/// <summary>
        /// Creates a TextBoxField with calculated font size for the given rectangle
        /// </summary>
        private static TextBoxField CreateTextBoxWithCalculatedFont(string name, string text, Rect rect, double fontSize, FontBase font)
        {
            TextBoxField field = new TextBoxField(name);
       
            field.TextProperties.FontSize = Unit.DipToPoint(fontSize);
            field.TextProperties.Font = font;
            field.Value = text;

            var widget = field.Widgets.AddWidget();
            widget.Rect = rect;
            widget.Border.Width = 0;
            widget.TextProperties.FontSize = Unit.DipToPoint(fontSize); 
            widget.TextProperties.Font = font;

            return field;
        }

        /// <summary>
        /// Calculates the optimal font size for text to fit within a specific rectangle
        /// </summary>
        public static double CalculateFontSizeForRectangle(string text, Rect rect, FontBase font)
        {
            double fontSize = 0;
            Size measuredSize = new Size(0, 0);
            Size availableSize = rect.Size;
            while (measuredSize.Width<availableSize.Width && measuredSize.Height< availableSize.Height)
            {
                fontSize++;
                Block block = new Block();
                block.TextProperties.FontSize = fontSize;
                block.TextProperties.Font = font;
                block.InsertText(text);
                measuredSize = block.Measure();
            }

            return fontSize-1;
        }

            // Example: Wide textbox with calculated font size
            string wideText = "This is a wide textbox that demonstrates horizontal fitting of text content.";
            Rect wideRect = new Rect(200, 500, 400, 30);
            double wideFontSize = CalculateFontSizeForRectangle(wideText, wideRect, font);

            TextBoxField wideTextBoxField = CreateTextBoxWithCalculatedFont("WideTextBox", wideText, wideRect, wideFontSize, font);
            document.AcroForm.FormFields.Add(wideTextBoxField);
            var wideWidget = wideTextBoxField.Widgets.First();
            page.Annotations.Add(wideWidget);
            wideWidget.RecalculateContent();

using Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Streaming;
using Telerik.Windows.Documents.Fixed.Model.Editing;
using Telerik.Windows.Documents.Fixed.Model.InteractiveForms;
using Telerik.Windows.Documents.Fixed.Model;
using Telerik.Documents.Primitives;
using System.Diagnostics;
using System.Reflection.Metadata;
using Telerik.Windows.Documents.Fixed.FormatProviders.Pdf;

namespace _1681158PdfInputFields
{
    internal class Program
    {
        static void Main(string[] args)
        {
           ExportExamplePdfForm();

        }

        public static void ExportExamplePdfForm()
        {
            RadFixedDocument fixedDoc = new RadFixedDocument();
            RadFixedPage fixedPage = fixedDoc.Pages.AddPage();
            FixedContentEditor editor = new FixedContentEditor(fixedPage);
            editor.Position.Translate(100, 100);
           
            
            TextBoxField textBox = new TextBoxField("textBox");
            fixedDoc.AcroForm.FormFields.Add(textBox);
            textBox.Value = "Sample text...";
            Size widgetDimensions = new Size(200, 30); 
            DrawNextWidgetWithDescription(editor, "TextBox", (e) => e.DrawWidget(textBox, widgetDimensions));

            string fileName = "output.pdf";
            File.Delete(fileName);
            // File.WriteAllBytes(fileName, new PdfFormatProvider().Export(fixedDoc, TimeSpan.FromSeconds(15)));


            string ResultFileName = "result.pdf";
            File.Delete(ResultFileName);
            using (PdfStreamWriter writer = new PdfStreamWriter(File.OpenWrite(ResultFileName)))
            {
                foreach (RadFixedPage page in fixedDoc.Pages)
                {
                    writer.WritePage(page);
                }
            }

            ProcessStartInfo psi = new ProcessStartInfo()
            {
                FileName = ResultFileName,
                UseShellExecute = true
            };
            Process.Start(psi);

            Console.WriteLine("Document created.");

             
        }

        private static void DrawNextWidgetWithDescription(FixedContentEditor editor, string description, Action<FixedContentEditor> drawWidgetWithEditor)
        {
            double padding = 20;
            drawWidgetWithEditor(editor);

            Size annotationSize = editor.Root.Annotations[editor.Root.Annotations.Count - 1].Rect.Size;
            double x = editor.Position.Matrix.OffsetX;
            double y = editor.Position.Matrix.OffsetY;

            Block block = new Block();
            block.TextProperties.FontSize = 20;
            block.VerticalAlignment = Telerik.Windows.Documents.Fixed.Model.Editing.Flow.VerticalAlignment.Center;
            block.InsertText(description);
            editor.Position.Translate(x + annotationSize.Width + padding, y);
            editor.DrawBlock(block, new Size(editor.Root.Size.Width, annotationSize.Height));

            editor.Position.Translate(x, y + annotationSize.Height + padding);
        }
    }
}