private static bool findPropagationPathUsingTest(
Control root, PropagationTest propagationTest, List <Control> path)
{
var outcome = propagationTest(root);
switch (outcome)
{
case PropagationTestOutcome.Miss:
return(false);
case PropagationTestOutcome.PassThrough:
if (!(root is IControlParent passThroughRootAsParent))
{
return(false);
}
path.Add(root);
if (tryFindPropagationPathForAnyChild(passThroughRootAsParent, propagationTest, path))
{
return(true);
}
path.RemoveAt(path.Count - 1);
return(false);
case PropagationTestOutcome.Hit:
path.Add(root);
if (!(root is IControlParent hitRootAsParent))
{
return(true);
}
tryFindPropagationPathForAnyChild(hitRootAsParent, propagationTest, path);
return(true);
default:
throw new ArgumentOutOfRangeException();
}
}
private static List <Control> findPropagationPathUsingTest(IControlParent root, PropagationTest propagationTest)
{
var path = new List <Control>();
tryFindPropagationPathForAnyChild(root, propagationTest, path);
return(path);
}
private static bool tryFindPropagationPathForAnyChild(
IControlParent parent, PropagationTest propagationTest, List <Control> path) =>
parent.Children.Reverse()
.Any(child => findPropagationPathUsingTest(child, propagationTest, path));
// Never returns the root as part of the path. public static EventPropagationPath FindPropagationPath(IControlParent root, PropagationTest propagationTest) => new EventPropagationPath(findPropagationPathUsingTest(root, propagationTest).AsReadOnly());
