Grid.cs

using System.Threading.Tasks;
using System.Xml;
using Waher.Layout.Layout2D.Model.Attributes;
 
namespace Waher.Layout.Layout2D.Model.Groups
{
    public class Grid : SpatialDistribution
    {
        private PositiveIntegerAttribute columns;
 
        public Grid(Layout2DDocument Document, ILayoutElement Parent)
            : base(Document, Parent)
        {
        }
 
        public override string LocalName => "Grid";
 
        public PositiveIntegerAttribute ColumnsAttribute
        {
            get => this.columns;
            set => this.columns = value;
        }
 
        public override Task FromXml(XmlElement Input)
        {
            this.columns = new PositiveIntegerAttribute(Input, "columns", this.Document);
            return base.FromXml(Input);
        }
 
        public override void ExportAttributes(XmlWriter Output)
        {
            base.ExportAttributes(Output);
 
            this.columns?.Export(Output);
        }
 
        public override ILayoutElement Create(Layout2DDocument Document, ILayoutElement Parent)
        {
            return new Grid(Document, Parent);
        }
 
        public override void CopyContents(ILayoutElement Destination)
        {
            base.CopyContents(Destination);
 
            if (Destination is Grid Dest)
                Dest.columns = this.columns?.CopyIfNotPreset(Destination.Document);
        }
 
        public override async Task<ICellLayout> GetCellLayout(DrawingState State)
        {
            int NrColumns = await this.columns.Evaluate(State.Session, 1);
 
            return new GridCells(State.Session, NrColumns);
        }
 
        public override void ExportStateAttributes(XmlWriter Output)
        {
            base.ExportStateAttributes(Output);
 
            this.columns?.ExportState(Output);
        }
 
    }
}