ListContainer.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;

namespace Lemma.Components
{
    public class ListContainer : UIComponent
    {
        public enum ListOrientation
        {
            Vertical, Horizontal
        }
        public Property<ListOrientation> Orientation = new Property<ListOrientation> { Value = ListOrientation.Vertical };
        public Property<float> Spacing = new Property<float> { Value = 2.0f };
        private NotifyBinding binding;

        public override void InitializeProperties()
        {
            base.InitializeProperties();
            this.Children.ItemAdded += new ListProperty<UIComponent>.ItemAddedEventHandler(
                delegate(int index, UIComponent t)
                {
                    this.rebuildBinding();
                });
            this.Children.ItemChanged += new ListProperty<UIComponent>.ItemChangedEventHandler(
                delegate(int index, UIComponent old, UIComponent newValue)
                {
                    this.rebuildBinding();
                });
            this.Children.ItemRemoved += new ListProperty<UIComponent>.ItemRemovedEventHandler(
                delegate(int index, UIComponent t)
                {
                    this.rebuildBinding();
                });
            this.rebuildBinding();
        }

        private void rebuildBinding()
        {
            if (this.binding != null)
                this.binding.Delete();
            List<IProperty> properties = new List<IProperty> { this.Orientation, this.Spacing };
            properties.AddRange(this.Children.SelectMany(x => new IProperty[] { x.ScaledSize, x.Visible }));
            this.binding = new NotifyBinding(delegate() { this.layoutDirty = true; }, properties.ToArray());
            this.layoutDirty = true;
        }

        protected override void updateLayout()
        {
            if (this.Orientation.Value == ListOrientation.Horizontal)
            {
                Vector2 pos = Vector2.Zero;
                float maxHeight = 0.0f;
                foreach (UIComponent child in this.Children)
                {
                    child.AnchorPoint.Value = Vector2.Zero;
                    child.Position.Value = pos;
                    Vector2 size = child.Visible ? child.ScaledSize : Vector2.Zero;
                    pos.X += size.X + this.Spacing;
                    maxHeight = Math.Max(maxHeight, size.Y);
                }
                this.Size.Value = new Vector2(pos.X - this.Spacing, maxHeight);
            }
            else
            {
                Vector2 pos = Vector2.Zero;
                float maxWidth = 0.0f;
                foreach (UIComponent child in this.Children)
                {
                    child.AnchorPoint.Value = Vector2.Zero;
                    child.Position.Value = pos;
                    Vector2 size = child.Visible ? child.ScaledSize : Vector2.Zero;
                    pos.Y += size.Y + this.Spacing;
                    maxWidth = Math.Max(maxWidth, size.X);
                }
                this.Size.Value = new Vector2(maxWidth, pos.Y - this.Spacing);
            }
        }
    }
}