Layout2D.cs

using SkiaSharp;
using System.Threading.Tasks;
using System.Xml;
using Waher.Layout.Layout2D.Model.Attributes;
using Waher.Layout.Layout2D.Model.Backgrounds;
using Waher.Layout.Layout2D.Model.Fonts;
using Waher.Layout.Layout2D.Model.Pens;
 
namespace Waher.Layout.Layout2D.Model
{
    public class Layout2D : LayoutContainer
    {
        private StringAttribute font;
        private StringAttribute pen;
        private StringAttribute background;
        private ColorAttribute textColor;
 
        public Layout2D(Layout2DDocument Document, ILayoutElement Parent)
            : base(Document, Parent)
        {
        }
 
        public override string LocalName => "Layout2D";
 
        public StringAttribute FontIdAttribute
        {
            get => this.font;
            set => this.font = value;
        }
 
        public StringAttribute PenIdAttribute
        {
            get => this.pen;
            set => this.pen = value;
        }
 
        public StringAttribute BackgroundIdAttribute
        {
            get => this.background;
            set => this.background = value;
        }
 
        public ColorAttribute TextColorAttribute
        {
            get => this.textColor;
            set => this.textColor = value;
        }
 
        public StringAttribute BackgroundColorAttribute
        {
            get => this.background;
            set => this.background = value;
        }
 
        public override Task FromXml(XmlElement Input)
        {
            this.font = new StringAttribute(Input, "font", this.Document);
            this.pen = new StringAttribute(Input, "pen", this.Document);
            this.background = new StringAttribute(Input, "background", this.Document);
            this.textColor = new ColorAttribute(Input, "textColor", this.Document);
 
            return base.FromXml(Input);
        }
 
        public override void ExportAttributes(XmlWriter Output)
        {
            base.ExportAttributes(Output);
 
            this.font?.Export(Output);
            this.pen?.Export(Output);
            this.background?.Export(Output);
            this.textColor?.Export(Output);
        }
 
        public override ILayoutElement Create(Layout2DDocument Document, ILayoutElement Parent)
        {
            return new Layout2D(Document, Parent);
        }
 
        public override void CopyContents(ILayoutElement Destination)
        {
            base.CopyContents(Destination);
 
            if (Destination is Layout2D Dest)
            {
                Dest.font = this.font?.CopyIfNotPreset(Destination.Document);
                Dest.pen = this.pen?.CopyIfNotPreset(Destination.Document);
                Dest.background = this.background?.CopyIfNotPreset(Destination.Document);
                Dest.textColor = this.textColor?.CopyIfNotPreset(Destination.Document);
            }
        }
 
        private Font fontDef = null;
        private Pen penDef = null;
        private Background backgroundDef = null;
 
        public override async Task DoMeasureDimensions(DrawingState State)
        {
            SKFont FontBak = null;
            SKPaint TextPenBak = null;
            SKPaint PenBak = null;
            SKPaint BackgroundBak = null;
 
            EvaluationResult<string> RefId = await this.font.TryEvaluate(State.Session);
            if (RefId.Ok &&
                this.Document.TryGetElement(RefId.Result, out ILayoutElement Element) &&
                Element is Font Font)
            {
                this.fontDef = Font;
 
                await Font.MeasureDimensions(State);
 
                FontBak = State.Font;
                State.Font = this.fontDef.FontDef;
 
                TextPenBak = State.TextPen;
                State.TextPen = this.fontDef.TextPen;
            }
 
            RefId = await this.pen.TryEvaluate(State.Session);
            if (RefId.Ok &&
                this.Document.TryGetElement(RefId.Result, out Element) &&
                Element is Pen Pen)
            {
                this.penDef = Pen;
                PenBak = State.ShapePen;
                State.ShapePen = Pen.Paint;
            }
 
            RefId = await this.background.TryEvaluate(State.Session);
            if (RefId.Ok &&
                this.Document.TryGetElement(RefId.Result, out Element) &&
                Element is Background Background)
            {
                this.backgroundDef = Background;
                BackgroundBak = State.ShapeFill;
                State.ShapeFill = Background.Paint;
            }
 
            await base.DoMeasureDimensions(State);
 
            if (!(FontBak is null))
                State.Font = FontBak;
 
            if (!(TextPenBak is null))
                State.TextPen = TextPenBak;
 
            if (!(PenBak is null))
                State.ShapePen = PenBak;
 
            if (!(BackgroundBak is null))
                State.ShapeFill = BackgroundBak;
        }
 
        public override void MeasurePositions(DrawingState State)
        {
            SKFont FontBak = null;
            SKPaint TextPenBak = null;
            SKPaint PenBak = null;
            SKPaint BackgroundBak = null;
 
            if (!(this.fontDef is null))
            {
                FontBak = State.Font;
                State.Font = this.fontDef.FontDef;
 
                TextPenBak = State.TextPen;
                State.TextPen = this.fontDef.TextPen;
            }
 
            if (!(this.penDef is null))
            {
                PenBak = State.ShapePen;
                State.ShapePen = this.penDef.Paint;
            }
 
            if (!(this.backgroundDef is null))
            {
                BackgroundBak = State.ShapeFill;
                State.ShapeFill = this.backgroundDef.Paint;
            }
 
            base.MeasurePositions(State);
 
            if (!(FontBak is null))
                State.Font = FontBak;
 
            if (!(TextPenBak is null))
                State.TextPen = TextPenBak;
 
            if (!(PenBak is null))
                State.ShapePen = PenBak;
 
            if (!(BackgroundBak is null))
                State.ShapeFill = BackgroundBak;
        }
 
        public override async Task Draw(DrawingState State)
        {
            SKFont FontBak = null;
            SKPaint TextPenBak = null;
            SKPaint PenBak = null;
            SKPaint BackgroundBak = null;
 
            if (!(this.fontDef is null))
            {
                FontBak = State.Font;
                State.Font = this.fontDef.FontDef;
 
                TextPenBak = State.TextPen;
                State.TextPen = this.fontDef.TextPen;
            }
 
            if (!(this.penDef is null))
            {
                PenBak = State.ShapePen;
                State.ShapePen = this.penDef.Paint;
            }
 
            if (!(this.backgroundDef is null))
            {
                BackgroundBak = State.ShapeFill;
                State.ShapeFill = this.backgroundDef.Paint;
 
                if (!(this.backgroundDef is SolidBackground))
                    State.Canvas.DrawRect(0, 0, State.AreaWidth, State.AreaHeight, State.ShapeFill);
            }
 
            await base.Draw(State);
 
            if (!(FontBak is null))
                State.Font = FontBak;
 
            if (!(TextPenBak is null))
                State.TextPen = TextPenBak;
 
            if (!(PenBak is null))
                State.ShapePen = PenBak;
 
            if (!(BackgroundBak is null))
                State.ShapeFill = BackgroundBak;
        }
 
        public override void ExportStateAttributes(XmlWriter Output)
        {
            base.ExportStateAttributes(Output);
 
            this.font?.ExportState(Output);
            this.pen?.ExportState(Output);
            this.background?.ExportState(Output);
            this.textColor?.ExportState(Output);
        }
    }
}