/// <summary>
/// Specify a method to be run before an existing command mapping.
/// </summary>
/// <typeparam name="TVirtualView">The cross-platform type.</typeparam>
/// <typeparam name="TViewHandler">The handler type.</typeparam>
/// <param name="commandMapper">The command mapper in which to change the mapping.</param>
/// <param name="key">The name of the command.</param>
/// <param name="method">The method to call before the existing mapping begins.</param>
public static void PrependToMapping <TVirtualView, TViewHandler>(this CommandMapper <TVirtualView, TViewHandler> commandMapper,
string key, Action <TViewHandler, TVirtualView, object?> method)
where TVirtualView : IElement where TViewHandler : IElementHandler
{
commandMapper.ModifyMapping(key, (handler, view, args, action) =>
{
method(handler, view, args);
action?.Invoke(handler, view, args);
});
}
/// <summary>
/// Modify a command mapping in place.
/// </summary>
/// <typeparam name="TVirtualView">The cross-platform type.</typeparam>
/// <typeparam name="TViewHandler">The handler type.</typeparam>
/// <param name="commandMapper">The command mapper in which to change the mapping.</param>
/// <param name="key">The name of the command.</param>
/// <param name="method">The modified method to call when the command is updated.</param>
public static void ModifyMapping <TVirtualView, TViewHandler>(this CommandMapper <TVirtualView, TViewHandler> commandMapper,
string key, Action <TViewHandler, TVirtualView, object?, Action <IElementHandler, IElement, object?>?> method)
where TVirtualView : IElement where TViewHandler : IElementHandler
{
var previousMethod = commandMapper.GetCommand(key);
commandMapper.Add(key, newMethod);
void newMethod(TViewHandler handler, TVirtualView view, object?args)
{
method(handler, view, args, previousMethod);
}
}
