FindAndHighlight.vb
''
'' This code is part of Document Solutions for PDF demos.
'' Copyright (c) MESCIUS inc. All rights reserved.
''
Imports System
Imports System.IO
Imports System.Drawing
Imports GrapeCity.Documents.Pdf
Imports GrapeCity.Documents.Text
Imports GrapeCity.Documents.Pdf.Annotations
Imports GrapeCity.Documents.Common

' This example shows how to find all occurrences of a word in a PDF document
' and highlight all those occurrences using the text markup highlight annotation.
'
' The PDF used in this example was downloaded from https://www.frontiersin.org/articles/10.3389/fendo.2022.1005722/full.
Public Class FindAndHighlight
    Public Function CreatePDF(stream As Stream) As Integer
        ' Load an existing PDF:
        Dim doc = New GcPdfDocument()
        Using fs = File.OpenRead(Path.Combine("Resources", "PDFs", "fendo-13-1005722.pdf"))
            doc.Load(fs)

            ' Find all occurrences of the word "childbirths":
            Dim found = doc.FindText(New FindTextParams("childbirths", True, False), Nothing)

            ' Add a text markup annotation to highlight each occurrence:
            For Each f In found
                Dim markup = New TextMarkupAnnotation() With {
                    .Page = doc.Pages(f.PageIndex),
                    .MarkupType = TextMarkupType.Highlight,
                    .Color = Color.Yellow
                }
                Dim area As List(Of Quadrilateral) = New List(Of Quadrilateral)
                For Each b In f.Bounds
                    area.Add(b)
                Next
                markup.Area = area
            Next

            ' Done:
            doc.Save(stream)
            Return doc.Pages.Count
        End Using
    End Function
End Class