/// <summary>
/// Initializes a new instance of the <see cref="CommandBinding"/> class.
/// </summary>
/// <param name="element">The element.</param>
/// <param name="eventName">Name of the event.</param>
/// <param name="command">The command.</param>
/// <param name="commandParameterBinding">The command parameter binding.</param>
/// <exception cref="ArgumentNullException">The <paramref name="element"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentException">The <paramref name="eventName"/> is <c>null</c> or whitespace.</exception>
/// <exception cref="ArgumentNullException">The <paramref name="command"/> is <c>null</c>.</exception>
public CommandBinding(object element, string eventName, ICatelCommand command, Binding commandParameterBinding = null)
{
Argument.IsNotNull("element", element);
Argument.IsNotNullOrWhitespace("eventName", eventName);
Argument.IsNotNull("command", command);
_element = element;
_command = command;
_commandParameterBinding = commandParameterBinding;
var elementType = _element.GetType();
_eventInfo = elementType.GetEventEx(eventName);
if (_eventInfo == null)
{
throw Log.ErrorAndCreateException<InvalidOperationException>("Event '{0}.{1}' not found, cannot create command binding", elementType.Name, eventName);
}
_enabledPropertyInfo = elementType.GetPropertyEx("Enabled");
_eventHandler = delegate
{
var commandParameter = _commandParameterBinding.GetBindingValue();
if (_command.CanExecute(commandParameter))
{
_command.Execute(commandParameter);
}
};
_eventInfo.AddEventHandler(element, _eventHandler);
_canExecuteChangedHandler = (sender, e) => UpdateEnabledState();
command.CanExecuteChanged += _canExecuteChangedHandler;
if (commandParameterBinding != null)
{
_commandBindingParameterValueChangedHandler = (sender, e) => UpdateEnabledState();
commandParameterBinding.ValueChanged += _commandBindingParameterValueChangedHandler;
}
UpdateEnabledState();
}
/// <summary>
/// Removes the binding.
/// </summary>
/// <param name="binding">The binding.</param>
/// <exception cref="ArgumentNullException">The <paramref name="binding"/> is <c>null</c>.</exception>
public void RemoveBinding(Binding binding)
{
Argument.IsNotNull("binding", binding);
Log.Debug("Removing binding '{0}'", binding);
for (int i = 0; i < _bindings.Count; i++)
{
if (ReferenceEquals(_bindings[i], binding))
{
_bindings.RemoveAt(i);
return;
}
}
}
/// <summary>
/// Adds a new binding.
/// </summary>
/// <param name="binding">The binding.</param>
/// <exception cref="ArgumentNullException">The <paramref name="binding"/> is <c>null</c>.</exception>
public void AddBinding(Binding binding)
{
Argument.IsNotNull("binding", binding);
Log.Debug("Adding binding '{0}'", binding);
_bindings.Add(binding);
}
/// <summary>
/// Uninitializes this binding.
/// </summary>
protected override void Uninitialize()
{
if (_eventHandler != null)
{
_eventInfo.RemoveEventHandler(_element, _eventHandler);
_eventHandler = null;
}
if (_canExecuteChangedHandler != null)
{
_command.CanExecuteChanged -= _canExecuteChangedHandler;
_canExecuteChangedHandler = null;
}
if (_commandBindingParameterValueChangedHandler != null)
{
_commandParameterBinding.ValueChanged -= _commandBindingParameterValueChangedHandler;
_commandBindingParameterValueChangedHandler = null;
}
_element = null;
_eventInfo = null;
_enabledPropertyInfo = null;
_command = null;
_commandParameterBinding = null;
// TODO: call commandParameterBinding.ClearBinding();?
}
