/// <summary>
/// Invoked to unhook an object from the command adapter.
/// </summary>
/// <param name="invoker">Object whose event will be unhooked</param>
/// <param name="eventName">Name of the event to unhook</param>
public override void RemoveInvoker(object invoker, string eventName)
{
Guard.ArgumentNotNull(invoker, "invoker");
Guard.ArgumentNotNullOrEmptyString(eventName, "eventName");
ThrowIfWrongType(invoker);
// get the specific invoker
TInvoker specificInvoker = (TInvoker)invoker;
if (this.invoker != specificInvoker)
{
throw new InvalidOperationException(Properties.Resources.DifferentInvoker);
}
// unhook the event of the cached invoker
this.UnhookEvent(this.eventSource, eventName);
// unregister the invoker key & command adapter
CommandAdapterManager.UnregisterAdapter(this, this.logicalInvoker);
// release all references regarding the invoker and the events
this.eventName = null;
this.invoker = null;
this.eventSource = null;
this.logicalInvoker = null;
}
/// <summary>
/// Informs the <see cref="CommandAdapter"/> that has been unbinded from the <see cref="Command"/>.
/// </summary>
/// <param name="command">The <see cref="Command"/> from with to unbind.</param>
public override void UnbindCommand(Command command)
{
// let the base class unbind the command
base.UnbindCommand(command);
// let the master list know that the adapter is no longer associated with a command since it may affect the state of the associated elements
CommandAdapterManager.NotifyCommandChanged(this, this.command, null);
// release the reference to the command
this.command = null;
// let the derived class know since the element state
// may need to be updated
this.OnCommandChanged(null);
}
/// <summary>
/// Informs the <see cref="CommandAdapter"/> that has been adapted to the <see cref="Command"/>.
/// </summary>
/// <param name="command">The <see cref="Command"/> to bind to.</param>
public override void BindCommand(Command command)
{
// let the base class bind to the command
base.BindCommand(command);
// let the master list know that the adapter is associated with a command since it may affect the state of the associated elements
CommandAdapterManager.NotifyCommandChanged(this, this.command, command);
// store a reference to the command
this.command = command;
// let the derived class know since the element state
// may need to be updated
this.OnCommandChanged(command);
}
/// <summary>
/// Invoked to associated the command adapter with an object whose event will trigger the execution of the associated command.
/// </summary>
/// <param name="invoker">Object whose event will be hooked</param>
/// <param name="eventName">Name of the event to hook</param>
public override void AddInvoker(object invoker, string eventName)
{
Guard.ArgumentNotNull(invoker, "invoker");
Guard.ArgumentNotNullOrEmptyString(eventName, "eventName");
ThrowIfWrongType(invoker);
if (this.invoker != null)
{
throw new InvalidOperationException(Properties.Resources.AdapterAlreadyHasInvoker);
}
// get the specific invoker
TInvoker specificInvoker = (TInvoker)invoker;
// get the object whose event will be caught
object eventSource = this.GetEventSource(specificInvoker, eventName);
if (eventSource == null)
{
throw new InvalidOperationException(Properties.Resources.InvalidInvokerEvent);
}
// hook the event of the event source. we do this first
// in case the event doesn't exist, etc.
this.HookEvent(eventSource, eventName);
// then cache the information so we can unhook
this.eventName = eventName; // name of the event hooked
this.invoker = specificInvoker; // element associated with the adapter
this.eventSource = eventSource; // object whose event we caught
// create an object that is used to identify the item
// we do this so if someone creates multiple adapters for the
// same logical object, we have all the commands associated
// with that object
this.logicalInvoker = this.CreateLogicalInvoker(specificInvoker);
// register the invoker key and adapter
CommandAdapterManager.RegisterAdapter(this, this.logicalInvoker);
}
