/* Based on VirtualizingWrapPanel created by S. Bäumlisberger licensed under MIT license.
   https://github.com/sbaeumlisberger/VirtualizingWrapPanel
   Copyright (C) S. Bäumlisberger
   All Rights Reserved. */

using System.Windows.Controls;

// ReSharper disable once CheckNamespace
namespace WPFluent.Controls;

/// <summary>
/// Virtualized <see cref="ItemsControl"/>. <para>Based on <see
/// href="https://github.com/sbaeumlisberger/VirtualizingWrapPanel"/>.</para>
/// </summary>
public class VirtualizingItemsControl : ItemsControl
{
    /// <summary>
    /// Identifies the <see cref="CacheLengthUnit"/> dependency property.
    /// </summary>
    public static readonly DependencyProperty CacheLengthUnitProperty = DependencyProperty.Register(
        nameof(CacheLengthUnit),
        typeof(VirtualizationCacheLengthUnit),
        typeof(VirtualizingItemsControl),
        new FrameworkPropertyMetadata(VirtualizationCacheLengthUnit.Page));

    /// <summary>
    /// Initializes a new instance of the <see cref="VirtualizingItemsControl"/> class.
    /// </summary>
    public VirtualizingItemsControl()
    {
        VirtualizingPanel.SetCacheLengthUnit(this, CacheLengthUnit);
        VirtualizingPanel.SetCacheLength(this, new VirtualizationCacheLength(1));
        VirtualizingPanel.SetIsVirtualizingWhenGrouping(this, true);
    }

    /// <summary>
    /// Gets or sets the cache length unit.
    /// </summary>
    public VirtualizationCacheLengthUnit CacheLengthUnit
    {
        get => VirtualizingPanel.GetCacheLengthUnit(this);
        set
        {
            SetValue(CacheLengthUnitProperty, value);
            VirtualizingPanel.SetCacheLengthUnit(this, value);
        }
    }
}