DocumentViewer Class

LEADTOOLS Document Viewer

Object Model

Syntax

C#
Visual Basic
Objective-C
Java
C++

public class DocumentViewer

'Declaration

Public Class DocumentViewer

'Usage

Dim instance As DocumentViewer

public ref class DocumentViewer

Remarks

The Document Viewer uses LEADTOOLS Raster and Documents support, Caching, SVG, OCR, Annotations and Image Viewer technologies to allow creating applications that can view, edit and modify any type of document on the desktop or web with minimal amount of code.

DocumentViewer is the main class used by the document viewer. It is not a control itself, instead it uses parent containers provided by the user to create the necessary UI controls. These containers are native controls in the calling platform - for example, native Control in Windows Forms and DIV elements in HTML/JavaScript.

The DocumentViewer has the following parts:

View: The part where the main content of the document is viewed. This part is not optional.
Thumbnails: The part where the thumbnail of the pages are viewer. This part is optional.
Bookmarks: The part where the bookmarks and table of content of the document is added. This part is optional.
Annotations: The part where the annotations toolbar and objects list is added. This part of optional.
Application User Interface: The rest are the UI elements of the user application and not part of the document viewer. These are typically standard menu and toolbar items that are tied to document viewer commands.

Example

This example will show to create a functional DocumentViewer in your Windows Forms application.

C#
Visual Basic
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

Imports Leadtools
Imports Leadtools.Controls
Imports Leadtools.Documents
Imports Leadtools.Documents.UI
Imports Leadtools.Codecs
Imports Leadtools.Caching
Imports Leadtools.Annotations.Core
Imports Leadtools.Forms.Ocr

<TestMethod> _
Public Sub DocumentViewer_Example()
   ' New Form to be used as our application
   Dim form As New MyForm()
   form.ShowDialog()
End Sub

Class MyForm
   Inherits Form
   Public Sub New()
      Me.Size = New Size(800, 800)
      Me.Text = "LEADTOOLS Document Viewer Example"
   End Sub

   Protected Overrides Sub OnLoad(e As EventArgs)
      If Not DesignMode Then
         ' Init OCR. This is optional and not required for the PDF document we are loading.
         ' But if image documents are loaded and text functionality is used, then we need OCR
         _ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.Advantage, False)
         _ocrEngine.Startup(Nothing, Nothing, Nothing, "C:\LEADTOOLS 19\Bin\Common\OcrAdvantageRuntime")

         Init()
      End If

      MyBase.OnLoad(e)
   End Sub

   ' Our document viewer instance
   Private _documentViewer As DocumentViewer

   ' Optional OCR engine to use in the example
   Private _ocrEngine As IOcrEngine

   Private Sub Init()
      ' Initialize the user interface
      InitUI()

      ' Init the cache. This is optional, but it can speed up viewing of large documents
      ' if not needed, remove this section
      DocumentFactory.Cache = New FileCache()

      ' Init the document viewer, pass along the panels
      Dim createOptions As New DocumentViewerCreateOptions()
      ' The middle panel for the view
      createOptions.ViewContainer = Me.Controls.Find("middlePanel", False)(0)
      ' The left panel for the thumbnails
      createOptions.ThumbnailsContainer = Me.Controls.Find("leftPanel", False)(0)
      ' The right panel is for bookmarks
      createOptions.BookmarksContainer = Me.Controls.Find("rightPanel", False)(0)
      ' Not using annotations for now
      createOptions.UseAnnotations = False

      ' Create the document viewer
      _documentViewer = DocumentViewerFactory.CreateDocumentViewer(createOptions)

      ' We prefer SVG viewing
      _documentViewer.View.PreferredItemType = DocumentViewerItemType.Svg

      ' Load a document
      Dim fileName As String = "C:\Users\Public\Documents\LEADTOOLS Images\Leadtools.pdf"
      Dim loadOptions As New LoadDocumentOptions()
      loadOptions.UseCache = Not IsNothing(DocumentFactory.Cache)
      Dim document As Document = DocumentFactory.LoadFromFile(fileName, loadOptions)

      AddHandler _documentViewer.Operation,
         Sub(sender, e)
            If e.Operation = DocumentViewerOperation.LoadingBookmarks Then
               ' Disable the bookmarks when we are loading, enable when we are done
               Dim rightPanel As Control = Me.Controls.Find("rightPanel", True)(0)
               If rightPanel.InvokeRequired Then
                  rightPanel.Invoke(DirectCast(Sub() rightPanel.Enabled = e.IsPostOperation, MethodInvoker))
               Else
                  rightPanel.Enabled = e.IsPostOperation
               End If
            End If
         End Sub

      ' If we have an OCR engine, use it
      document.Text.OcrEngine = _ocrEngine

      ' Set it in the viewer
      _documentViewer.SetDocument(document)

      ' Run pan/zoom
      Dim interactiveComboBox As ComboBox = CType(Me.Controls.Find("interactiveComboBox", True)(0), ComboBox)
      interactiveComboBox.SelectedItem = DocumentViewerCommands.InteractivePanZoom
   End Sub

   Private Sub InitUI()
      ' Add a panel on the left for the document viewer thumbnails part
      Dim leftPanel As New Panel()
      leftPanel.Name = "leftPanel"
      leftPanel.Width = 200
      leftPanel.Dock = DockStyle.Left
      leftPanel.BackColor = Color.Gray
      leftPanel.BorderStyle = BorderStyle.FixedSingle
      Me.Controls.Add(leftPanel)

      ' Add a panel to the right, this will work for the bookmarks or annotations part
      Dim rightPanel As New Panel()
      rightPanel.Name = "rightPanel"
      rightPanel.Width = 200
      rightPanel.Dock = DockStyle.Right
      rightPanel.BackColor = Color.LightBlue
      rightPanel.BorderStyle = BorderStyle.FixedSingle
      Me.Controls.Add(rightPanel)

      ' Add a panel to fill the rest, for the document viewer
      Dim middlePanel As New Panel()
      middlePanel.Name = "middlePanel"
      middlePanel.BackColor = Color.DarkGray
      middlePanel.BorderStyle = BorderStyle.None
      middlePanel.Dock = DockStyle.Fill
      Me.Controls.Add(middlePanel)

      ' Add a top panel to host our application controls
      Dim topPanel As New Panel()
      topPanel.Name = "topPanel"
      topPanel.Height = 100
      topPanel.Dock = DockStyle.Top
      topPanel.BorderStyle = BorderStyle.FixedSingle
      Me.Controls.Add(topPanel)

      middlePanel.BringToFront()

      ' Add buttons for the UI

      ' Combo box for interactive modes
      Dim interactiveComboBox As New ComboBox()
      interactiveComboBox.Name = "interactiveComboBox"
      interactiveComboBox.DropDownStyle = ComboBoxStyle.DropDownList
      ' The command names for the items so we can just run them
      interactiveComboBox.Items.Add(DocumentViewerCommands.InteractivePanZoom)
      interactiveComboBox.Items.Add(DocumentViewerCommands.InteractiveSelectText)
      AddHandler interactiveComboBox.SelectedIndexChanged,
         Sub(sender, e)
            Dim commandName As String = CType(interactiveComboBox.SelectedItem, String)
            _documentViewer.Commands.Run(commandName)
         End Sub
      topPanel.Controls.Add(interactiveComboBox)

      ' Generic label for information used by the examples
      Dim infoLabel As New Label()
      infoLabel.Name = "infoLabel"
      infoLabel.Text = "Info..."
      infoLabel.AutoSize = False
      infoLabel.Width = 400
      infoLabel.Left = interactiveComboBox.Right + 20
      topPanel.Controls.Add(infoLabel)

      Dim exampleButton As New Button()
      exampleButton.Top = interactiveComboBox.Bottom + 2
      exampleButton.Name = "exampleButton"
      exampleButton.Text = "&Example"
      AddHandler exampleButton.Click, Sub(sender, e) Example(exampleButton)
      topPanel.Controls.Add(exampleButton)
   End Sub

   Private Sub Example(exampleButton As Button)
      ' Add the example code here
      MessageBox.Show(Me, "Ready")
   End Sub
End Class

using Leadtools;
using Leadtools.Controls;
using Leadtools.Documents;
using Leadtools.Documents.UI;
using Leadtools.Codecs;
using Leadtools.Caching;
using Leadtools.Annotations.Core;
using Leadtools.Forms.Ocr;

[TestMethod]
public void DocumentViewer_Example()
{
   // New Form to be used as our application
   var form = new MyForm();
   form.ShowDialog();
}
class MyForm : Form
{
   public MyForm()
   {
      this.Size = new Size(800, 800);
      this.Text = "LEADTOOLS Document Viewer Example";
   }

   protected override void OnLoad(EventArgs e)
   {
      if (!DesignMode)
      {
         // Init OCR. This is optional and not required for the PDF document we are loading.
         // But if image documents are loaded and text functionality is used, then we need OCR
         _ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.Advantage, false);
         _ocrEngine.Startup(null, null, null, @"C:\LEADTOOLS 19\Bin\Common\OcrAdvantageRuntime");

         Init();
      }

      base.OnLoad(e);
   }

   // Our document viewer instance
   private DocumentViewer _documentViewer;

   // Optional OCR engine to use in the example
   private IOcrEngine _ocrEngine;

   private void Init()
   {
      // Initialize the user interface
      InitUI();

      // Init the cache. This is optional, but it can speed up viewing of large documents
      // if not needed, remove this section
      DocumentFactory.Cache = new FileCache();

      // Init the document viewer, pass along the panels
      var createOptions = new DocumentViewerCreateOptions
      {
         // The middle panel for the view
         ViewContainer = this.Controls.Find("middlePanel", false)[0],
         // The left panel for the thumbnails
         ThumbnailsContainer = this.Controls.Find("leftPanel", false)[0],
         // The right panel is for bookmarks
         BookmarksContainer = this.Controls.Find("rightPanel", false)[0],
         // Not using annotations for now
         UseAnnotations = false
      };

      // Create the document viewer
      _documentViewer = DocumentViewerFactory.CreateDocumentViewer(createOptions);

      // We prefer SVG viewing
      _documentViewer.View.PreferredItemType = DocumentViewerItemType.Svg;

      // Load a document
      var fileName = @"C:\Users\Public\Documents\LEADTOOLS Images\Leadtools.pdf";
      var document = DocumentFactory.LoadFromFile(
         fileName,
         new LoadDocumentOptions { UseCache = DocumentFactory.Cache != null });

      _documentViewer.Operation += (sender, e) =>
      {
         if (e.Operation == DocumentViewerOperation.LoadingBookmarks)
         {
            // Disable the bookmarks when we are loading, enable when we are done
            var rightPanel = this.Controls.Find("rightPanel", true)[0];
            if (rightPanel.InvokeRequired)
            {
               rightPanel.Invoke((MethodInvoker)delegate { rightPanel.Enabled = e.IsPostOperation; });
            }
            else
            {
               rightPanel.Enabled = e.IsPostOperation;
            }
         }
      };

      // If we have an OCR engine, use it
      document.Text.OcrEngine = _ocrEngine;

      // Set it in the viewer
      _documentViewer.SetDocument(document);

      // Run pan/zoom
      var interactiveComboBox = this.Controls.Find("interactiveComboBox", true)[0] as ComboBox;
      interactiveComboBox.SelectedItem = DocumentViewerCommands.InteractivePanZoom;
   }

   private void InitUI()
   {
      // Add a panel on the left for the document viewer thumbnails part
      var leftPanel = new Panel();
      leftPanel.Name = "leftPanel";
      leftPanel.Width = 200;
      leftPanel.Dock = DockStyle.Left;
      leftPanel.BackColor = Color.Gray;
      leftPanel.BorderStyle = BorderStyle.FixedSingle;
      this.Controls.Add(leftPanel);

      // Add a panel to the right, this will work for the bookmarks or annotations part
      var rightPanel = new Panel();
      rightPanel.Name = "rightPanel";
      rightPanel.Width = 200;
      rightPanel.Dock = DockStyle.Right;
      rightPanel.BackColor = Color.LightBlue;
      rightPanel.BorderStyle = BorderStyle.FixedSingle;
      this.Controls.Add(rightPanel);

      // Add a panel to fill the rest, for the document viewer
      var middlePanel = new Panel();
      middlePanel.Name = "middlePanel";
      middlePanel.BackColor = Color.DarkGray;
      middlePanel.BorderStyle = BorderStyle.None;
      middlePanel.Dock = DockStyle.Fill;
      this.Controls.Add(middlePanel);

      // Add a top panel to host our application controls
      var topPanel = new Panel();
      topPanel.Name = "topPanel";
      topPanel.Height = 100;
      topPanel.Dock = DockStyle.Top;
      topPanel.BorderStyle = BorderStyle.FixedSingle;
      this.Controls.Add(topPanel);

      middlePanel.BringToFront();

      // Add buttons for the UI

      // Combo box for interactive modes
      var interactiveComboBox = new ComboBox();
      interactiveComboBox.Name = "interactiveComboBox";
      interactiveComboBox.DropDownStyle = ComboBoxStyle.DropDownList;
      // The command names for the items so we can just run them
      interactiveComboBox.Items.Add(DocumentViewerCommands.InteractivePanZoom);
      interactiveComboBox.Items.Add(DocumentViewerCommands.InteractiveSelectText);
      interactiveComboBox.SelectedIndexChanged += (sender, e) =>
      {
         var commandName = interactiveComboBox.SelectedItem as string;
         _documentViewer.Commands.Run(commandName);
      };
      topPanel.Controls.Add(interactiveComboBox);

      // Generic label for information used by the examples
      var infoLabel = new Label();
      infoLabel.Name = "infoLabel";
      infoLabel.Text = "Info...";
      infoLabel.AutoSize = false;
      infoLabel.Width = 400;
      infoLabel.Left = interactiveComboBox.Right + 20;
      topPanel.Controls.Add(infoLabel);

      var exampleButton = new Button();
      exampleButton.Top = interactiveComboBox.Bottom + 2;
      exampleButton.Name = "exampleButton";
      exampleButton.Text = "&Example";
      exampleButton.Click += (sender, e) => Example(exampleButton);
      topPanel.Controls.Add(exampleButton);
   }

   private void Example(Button exampleButton)
   {
      // Add the example code here
      MessageBox.Show(this, "Ready");
   }
}

Requirements

Target Platforms

Reference

DocumentViewer Members
Leadtools.Documents.UI Namespace
Using LEADTOOLS Document Viewer
Document Viewer Commands
Document Viewer Operations
Documents Library Features
Loading Using LEADTOOLS Documents Library
Uploading Using the Documents Library
Documents Library Coordinate System
Parsing Text with the Documents Library
Barcode processing with the Documents Library
Loading Encrypted Files Using the Documents Library
Using LEADTOOLS Document Viewer