ImageInternal.cs

using System.Threading.Tasks;
using System.Xml;
using SkiaSharp;
using Waher.Layout.Layout2D.Model.Attributes;
 
namespace Waher.Layout.Layout2D.Model.Images
{
    public class ImageInternal : Image
    {
        private StringAttribute cid;
 
        public ImageInternal(Layout2DDocument Document, ILayoutElement Parent)
            : base(Document, Parent)
        {
        }
 
        public override string LocalName => "ImageInternal";
 
        public StringAttribute CidAttribute
        {
            get => this.cid;
            set => this.cid = value;
        }
 
        public override Task FromXml(XmlElement Input)
        {
            this.cid = new StringAttribute(Input, "cid", this.Document);
            return base.FromXml(Input);
        }
 
        public override void ExportAttributes(XmlWriter Output)
        {
            base.ExportAttributes(Output);
 
            this.cid?.Export(Output);
        }
 
        public override ILayoutElement Create(Layout2DDocument Document, ILayoutElement Parent)
        {
            return new ImageInternal(Document, Parent);
        }
 
        public override void CopyContents(ILayoutElement Destination)
        {
            base.CopyContents(Destination);
 
            if (Destination is ImageInternal Dest)
                Dest.cid = this.cid?.CopyIfNotPreset(Destination.Document);
        }
 
        protected override async Task<SKImage> LoadImage(DrawingState State)
        {
            string ContentId = await this.cid.Evaluate(State.Session, string.Empty);
            if (!string.IsNullOrEmpty(ContentId) &&
                this.Document.TryGetContent(ContentId, out object Content) &&
                Content is SKImage Image)
            {
                return Image;
            }
            else
                return null;
        }
 
        public override void ExportStateAttributes(XmlWriter Output)
        {
            base.ExportStateAttributes(Output);
 
            this.cid?.ExportState(Output);
        }
    }
}