private CommandHandlerWrapper FindCommandHandlerInVisualTree(CommandDefinitionBase commandDefinition, IInputElement target)
{
if (!(target is DependencyObject visualObject))
{
return(null);
}
object previousDataContext = null;
do
{
var frameworkElement = visualObject as FrameworkElement;
var dataContext = frameworkElement?.DataContext;
if (dataContext != null && !ReferenceEquals(dataContext, previousDataContext))
{
if (dataContext is ICommandRerouter context)
{
var commandRerouter = context;
var commandTarget = commandRerouter.GetHandler(commandDefinition);
if (commandTarget != null)
{
if (IsCommandHandlerForCommandDefinitionType(commandTarget, commandDefinition.GetType()))
{
return(CreateCommandHandlerWrapper(commandDefinition.GetType(), commandTarget));
}
throw new InvalidOperationException("This object does not handle the specified command definition.");
}
}
if (IsCommandHandlerForCommandDefinitionType(dataContext, commandDefinition.GetType()))
{
return(CreateCommandHandlerWrapper(commandDefinition.GetType(), dataContext));
}
previousDataContext = dataContext;
}
visualObject = VisualTreeHelper.GetParent(visualObject);
} while (visualObject != null);
return(null);
}
public ICommandHandlerProxy GetCommandHandlerProxy(CommandDefinitionBase commandDefinition)
{
var handler = GetCommandHandler(commandDefinition);
if (handler != null)
{
var type = typeof(CommandHandlerProxy <>).MakeGenericType(commandDefinition.GetType());
return((ICommandHandlerProxy)Activator.CreateInstance(type, handler));
}
return(null);
}
public CommandHandlerWrapper GetCommandHandler(CommandDefinitionBase commandDefinition)
{
CommandHandlerWrapper commandHandler;
var shell = IoC.Get <IDockingHostViewModel>();
var activeItemViewModel = shell.ActiveLayoutItemBase;
if (activeItemViewModel != null)
{
commandHandler = GetCommandHandlerForLayoutItem(commandDefinition, activeItemViewModel);
if (commandHandler != null)
{
return(commandHandler);
}
}
var activeDocumentViewModel = shell.ActiveItem;
if (activeDocumentViewModel != null && !Equals(activeDocumentViewModel, activeItemViewModel))
{
commandHandler = GetCommandHandlerForLayoutItem(commandDefinition, activeDocumentViewModel);
if (commandHandler != null)
{
return(commandHandler);
}
}
// If none of the objects in the DataContext hierarchy handle the command,
// fallback to the global handler.
if (!_globalCommandHandlerWrappers.TryGetValue(commandDefinition.GetType(), out commandHandler))
{
return(null);
}
return(commandHandler);
}
public ICommandHandler GetCommandHandler(CommandDefinitionBase commandDefinition)
{
_commandHandlers.TryGetValue(commandDefinition.GetType(), out var handler);
return(handler);
}