Imports Bytescout.PDF

''' <summary>
''' This example demonstrates how to create invoice which can span multiple pages.
''' </summary>
Class Program

#Region "Global Declarations"

    Const HeightConsumedByTableRow As Int32 = 20

    Shared ContentHeightStart As Int32 = 100
    Shared ContentHeightEnd As Int32 = 700

    Shared HeightUtilized As Int32 = 100

    Shared _RowCounter As Int32 = 1

    Shared pdfDocument As Document
    Shared page As Page

#End Region


    Shared Sub Main()

#Region "Declarations and Implementations"

        Dim SolidPen As New SolidPen()

        Dim blackBrush As New SolidBrush(New ColorRGB(0, 0, 0))

        Dim headerFont As New Font(StandardFonts.TimesBold, 24)
        Dim headerFont2 As New Font(StandardFonts.TimesBold, 16)

        Dim contentFont_12 As New Font(StandardFonts.TimesBold, 12)
        Dim contentFont_10 As New Font(StandardFonts.Times, 10)

        ' Create New document
        pdfDocument = New Document()
        pdfDocument.RegistrationName = "demo"
        pdfDocument.RegistrationKey = "demo"

        ' If you wish to load an existing document uncomment the line below And comment the Add page section instead
        ' pdfDocument.Load(".\existing_document.pdf")

#End Region

        ' Add New page
        AddNewPage()

        ' 1. Add Content 
        page.Canvas.DrawString("COMPANY NAME", contentFont_12, blackBrush, 50, HeightUtilized)
        HeightUtilized += 20

        page.Canvas.DrawString("Address", contentFont_10, blackBrush, 50, HeightUtilized)
        page.Canvas.DrawString("DATE", contentFont_10, blackBrush, 400, HeightUtilized)
        HeightUtilized += 20

        page.Canvas.DrawString("Phone, fax", contentFont_10, blackBrush, 50, HeightUtilized)
        page.Canvas.DrawString("INVOICE #", contentFont_10, blackBrush, 400, HeightUtilized)
        HeightUtilized += 20

        page.Canvas.DrawString("E-mail", contentFont_10, blackBrush, 50, HeightUtilized)
        page.Canvas.DrawString("FOR", contentFont_10, blackBrush, 400, HeightUtilized)

        ' Add some vertical space
        HeightUtilized += 50


        ' 2. Add Table which can span multipage 
        Console.WriteLine("Enter the number of rows to add to the table:")
        Dim numberOfRows As Int32 = Convert.ToInt32(Console.ReadLine())
        DrawTable(NumberOfRows:=numberOfRows)

        ' 3. Add Signature 
        ' Check New page needed for adding signature
        If (CheckNewPageNeeded(70)) Then
            AddNewPage()
        End If

        page.Canvas.DrawString("Signature", contentFont_12, blackBrush, 400, (HeightUtilized + 57))
        page.Canvas.DrawLine(SolidPen, 450, (HeightUtilized + 70), 570, (HeightUtilized + 70))


        '4. Add Header And Footer
        For pageIndex = 0 To pdfDocument.Pages.Count - 1

            Dim curPage As Page = pdfDocument.Pages(pageIndex)

            ' Add Logo
            Dim imageLogo As Image = New Image("logo.png")
            curPage.Canvas.DrawImage(imageLogo, 20, 45, imageLogo.Width / 2, imageLogo.Height / 2)

            ' Add requisites
            curPage.Canvas.DrawString("INVOICE", headerFont, blackBrush, 450, 55)

            ' Add Page Number
            curPage.Canvas.DrawLine(SolidPen, 20, 750, 590, 750)
            curPage.Canvas.DrawString($"Page: {pageIndex + 1} of {pdfDocument.Pages.Count}", contentFont_10, blackBrush, 30, 760)

        Next

        ' Save document to file
        pdfDocument.Save("result.pdf")

        ' Cleanup 
        pdfDocument.Dispose()

        ' Open document in default PDF viewer app
        Process.Start("result.pdf")

    End Sub

    ''' <summary>
    ''' Checks whether new page is needed
    ''' </summary>
    ''' <param name="expectedHeight"></param>
    ''' <returns></returns>
    Shared Function CheckNewPageNeeded(expectedHeight As Int32) As Boolean
        Return (HeightUtilized + expectedHeight) > ContentHeightEnd
    End Function

    ''' <summary>
    ''' Adds new page, and also set height utilized
    ''' </summary>
    Shared Sub AddNewPage()
        ' Add page
        page = New Page(PaperFormat.Letter, PaperOrientation.Portrait)
        pdfDocument.Pages.Add(page)

        ' Reset Height Utilized
        HeightUtilized = ContentHeightStart
    End Sub


    ''' <summary>
    ''' Draw table
    ''' </summary>
    ''' <param name="NumberOfRows"></param>
    Shared Sub DrawTable(NumberOfRows As Int32)

        While (NumberOfRows > 0)

            ' Get number of rows can be added in current page
            Dim NumberOfRowsCanBeAddedInCurrentPage As Int32 = GetNumberOfRowsCanBeAddedInCurrentPage()

            If (NumberOfRowsCanBeAddedInCurrentPage > 0) Then
                Dim Table = GetTable(Math.Min(NumberOfRows, NumberOfRowsCanBeAddedInCurrentPage))
                page.Canvas.DrawTable(Table, 50, HeightUtilized)

                ' Update Height Utilized
                HeightUtilized += (Math.Min(NumberOfRows, NumberOfRowsCanBeAddedInCurrentPage) * HeightConsumedByTableRow)

                NumberOfRows -= Math.Min(NumberOfRows, NumberOfRowsCanBeAddedInCurrentPage)
            Else
                ' Add New page
                AddNewPage()
            End If

        End While

    End Sub


    ''' <summary>
    ''' Get Table Header with Content
    ''' </summary>
    ''' <param name="NumberOfRows"></param>
    ''' <returns></returns>
    Shared Function GetTable(NumberOfRows As Int32) As Table

        Dim fontTableHeader As Font = New Font(StandardFonts.TimesBold, 11)
        Dim fontTableRow As Font = New Font(StandardFonts.Times, 10)

        Dim Table As New Table()

        ' 1. Add Table Header 
        Table.Columns.Add(New TableColumn("Description", "Description"))
        Table.Columns(0).Width = 220
        Table.Columns(0).Font = fontTableHeader
        Table.Columns(0).TextFormat.HorizontalAlign = HorizontalAlign.Left

        Table.Columns.Add(New TableColumn("Quantity", "Quantity"))
        Table.Columns(1).Width = 80
        Table.Columns(1).Font = fontTableHeader
        Table.Columns(1).TextFormat.HorizontalAlign = HorizontalAlign.Right

        Table.Columns.Add(New TableColumn("Price", "Price"))
        Table.Columns(2).Width = 100
        Table.Columns(2).Font = fontTableHeader
        Table.Columns(2).TextFormat.HorizontalAlign = HorizontalAlign.Right

        Table.Columns.Add(New TableColumn("Amount", "Amount"))
        Table.Columns(3).Width = 120
        Table.Columns(3).Font = fontTableHeader
        Table.Columns(3).TextFormat.HorizontalAlign = HorizontalAlign.Right

        ' 2. Add Table Content 
        For index = 0 To NumberOfRows - 1

            ' Create New row And set its background color
            Dim row As TableRow = Table.NewRow()

            ' Set row header text
            row("Description").Text = $"Description For item - {_RowCounter}"
            row("Description").Font = fontTableRow
            row("Description").TextFormat.HorizontalAlign = HorizontalAlign.Left

            row("Quantity").Text = "###"
            row("Quantity").Font = fontTableRow
            row("Quantity").TextFormat.HorizontalAlign = HorizontalAlign.Right

            row("Price").Text = "$$$.$$"
            row("Price").Font = fontTableRow
            row("Price").TextFormat.HorizontalAlign = HorizontalAlign.Right

            row("Amount").Text = "$$$.$$"
            row("Amount").Font = fontTableRow
            row("Amount").TextFormat.HorizontalAlign = HorizontalAlign.Right

            ' Add the row to the table
            Table.Rows.Add(row)

            ' Increase _RowCounter
            _RowCounter += 1
        Next

        Return Table

    End Function

    ''' <summary>
    ''' Get number of rows can be added in current page
    ''' </summary>
    ''' <returns></returns>
    Shared Function GetNumberOfRowsCanBeAddedInCurrentPage() As Integer
        Return (ContentHeightEnd - HeightUtilized) / HeightConsumedByTableRow
    End Function

End Class