//// This code is part of Document Solutions for PDF .NET demos.// Copyright (c) MESCIUS inc. All rights reserved.//
using System.IO;using System.Drawing;using GrapeCity.Documents.Common;using GrapeCity.Documents.Pdf;using GrapeCity.Documents.Pdf.Layers;
namespace DsPdfWeb.Demos{    // This example shows how to search for text in certain layers only.    // The input PDF for this sample was created by LangLayers.    public class SearchInLayers    {        public int CreatePDF(Stream stream)        {            using var fs = File.OpenRead(Path.Combine("Resources", "PDFs", "lang-layers.pdf"));            var doc = new GcPdfDocument();            doc.Load(fs);
            var regex = "\\b(Windows|macOS|Linux|Mac)\\b";            // var regex = @"(?=(\W|^))(shoes|shirt|pants)(?!(\W|$))";            FindInLayer(doc, "English", regex, Color.FromArgb(100, Color.Red));            FindInLayer(doc, "French", regex, Color.FromArgb(100, Color.Blue));            FindInLayer(doc, "Russian", regex, Color.FromArgb(100, Color.Green));
            // Save the PDF:            doc.Save(stream);            return doc.Pages.Count;        }
        static void FindInLayer(GcPdfDocument doc, string layer, string text, Color highlight)        {            // Create a view state with just the specified layer visible:            var viewState = new ViewState(doc);            viewState.SetLayersUIStateExcept(false, layer);            viewState.SetLayersUIState(true, layer);
            // Create a FindTextParams using our custom view state            // so that the search is limited to the specified layer only:            var ftp = new FindTextParams(text, false, false, viewState, 72f, 72f, true, true);
            // Find all occurrences of the search text:            var finds = doc.FindText(ftp, OutputRange.All);
            // Highlight all occurrences on the specified layer only:            foreach (var find in finds)                foreach (var ql in find.Bounds)                {                    var g = doc.Pages[find.PageIndex].Graphics;                    g.BeginLayer(layer);                    doc.Pages[find.PageIndex].Graphics.FillPolygon(ql, highlight);                    g.EndLayer();                }        }    }}