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

using Avalonia;
using Avalonia.Controls;
using Avalonia.Controls.Platform;
using Avalonia.Controls.Shapes;
using Avalonia.Layout;
using Avalonia.Media;
using Avalonia.Media.TextFormatting;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace InABox.Avalonia.Components.ImageEditing;

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

    public Point Point { get; set; }

    public Size Size { get; set; }

    public string Text { get; set; } = "";

    private TextBlock Control = new();

    public Control GetControl() => Control;

    public void Update()
    {
        Canvas.SetLeft(Control, Point.X);
        Canvas.SetTop(Control, Point.Y);

        var font = new Typeface(Control.FontFamily);

        var formatted = new FormattedText(Text, CultureInfo.CurrentCulture, FlowDirection.LeftToRight, font, 12, PrimaryBrush);

        var width = formatted.WidthIncludingTrailingWhitespace;
        var height = formatted.Height;

        if(Size.Width == 0)
        {
            Size = Size.WithWidth(width);
        }
        if(Size.Height == 0)
        {
            Size = Size.WithHeight(height);
        }

        var scaleFactor = Math.Min(Size.Width / width, Size.Height / height);

        Control.FontSize = 12 * scaleFactor;
        Control.Text = Text;
        Control.Foreground = PrimaryBrush;
    }

    public void SetActive(bool active)
    {
    }
}