private void AssignValue(IObservablePropertyBinding <T> dst, IObservablePropertyBinding <T> src)
{
// only do the assignment if the value is actually different
// otherwise we may get infinite recursion in the bi-directional case
if (!object.Equals(dst.PropertyValue, src.PropertyValue))
{
dst.PropertyValue = src.PropertyValue;
}
}
/// <summary>
/// Constructor.
/// </summary>
/// <param name="primary">The primary property, which serves as the subject.</param>
/// <param name="secondary">The secondary property, which observes the subject and tracks its value.</param>
/// <param name="bidirectional">If true, the primary property will also track the value of the secondary property.</param>
private ObservablePropertyCoupler(IObservablePropertyBinding <T> primary, IObservablePropertyBinding <T> secondary, bool bidirectional)
{
Platform.CheckForNullReference(primary, "primary");
Platform.CheckForNullReference(secondary, "secondary");
_primary = primary;
_secondary = secondary;
_bidirectional = bidirectional;
// set up the coupling
_primary.PropertyChanged += PrimaryChangedEventHandler;
if (_bidirectional)
{
_secondary.PropertyChanged += SecondaryChangedEventHandler;
}
// initialize secondary value from primary
_secondary.PropertyValue = _primary.PropertyValue;
}
/// <summary>
/// Establishes the coupling between the specified primary and secondary properties.
/// </summary>
/// <remarks>
/// The value of the secondary property will be initialized to the value of the primary property,
/// and will continue to be synchronized for the duration of the lifetime of this object. The coupling is
/// optionally bi-directional, in which case changes made to the secondary property are also propagated
/// back to the primary property. To remove the coupling at any point in the future, retain the returned
/// object, and call Dispose() on it to remove the coupling.
/// </remarks>
/// <param name="primary">The primary property, which serves as the subject.</param>
/// <param name="secondary">The secondary property, which observes the subject and tracks its value.</param>
/// <param name="bidirectional">If true, the primary property will also track the value of the secondary property.</param>
/// <returns>A property coupler object, which can optionally be retained for eventual disposal.</returns>
public static ObservablePropertyCoupler <T> Couple(IObservablePropertyBinding <T> primary, IObservablePropertyBinding <T> secondary, bool bidirectional)
{
return(new ObservablePropertyCoupler <T>(primary, secondary, bidirectional));
}
/// <summary>
/// Establishes the coupling between the specified primary and secondary properties.
/// </summary>
/// <remarks>
/// The value of the secondary property will be initialized to the value of the primary property,
/// and will continue to be synchronized for the duration of the lifetime of this object.
/// To remove the coupling at any point in the future, retain the returned object, and
/// call Dispose() on it to remove the coupling.
/// </remarks>
/// <param name="primary">The primary property, which serves as the subject.</param>
/// <param name="secondary">The secondary property, which observes the subject and tracks its value.</param>
/// <returns>A property coupler object, which can optionally be retained for eventual disposal.</returns>
public static ObservablePropertyCoupler <T> Couple(IObservablePropertyBinding <T> primary, IObservablePropertyBinding <T> secondary)
{
return(new ObservablePropertyCoupler <T>(primary, secondary, false));
}
