VintaSoft Imaging .NET SDK 11.0
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    PDF: Add a JavaScript calculator to a PDF interactive form
    In This Topic

    Here is an example that demonstrates how to create a calculator (a group of fields with JavaScript code) and add the calculator to an interactive form of PDF document:

    ' The project, which uses this code, must have references to the following assemblies:
    ' - Vintasoft.Imaging
    ' - Vintasoft.Imaging.Pdf
    
    ''' <summary>
    ''' Creates a PDF document with calculated interactive form field.
    ''' </summary>
    ''' <param name="filename">The filename.</param>
    Public Shared Sub CreateDocumentWithCalculatedInteractiveFormField(filename As String)
        ' create PDF document
        Using document As New Vintasoft.Imaging.Pdf.PdfDocument()
            ' create interactive form in PDF document
            document.InteractiveForm = New Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfDocumentInteractiveForm(document)
    
            ' specify that the viewer application must construct appearance streams and
            ' appearance properties for all widget annotations
            document.InteractiveForm.NeedAppearances = True
    
            ' font and font size
            Dim fontSize As Single = 12
            Dim font As Vintasoft.Imaging.Pdf.Tree.Fonts.PdfFont = document.FontManager.GetStandardFont(Vintasoft.Imaging.Pdf.Tree.Fonts.PdfStandardFontType.TimesRoman)
    
            ' create an empty page
            Dim page As New Vintasoft.Imaging.Pdf.Tree.PdfPage(document, Vintasoft.Imaging.PaperSizeKind.A4)
            ' add page to the document
            document.Pages.Add(page)
    
            Dim width As Single = 60
            Dim height As Single = 40
            ' create a rectangle that defines the object (first field) position on PDF page
            Dim rect As New System.Drawing.RectangleF((page.Size.Width - width * 5) / 2, ((page.Size.Height - height) / 3) * 2, width, height)
    
            ' open PdfGraphics on page
            Using graphics As Vintasoft.Imaging.Pdf.Drawing.PdfGraphics = page.GetGraphics()
                ' create calculator field: group of three fields
                Dim calculator As New Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormField(document, "Calculator")
                calculator.SetTextDefaultAppearance(font, fontSize * 1.5F, System.Drawing.Color.Black)
                calculator.TextQuadding = Vintasoft.Imaging.Pdf.Tree.InteractiveForms.TextQuaddingType.Centered
    
                ' create the border style
                Dim borderStyle As New Vintasoft.Imaging.Pdf.Tree.Annotations.PdfAnnotationBorderStyle(document)
                borderStyle.Style = Vintasoft.Imaging.Pdf.Tree.Annotations.PdfAnnotationBorderStyleType.Inset
                borderStyle.Width = 1
    
                ' create the appearance characteristics
                Dim appearanceCharacteristics As New Vintasoft.Imaging.Pdf.Tree.Annotations.PdfAnnotationAppearanceCharacteristics(document)
                appearanceCharacteristics.BorderColor = System.Drawing.Color.Gray
    
                ' create the left text box
                Dim textField As New Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormTextField(document, "Left", rect, "2")
                textField.DefaultValue = textField.Value
                textField.Annotation.BorderStyle = borderStyle
                textField.Annotation.AppearanceCharacteristics = appearanceCharacteristics
                ' add the left text box to the calculator
                calculator.Kids.Add(textField)
    
                ' update the rectangle that defines the object position on PDF page
                rect.X += rect.Width
    
                ' draw the symbol '+' on the page
                graphics.DrawString("+", font, fontSize * 1.5F, New Vintasoft.Imaging.Pdf.Drawing.PdfBrush(System.Drawing.Color.Black), rect, Vintasoft.Imaging.Pdf.Drawing.PdfContentAlignment.Center, _
                    False)
    
                ' update the rectangle that defines the object position on PDF page
                rect.X += rect.Width
    
                ' create the right text box
                textField = New Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormTextField(document, "Right", rect, "3")
                textField.DefaultValue = textField.Value
                textField.Annotation.BorderStyle = borderStyle
                textField.Annotation.AppearanceCharacteristics = appearanceCharacteristics
                ' add the right text box to the calculator
                calculator.Kids.Add(textField)
    
                ' update the rectangle that defines the object position on PDF page
                rect.X += rect.Width
    
                ' draw the symbol '=' on the page
                graphics.DrawString("=", font, fontSize * 1.5F, New Vintasoft.Imaging.Pdf.Drawing.PdfBrush(System.Drawing.Color.Black), rect, Vintasoft.Imaging.Pdf.Drawing.PdfContentAlignment.Center, _
                    False)
    
                ' create the calculator program written on JavaScript
                Dim javaScriptCode As New System.Text.StringBuilder()
                javaScriptCode.Append("var left = this.getField('Calculator.Left');")
                javaScriptCode.Append("var right = this.getField('Calculator.Right');")
                javaScriptCode.Append("var result = this.getField('Calculator.Result');")
                javaScriptCode.Append("result.value = left.value + right.value;")
                Dim calculatorProgram As New Vintasoft.Imaging.Pdf.Tree.PdfJavaScriptAction(document, javaScriptCode.ToString())
    
                ' update the rectangle that defines the object position on PDF page
                rect.X += rect.Width
    
                ' create the result text box
                textField = New Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormTextField(document, "Result", rect)
                textField.IsReadOnly = True
                textField.Annotation.BorderStyle = borderStyle
                textField.Annotation.AppearanceCharacteristics = appearanceCharacteristics
                ' set a program that will calculate value of result field
                textField.AdditionalActions = New Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormFieldAdditionalActions(document)
                textField.AdditionalActions.Calculate = calculatorProgram
                ' specify that calcualtor program must be executed when page is opened
                textField.Annotation.AdditionalActions.PageOpen = calculatorProgram
                ' add the result text box to the calculator
                calculator.Kids.Add(textField)
    
                ' add result field to the calculated fields (calcualtion order)
                ' of the document interactive form fields
                document.InteractiveForm.CalculationOrder = New Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormFieldList(document)
                document.InteractiveForm.CalculationOrder.Add(textField)
    
                ' add field group to the document
                document.InteractiveForm.Fields.Add(calculator)
    
                ' add annotations, associated with field group, to the page
                page.Annotations = New Vintasoft.Imaging.Pdf.Tree.Annotations.PdfAnnotationList(document)
                page.Annotations.AddRange(calculator.GetAnnotations())
    
                ' update appearance of field group
                calculator.UpdateAppearance()
            End Using
    
            ' save the document
            document.Save(filename)
        End Using
    End Sub
    
    // The project, which uses this code, must have references to the following assemblies:
    // - Vintasoft.Imaging
    // - Vintasoft.Imaging.Pdf
    
    /// <summary>
    /// Creates a PDF document with calculated interactive form field.
    /// </summary>
    /// <param name="filename">The filename.</param>
    public static void CreateDocumentWithCalculatedInteractiveFormField(string filename)
    {
        // create PDF document
        using (Vintasoft.Imaging.Pdf.PdfDocument document = new Vintasoft.Imaging.Pdf.PdfDocument())
        {
            // create interactive form in PDF document
            document.InteractiveForm = 
                new Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfDocumentInteractiveForm(document);
    
            // specify that the viewer application must construct appearance streams and
            // appearance properties for all widget annotations
            document.InteractiveForm.NeedAppearances = true;
    
            // font and font size
            float fontSize = 12;
            Vintasoft.Imaging.Pdf.Tree.Fonts.PdfFont font = 
                document.FontManager.GetStandardFont(Vintasoft.Imaging.Pdf.Tree.Fonts.PdfStandardFontType.TimesRoman);
    
            // create an empty page
            Vintasoft.Imaging.Pdf.Tree.PdfPage page = new Vintasoft.Imaging.Pdf.Tree.PdfPage(
                document, Vintasoft.Imaging.PaperSizeKind.A4);
            // add page to the document
            document.Pages.Add(page);
    
            float width = 60;
            float height = 40;
            // create a rectangle that defines the object (first field) position on PDF page
            System.Drawing.RectangleF rect = new System.Drawing.RectangleF(
                (page.Size.Width - width * 5) / 2,
                ((page.Size.Height - height) / 3) * 2,
                width, height);
    
            // open PdfGraphics on page
            using (Vintasoft.Imaging.Pdf.Drawing.PdfGraphics graphics = page.GetGraphics())
            {
                // create calculator field: group of three fields
                Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormField calculator =
                    new Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormField(document, "Calculator");
                calculator.SetTextDefaultAppearance(font, fontSize * 1.5f, System.Drawing.Color.Black);
                calculator.TextQuadding = Vintasoft.Imaging.Pdf.Tree.InteractiveForms.TextQuaddingType.Centered;
    
                // create the border style
                Vintasoft.Imaging.Pdf.Tree.Annotations.PdfAnnotationBorderStyle borderStyle = 
                    new Vintasoft.Imaging.Pdf.Tree.Annotations.PdfAnnotationBorderStyle(document);
                borderStyle.Style = Vintasoft.Imaging.Pdf.Tree.Annotations.PdfAnnotationBorderStyleType.Inset;
                borderStyle.Width = 1;
    
                // create the appearance characteristics
                Vintasoft.Imaging.Pdf.Tree.Annotations.PdfAnnotationAppearanceCharacteristics appearanceCharacteristics =
                    new Vintasoft.Imaging.Pdf.Tree.Annotations.PdfAnnotationAppearanceCharacteristics(document);
                appearanceCharacteristics.BorderColor = System.Drawing.Color.Gray;
    
                // create the left text box
                Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormTextField textField =
                    new Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormTextField(document, "Left", rect, "2");
                textField.DefaultValue = textField.Value;
                textField.Annotation.BorderStyle = borderStyle;
                textField.Annotation.AppearanceCharacteristics = appearanceCharacteristics;
                // add the left text box to the calculator
                calculator.Kids.Add(textField);
    
                // update the rectangle that defines the object position on PDF page
                rect.X += rect.Width;
    
                // draw the symbol '+' on the page
                graphics.DrawString("+", font, fontSize * 1.5f,
                    new Vintasoft.Imaging.Pdf.Drawing.PdfBrush(System.Drawing.Color.Black), rect, 
                    Vintasoft.Imaging.Pdf.Drawing.PdfContentAlignment.Center, false);
    
                // update the rectangle that defines the object position on PDF page
                rect.X += rect.Width;
    
                // create the right text box
                textField = new Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormTextField(document, "Right", rect, "3");
                textField.DefaultValue = textField.Value;
                textField.Annotation.BorderStyle = borderStyle;
                textField.Annotation.AppearanceCharacteristics = appearanceCharacteristics;
                // add the right text box to the calculator
                calculator.Kids.Add(textField);
    
                // update the rectangle that defines the object position on PDF page
                rect.X += rect.Width;
    
                // draw the symbol '=' on the page
                graphics.DrawString("=", font, fontSize * 1.5f,
                    new Vintasoft.Imaging.Pdf.Drawing.PdfBrush(System.Drawing.Color.Black), rect, 
                    Vintasoft.Imaging.Pdf.Drawing.PdfContentAlignment.Center, false);
    
                // create the calculator program written on JavaScript
                System.Text.StringBuilder javaScriptCode = new System.Text.StringBuilder();
                javaScriptCode.Append("var left = this.getField('Calculator.Left');");
                javaScriptCode.Append("var right = this.getField('Calculator.Right');");
                javaScriptCode.Append("var result = this.getField('Calculator.Result');");
                javaScriptCode.Append("result.value = left.value + right.value;");
                Vintasoft.Imaging.Pdf.Tree.PdfJavaScriptAction calculatorProgram =
                    new Vintasoft.Imaging.Pdf.Tree.PdfJavaScriptAction(document, javaScriptCode.ToString());
    
                // update the rectangle that defines the object position on PDF page
                rect.X += rect.Width;
    
                // create the result text box
                textField = new Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormTextField(document, "Result", rect);
                textField.IsReadOnly = true;
                textField.Annotation.BorderStyle = borderStyle;
                textField.Annotation.AppearanceCharacteristics = appearanceCharacteristics;
                // set a program that will calculate value of result field
                textField.AdditionalActions = 
                    new Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormFieldAdditionalActions(document);
                textField.AdditionalActions.Calculate = calculatorProgram;
                // specify that calcualtor program must be executed when page is opened
                textField.Annotation.AdditionalActions.PageOpen = calculatorProgram;
                // add the result text box to the calculator
                calculator.Kids.Add(textField);
    
                // add result field to the calculated fields (calcualtion order)
                // of the document interactive form fields
                document.InteractiveForm.CalculationOrder = 
                    new Vintasoft.Imaging.Pdf.Tree.InteractiveForms.PdfInteractiveFormFieldList(document);
                document.InteractiveForm.CalculationOrder.Add(textField);
    
                // add field group to the document
                document.InteractiveForm.Fields.Add(calculator);
    
                // add annotations, associated with field group, to the page
                page.Annotations = new Vintasoft.Imaging.Pdf.Tree.Annotations.PdfAnnotationList(document);
                page.Annotations.AddRange(calculator.GetAnnotations());
    
                // update appearance of field group
                calculator.UpdateAppearance();
            }
    
            // save the document
            document.Save(filename);
        }
    }