qamp/Qrakhen.Qamp.Editor/Controls/LineRenderer.xaml.cs

using Qrakhen.Qamp.Memory;
using System;
using System.ComponentModel;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
namespace Qrakhen.Qamp.Editor.Controls;

public partial class LineRenderer : UserControl
{
   private readonly Typeface _typeface = new(new FontFamily("Consolas"), FontStyles.Normal, FontWeights.Normal, FontStretches.Normal);
   private const double FontSize = 14;
   private const double LineHeight = 18;

   public Pen Pen { get; set; }
   public Brush Highlighter { get; set; }

   public LineRenderer()
   {
      Height = LineHeight;
      SnapsToDevicePixels = true;
      Highlighter = new SolidColorBrush(Color.FromArgb(0xff, 0x24, 0x92, 0x72));
      Pen = new Pen(Highlighter, 2);
   }

   protected override void OnRender(DrawingContext drawingContext)
   {
      base.OnRender(drawingContext);

      if (string.IsNullOrEmpty(LineBuffer.Cached))
         return;

      var formattedText = TextHelper.GetText(
         LineBuffer.Cached,
         FontSize,
         Brushes.White,
         VisualTreeHelper.GetDpi(this).PixelsPerDip
      );

      var x = Random.Shared.Next(0, LineBuffer.Tail);
      var s = new BufferSpan(x, Random.Shared.Next(x, LineBuffer.Tail));
      Selection = s;

      var highlighter = TextHelper.GetText(
         new string(' ', Selection.Start) + new string('█', Selection.End - Selection.Start),
         FontSize,
         Highlighter,
         VisualTreeHelper.GetDpi(this).PixelsPerDip
      );

      drawingContext.DrawText(highlighter, new Point(2, 0));
      drawingContext.DrawText(formattedText, new Point(2, 0));
   }

   public static readonly DependencyProperty LineBufferProperty =
        DependencyProperty.Register(
            nameof(LineBuffer),
            typeof(LineBuffer),
            typeof(LineRenderer),
            new FrameworkPropertyMetadata(null, OnLineBufferChanged));

   public LineBuffer LineBuffer {
      get => (LineBuffer)GetValue(LineBufferProperty);
      set => SetValue(LineBufferProperty, value);
   }

   private static void OnLineBufferChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
   {
      if (d is LineRenderer renderer) {
         if (e.OldValue is LineBuffer oldBuffer && oldBuffer != null) {
            oldBuffer.PropertyChanged -= renderer.OnLineBufferPropertyChanged;
         }

         if (e.NewValue is LineBuffer newBuffer && newBuffer != null) {
            newBuffer.PropertyChanged += renderer.OnLineBufferPropertyChanged;
         }

         renderer.InvalidateVisual();
      }
   }

   private void OnLineBufferPropertyChanged(object? sender, PropertyChangedEventArgs e)
   {
      if (e.PropertyName == nameof(LineBuffer.Cached))
         InvalidateVisual();
   }



   public static readonly DependencyProperty SelectionProperty =
        DependencyProperty.Register(
            nameof(Selection),
            typeof(BufferSpan),
            typeof(LineRenderer),
            new FrameworkPropertyMetadata(BufferSpan.None, OnSelectionChanged));

   public BufferSpan Selection {
      get => (BufferSpan)GetValue(SelectionProperty);
      set => SetValue(SelectionProperty, value);
   }

   private static void OnSelectionChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
   {
      if (d is LineRenderer renderer) {
         if (e.OldValue is LineBuffer oldBuffer && oldBuffer != null) {
            oldBuffer.PropertyChanged -= renderer.OnLineBufferPropertyChanged;
         }

         if (e.NewValue is LineBuffer newBuffer && newBuffer != null) {
            newBuffer.PropertyChanged += renderer.OnLineBufferPropertyChanged;
         }

         renderer.InvalidateVisual();
      }
   }

}