''' <summary>
''' Sets the PdfTextMarkupTool as current tool of specified image viewer.
''' </summary>
''' <param name="imageViewer">The image viewer.</param>
Public Shared Sub SetPdfTextMarkupTool(imageViewer As Vintasoft.Imaging.UI.ImageViewer)
    ' create an instance of the PdfTextMarkupTool class
    Dim textMarkupTool As New Vintasoft.Imaging.Pdf.UI.PdfTextMarkupTool()

    ' set text markup mode to "Highlight"
    textMarkupTool.MarkupMode = Vintasoft.Imaging.Pdf.UI.PdfTextMarkupToolMode.Highlight

    ' set color of markup annotation to "Orange"
    textMarkupTool.HighlightColor = System.Drawing.Color.Orange

    ' subscribe to the MarkupAnnotationCreated event
    AddHandler textMarkupTool.MarkupAnnotationCreated, AddressOf TextMarkupTool_MarkupAnnotationCreated

    ' get TextSelectionTool from image viewer
    Dim textSelectionTool As Vintasoft.Imaging.UI.VisualTools.TextSelectionTool = GetTextSelectionTool(imageViewer)

    ' set the PdfTextMarkupTool+TextSelectionTool as visual tool of the image viewer
    imageViewer.VisualTool = New Vintasoft.Imaging.UI.VisualTools.CompositeVisualTool(textMarkupTool, textSelectionTool)
End Sub

''' <summary>
''' Returns the text selection tool for specified image viewer.
''' </summary>
''' <param name="imageViewer">The image viewer.</param>
''' <returns>The text selection tool.</returns>
Private Shared Function GetTextSelectionTool(imageViewer As Vintasoft.Imaging.UI.ImageViewer) As Vintasoft.Imaging.UI.VisualTools.TextSelectionTool
    ' search a TextSelectionTool in visual tools of the image viewer
    Dim textSelectionTool As Vintasoft.Imaging.UI.VisualTools.TextSelectionTool = Vintasoft.Imaging.UI.VisualTools.VisualTool.FindVisualTool(Of Vintasoft.Imaging.UI.VisualTools.TextSelectionTool)(imageViewer.VisualTool)
    If textSelectionTool IsNot Nothing Then
        Return textSelectionTool
    End If

    ' create an instance of text selection tool
    Return New Vintasoft.Imaging.UI.VisualTools.TextSelectionTool()
End Function

''' <summary>
''' Handles the MarkupAnnotationCreated event of the PdfTextMarkupTool visual tool.
''' </summary>
Private Shared Sub TextMarkupTool_MarkupAnnotationCreated(sender As Object, e As Vintasoft.Imaging.Pdf.UI.PdfMarkupAnnotationEventArgs)
    ' set user name as title of text markup annotation
    e.MarkupAnnotation.Title = System.Environment.UserName
End Sub

/// <summary>
/// Sets the PdfTextMarkupTool as current tool of specified image viewer.
/// </summary>
/// <param name="imageViewer">The image viewer.</param>
public static void SetPdfTextMarkupTool(Vintasoft.Imaging.UI.ImageViewer imageViewer)
{
    // create an instance of the PdfTextMarkupTool class
    Vintasoft.Imaging.Pdf.UI.PdfTextMarkupTool textMarkupTool = new Vintasoft.Imaging.Pdf.UI.PdfTextMarkupTool();

    // set text markup mode to "Highlight"
    textMarkupTool.MarkupMode = Vintasoft.Imaging.Pdf.UI.PdfTextMarkupToolMode.Highlight;

    // set color of markup annotation to "Orange"
    textMarkupTool.HighlightColor = System.Drawing.Color.Orange;

    // subscribe to the MarkupAnnotationCreated event
    textMarkupTool.MarkupAnnotationCreated += TextMarkupTool_MarkupAnnotationCreated;

    // get TextSelectionTool from image viewer
    Vintasoft.Imaging.UI.VisualTools.TextSelectionTool textSelectionTool = GetTextSelectionTool(imageViewer);

    // set the PdfTextMarkupTool+TextSelectionTool as visual tool of the image viewer
    imageViewer.VisualTool = new Vintasoft.Imaging.UI.VisualTools.CompositeVisualTool(textMarkupTool, textSelectionTool);
}

/// <summary>
/// Returns the text selection tool for specified image viewer.
/// </summary>
/// <param name="imageViewer">The image viewer.</param>
/// <returns>The text selection tool.</returns>
private static Vintasoft.Imaging.UI.VisualTools.TextSelectionTool GetTextSelectionTool(Vintasoft.Imaging.UI.ImageViewer imageViewer)
{
    // search a TextSelectionTool in visual tools of the image viewer
    Vintasoft.Imaging.UI.VisualTools.TextSelectionTool textSelectionTool =
        Vintasoft.Imaging.UI.VisualTools.VisualTool.FindVisualTool<Vintasoft.Imaging.UI.VisualTools.TextSelectionTool>(imageViewer.VisualTool);
    if (textSelectionTool != null)
        return textSelectionTool;

    // create an instance of text selection tool
    return new Vintasoft.Imaging.UI.VisualTools.TextSelectionTool();
}

/// <summary>
/// Handles the MarkupAnnotationCreated event of the PdfTextMarkupTool visual tool.
/// </summary>
private static void TextMarkupTool_MarkupAnnotationCreated(object sender, Vintasoft.Imaging.Pdf.UI.PdfMarkupAnnotationEventArgs e)
{
    // set user name as title of text markup annotation
    e.MarkupAnnotation.Title = System.Environment.UserName;
}