gotoPage Method

export class ViewerInitializer { 
   private callback: (viewer: lt.Document.Viewer.DocumentViewer) => void = null; 
 
   constructor(callback?: (viewer: lt.Document.Viewer.DocumentViewer) => void) { 
      this.callback = callback; 
      this.init(); 
   } 
 
   public static showServiceError = (jqXHR, statusText, errorThrown) => { 
      alert('Error returned from service. See the console for details.') 
      const serviceError = lt.Document.ServiceError.parseError(jqXHR, statusText, errorThrown); 
      console.error(serviceError); 
   } 
 
   private init = () => { 
      this.initFactory(); 
      this.testConnection(); 
   } 
 
   private initFactory = () => { 
      lt.RasterSupport.setLicenseUri('https://demo.leadtools.com/licenses/js/LEADTOOLSEVAL.txt', 'EVAL', null); 
 
      // To communicate with the DocumentsService, it must be running! 
      // Change these parameters to match the path to the service. 
      lt.Document.DocumentFactory.serviceHost = 'http://localhost:40000'; 
      lt.Document.DocumentFactory.servicePath = ''; 
      lt.Document.DocumentFactory.serviceApiPath = 'api'; 
   } 
 
   private testConnection = () => { 
      const serviceStatus = document.getElementById('serviceStatus'); 
      serviceStatus.innerHTML = 'Connecting to service: ' + lt.Document.DocumentFactory.serviceUri; 
 
      lt.Document.DocumentFactory.verifyService() 
         .done((serviceData) => { 
            serviceStatus.innerHTML = 'Service connection verified!'; 
            this.createDocumentViewer(); 
         }) 
         .fail((jqXHR, statusText, errorThrown) => { 
            serviceStatus.innerHTML = 'Service connection unavailable.'; 
            ViewerInitializer.showServiceError(jqXHR, statusText, errorThrown); 
         }); 
   } 
 
   private createDocumentViewer = () => { 
      // Initialize the user interface 
      const interactiveSelect = document.getElementById('interactiveSelect'); 
 
      const panZoomOption = document.createElement('option'); 
      panZoomOption.innerHTML = 'Pan / Zoom'; 
      panZoomOption.value = lt.Document.Viewer.DocumentViewerCommands.interactivePanZoom; 
      interactiveSelect.appendChild(panZoomOption); 
 
      const textOption = document.createElement('option'); 
      textOption.value = lt.Document.Viewer.DocumentViewerCommands.interactiveSelectText; 
      textOption.innerHTML = 'Select Text'; 
      interactiveSelect.appendChild(textOption); 
 
      let documentViewer: lt.Document.Viewer.DocumentViewer = null; 
      interactiveSelect.onchange = (e) => documentViewer.commands.run((e.target as HTMLSelectElement).value, null); 
 
      const annotationsSelect = document.getElementById('annotationsSelect'); 
 
      const annSelectOption = document.createElement('option'); 
      annSelectOption.innerHTML = 'Select Annotation'; 
      annSelectOption.value = lt.Annotations.Engine.AnnObject.selectObjectId.toString(); 
      annotationsSelect.appendChild(annSelectOption); 
 
      const annLineOption = document.createElement('option'); 
      annLineOption.innerHTML = 'Line Object'; 
      annLineOption.value = lt.Annotations.Engine.AnnObject.lineObjectId.toString(); 
      annotationsSelect.appendChild(annLineOption); 
 
      const annRectOption = document.createElement('option'); 
      annRectOption.innerHTML = 'Rectangle Object'; 
      annRectOption.value = lt.Annotations.Engine.AnnObject.rectangleObjectId.toString(); 
      annotationsSelect.appendChild(annRectOption); 
      annotationsSelect.onchange = (e) => { 
         const value = +(e.currentTarget as HTMLSelectElement).value; 
         documentViewer.annotations.automationManager.currentObjectId = value; 
      } 
 
      // Init the document viewer, pass along the panels 
      const createOptions = new lt.Document.Viewer.DocumentViewerCreateOptions(); 
      // We are not going to use elements mode in this example 
      createOptions.viewCreateOptions.useElements = false; 
      createOptions.thumbnailsCreateOptions.useElements = false; 
 
      // The middle panel for the view 
      createOptions.viewContainer = document.getElementById('viewer'); 
      // The left panel for the thumbnails 
      createOptions.thumbnailsContainer = document.getElementById('thumbnails'); 
      // The right panel is for bookmarks 
      createOptions.bookmarksContainer = document.getElementById('bookmarks'); 
      createOptions.useAnnotations = true; 
 
      // Create the document viewer 
      documentViewer = lt.Document.Viewer.DocumentViewerFactory.createDocumentViewer(createOptions); 
 
      // We prefer SVG viewing 
      documentViewer.view.preferredItemType = lt.Document.Viewer.DocumentViewerItemType.svg; 
 
      // Create html5 rendering engine 
      documentViewer.annotations.automationManager.renderingEngine = new lt.Annotations.Rendering.AnnHtml5RenderingEngine(); 
      // Initialize documentViewer annotations 
      documentViewer.annotations.initialize(); 
 
      documentViewer.annotations.automationManager.currentObjectIdChanged.add(function (sender, e) { 
         // When done drawing, the manager will return to the select object; so we need force the annotationsSelect element to return to the select object option 
         (annotationsSelect as HTMLSelectElement).value = sender.currentObjectId; 
      }); 
 
      this.loadDefaultDoc(documentViewer, interactiveSelect as HTMLSelectElement) 
   } 
 
   private loadDefaultDoc = (viewer: lt.Document.Viewer.DocumentViewer, interactiveSelect: HTMLSelectElement) => { 
      // Load a PDF document 
      const url = 'https://demo.leadtools.com/images/pdf/leadtools.pdf'; 
      lt.Document.DocumentFactory.loadFromUri(url, null) 
         .done((doc: lt.Document.LEADDocument) => { 
            const ready = () => { 
               viewer.setDocument(doc); 
               const panZoom = lt.Document.Viewer.DocumentViewerCommands.interactivePanZoom; 
               interactiveSelect.value = panZoom; 
               viewer.commands.run(panZoom, null); 
               if(this.callback) 
                  this.callback(viewer); 
            } 
 
            if (doc.isStructureSupported && !doc.structure.isParsed) 
               doc.structure.parse() 
                  .done(ready) 
                  .fail(ViewerInitializer.showServiceError); 
            else 
               ready(); 
         }) 
         .fail(ViewerInitializer.showServiceError); 
   } 
} 

import { ViewerInitializer } from "../utilities/ViewerInitializer"; 
 
export class GoToPageJSExample { 
    run = () => { 
        new ViewerInitializer(this.goTo); 
    } 
 
    goTo = (documentViewer) => { 
        const outputElement = document.getElementById("output"); 
 
        // Add a button to change the page 
        const button = document.createElement("button"); 
        outputElement.appendChild(button); 
 
        button.innerHTML = "Change Page"; 
        button.onclick = function () { 
            // Go towards the last page 
            if (documentViewer.currentPageNumber < documentViewer.pageCount) { 
                documentViewer.gotoPage(documentViewer.currentPageNumber + 1); 
            } else { 
                alert("You've reached the last page!"); 
            } 
        } 
    } 
} 

export class ViewerInitializer { 
   constructor(callback) { 
      this.callback = callback; 
      this.init(); 
   } 
 
   static showServiceError = (jqXHR, statusText, errorThrown) => { 
      alert("Error returned from service. See the console for details.") 
      const serviceError = lt.Document.ServiceError.parseError(jqXHR, statusText, errorThrown); 
      console.error(serviceError); 
   } 
 
   init = () => { 
      this.initFactory(); 
      this.testConnection(); 
   } 
 
   initFactory = () => { 
      lt.RasterSupport.setLicenseUri("https://demo.leadtools.com/licenses/js/LEADTOOLSEVAL.txt", "EVAL", null); 
 
      // To communicate with the DocumentsService, it must be running! 
      // Change these parameters to match the path to the service. 
      lt.Document.DocumentFactory.serviceHost = "http://localhost:40000"; 
      lt.Document.DocumentFactory.servicePath = ""; 
      lt.Document.DocumentFactory.serviceApiPath = "api"; 
   } 
 
   testConnection = () => { 
      const serviceStatus = document.getElementById("serviceStatus"); 
      serviceStatus.innerHTML = "Connecting to service: " + lt.Document.DocumentFactory.serviceUri; 
 
      lt.Document.DocumentFactory.verifyService() 
         .done((serviceData) => { 
            serviceStatus.innerHTML = "Service connection verified!"; 
            this.createDocumentViewer(); 
         }) 
         .fail((jqXHR, statusText, errorThrown) => { 
            serviceStatus.innerHTML = "Service connection unavailable."; 
            ViewerInitializer.showServiceError(jqXHR, statusText, errorThrown); 
         }); 
   } 
 
   createDocumentViewer = () => { 
      // Initialize the user interface 
      const interactiveSelect = document.getElementById("interactiveSelect"); 
 
      const panZoomOption = document.createElement("option"); 
      panZoomOption.innerHTML = "Pan / Zoom"; 
      panZoomOption.value = lt.Document.Viewer.DocumentViewerCommands.interactivePanZoom; 
      interactiveSelect.appendChild(panZoomOption); 
 
      const textOption = document.createElement("option"); 
      textOption.value = lt.Document.Viewer.DocumentViewerCommands.interactiveSelectText; 
      textOption.innerHTML = "Select Text"; 
      interactiveSelect.appendChild(textOption); 
 
      let documentViewer = null; 
      interactiveSelect.onchange = (e) => documentViewer.commands.run(e.target.value, null); 
 
      const annotationsSelect = document.getElementById("annotationsSelect"); 
 
      const annSelectOption = document.createElement("option"); 
      annSelectOption.innerHTML = "Select Annotation"; 
      annSelectOption.value = lt.Annotations.Engine.AnnObject.selectObjectId.toString(); 
      annotationsSelect.appendChild(annSelectOption); 
 
      const annLineOption = document.createElement("option"); 
      annLineOption.innerHTML = "Line Object"; 
      annLineOption.value = lt.Annotations.Engine.AnnObject.lineObjectId.toString(); 
      annotationsSelect.appendChild(annLineOption); 
 
      const annRectOption = document.createElement("option"); 
      annRectOption.innerHTML = "Rectangle Object"; 
      annRectOption.value = lt.Annotations.Engine.AnnObject.rectangleObjectId.toString(); 
      annotationsSelect.appendChild(annRectOption); 
      annotationsSelect.onchange = (e) => { 
         const value = +e.currentTarget.value; 
         documentViewer.annotations.automationManager.currentObjectId = value; 
      } 
 
      // Init the document viewer, pass along the panels 
      const createOptions = new lt.Document.Viewer.DocumentViewerCreateOptions(); 
      // We are not going to use elements mode in this example 
      createOptions.viewCreateOptions.useElements = false; 
      createOptions.thumbnailsCreateOptions.useElements = false; 
 
      // The middle panel for the view 
      createOptions.viewContainer = document.getElementById("viewer"); 
      // The left panel for the thumbnails 
      createOptions.thumbnailsContainer = document.getElementById("thumbnails"); 
      // The right panel is for bookmarks 
      createOptions.bookmarksContainer = document.getElementById("bookmarks"); 
      createOptions.useAnnotations = true; 
 
      // Create the document viewer 
      documentViewer = lt.Document.Viewer.DocumentViewerFactory.createDocumentViewer(createOptions); 
 
      // We prefer SVG viewing 
      documentViewer.view.preferredItemType = lt.Document.Viewer.DocumentViewerItemType.svg; 
 
      // Create html5 rendering engine 
      documentViewer.annotations.automationManager.renderingEngine = new lt.Annotations.Rendering.AnnHtml5RenderingEngine(); 
      // Initialize documentViewer annotations 
      documentViewer.annotations.initialize(); 
 
      documentViewer.annotations.automationManager.currentObjectIdChanged.add(function (sender, e) { 
         // When done drawing, the manager will return to the select object; so we need force the annotationsSelect element to return to the select object option 
         annotationsSelect.value = sender.currentObjectId; 
      }); 
 
      this.loadDefaultDoc(documentViewer, interactiveSelect) 
   } 
 
   loadDefaultDoc = (viewer, interactiveSelect) => { 
      // Load a PDF document 
      const url = "https://demo.leadtools.com/images/pdf/leadtools.pdf"; 
      lt.Document.DocumentFactory.loadFromUri(url, null) 
         .done((doc) => { 
            const ready = () => { 
               viewer.setDocument(doc); 
               const panZoom = lt.Document.Viewer.DocumentViewerCommands.interactivePanZoom; 
               interactiveSelect.value = panZoom; 
               viewer.commands.run(panZoom, null); 
               if(this.callback) 
                  this.callback(viewer); 
            } 
 
            if (doc.isStructureSupported && !doc.structure.isParsed) 
               doc.structure.parse() 
                  .done(ready) 
                  .fail(ViewerInitializer.showServiceError); 
            else 
               ready(); 
         }) 
         .fail(ViewerInitializer.showServiceError); 
   } 
} 

<!doctype html> 
<html lang="en"> 
<title>DocViewer Example | DocumentViewer</title> 
 
<head> 
   <script src="https://code.jquery.com/jquery-2.2.4.min.js" 
      integrity="sha256-BbhdlvQf/xTY9gja0Dq3HiwQF8LaCRTXxZKRutelT44=" crossorigin="anonymous"></script> 
 
   <script src="../LT/Leadtools.js"></script> 
   <script src="../LT/Leadtools.Controls.js"></script> 
   <script src="../LT/Leadtools.Annotations.Engine.js"></script> 
   <script src="../LT/Leadtools.Annotations.Designers.js"></script> 
   <script src="../LT/Leadtools.Annotations.Rendering.Javascript.js"></script> 
   <script src="../LT/Leadtools.Annotations.Automation.js"></script> 
   <script src="../LT/Leadtools.ImageProcessing.Main.js"></script> 
   <script src="../LT/Leadtools.ImageProcessing.Color.js"></script> 
   <script src="../LT/Leadtools.ImageProcessing.Core.js"></script> 
   <script src="../LT/Leadtools.ImageProcessing.Effects.js"></script> 
   <script src="../LT/Leadtools.Document.js"></script> 
   <script src="../LT/Leadtools.Document.Viewer.js"></script> 
   <link rel="stylesheet" type="text/css" href="../css/examples.css"> 
 
   <!-- All demo files are bundled and appended to the window --> 
   <script src="../bundle.js" type="text/javascript"></script> 
</head> 
 
 
<body> 
   <div class="container"> 
      <div class="toolbar"> 
         <div class="vcenter push-right"> 
            <button type="button" id="exampleButton">Run Example</button> 
         </div> 
         <div class="vcenter push-right"> 
            <label for="interactiveSelect">Interactive mode:</label> 
            <select id="interactiveSelect"></select> 
         </div> 
         <div class="vcenter push-right"> 
            <label for="annotationsSelect">Annotations objects:</label> 
            <select id="annotationsSelect"></select> 
         </div> 
         <div id="output" class="vcenter push-right"></div> 
         <div id="serviceStatus" class="vcenter push-right"></div> 
      </div> 
      <div class="docContainer"> 
         <div class="sidepanel" id="thumbnails"></div> 
         <div class="centerpanel" id="viewer"></div> 
         <div class="sidepanel" id="bookmarks"></div> 
      </div> 
   </div> 
</body> 
<script> 
   window.onload = () => { 
      const button = document.getElementById('exampleButton'); 
      button.onclick = () => { 
         const example = new window.examples.GoToPageExample(); 
         example.run(); 
      } 
   }; 
</script> 
 
</html> 

 /* 
   Remove default body styling. 
   Set the body to flex as a column; 
*/ 
body { 
   margin: 0; 
   display: flex; 
   flex-direction: column; 
} 
 
.container { 
   margin: 10px; 
   width: calc(100% - 20px); 
   height: calc(100vh - 20px); 
} 
 
.toolbar { 
   height: 5%; 
   width: 100%; 
   border-bottom: 2px solid #333; 
   flex-direction: row; 
   display: flex; 
} 
#bookmarks{ 
   overflow: hidden; 
} 
 
.vcenter { 
   margin-top: auto; 
   margin-bottom: auto; 
} 
 
.hcenter{ 
   margin-left: auto; 
   margin-right: auto; 
} 
 
.push-right{ 
   margin-left: 10px; 
} 
 
.docContainer{ 
   height: 95%; 
   width: 100%; 
   display: flex; 
   flex-direction: row; 
} 
 
.sidepanel{ 
   width: 15%; 
   height: 100%; 
} 
 
.centerpanel{ 
   width:100%; 
   height:100%; 
} 
 
 /* Styles for Elements Mode. */ 
 .lt-item, .lt-image-border { 
   /* Box Shadow (view, item, image border) */ 
   box-shadow: #333 2px 2px 5px 1px; 
 } 
 .lt-view,.lt-thumb-item { 
   /* View */ 
   margin: 5px; 
   padding: 5px; 
 } 
 .lt-item { 
   /* Item */ 
   border: 2px solid #6ecaab; 
   background-color: #b2decf; 
   padding: 10px; 
 } 
 .lt-image-border { 
   /* Image Border */ 
   border: 3px solid #444; 
   background-color: white; 
 } 
 .lt-thumb-item { 
   /* Thumbnail Item */ 
   border: 2px solid #6ecaab; 
   background-color: #b2decf; 
 } 
 .lt-thumb-item.lt-thumb-item-selected { 
   /* Selected Thumbnail Item */ 
   border: 2px solid #59b2ba; 
   background-color: #8ce1e1; 
 } 
 .lt-thumb-item-hovered { 
   /* Hovered Thumbnail Item */ 
   border: 2px solid #52b996; 
   background-color: #87c7b1; 
 } 
 .small-modal { 
   max-width: 200px; 
   width: 200px; 
 }