// public class MyChild { public SomeChildProperty { get; set; } }
/// public class MyModel { public ChildObject { get; set; } }
///
/// var model = new MyModel();
/// Binding.Property(model, (MyModel m) => m.ChildObject).Child(Binding.Property("SomeChildProperty"));
/// </code>
/// </example>
/// <returns>The binding to the child property accessed through the current binding.</returns>
/// <param name="binding">Binding to get the child value from this binding.</param>
/// <typeparam name="TNewValue">The type of the child property value.</typeparam>
public new BindableBinding <T, TNewValue> Child <TNewValue>(IndirectBinding <TNewValue> binding)
{
object childBindingReference = null;
EventHandler <EventArgs> eventHandler = null;
EventHandler <EventArgs> valueChanged = (sender, e) =>
{
binding.RemoveValueChangedHandler(childBindingReference, eventHandler);
eventHandler?.Invoke(sender, e);
childBindingReference = binding.AddValueChangedHandler(DataValue, eventHandler);
};
return(new BindableBinding <T, TNewValue>(
DataItem,
c => binding.GetValue(DataValue),
(c, v) => binding.SetValue(DataValue, v),
addChangeEvent: (c, ev) =>
{
eventHandler = ev;
DataValueChanged += valueChanged;
childBindingReference = binding.AddValueChangedHandler(DataValue, ev);
},
removeChangeEvent: (c, ev) =>
{
binding.RemoveValueChangedHandler(childBindingReference, ev);
DataValueChanged -= valueChanged;
}
));
}
/// <summary>
/// Binds to the specified child <paramref name="binding"/> of this binding.
/// </summary>
/// <remarks>
/// This can be used to bind to child objects of your view model, for example
/// <code>model.SomeProperty.ChildProperty</code>.
/// </remarks>
/// <example>
/// Use this like so:
/// <code>
/// public class MyChild { public SomeChildProperty { get; set; } }
/// public class MyModel { public ChildObject { get; set; } }
///
/// var model = new MyModel();
/// Binding.Property(model, (MyModel m) => m.ChildObject).Child(Binding.Property("SomeChildProperty"));
/// </code>
/// </example>
/// <returns>The binding to the child property accessed through the current binding.</returns>
/// <param name="binding">Binding to get the child value from this binding.</param>
/// <typeparam name="TValue">The type of the child property value.</typeparam>
public DirectBinding <TValue> Child <TValue>(IndirectBinding <TValue> binding)
{
object childBindingReference = null;
EventHandler <EventArgs> eventHandler = null;
EventHandler <EventArgs> valueChanged = (sender, e) =>
{
binding.RemoveValueChangedHandler(childBindingReference, eventHandler);
eventHandler?.Invoke(sender, e);
childBindingReference = binding.AddValueChangedHandler(DataValue, eventHandler);
};
return(new DelegateBinding <TValue>(
() => binding.GetValue(DataValue),
v => binding.SetValue(DataValue, v),
addChangeEvent: ev =>
{
eventHandler = ev;
DataValueChanged += valueChanged;
childBindingReference = binding.AddValueChangedHandler(DataValue, ev);
},
removeChangeEvent: ev =>
{
binding.RemoveValueChangedHandler(childBindingReference, ev);
DataValueChanged -= valueChanged;
}
));
}
/// <summary>
/// Binds to the specified child <paramref name="binding"/> of this binding.
/// </summary>
/// <remarks>
/// This can be used to bind to child objects of your view model, for example
/// <code>model.SomeProperty.ChildProperty</code>.
/// </remarks>
/// <example>
/// Use this like so:
/// <code>
/// public class MyChild { public SomeChildProperty { get; set; } }
/// public class MyModel { public ChildObject { get; set; } }
///
/// Binding.Property((MyModel m) => m.ChildObject).Child(Binding.Property("SomeChildProperty"));
/// </code>
/// </example>
/// <returns>The binding to the child property accessed through the current binding.</returns>
/// <param name="binding">Binding to get the child value from this binding.</param>
/// <typeparam name="TNewValue">The type of the child property value.</typeparam>
public IndirectBinding <TNewValue> Child <TNewValue>(IndirectBinding <TNewValue> binding)
{
object bindingReference = null;
object childBindingReference = null;
object context = null;
EventHandler <EventArgs> eventHandler = null;
EventHandler <EventArgs> valueChanged = (sender, e) =>
{
binding.RemoveValueChangedHandler(childBindingReference, eventHandler);
eventHandler?.Invoke(sender, e);
childBindingReference = binding.AddValueChangedHandler(GetValue(context), eventHandler);
};
return(new DelegateBinding <object, TNewValue>(
c => binding.GetValue(GetValue(context = c)),
(c, v) => binding.SetValue(GetValue(context = c), v),
addChangeEvent: (c, ev) =>
{
context = c;
eventHandler = ev;
bindingReference = AddValueChangedHandler(c, valueChanged);
childBindingReference = binding.AddValueChangedHandler(GetValue(c), ev);
},
removeChangeEvent: (c, ev) =>
{
binding.RemoveValueChangedHandler(childBindingReference, ev);
RemoveValueChangedHandler(bindingReference, valueChanged);
}
));
}
/// <inheritdoc/>
protected override void InternalSetValue(object dataItem, TChild value)
{
if (IsStruct)
{
// box value to object so it is passed by reference
object childItem = _parent.GetValue(dataItem);
// set the child value
_child.SetValue(childItem, value);
// set value back since it is a struct
_parent.SetValue(dataItem, (TParent)childItem);
}
else
{
var childItem = _parent.GetValue(dataItem);
_child.SetValue(childItem, value);
}
}
/// <summary>
/// Binds to the specified child <paramref name="binding"/> of this binding.
/// </summary>
/// <remarks>
/// This can be used to bind to child objects of your view model, for example
/// <code>model.SomeProperty.ChildProperty</code>.
/// </remarks>
/// <example>
/// Use this like so:
/// <code>
/// public class MyChild { public SomeChildProperty { get; set; } }
/// public class MyModel { public ChildObject { get; set; } }
///
/// var model = new MyModel();
/// Binding.Property(model, (MyModel m) => m.ChildObject).Child(Binding.Property("SomeChildProperty"));
/// </code>
/// </example>
/// <returns>The binding to the child property accessed through the current binding.</returns>
/// <param name="binding">Binding to get the child value from this binding.</param>
/// <typeparam name="TValue">The type of the child property value.</typeparam>
public DirectBinding <TValue> Child <TValue>(IndirectBinding <TValue> binding)
{
object childBindingReference = null;
EventHandler <EventArgs> eventHandler = null;
void valueChanged(object sender, EventArgs e)
{
binding.RemoveValueChangedHandler(childBindingReference, eventHandler);
eventHandler?.Invoke(sender, e);
childBindingReference = binding.AddValueChangedHandler(DataValue, eventHandler);
}
void setValueStruct(TValue v)
{
object parentValue = DataValue;
binding.SetValue(parentValue, v);
DataValue = (T)parentValue;
}
void setValueObject(TValue v) => binding.SetValue(DataValue, v);
var isStruct = typeof(T).GetTypeInfo().IsValueType;
return(new DelegateBinding <TValue>(
() => binding.GetValue(DataValue),
isStruct ? (Action <TValue>)setValueStruct : setValueObject,
addChangeEvent: ev =>
{
eventHandler = ev;
DataValueChanged += valueChanged;
childBindingReference = binding.AddValueChangedHandler(DataValue, ev);
},
removeChangeEvent: ev =>
{
binding.RemoveValueChangedHandler(childBindingReference, ev);
DataValueChanged -= valueChanged;
}
));
}
/// <inheritdoc/>
protected override void InternalSetValue(object dataItem, TChild value)
{
if (IsStruct)
{
// box value to object so it is passed by reference
object childItem = _parent.GetValue(dataItem);
// set the child value
_child.SetValue(childItem, value);
// set value back since it is a struct
_parent.SetValue(dataItem, (TParent)childItem);
}
else
{
var childItem = _parent.GetValue(dataItem);
_child.SetValue(childItem, value);
// if this is an object binding, check to see if we are a boxed struct
var isStruct = typeof(TParent) == typeof(object) && childItem?.GetType().GetTypeInfo().IsValueType == true;
if (isStruct)
{
_parent.SetValue(dataItem, childItem);
}
}
}