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Work with Automated Annotations - HTML5 JavaScript

This tutorial shows how to create a JavaScript application that works with LEADTOOLS Automated Annotations.

Overview
Summary	This tutorial covers how to use automated annotations.
Completion Time	20 minutes
Visual Studio Project	Download tutorial project (1 MB)
Platform	JS Web Application
IDE	Visual Studio Code - Client
Development License	Download LEADTOOLS

Required Knowledge

Get familiar with the basic steps of creating a project and loading files inside the HTML5/JS Image Viewer by reviewing the Add References and Set a License - HTML5 JavaScript and Display Images in an Image Viewer - HTML5 JavaScript tutorials, before working on the Work with Automated Annotations - HTML5 JavaScript tutorial.

This tutorial makes use of http-server, a console command for running a static file server. To install http-server first install Node.js and then install http-server.

Create the Project and Add LEADTOOLS References

Create a project folder that contains the following:

index.html file
app.js file
lib folder
LEADTOOLS folder

The references needed depend upon the purpose of the project. This tutorial requires the following JS files, which can be found here: <INSTALL_DIR>\LEADTOOLS23\Bin\JS

Leadtools.js
Leadtools.Controls.js
Leadtools.Annotations.Engine
Leadtools.Annotations.Rendering.JavaScript.js
Leadtools.Annotations.Designers.js
Leadtools.Annotations.Automation.js
Leadtools.Demos.js
Leadtools.Demos.Annotations.js

Make sure to copy these files to the lib folder and to import them in the index.html file.

Note

The Leadtools.Demos.js and Leadtools.Demos.Annotations.js libraries are in this directory: <INSTALL_DIR>\LEADTOOLS23\Bin\JS\DemoLibraries\.

Set the License File

The License unlocks the features needed for the project. It must be set before any toolkit function is called. For details including tutorials for different platforms, refer to Setting a Runtime License.

There are two types of runtime licenses:

Evaluation license, obtained at the time the evaluation toolkit is downloaded. It allows the toolkit to be evaluated.
Deployment license. If a Deployment license file and developer key are needed, refer to Obtaining a License.

Default Annotation Resources

The annotation framework allows the user to define the images to be used for various annotations (stamps, point, lock, and hotspot). A default set of images for these objects is included with the toolkit. For this tutorial, we will use the default images here: <INSTALL_DIR>\LEADTOOLS23\Examples\Annotation\JS\AnnotationsDemo\site\Resources.

In order to make these objects available to your application, copy the Resources directory to the project folder.

Start with the HTML File

With the project created, dependencies and resources added, license set, and the display an image code added, coding can begin.

Open the index.html file located in the project folder and add the following lines in the <head> tag:

<head> 
    <meta charset="UTF-8" /> 
    <meta name="viewport" content="width=device-width, initial-scale=1.0" /> 
    <title>LEADTOOLS Demo</title> 
    <script type="text/javascript" src="./lib/Leadtools.js"></script> 
    <script type="text/javascript" src="./lib/Leadtools.Controls.js"></script> 
    <script type="text/javascript" src="./lib/Leadtools.Annotations.Engine.js"></script> 
    <script type="text/javascript" src="./lib/Leadtools.Annotations.Rendering.JavaScript.js"></script> 
    <script type="text/javascript" src="./lib/Leadtools.Annotations.Designers.js"></script> 
    <script type="text/javascript" src="./lib/Leadtools.Annotations.Automation.js"></script> 
    <script type="text/javascript" src="./lib/Leadtools.Demos.js"></script> 
    <script type="text/javascript" src="./lib/Leadtools.Demos.Annotations.js"></script> 
    <script type="text/javascript" src="./app.js"></script> 
</head>

This will attach the LEADTOOLS dependencies to the index.html page.

Then add the following <select> elements to the body of the index.html:

<body> 
    <!-- DIV to use as the container for the LEADTOOLS image viewer --> 
    <div id="imageViewerDiv" style="width: 600px; height: 600px; background-color: darkgray"></div> 
    <label for="currentObject">Annotation Object:</label> 
    <select id="currentObject"></select> 
    <label for="userMode">User mode:</label> 
    <select id="userMode"> 
        <option>Design</option> 
        <option>Run</option> 
    </select> 
</body>

These options will be used to select the current user-mode, and the various types of annotation objects.

Update the JavaScript File

To set up the automation manager and the automation object for the application, open the app.js file and replace its contents with the following code:

window.onload = function () { 
    const licenseUrl = "https://demo.leadtools.com/licenses/js/LEADTOOLSEVAL.txt"; 
    const developerKey = "EVAL"; 
    lt.RasterSupport.setLicenseUri(licenseUrl, developerKey, function (setLicenseResult) { 
        // Check the status of the license 
        if (setLicenseResult.result) { 
            console.log("LEADTOOLS client license set successfully"); 
        } else { 
            const msg = "LEADTOOLS License is missing, invalid or expired\nError:\n"; 
            console.log(msg); 
            alert(msg); 
        } 
    }); 
    // Get the container DIV 
    const imageViewerDiv = document.getElementById("imageViewerDiv"); 
    // Create the image viewer inside it 
    const createOptions = new lt.Controls.ImageViewerCreateOptions(imageViewerDiv); 
    const imageViewer = new lt.Controls.ImageViewer(createOptions); 
    // Add handler to show an alert on errors 
    imageViewer.itemError.add(function (sender, e) { 
        alert("Error loading " + e.data.srcElement.src); 
    }); 
    imageViewer.imageUrl = "https://demo.leadtools.com/images/png/pngimage.png"; 
 
    // Create and set up the automation manager using the HTML5 rendering engine 
    const renderingEngine = new lt.Annotations.Rendering.AnnHtml5RenderingEngine(); 
    const manager = new lt.Annotations.Automation.AnnAutomationManager.create(renderingEngine); 
 
    // Create the default annotations objects 
    manager.createDefaultObjects(); 
 
    const currentObject = document.getElementById("currentObject"); 
 
    const automationObjCount = manager.objects.count; 
    for (let i = 0; i < automationObjCount; i++) { 
        // Get the object 
        let automationObj = manager.objects.item(i); 
 
        // Add its name to the select element 
        let name = automationObj.name; 
        let id = automationObj.id; 
        currentObject.options[currentObject.options.length] = new Option(name, id); 
    } 
 
    // Hook to its change event 
    currentObject.addEventListener("change", function () { 
        // Get the object ID 
        let id = parseInt(currentObject.options[currentObject.selectedIndex].value); 
 
        // Set it as the current object in the manager 
        manager.currentObjectId = id; 
    }); 
 
    // When the current object ID changes, we need to update our select 
    manager.currentObjectIdChanged.add(function (sender, e) { 
        let currentObjectId = manager.currentObjectId; 
        for (let i = 0; i < currentObject.options.length; i++) { 
            let id = parseInt(currentObject.options[i].value); 
            if (id === currentObjectId) { 
                currentObject.selectedIndex = i; 
                break; 
            } 
        } 
    }); 
 
    const userMode = document.getElementById("userMode"); 
    // Hook to its change event 
    userMode.addEventListener("change", function () { 
        // Get the selected mode 
        let mode = userMode.options[userMode.selectedIndex].innerHTML; 
        if (mode == "Design") { 
            manager.userMode = lt.Annotations.Engine.AnnUserMode.design; 
        } else { 
            manager.userMode = lt.Annotations.Engine.AnnUserMode.run; 
        } 
    }); 
 
    // Create an instance of the Automation control object that works with LEADTOOLS ImageViewer 
    const automationControl = new lt.Demos.Annotations.ImageViewerAutomationControl(); 
    // Attach our image viewer 
    automationControl.imageViewer = imageViewer; 
 
    // Set the image viewer interactive mode 
    const automationInteractiveMode = new lt.Demos.Annotations.AutomationInteractiveMode(); 
    automationInteractiveMode.automationControl = automationControl; 
    imageViewer.defaultInteractiveMode = automationInteractiveMode; 
 
    // set up the automation (will create the container as well) 
    const automation = new lt.Annotations.Automation.AnnAutomation(manager, automationControl); 
    // Add handler to update the container size when the image size changes 
    imageViewer.itemChanged.add(function (sender, e) { 
        let container = automation.container; 
        container.size = container.mapper.sizeToContainerCoordinates(imageViewer.imageSize); 
    }); 
 
    // set up this automation as the active one 
    automation.active = true; 
 
    // Hook to the run even so we know when an object enters run mode 
    automation.run.add(function (sender, e) { 
        // e is of type AnnRunDesignerEventArgs 
        if (e.operationStatus == lt.Annotations.Engine.AnnDesignerOperationStatus.start) { 
            // Get the object being run 
            alert("In run mode, you clicked an object of id " + e.object.id); 
        } 
    }); 
 
    // Optional: Add the resources to the automation manager 
    addResources(manager); 
}; 
 
function addResources(manager) { 
    // Add images for the stamp, point, hot spot, and lock annotations 
    const resources = new lt.Annotations.Engine.AnnResources(); 
    manager.resources = resources; 
    const rubberStampsResources = resources.rubberStamps; 
    const imagesResources = resources.images; 
 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampApproved] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/approved.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampAssigned] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Assigned.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampClient] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Client.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampChecked] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/checked.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampCopy] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Copy.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampDraft] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Draft.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampExtended] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Extended.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampFax] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Fax.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampFaxed] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Faxed.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampImportant] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Important.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampInvoice] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Invoice.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampNotice] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Notice.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampPaid] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Paid.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampOfficial] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Official.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampOnFile] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Onfile.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampPassed] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Passed.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampPending] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Pending.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampProcessed] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Processed.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampReceived] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Received.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampRejected] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/rejected.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampRelease] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Release.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampSent] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Sent.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampShipped] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/Shipped.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampTopSecret] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/topsecret.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampUrgent] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/urgent.png"); 
    rubberStampsResources[lt.Annotations.Engine.AnnRubberStampType.stampVoid] = new lt.Annotations.Engine.AnnPicture("resources/objects/RubberStamps/void.png"); 
    imagesResources.add(new lt.Annotations.Engine.AnnPicture("resources/objects/Point.png")); 
    imagesResources.add(new lt.Annotations.Engine.AnnPicture("resources/objects/lock.png")); 
    imagesResources.add(new lt.Annotations.Engine.AnnPicture("resources/objects/hotspot.png")); 
}

Run the Project

Open the Command Line, and navigate to the project folder. Use the following command to run a static file server.

http-server

The server should start and run on http:localhost:8080. A message should appear in the console indicating all of the ports that the server is available on.

Ports indicating that the server is running.

While in design mode, the user can select various annotations objects and draw them on the displayed image. When an object is clicked in run mode, an alert is shown indicating which object was clicked. The application can handle how annotations behave in run mode by handling the automation run event.

Wrap-up

This tutorial showed how to work with automated annotations in a HTML5/JS application.