public void Should_Track_Bounds()
{
using (UnitTestApplication.Start(TestServices.StyledWindow))
{
var target = new BoundsTracker();
var control = default(Rectangle);
var tree = new Decorator
{
Padding = new Thickness(10),
Child = new Decorator
{
Padding = new Thickness(5),
Child = control = new Rectangle
{
Width = 15,
Height = 15,
},
}
};
var context = new DrawingContext(Mock.Of<IDrawingContextImpl>());
tree.Measure(Size.Infinity);
tree.Arrange(new Rect(0, 0, 100, 100));
context.Render(tree);
var track = target.Track(control);
var results = new List<TransformedBounds?>();
track.Subscribe(results.Add);
Assert.Equal(new Rect(0, 0, 15, 15), results[0].Value.Bounds);
Assert.Equal(Matrix.CreateTranslation(42, 42), results[0].Value.Transform);
}
}
/// <summary>
/// Enumerates the visuals in the visual tree whose bounds contain a point.
/// </summary>
/// <param name="visual">The root visual to test.</param>
/// <param name="p">The point.</param>
/// <param name="filter">
/// A filter predicate. If the predicate returns false then the visual and all its
/// children will be excluded from the results.
/// </param>
/// <returns>The visuals at the requested point.</returns>
public static IEnumerable <IVisual> GetVisualsAt(
this IVisual visual,
Point p,
Func <IVisual, bool> filter)
{
Contract.Requires <ArgumentNullException>(visual != null);
if (filter?.Invoke(visual) != false)
{
bool containsPoint = BoundsTracker.GetTransformedBounds((Visual)visual)?.Contains(p) == true;
if ((containsPoint || !visual.ClipToBounds) && visual.VisualChildren.Any())
{
foreach (var child in visual.VisualChildren.SortByZIndex())
{
foreach (var result in child.GetVisualsAt(p, filter))
{
yield return(result);
}
}
}
if (containsPoint)
{
yield return(visual);
}
}
}
