ImageViewerImageLoadingEventArgs Object

Summary

Data for the image loading event.

Syntax
TypeScript
JavaScript
function lt.Controls.ImageViewerImageLoadingEventArgs 
	extends System.EventArgs 
class lt.Controls.ImageViewerImageLoadingEventArgs() 
	extends LeadEventArgs 
Remarks

A new ImageViewerImageLoadingEventArgs is passed to callbacks for the ImageLoading event, which occurs when an image needs to load because Url or BackImageUrl was set. It may also occur when an image is reloaded when AutoRemoveItemElements is true.

The ImageLoader from this instance should not be run; it will start after all callbacks for the ImageLoading event have completed.

Example
ImageLoading.ts
ImageViewer.ts
ImageLoading.js
ImageViewer.js
ImageLoading.html
import { ImageViewer_Example } from "../ImageViewer"; 
 
export class ImageViewer_ImageLoadingExample { 
   private viewerExample; 
   constructor() { 
      this.viewerExample = new ImageViewer_Example(this.run); 
   } 
 
   private run = (viewer: lt.Controls.ImageViewer) => { 
      viewer.items.clear(); 
      viewer.viewLayout = new lt.Controls.ImageViewerVerticalViewLayout(); 
 
      const output = document.getElementById("output"); 
      viewer.imageLoading.add((sender, e) => { 
         // We now have access to imageLoader and item 
         // We can change any settings we want 
         const imageLoader: lt.ImageLoader = e.imageLoader; 
         output.innerHTML = "Image about to load: " + imageLoader.url; 
      }); 
 
      let item: lt.Controls.ImageViewerItem = new lt.Controls.ImageViewerItem(); 
      // Image will not load immediately. Must be added to ImageViewer. 
      item.url = "https://demo.leadtools.com/images/png/pngimage.png"; 
      item.text = "Text"; 
 
      setTimeout(() => { 
         // We set a timeout for 4 seconds, to show that the event 
         // will execute right before image is loaded 
         viewer.items.add(item); 
      }, 1100); 
   } 
} 
export class ImageViewer_Example { 
   // LEADTOOLS ImageViewer to be used with this example 
   protected imageViewer: lt.Controls.ImageViewer = null; 
   // Generic state value used by the examples 
   public timesClicked: number = 0; 
 
   constructor(callback?: (viewer: lt.Controls.ImageViewer) => void) { 
      // Set the LEADTOOLS license. Replace this with your actual license file 
      lt.RasterSupport.setLicenseUri("https://demo.leadtools.com/licenses/js/LEADTOOLSEVAL.txt", "EVAL", null); 
 
      // Create an image viewer inside the imageViewerDiv element 
      const imageViewerDiv = document.getElementById("imageViewerDiv"); 
      const createOptions: lt.Controls.ImageViewerCreateOptions = new lt.Controls.ImageViewerCreateOptions(imageViewerDiv); 
      this.imageViewer = new lt.Controls.ImageViewer(createOptions); 
      this.imageViewer.viewVerticalAlignment = lt.Controls.ControlAlignment.center; 
      this.imageViewer.viewHorizontalAlignment = lt.Controls.ControlAlignment.center; 
      this.imageViewer.autoCreateCanvas = true; 
 
      // Add Pan/Zoom interactive mode 
      // Click and drag to pan, CTRL-Click and drag to zoom in and out 
      this.imageViewer.interactiveModes.add(new lt.Controls.ImageViewerPanZoomInteractiveMode()); 
 
      // Load an image 
      this.imageViewer.imageUrl = "https://demo.leadtools.com/images/jpeg/cannon.jpg"; 
 
      this.imageViewer.zoom(lt.Controls.ControlSizeMode.fit, .9, this.imageViewer.defaultZoomOrigin); 
 
      const exampleButton = document.getElementById("exampleButton"); 
      exampleButton.addEventListener("click", () => { 
         this.timesClicked++; 
         // Run the example 
         if (callback) 
            callback(this.imageViewer); 
      }); 
   } 
} 
import { ImageViewer_Example } from "../ImageViewer"; 
 
export class ImageViewer_FloaterExample { 
   viewerExample; 
   constructor() { 
      this.viewerExample = new ImageViewer_Example(this.run); 
   } 
 
   run = (viewer) => { 
      viewer.items.clear(); 
      viewer.viewLayout = new lt.Controls.ImageViewerVerticalViewLayout(); 
 
      const output = document.getElementById("output"); 
      viewer.imageLoading.add((sender, e) => { 
         // We now have access to imageLoader and item 
         // We can change any settings we want 
         const imageLoader = e.imageLoader; 
         output.innerHTML = "Image about to load: " + imageLoader.url; 
      }); 
 
      let item = new lt.Controls.ImageViewerItem(); 
      // Image will not load immediately. Must be added to ImageViewer. 
      item.url = "https://demo.leadtools.com/images/png/pngimage.png"; 
      item.text = "Text"; 
 
      setTimeout(() => { 
         // We set a timeout for 4 seconds, to show that the event 
         // will execute right before image is loaded 
         viewer.items.add(item); 
      }, 1100); 
   } 
} 
export class ImageViewer_Example { 
   // LEADTOOLS ImageViewer to be used with this example 
   imageViewer = null; 
   // Generic state value used by the examples 
   timesClicked = 0; 
 
   constructor(callback) { 
      // Set the LEADTOOLS license. Replace this with your actual license file 
      lt.RasterSupport.setLicenseUri("https://demo.leadtools.com/licenses/js/LEADTOOLSEVAL.txt", "EVAL", null); 
 
      // Create an image viewer inside the imageViewerDiv element 
      const imageViewerDiv = document.getElementById("imageViewerDiv"); 
      const createOptions = new lt.Controls.ImageViewerCreateOptions(imageViewerDiv); 
      this.imageViewer = new lt.Controls.ImageViewer(createOptions); 
      this.imageViewer.viewVerticalAlignment = lt.Controls.ControlAlignment.center; 
      this.imageViewer.viewHorizontalAlignment = lt.Controls.ControlAlignment.center; 
      this.imageViewer.autoCreateCanvas = true; 
 
      // Add Pan/Zoom interactive mode 
      // Click and drag to pan, CTRL-Click and drag to zoom in and out 
      this.imageViewer.interactiveModes.add(new lt.Controls.ImageViewerPanZoomInteractiveMode()); 
 
      // Load an image 
      this.imageViewer.imageUrl = "https://demo.leadtools.com/images/jpeg/cannon.jpg"; 
 
      this.imageViewer.zoom(lt.Controls.ControlSizeMode.fit, .9, this.imageViewer.defaultZoomOrigin); 
 
      const exampleButton = document.getElementById("exampleButton"); 
      exampleButton.addEventListener("click", () => { 
         this.timesClicked++; 
         // Run the example 
         if (callback) 
            callback(this.imageViewer); 
      }); 
   } 
} 
<!doctype html> 
<html lang="en"> 
<title>Controls Example | ImageLoading</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> 
   <style> 
      body { 
         font-family: 'Segoe UI', sans-serif; 
      } 
 
      #imageViewerDiv { 
         border: 1px solid #888; 
         width: 500px; 
         height: 500px; 
         background-color: #eee; 
      } 
   </style> 
 
   <!-- All demo files are bundled and appended to the window --> 
   <script src="../../bundle.js" type="text/javascript"></script> 
</head> 
 
<body> 
   <p>Press and drag on the image to pan.</p> 
   <p>Hold down the control key and press and drag on the image or pinch with two fingers to zoom in and out.</p> 
   <div> 
      <button type="button" id="exampleButton">Run Example</button> 
   </div> 
   <div id="imageViewerDiv"></div> 
   <div id="output"></div> 
</body> 
 
<script> 
   window.onload = () => { 
      const example = new window.examples.ImageViewer.ImageLoading(); 
 
   }; 
</script> 
</html> 
Requirements

Target Platforms

Help Version 22.0.2023.2.4
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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.

Leadtools.Controls Assembly

Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.