inabox/InABox.Avalonia/Components/ImageEditor/Objects/SelectionObject.cs

using Avalonia;
using Avalonia.Controls;
using Avalonia.Controls.Shapes;
using Avalonia.Media;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace InABox.Avalonia.Components.ImageEditing;

internal class SelectionObject : IImageEditorObject
{
    public IBrush? PrimaryBrush { get; set; }

    public Point Point1 { get; set; }

    public Point Point2 { get; set; }

    private Rectangle Control = new();

    public Control GetControl() => Control;

    public Point GetTopLeft()
    {
        return new(
            Math.Min(Point1.X, Point2.X),
            Math.Min(Point1.Y, Point2.Y));
    }
    public Size GetSize()
    {
        return new(
            Math.Abs(Point2.X - Point1.X),
            Math.Abs(Point2.Y - Point1.Y));
    }

    public void Update()
    {
        Control.Stroke = GetBrush();
        Control.StrokeThickness = 5;
        Control.StrokeDashArray = [2, 2];

        var topLeft = GetTopLeft();
        var size = GetSize();

        Canvas.SetLeft(Control, topLeft.X);
        Canvas.SetTop(Control, topLeft.Y);
        Control.Width = size.Width;
        Control.Height = size.Height;
    }

    private IBrush? GetBrush()
    {
        var brush = new VisualBrush
        {
            TileMode = TileMode.Tile,
            DestinationRect = new(0, 0, 4, 4, RelativeUnit.Absolute)
        };
        var canvas = new Canvas
        {
            Width = 10,
            Height = 10
        };
        var rect1 = new Rectangle { Width = 5, Height = 5 };
        var rect2 = new Rectangle { Width = 5, Height = 5 };
        var rect3 = new Rectangle { Width = 5, Height = 5 };
        var rect4 = new Rectangle { Width = 5, Height = 5 };

        Canvas.SetLeft(rect2, 5);
        Canvas.SetTop(rect2, 0);

        Canvas.SetLeft(rect3, 5);
        Canvas.SetTop(rect3, 5);

        Canvas.SetLeft(rect4, 0);
        Canvas.SetTop(rect4, 5);

        rect1.Fill = new SolidColorBrush(Colors.White);
        rect2.Fill = new SolidColorBrush(Colors.Black);
        rect3.Fill = new SolidColorBrush(Colors.White);
        rect4.Fill = new SolidColorBrush(Colors.Black);

        canvas.Children.Add(rect1);
        canvas.Children.Add(rect2);
        canvas.Children.Add(rect3);

        brush.Visual = canvas;
        return brush;
    }

    public void SetActive(bool active)
    {
    }
}