ImageInternal.cs

using SkiaSharp;
using System.Threading.Tasks;
using System.Xml;
using Waher.Layout.Layout2D.Model.Attributes;
using Waher.Script;
using Waher.Script.Graphs;
 
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))
                return null;
 
            if (this.Document.TryGetContent(ContentId, out object Content))
                return Content as SKImage;
 
            if (State.Session.TryGetVariable(ContentId, out Variable v))
            {
                object Obj = v.ValueObject;
 
                if (Obj is SKImage Image)
                    return Image;
 
                if (Obj is PixelInformation Pixels)
                    return Pixels.CreateBitmap();
 
                if (Obj is Graph Graph)
                {
                    Pixels = Graph.CreatePixels(State.Session);
                    return Pixels.CreateBitmap();
                }
            }
 
            return await this.Document.RaiseGetInternalImage(ContentId);
        }
 
        public override void ExportStateAttributes(XmlWriter Output)
        {
            base.ExportStateAttributes(Output);
 
            this.cid?.ExportState(Output);
        }
    }
}