maui-linux/Xamarin.Forms.Platform.Android/Renderers/DescendantFocusToggler.cs

42 строки
1.1 KiB
C#

using System;
using Android.Views;
namespace Xamarin.Forms.Platform.Android
{
internal class DescendantFocusToggler : IDescendantFocusToggler
{
public bool RequestFocus(global::Android.Views.View control, Func<bool> baseRequestFocus)
{
IViewParent ancestor = control.Parent;
var previousFocusability = DescendantFocusability.BlockDescendants;
ConditionalFocusLayout cfl = null;
// Work our way up through the tree until we find a ConditionalFocusLayout
while (ancestor is ViewGroup)
{
cfl = ancestor as ConditionalFocusLayout;
if (cfl != null)
{
previousFocusability = cfl.DescendantFocusability;
// Toggle DescendantFocusability to allow this control to get focus
cfl.DescendantFocusability = DescendantFocusability.AfterDescendants;
break;
}
ancestor = ancestor.Parent;
}
// Call the original RequestFocus implementation for the View
bool result = baseRequestFocus();
if (cfl != null)
{
// Toggle descendantfocusability back to whatever it was
cfl.DescendantFocusability = previousFocusability;
}
return result;
}
}
}