PDF Viewer Control Without Acrobat Reader Installed

Imports System.Text.RegularExpressions
Imports System.Drawing.Imaging
Imports System.Drawing
Imports System.Windows.Forms
Imports PDFLibNet
Imports System.ComponentModel

Public Class PDFViewer
  Private mOriginalFileName
  Private mPDFFileName As String
  Private mPDFPageCount As Integer
  Private mCurrentPageNumber As Integer
  Private m_PanStartPoint As Point
  Private mBookmarks As ArrayList
  Private mAllowBookmarks As Boolean = True
  Private mUseXPDF As Boolean = True
  Private mPDFDoc As PDFLibNet.PDFWrapper
  Private FromBeginning As Boolean = True
  Private XPDFPrintingPicBox As New PictureBox
  Private mContinuousPages As Boolean = False
  Private PageInitDone As Boolean = False
  Private ScrollBarPosition As Integer = 0
  Private ScrollUnitsPerPage As Integer = 0
  Private ContinuousImages As List(Of System.Drawing.Image)
  Private mUserPassword As String = ""
  Private mOwnerPassword As String = ""
  Private mPassword As String = ""
  'Optimal render
  Private mLastPageNumber As Integer
  Private mResizeStopped As Boolean = False
  Private mResizeCheckTimer As New Timer
  Private mPDFViewerHeight As Integer
  Private mPDFViewerWidth As Integer
  Private mRotation As List(Of Integer)


  Public Property FileName() As String
    Get
      Return mOriginalFileName
    End Get
    Set(ByVal value As String)
      If Nothing = value Or value = "" Then
        Exit Property
      End If
      mOriginalFileName = value
      mUserPassword = ""
      mOwnerPassword = ""
      mPassword = ""
      Dim userPassword As String = Nothing
      If ImageUtil.IsTiff(value) Then
        'Tiff Specific behavior
        InitBottomToolbar("TIFF")
      ElseIf ImageUtil.IsPDF(value) Then
        Cursor.Current = Cursors.WaitCursor
        If iTextSharpUtil.IsEncrypted(value) Then
FileIsEncrypted:
          Dim frmPassword As New Password
          Dim result As DialogResult = frmPassword.ShowDialog()
          If result = DialogResult.OK Then
            If Not frmPassword.OwnerPassword = "" Then
              mOwnerPassword = frmPassword.OwnerPassword
              If iTextSharpUtil.IsPasswordValid(value, frmPassword.OwnerPassword) = False Then
                MsgBox("Owner password is incorrect.", MsgBoxStyle.Critical, "Incorrect Password")
                Cursor.Current = Cursors.Default
                Exit Property
              Else
                mOwnerPassword = frmPassword.OwnerPassword
                mPassword = mOwnerPassword
              End If
            End If
            If Not frmPassword.UserPassword = "" Then
              If iTextSharpUtil.IsPasswordValid(value, frmPassword.UserPassword) = False Then
                MsgBox("User password is incorrect.", MsgBoxStyle.Critical, "Incorrect Password")
                Cursor.Current = Cursors.Default
                Exit Property
              Else
                mUserPassword = frmPassword.UserPassword
                mPassword = mUserPassword
              End If
            End If
          End If
        End If
        If mUseXPDF Then
          If Not Nothing Is mPDFDoc Then
            mPDFDoc.Dispose()
          End If
          Try
            mPDFDoc = New PDFLibNet.PDFWrapper("")
            If mOwnerPassword <> "" Then
              mPDFDoc.OwnerPassword = mOwnerPassword
              mPassword = mOwnerPassword
            End If
            If mUserPassword <> "" Then
              mPDFDoc.UserPassword = mUserPassword
              mPassword = mUserPassword
            End If
            mPDFDoc.LoadPDF(value)
          Catch ex As System.Security.SecurityException
            GoTo FileIsEncrypted
          Catch ex As Exception
            If Not Nothing Is mPDFDoc Then
              mPDFDoc.Dispose()
            End If
            GoTo GhostScriptFallBack
          End Try
          InitBottomToolbar("XPDF")
        Else
GhostScriptFallBack:
          InitBottomToolbar("GS")
        End If
      Else
        Me.Enabled = False
      End If
      mPDFFileName = value
      InitViewModes()
      InitPageRange()
      InitRotation()
      InitializePageView(ViewMode.FIT_WIDTH)
      If mAllowBookmarks And ImageUtil.IsPDF(mOriginalFileName) Then
        InitBookmarks()
      Else
        HideBookmarks()
      End If
      DisplayCurrentPage()
      tscbZoom.SelectedIndex = 1
      Me.Enabled = True
      Cursor.Current = Cursors.Default
    End Set
  End Property

  'Public Property ContinuousPages() As Boolean
  '    Get
  '        Return mContinuousPages
  '    End Get
  '    Set(ByVal value As Boolean)
  '        mContinuousPages = value
  '    End Set
  'End Property

  Public Property UseXPDF() As Boolean
    Get
      Return mUseXPDF
    End Get
    Set(ByVal value As Boolean)
      mUseXPDF = value
    End Set
  End Property

  Public Property AllowBookmarks() As Boolean
    Get
      Return mAllowBookmarks
    End Get
    Set(ByVal value As Boolean)
      mAllowBookmarks = value
      If value = False Then
        HideBookmarks()
      End If
    End Set
  End Property

  Public ReadOnly Property PageCount(ByVal FileName As String)
    Get
      Return ImageUtil.GetImageFrameCount(FileName)
    End Get
  End Property

  Public ReadOnly Property Print(ByVal FileName As String)
    Get
      PrinterUtil.PrintImagesToPrinter(FileName)
      Return 1
    End Get
  End Property

  Public Sub SelectFile()
    OpenFileDialog1.Filter = "PDF or TIFF files (*.pdf;*.tif)|*.pdf;*.tif"
    OpenFileDialog1.FileName = ""
    OpenFileDialog1.Title = "Select a PDF or TIFF file to open"
    OpenFileDialog1.Multiselect = False
    OpenFileDialog1.ShowDialog()
    FileName = OpenFileDialog1.FileName
  End Sub

  Public Function OCRCurrentPage() As String
    Cursor.Current = Cursors.WaitCursor
    Dim TempFile As String = System.IO.Path.GetTempPath & Now.Ticks & ".txt"
    OCRCurrentPage = ""
    Try
      AFPDFLibUtil.ExportPDF(mPDFDoc, TempFile, mCurrentPageNumber, mCurrentPageNumber)
      OCRCurrentPage = System.IO.File.ReadAllText(TempFile)
      System.IO.File.Delete(TempFile)
      If Regex.IsMatch(OCRCurrentPage, "\w") = False Then
        GoTo OCRCurrentImage
      End If
    Catch ex As Exception
      If Regex.IsMatch(OCRCurrentPage, "\w") = False Then
        GoTo OCRCurrentImage
      End If
    End Try
    Cursor.Current = Cursors.Default
    Exit Function
OCRCurrentImage:
    Try
      OCRCurrentPage = TesseractOCR.OCRImage(FindPictureBox("SinglePicBox").Image, TesseractOCR.Language.English)
    Catch ex As Exception
      'OCR failed
    End Try
    Cursor.Current = Cursors.Default
  End Function

  Private Sub ConvertGraphicsToPDF()
    OpenFileDialog1.Filter = "Image Files(*.BMP;*.JPG;*.GIF;*.PNG;*.TIF)|*.BMP;*.JPG;*.GIF;*.PNG;*.TIF"
    OpenFileDialog1.FileName = ""
    OpenFileDialog1.Title = "Select multiple image files to convert to PDF"
    OpenFileDialog1.Multiselect = True
    If OpenFileDialog1.ShowDialog() = Windows.Forms.DialogResult.OK Then
      Dim exportOptionsDialog As New ExportImageOptions(OpenFileDialog1.FileNames)
      exportOptionsDialog.ShowDialog()
      Try
        FileName = exportOptionsDialog.SavedFileName
      Catch ex As Exception
        'do nothing
      End Try
    End If

  End Sub

  Private Sub PDFViewer_ControlRemoved(ByVal sender As Object, ByVal e As System.Windows.Forms.ControlEventArgs) Handles Me.ControlRemoved
    If Not Nothing Is mPDFDoc Then
      mPDFDoc.Dispose()
    End If
  End Sub

  Private Sub PDFViewer_Disposed(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Disposed
    If Not Nothing Is mPDFDoc Then
      mPDFDoc.Dispose()
    End If
  End Sub

  Private Sub PDFViewer_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    'Do something on control load
    HideBookmarks()
  End Sub

  Private Sub Timer1_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles Timer1.Tick
    If Me.Height = mPDFViewerHeight And Me.Width = mPDFViewerWidth Then
      If mResizeStopped = False Then
        DisplayCurrentPage()
        mResizeStopped = True
      End If
      Timer1.Enabled = False
    End If
  End Sub

  Private Sub PDFViewer_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Resize
    If PageInitDone = True Then
      CenterPicBoxInPanel(FindPictureBox("SinglePicBox"))
    End If
  End Sub

  Private Sub tsPrevious_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tsPrevious.Click
    mLastPageNumber = mCurrentPageNumber
    mCurrentPageNumber -= 1
    DisplayCurrentPage()
  End Sub

  Private Sub tsNext_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tsNext.Click
    mLastPageNumber = mCurrentPageNumber
    mCurrentPageNumber += 1
    DisplayCurrentPage()
  End Sub

  Private Sub tsZoomOut_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tsZoomOut.Click
    Dim objPictureBox As PictureBox = FindPictureBox(mCurrentPageNumber)
    ImageUtil.PictureBoxZoomOut(objPictureBox)
    objPictureBox.Refresh()
    'tscbZoom.Text = GetCurrentScalePercentage() & " %"
    DisplayCurrentPage()
  End Sub

  Private Sub tsZoomIn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tsZoomIn.Click
    'If GetCurrentScalePercentage() > 500 Then
    '  Exit Sub
    'End If
    Dim objPictureBox As PictureBox = FindPictureBox(mCurrentPageNumber)
    ImageUtil.PictureBoxZoomIn(objPictureBox)
    objPictureBox.Refresh()
    'tscbZoom.Text = GetCurrentScalePercentage() & " %"
    DisplayCurrentPage()
  End Sub

  Private Sub tsPageNum_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles tsPageNum.KeyPress
    If (Asc(e.KeyChar) = Keys.Enter) Then
      If tsPageNum.Text = "" Then
        mCurrentPageNumber = 1
      Else
        mCurrentPageNumber = tsPageNum.Text
      End If
      DisplayCurrentPage()
    Else
      e.Handled = TrapKey(Asc(e.KeyChar))
    End If
  End Sub

  Private Sub tsPageNum_Leave(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tsPageNum.Leave
    mCurrentPageNumber = tsPageNum.Text
    DisplayCurrentPage()
  End Sub

  Private Sub tscbZoom_Change(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tscbZoom.SelectedIndexChanged
    Select Case tscbZoom.Text
      Case "Fit To Screen"
        If mContinuousPages Then
          InitializePageView(ViewMode.FIT_TO_SCREEN)
        Else
          ApplyZoom(ViewMode.FIT_TO_SCREEN)
        End If
      Case "Actual Size"
        If mContinuousPages Then
          InitializePageView(ViewMode.ACTUAL_SIZE)
        Else
          ApplyZoom(ViewMode.ACTUAL_SIZE)
        End If
      Case "Fit To Width"
        If mContinuousPages Then
          InitializePageView(ViewMode.FIT_WIDTH)
        Else
          ApplyZoom(ViewMode.FIT_WIDTH)
        End If
    End Select
    CenterPicBoxInPanel(FindPictureBox("SinglePicBox"))
    DisplayCurrentPage()
  End Sub

  Private Sub tsPrint_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tsPrint.Click
    If ImageUtil.IsPDF(mOriginalFileName) Or ImageUtil.IsTiff(mOriginalFileName) Then
      PrinterUtil.PrintImagesToPrinter(mOriginalFileName)
    End If
  End Sub

  Private Sub tsRotateCC_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tsRotateCC.Click
    mRotation(mCurrentPageNumber - 1) -= 1
    ImageUtil.RotateImageCounterclockwise(FindPictureBox(mCurrentPageNumber))
  End Sub

  Private Sub tsRotateC_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tsRotateC.Click
    mRotation(mCurrentPageNumber - 1) += 1
    ImageUtil.RotateImageClockwise(FindPictureBox(mCurrentPageNumber))
  End Sub

  Private Sub tsExport_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tsExport.Click
    If ImageUtil.IsPDF(mOriginalFileName) Then
      Dim exportOptionsDialog As New ExportOptions(mPDFFileName, mPDFDoc, mPassword)
      exportOptionsDialog.ShowDialog()
    ElseIf ImageUtil.IsTiff(mOriginalFileName) Then
      Dim FileArray(0) As String
      FileArray(0) = mPDFFileName
      Dim exportOptionsDialog As New ExportImageOptions(FileArray)
      exportOptionsDialog.ShowDialog()
    End If
    Me.Focus()
  End Sub

  Private Sub tsImport_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tsImport.Click
    ConvertGraphicsToPDF()
  End Sub

#Region "Constraints"

  Private Sub CheckPageBounds()

    If mCurrentPageNumber >= mPDFPageCount Then
      mCurrentPageNumber = mPDFPageCount
      tsNext.Enabled = False
    ElseIf mCurrentPageNumber <= 1 Then
      mCurrentPageNumber = 1
      tsPrevious.Enabled = False
    End If

    If mCurrentPageNumber < mPDFPageCount And mPDFPageCount > 1 And mCurrentPageNumber > 1 Then
      tsNext.Enabled = True
      tsPrevious.Enabled = True
    End If

    If mCurrentPageNumber = mPDFPageCount And mPDFPageCount > 1 And mCurrentPageNumber > 1 Then
      tsPrevious.Enabled = True
    End If

    If mCurrentPageNumber = 1 And mPDFPageCount > 1 Then
      tsNext.Enabled = True
    End If

    If mPDFPageCount = 1 Then
      tsNext.Enabled = False
      tsPrevious.Enabled = False
    End If

  End Sub

#End Region

#Region "Helper Functions"

  Private Function GetImageFromFile(ByVal sFileName As String, ByVal iFrameNumber As Integer, Optional ByVal DPI As Integer = 0) As System.Drawing.Image
    'Cursor.Current = Cursors.WaitCursor
    GetImageFromFile = Nothing
    If mUseXPDF And ImageUtil.IsPDF(sFileName) Then 'Use AFPDFLib (XPDF)
      Try
        GetImageFromFile = AFPDFLibUtil.GetImageFromPDF(mPDFDoc, iFrameNumber + 1, DPI)
      Catch ex As Exception
        InitBottomToolbar("GS")
        GoTo GhostScriptFallBack
      End Try
    Else 'Use Ghostscript
GhostScriptFallBack:
      If ImageUtil.IsPDF(sFileName) Then 'convert one frame to a tiff for viewing
        GetImageFromFile = ConvertPDF.PDFConvert.GetPageFromPDF(sFileName, iFrameNumber + 1, DPI, mPassword)
      ElseIf ImageUtil.IsTiff(sFileName) Then
        GetImageFromFile = ImageUtil.GetFrameFromTiff(sFileName, iFrameNumber)
      End If
    End If
    ImageUtil.ApplyRotation(GetImageFromFile, mRotation(iFrameNumber))
  End Function

  Private Sub InitPageRange()
    mPDFPageCount = ImageUtil.GetImageFrameCount(mPDFFileName, mPassword)
    mCurrentPageNumber = 1
  End Sub

  Private Sub InitBookmarks()
    TreeView1.Nodes.Clear()
    Dim HasBookmarks As Boolean = False
    Try
      If mUseXPDF Then
        HasBookmarks = AFPDFLibUtil.FillTree(TreeView1, mPDFDoc)
        AddHandler TreeView1.NodeMouseClick, AddressOf AFPDFLib_NodeMouseClick
        RemoveHandler TreeView1.NodeMouseClick, AddressOf ItextSharp_NodeMouseClick
      Else
        HasBookmarks = iTextSharpUtil.BuildBookmarkTreeFromPDF(mOriginalFileName, TreeView1.Nodes, mPassword)
        AddHandler TreeView1.NodeMouseClick, AddressOf ItextSharp_NodeMouseClick
        RemoveHandler TreeView1.NodeMouseClick, AddressOf AFPDFLib_NodeMouseClick
      End If
    Catch ex As Exception
      'Some bookmark structures do not parse from XML yet.
      'TODO
    End Try
    If HasBookmarks Then
      ShowBookmarks()
      TreeView1.ExpandAll()
      TreeView1.SelectedNode = TreeView1.Nodes.Item(0)
    Else
      HideBookmarks()
    End If
  End Sub

  Private Sub InitBottomToolbar(ByVal Mode As String)
    If Mode = "TIFF" Then
      btSearch.Visible = False
      btNext.Visible = False
      tbSearchText.Visible = False
      ToolStripSeparator5.Visible = False
      tsExport.Visible = True
      tsExport.ToolTipText = "Export TIFF file to the PDF file format"
    ElseIf Mode = "GS" Then
      btSearch.Visible = False
      btNext.Visible = False
      tbSearchText.Visible = False
      ToolStripSeparator5.Visible = False
      tsExport.Visible = False
    ElseIf Mode = "XPDF" Then
      btSearch.Visible = True
      btNext.Visible = True
      tbSearchText.Visible = True
      ToolStripSeparator5.Visible = True
      tsExport.Visible = True
      tsExport.ToolTipText = "Export PDF to another file format"
    End If
  End Sub

  Private Sub HideBookmarks()
    TreeView1.Visible = False
    TableLayoutPanel1.SetColumnSpan(TreeView1, 2)
    TableLayoutPanel1.SetColumnSpan(Panel1, 2)
    TableLayoutPanel1.SetColumn(Panel1, 0)
    TableLayoutPanel1.SetColumn(TreeView1, 1)
  End Sub

  Private Sub ShowBookmarks()
    TreeView1.Visible = True
    TableLayoutPanel1.SetColumnSpan(TreeView1, 1)
    TableLayoutPanel1.SetColumnSpan(Panel1, 1)
    TableLayoutPanel1.SetColumn(Panel1, 1)
    TableLayoutPanel1.SetColumn(TreeView1, 0)
  End Sub

  Public Enum ViewMode
    FIT_TO_SCREEN
    FIT_WIDTH
    ACTUAL_SIZE
  End Enum

  Private Sub InitRotation()
    mRotation = New List(Of Integer)
    For i As Integer = 1 To mPDFPageCount
      mRotation.Add(0)
    Next
  End Sub

  Private Sub InitViewModes()
    tscbZoom.Items.Clear()
    tscbZoom.Items.Add("Fit To Screen")
    tscbZoom.Items.Add("Fit To Width")
    If ImageUtil.IsTiff(mPDFFileName) Then
      tscbZoom.Items.Add("Actual Size")
    End If
  End Sub

  Private Sub InitializePageView(Optional ByVal Mode As ViewMode = ViewMode.FIT_TO_SCREEN)
    Dim myFlowLayoutPanel As New FlowLayoutPanel
    Panel1.SuspendLayout()
    Panel1.Controls.Clear()
    If mContinuousPages Then
      myFlowLayoutPanel.Dock = DockStyle.Fill
      myFlowLayoutPanel.FlowDirection = FlowDirection.TopDown
      myFlowLayoutPanel.AutoScroll = True
      myFlowLayoutPanel.Width = Panel1.Width - 20
      myFlowLayoutPanel.Height = Panel1.Height - 20
      myFlowLayoutPanel.WrapContents = False
      AddHandler myFlowLayoutPanel.Scroll, AddressOf FlowPanel_Scroll
      For i As Integer = 1 To mPDFPageCount
        Dim ObjPictureBox As New PictureBox
        ObjPictureBox.Name = i.ToString
        ObjPictureBox.SizeMode = PictureBoxSizeMode.Zoom
        ObjPictureBox.Height = myFlowLayoutPanel.Height - 14
        ObjPictureBox.Width = myFlowLayoutPanel.Width - 14
        ObjPictureBox.Location = New Point(0, 0)
        AddHandler ObjPictureBox.MouseUp, AddressOf picImage_MouseUp
        AddHandler ObjPictureBox.MouseDown, AddressOf picImage_MouseDown
        AddHandler ObjPictureBox.MouseMove, AddressOf picImage_MouseMove
        'ObjPictureBox.Image = New System.Drawing.Bitmap(1, 1)
        'ShowImageFromFile(mPDFFileName, i - 1, ObjPictureBox)
        myFlowLayoutPanel.Controls.Add(ObjPictureBox)
      Next
      Dim EndPictureBox As New PictureBox
      EndPictureBox.Name = "0"
      EndPictureBox.Height = 1
      EndPictureBox.Width = 1
      EndPictureBox.Location = New Point(0, 0)
      myFlowLayoutPanel.Controls.Add(EndPictureBox)
      ApplyToAllPictureBoxes(myFlowLayoutPanel, Mode)
      Panel1.Controls.Add(myFlowLayoutPanel)
      ScrollUnitsPerPage = FindFlowLayoutPanel().VerticalScroll.Maximum / mPDFPageCount
    Else
      Dim objPictureBox As New PictureBox
      objPictureBox.Name = "SinglePicBox"
      Panel1.Controls.Add(objPictureBox)
      objPictureBox.SizeMode = PictureBoxSizeMode.Zoom
      objPictureBox.Dock = DockStyle.None
      objPictureBox.Height = Panel1.Height - 14
      objPictureBox.Width = Panel1.Width - 14
      objPictureBox.Location = New Point(0, 0)
      AddHandler objPictureBox.MouseUp, AddressOf picImage_MouseUp
      AddHandler objPictureBox.MouseDown, AddressOf picImage_MouseDown
      AddHandler objPictureBox.MouseMove, AddressOf picImage_MouseMove
      ApplyToAllPictureBoxes(Panel1, Mode)
    End If
    Panel1.ResumeLayout()
    PageInitDone = True
  End Sub

  Private Sub ApplyZoom(ByVal Mode As ViewMode)
    Dim oPictureBox As PictureBox = FindPictureBox("SinglePicBox")
    If Mode = ViewMode.FIT_TO_SCREEN Then
      Dim picHeight As Integer = oPictureBox.Height
      Dim picWidth As Integer = oPictureBox.Width
      Dim parentHeight As Integer = oPictureBox.Parent.ClientSize.Height - 14
      Dim parentWidth As Integer = oPictureBox.Parent.ClientSize.Width - 14
      Dim HScale As Single = parentWidth / picWidth
      Dim VScale As Single = parentHeight / picHeight
      If VScale > HScale Then
        oPictureBox.Height = picHeight * HScale
        oPictureBox.Width = picWidth * HScale
      Else
        oPictureBox.Height = picHeight * VScale
        oPictureBox.Width = picWidth * VScale
      End If
    ElseIf Mode = ViewMode.FIT_WIDTH And Not Nothing Is oPictureBox.Image Then
      oPictureBox.Width = oPictureBox.Parent.ClientSize.Width - 18
      Dim ScaleAmount As Double = (oPictureBox.Width / oPictureBox.Image.Width)
      oPictureBox.Height = CInt(oPictureBox.Image.Height * ScaleAmount)
    ElseIf Mode = ViewMode.ACTUAL_SIZE And Not Nothing Is oPictureBox.Image Then
      oPictureBox.Width = oPictureBox.Image.Width
      oPictureBox.Height = oPictureBox.Image.Height
    End If
    CenterPicBoxInPanel(FindPictureBox("SinglePicBox"))
    'tscbZoom.Text = GetCurrentScalePercentage() & " %"
  End Sub

  Private Sub MakePictureBox1To1WithImage(ByRef oPictureBox As PictureBox, Optional ByRef newImage As Drawing.Image = Nothing)

    If Not Nothing Is newImage Then
      oPictureBox.Width = newImage.Width
      oPictureBox.Height = newImage.Height
    Else
      oPictureBox.Width = oPictureBox.Image.Width
      oPictureBox.Height = oPictureBox.Image.Height
    End If

  End Sub

  Private Sub AutoRotatePicBox(ByRef oPictureBox As PictureBox, ByRef newImage As Drawing.Image)
    Dim picHeight As Integer = oPictureBox.Height
    Dim picWidth As Integer = oPictureBox.Width
    Dim imgHeight As Integer = newImage.Height
    Dim imgWidth As Integer = newImage.Width
    If (picWidth > picHeight And imgWidth < imgHeight) Or (picWidth < picHeight And imgWidth > imgHeight) Then
      oPictureBox.Width = picHeight
      oPictureBox.Height = picWidth
    End If
  End Sub

  Private Sub CenterPicBoxInPanel(ByRef oPictureBox As PictureBox)
    ImageUtil.RecalcPageLocation(oPictureBox)
  End Sub

  Private Delegate Sub ShowImage(ByVal sFileName As String, ByVal iFrameNumber As Integer, ByRef oPictureBox As PictureBox, ByVal XPDFDPI As Integer)

  Private Sub FlowPanel_Scroll(ByVal sender As Object, ByVal e As System.Windows.Forms.ScrollEventArgs)
    ScrollBarPosition = e.NewValue()
    Dim ImagesWereLoaded As Boolean = False
    For i As Integer = 0 To 1
      Dim pageNumber As Integer = (System.Math.Floor(ScrollBarPosition / ScrollUnitsPerPage) + 1) + i
      If pageNumber >= 1 And pageNumber <= mPDFPageCount Then
        If Nothing Is FindPictureBox(pageNumber).Image Then
          FindPictureBox(pageNumber).Image = GetImageFromFile(mPDFFileName, pageNumber - 1, 72)
          ImagesWereLoaded = True
          FindPictureBox(pageNumber).Refresh()
        End If
      End If
    Next
    If ImagesWereLoaded Then
      Dim lastPage As Integer = System.Math.Floor(ScrollBarPosition / ScrollUnitsPerPage) + 2
      If lastPage > mPDFPageCount Then
        lastPage = mPDFPageCount
      End If
      Dim firstPage As Integer = System.Math.Floor(ScrollBarPosition / ScrollUnitsPerPage) + 1
      If firstPage < 1 Then
        firstPage = 1
      End If
      ClearAllPictureBoxes(firstPage, lastPage)
    End If
    mCurrentPageNumber = System.Math.Floor(ScrollBarPosition / ScrollUnitsPerPage) + 1
    UpdatePageLabel()
  End Sub

  Private Sub UpdatePageLabel()
    tsPageLabel.Text = "Page " & mCurrentPageNumber & " of " & mPDFPageCount
    tsPageNum.Text = mCurrentPageNumber
  End Sub

  'Private Sub DisplayCurrentPage()
  '  CheckPageBounds()
  '  UpdatePageLabel()
  '  ShowImageFromFile(mPDFFileName, mCurrentPageNumber - 1, FindPictureBox(mCurrentPageNumber))
  '  If mContinuousPages Then
  '    FindFlowLayoutPanel().ScrollControlIntoView(FindPictureBox(mCurrentPageNumber))
  '    ClearAllPictureBoxes(mCurrentPageNumber, mCurrentPageNumber)
  '  End If
  'End Sub

  Private Sub DisplayCurrentPage()
    Dim oPict As PictureBox = FindPictureBox(mCurrentPageNumber)
    If mLastPageNumber <> mCurrentPageNumber Then
      CheckPageBounds()
      UpdatePageLabel()
      Dim newImage As Drawing.Image
      If mUseXPDF Then
        newImage = GetImageFromFile(mPDFFileName, mCurrentPageNumber - 1, AFPDFLibUtil.GetOptimalDPI(mPDFDoc, oPict))
      Else
        Dim optimalDPI As Integer = 0
        If ImageUtil.IsPDF(mPDFFileName) Then
          optimalDPI = iTextSharpUtil.GetOptimalDPI(mPDFFileName, mCurrentPageNumber, oPict, mPassword)
        End If
        newImage = GetImageFromFile(mPDFFileName, mCurrentPageNumber - 1, optimalDPI)
      End If
      If Not Nothing Is newImage Then
        AutoRotatePicBox(oPict, newImage)
        If ImageUtil.IsPDF(mPDFFileName) Then
          MakePictureBox1To1WithImage(oPict, newImage)
        End If
        CenterPicBoxInPanel(oPict)
        oPict.Image = newImage
      End If
      oPict.Refresh()
      If mContinuousPages Then
        FindFlowLayoutPanel().ScrollControlIntoView(oPict)
        ClearAllPictureBoxes(mCurrentPageNumber, mCurrentPageNumber)
      End If
      Exit Sub
    End If
    AutoRotatePicBox(oPict, oPict.Image)
    If ImageUtil.IsPDF(mPDFFileName) Then
      MakePictureBox1To1WithImage(oPict, oPict.Image)
    End If
    CenterPicBoxInPanel(oPict)
  End Sub

  'Private Function GetCurrentScalePercentage() As Integer
  '  GetCurrentScalePercentage = 0
  '  Dim objPictureBox As PictureBox = FindPictureBox("SinglePicBox")
  '  If Not Nothing Is objPictureBox.Image Then
  '    Dim OriginalWidth As Integer = objPictureBox.Image.Width
  '    Dim CurrentWidth As Integer = objPictureBox.Width
  '    GetCurrentScalePercentage = CInt((CurrentWidth / OriginalWidth) * 100)
  '  End If
  'End Function

  Private Function FindPictureBox(ByVal controlName As String) As PictureBox
    If mContinuousPages Then
      FindPictureBox = FindControl(Panel1, controlName)
    Else
      FindPictureBox = FindControl(Panel1, "SinglePicBox")
    End If
  End Function

  Public Function FindControl(ByVal container As Control, ByVal name As String) As Control
    If container.Name = name Then
      Return container
    End If

    For Each ctrl As Control In container.Controls
      Dim foundCtrl As Control = FindControl(ctrl, name)
      If foundCtrl IsNot Nothing Then
        Return foundCtrl
      End If
    Next
    Return Nothing
  End Function

  Private Sub ClearAllPictureBoxes(ByVal StartingPageNumber As Integer, ByVal EndingPageNumber As Integer)
    Dim PagesToKeep As New List(Of String)
    PagesToKeep.Add("0")
    For i As Integer = StartingPageNumber To EndingPageNumber
      PagesToKeep.Add(i.ToString)
    Next
    For Each oControl As Control In Panel1.Controls
      For Each childControl As Control In oControl.Controls
        If TypeOf childControl Is PictureBox And Not PagesToKeep.Contains(childControl.Name) Then
          CType(childControl, PictureBox).Image = Nothing
        End If
      Next
    Next
    GC.Collect()
  End Sub

  Private Sub ApplyToAllPictureBoxes(ByRef oControl As Control, ByVal Mode As ViewMode)
    Dim dummyPictureBox As New PictureBox
    Dim optimalDPI As Integer = 0
    If ImageUtil.IsPDF(mPDFFileName) Then
      If mUseXPDF Then
        optimalDPI = AFPDFLibUtil.GetOptimalDPI(mPDFDoc, dummyPictureBox)
      End If
    End If
    dummyPictureBox.Image = GetImageFromFile(mPDFFileName, mCurrentPageNumber - 1, optimalDPI)
    For Each childControl In oControl.Controls
      If TypeOf childControl Is PictureBox Then
        If Mode = ViewMode.FIT_TO_SCREEN Then
          childControl.Height = childControl.Parent.ClientSize.Height - 14
          childControl.Width = childControl.Parent.ClientSize.Width - 14
        ElseIf Mode = ViewMode.FIT_WIDTH And Not Nothing Is dummyPictureBox.Image Then
          childControl.Width = childControl.Parent.ClientSize.Width - 18
          Dim ScaleAmount As Double = (childControl.Width / dummyPictureBox.Image.Width)
          childControl.Height = CInt(dummyPictureBox.Image.Height * ScaleAmount)
        ElseIf Mode = ViewMode.ACTUAL_SIZE And Not Nothing Is dummyPictureBox.Image Then
          childControl.Width = dummyPictureBox.Image.Width
          childControl.Height = dummyPictureBox.Image.Height
        End If
      End If
    Next
    GC.Collect()
  End Sub

  Private Function FindFlowLayoutPanel() As FlowLayoutPanel
    FindFlowLayoutPanel = Nothing
    For Each oControl In Panel1.Controls
      If TypeOf oControl Is FlowLayoutPanel Then
        Return oControl
      End If
    Next
  End Function

  Private Sub FitToScreen(Optional ByVal drawPage As Boolean = False)
    If mContinuousPages Then
      InitializePageView(ViewMode.FIT_TO_SCREEN)
      DisplayCurrentPage()
    Else
      ApplyZoom(ViewMode.FIT_TO_SCREEN)
      If drawPage Then
        DisplayCurrentPage()
      End If
    End If

    UpdatePageLabel()
  End Sub

  Private Function TrapKey(ByVal KCode As String) As Boolean
    If (KCode >= 48 And KCode <= 57) Or KCode = 8 Then
      TrapKey = False
    Else
      TrapKey = True
    End If
  End Function

#End Region

#Region "XPDF specific events"

  Private Sub AFPDFLib_NodeMouseClick(ByVal sender As Object, ByVal e As TreeNodeMouseClickEventArgs)
    Dim ol As OutlineItem = DirectCast(e.Node.Tag, OutlineItem)
    If ol IsNot Nothing Then
      Dim ret As Long = ol.DoAction()
      Select Case ol.GetKind()
        Case LinkActionKind.actionGoTo, LinkActionKind.actionGoToR
          If Not mContinuousPages Then
            ScrolltoTop(CInt(ret))
          End If
          Exit Select
        Case LinkActionKind.actionLaunch
          Exit Select
        Case LinkActionKind.actionMovie
          Exit Select
        Case LinkActionKind.actionURI
          Exit Select
      End Select
      mCurrentPageNumber = mPDFDoc.CurrentPage
      DisplayCurrentPage()
    End If
  End Sub

  Private Sub ScrolltoTop(ByVal y As Integer)
    Dim dr As Point = Panel1.AutoScrollPosition
    If mPDFDoc.PageHeight > Panel1.Height Then
      dr.Y = y '* (GetCurrentScalePercentage() / 100)
    End If
    Panel1.AutoScrollPosition = dr
  End Sub

  Private Sub btSearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btSearch.Click
    Dim res As Integer = 0
    Dim searchArgs As New SearchArgs(tbSearchText.Text, True, False, True, False, False)
    res = SearchCallBack(sender, searchArgs)
  End Sub

  Private Sub btNext_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btNext.Click
    Dim res As Integer = 0
    res = SearchCallBack(sender, New SearchArgs(tbSearchText.Text, FromBeginning, False, True, True, False))
    FromBeginning = False
    If res = 0 Then
      If MessageBox.Show("No results were found. Would you like to start from the beginning?", Text, MessageBoxButtons.YesNo, MessageBoxIcon.Question) = DialogResult.Yes Then
        FromBeginning = True
        btNext_Click(Nothing, Nothing)
      End If
    End If
  End Sub

  Private Function SearchCallBack(ByVal sender As Object, ByVal e As SearchArgs) As Integer
    Cursor.Current = Cursors.WaitCursor
    Dim lFound As Integer = 0
    If mPDFDoc IsNot Nothing Then
      mPDFDoc.SearchCaseSensitive = e.Exact

      If e.FromBegin Then
        lFound = mPDFDoc.FindFirst(e.Text, If(e.WholeDoc, PDFLibNet.PDFSearchOrder.PDFSearchFromdBegin, PDFLibNet.PDFSearchOrder.PDFSearchFromCurrent), e.Up, False)
      ElseIf e.FindNext Then

        If e.Up Then
          lFound = mPDFDoc.FindPrevious(e.Text)
        Else
          lFound = mPDFDoc.FindNext(e.Text)

        End If
      Else

        lFound = mPDFDoc.FindText(e.Text, mPDFDoc.CurrentPage, (If(e.WholeDoc, PDFLibNet.PDFSearchOrder.PDFSearchFromdBegin, PDFLibNet.PDFSearchOrder.PDFSearchFromCurrent)), e.Exact, e.Up, True, _
         e.WholeDoc)
      End If
      If lFound > 0 Then

        mPDFDoc.CurrentPage = mPDFDoc.SearchResults(0).Page
        mCurrentPageNumber = mPDFDoc.CurrentPage
        DisplayCurrentPage()
        If Not mContinuousPages Then
          FocusSearchResult(mPDFDoc.SearchResults(0))
        End If
      End If
    End If
    Return lFound
    Cursor.Current = Cursors.Default
  End Function

  Private Sub FocusSearchResult(ByVal res As PDFLibNet.PDFSearchResult)
    Dim objPanel As Panel = Panel1
    Dim objPictureBox As PictureBox = FindPictureBox("SinglePicBox")
    Dim dr As Point = objPanel.AutoScrollPosition
    Dim XPercentage As Single = objPictureBox.Width / mPDFDoc.PageWidth
    Dim YPercentage As Single = objPictureBox.Height / mPDFDoc.PageHeight
    Dim WidthOffset As Integer = (objPanel.HorizontalScroll.Maximum - (mPDFDoc.PageWidth * YPercentage)) / 2
    Dim HeightOffset As Integer = (objPanel.VerticalScroll.Maximum - objPictureBox.Height) / 2
    If (mPDFDoc.PageWidth * XPercentage) > objPanel.Width Then
      dr.X = (res.Position.Left * YPercentage)
      If WidthOffset > 1 Then
        dr.X += WidthOffset
      End If
    End If
    If (mPDFDoc.PageHeight * YPercentage) > objPanel.Height Then
      dr.Y = res.Position.Top * YPercentage
      If HeightOffset > 1 Then
        dr.Y += HeightOffset
      End If
    End If

    objPanel.AutoScrollPosition = dr
  End Sub


#End Region

#Region "ITextSharp specific events"

  Private Sub ItextSharp_NodeMouseClick(ByVal sender As Object, ByVal e As TreeNodeMouseClickEventArgs)
    Dim item As iTextOutline = CType(e.Node.Tag, iTextOutline)
    If item.Page <> "" Then
      mCurrentPageNumber = Regex.Replace(item.Page, "(^\d+).+$", "$1")
      DisplayCurrentPage()
    End If
  End Sub

#End Region

#Region "Panning the image with left mouse click held down"

  Private Sub picImage_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
    'Capture the initial point 	
    Cursor = Cursors.Hand
    m_PanStartPoint = New Point(e.X, e.Y)
  End Sub

  Private Sub picImage_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
    'Capture the initial point 	
    Cursor = Cursors.Default
  End Sub

  Private Sub picImage_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
    'Verify Left Button is pressed while the mouse is moving	
    If e.Button = Windows.Forms.MouseButtons.Left Then
      'Here we get the change in coordinates.		
      Dim DeltaX As Integer = (m_PanStartPoint.X - e.X)
      Dim DeltaY As Integer = (m_PanStartPoint.Y - e.Y)
      'Then we set the new autoscroll position.		
      'ALWAYS pass positive integers to the panels autoScrollPosition method		
      sender.Parent.AutoScrollPosition = New Drawing.Point((DeltaX - sender.Parent.AutoScrollPosition.X), (DeltaY - sender.Parent.AutoScrollPosition.Y))
    End If
  End Sub

  'Private Sub MouseWheel(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseWheel
  '  Dim iClicks As Integer = e.Delta
  '  If iClicks > 0 Then
  '    ImageUtil.PictureBoxZoomOut(PictureBox1)
  '  Else
  '    ImageUtil.PictureBoxZoomIn(PictureBox1)
  '  End If
  '  ShowCurrentScalePercentage()
  'End Sub

#End Region

End Class