Avalonia/src/Avalonia.Base/Layout/IFlowLayoutAlgorithmDelegates.cs

// This source file is adapted from the WinUI project.
// (https://github.com/microsoft/microsoft-ui-xaml)
//
// Licensed to The Avalonia Project under MIT License, courtesy of The .NET Foundation.

namespace Avalonia.Layout
{
    internal struct FlowLayoutAnchorInfo
    {
        public int Index { get; set; }
        public double Offset { get; set; }
    }

    internal interface IFlowLayoutAlgorithmDelegates
    {
        Size Algorithm_GetMeasureSize(int index, Size availableSize, VirtualizingLayoutContext context);
        Size Algorithm_GetProvisionalArrangeSize(int index, Size measureSize, Size desiredSize, VirtualizingLayoutContext context);
        bool Algorithm_ShouldBreakLine(int index, double remainingSpace);
        FlowLayoutAnchorInfo Algorithm_GetAnchorForRealizationRect(Size availableSize, VirtualizingLayoutContext context);
        FlowLayoutAnchorInfo Algorithm_GetAnchorForTargetElement(int targetIndex, Size availableSize, VirtualizingLayoutContext context);
        Rect Algorithm_GetExtent(
            Size availableSize,
            VirtualizingLayoutContext context,
            Layoutable? firstRealized,
            int firstRealizedItemIndex,
            Rect firstRealizedLayoutBounds,
            Layoutable? lastRealized,
            int lastRealizedItemIndex,
            Rect lastRealizedLayoutBounds);
        void Algorithm_OnElementMeasured(
            Layoutable element,
            int index,
            Size availableSize,
            Size measureSize,
            Size desiredSize,
            Size provisionalArrangeSize,
            VirtualizingLayoutContext context);
        void Algorithm_OnLineArranged(
            int startIndex,
            int countInLine,
            double lineSize,
            VirtualizingLayoutContext context);
    }
}