stable

src/Kniip/Editor/Annotations/HighlightAnnotation.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Windows;
+using System.Windows.Media;
+
+namespace Kniip.Editor.Annotations;
+
+/// <summary>Markeerstift: half-transparant, als rechte horizontale streep of uit de vrije hand.</summary>
+public sealed class HighlightAnnotation : Annotation
+{
+    private const byte HighlightAlpha = 110;
+
+    public List<Point> Points { get; set; } = new();
+
+    public bool Straight { get; set; }
+
+    public override ToolKind Kind => ToolKind.Highlight;
+
+    public override Rect Bounds
+    {
+        get
+        {
+            if (Points.Count == 0)
+            {
+                return Rect.Empty;
+            }
+
+            double minX = Points.Min(p => p.X), maxX = Points.Max(p => p.X);
+            double minY = Points.Min(p => p.Y), maxY = Points.Max(p => p.Y);
+            var r = new Rect(new Point(minX, minY), new Point(maxX, maxY));
+            r.Inflate(Style.Thickness / 2, Style.Thickness / 2);
+            return r;
+        }
+    }
+
+    public override bool IsDegenerate
+    {
+        get
+        {
+            if (Points.Count < 2)
+            {
+                return true;
+            }
+
+            Rect r = Bounds;
+            return r.Width - Style.Thickness < 3 && r.Height - Style.Thickness < 3;
+        }
+    }
+
+    public override void Render(DrawingContext dc, EditorDocument document)
+    {
+        if (Points.Count < 2)
+        {
+            return;
+        }
+
+        Color c = Style.Stroke;
+        var color = Color.FromArgb(HighlightAlpha, c.R, c.G, c.B);
+        Pen? pen = RenderHelpers.CreatePen(color, Style.Thickness, LineDash.Solid,
+            Straight ? PenLineCap.Square : PenLineCap.Round);
+        if (pen == null)
+        {
+            return;
+        }
+
+        // Eén geometrie, zodat overlappende delen niet dubbel zo donker worden.
+        var geometry = new StreamGeometry();
+        using (StreamGeometryContext ctx = geometry.Open())
+        {
+            ctx.BeginFigure(Points[0], false, false);
+            ctx.PolyLineTo(Points.Skip(1).ToList(), true, true);
+        }
+
+        geometry.Freeze();
+        dc.DrawGeometry(null, pen, geometry);
+    }
+
+    public override bool HitTest(Point point, double tolerance)
+    {
+        double limit = tolerance + Style.Thickness / 2;
+        for (int i = 1; i < Points.Count; i++)
+        {
+            if (RenderHelpers.DistanceToSegment(point, Points[i - 1], Points[i]) <= limit)
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    public override void Move(Vector delta)
+    {
+        for (int i = 0; i < Points.Count; i++)
+        {
+            Points[i] += delta;
+        }
+    }
+
+    public override IReadOnlyList<Point> GetHandles() =>
+        Straight && Points.Count == 2 ? new[] { Points[0], Points[1] } : Array.Empty<Point>();
+
+    public override void MoveHandle(int index, Point point, bool constrain)
+    {
+        if (!Straight || Points.Count != 2)
+        {
+            return;
+        }
+
+        Points[index] = new Point(point.X, Points[1 - index].Y);
+    }
+
+    public override Annotation Clone()
+    {
+        var clone = (HighlightAnnotation)base.Clone();
+        clone.Points = new List<Point>(Points);
+        return clone;
+    }
+}