itemDragDrop Event

Summary

Occurs when data is being dragged or dropped from/to this ImageViewer.

Syntax
TypeScript
JavaScript
Object.defineProperty(ImageViewer.prototype,'itemDragDrop', 
	get: function(), 
	set: function(value) 
) 
itemDragDrop: LeadEvent; 
Event Data
ParameterTypeDescription
sendervarThe source of the event.
eImageViewerItemDragDropEventArgsThe event data.
Remarks

For more information, refer to Image Viewer Drag and Drop.

Example

This example will show how to use the ImageViewer as the drop target of a drag/drop operation.

ItemDragDrop.ts
ImageViewer.ts
ItemDragDrop.js
ImageViewer.js
ItemDragDrop.html
import { ImageViewer_Example } from "../ImageViewer"; 
 
export class ImageViewer_ItemDragDropExample { 
   private viewerExample; 
   constructor() { 
      this.viewerExample = new ImageViewer_Example(this.run); 
   } 
 
   private run = (viewer: lt.Controls.ImageViewer) => { 
      // Set margins, padding, and borders 
      viewer.viewMargin = lt.Controls.ControlPadding.createAll(15); 
      viewer.itemPadding = lt.Controls.ControlPadding.createAll(20); 
      viewer.itemBorderThickness = 5; 
      viewer.itemMargin = lt.Controls.ControlPadding.createAll(10); 
 
      // Clear the items and add new ones 
      viewer.beginUpdate(); 
      viewer.items.clear(); 
      viewer.viewLayout = new lt.Controls.ImageViewerVerticalViewLayout(); 
      let item0: lt.Controls.ImageViewerItem = new lt.Controls.ImageViewerItem(); 
      item0.text = "Item 0"; 
      item0.url = "https://demo.leadtools.com/images/jpeg/cannon.jpg"; 
      viewer.items.add(item0); 
      let item1: lt.Controls.ImageViewerItem = new lt.Controls.ImageViewerItem(); 
      item1.text = "Item 1"; 
      item1.url = "https://demo.leadtools.com/images/png/pngimage.png"; 
      viewer.items.add(item1); 
      viewer.endUpdate(); 
 
      viewer.allowDrop = true; 
      viewer.activeItem = viewer.items.item(0); 
 
      viewer.interactiveModes.beginUpdate(); 
      const dragMode = new lt.Controls.ImageViewerDragInteractiveMode(); 
      viewer.interactiveModes.insert(0, dragMode); 
      viewer.interactiveModes.endUpdate(); 
 
      const getOpName = (value) => { 
         const enumOb = lt.Controls.ImageViewerItemDragDropOperation; 
         for (const prop in enumOb) { 
            if (enumOb.hasOwnProperty(prop)) { 
               if (enumOb[prop] === value) 
                  return prop; 
            } 
         } 
         return null; 
      } 
 
      let previousOp: lt.Controls.ImageViewerItemDragDropOperation = null; 
 
      // Drag items to use 
      viewer.itemDragDrop.add((sender, e) => { 
         if (previousOp === e.operation) 
            return; 
         previousOp = e.operation; 
 
         const sourceItem: lt.Controls.ImageViewerItem = e.sourceItem; 
         const sourceImageViewer: lt.Controls.ImageViewer = e.sourceImageViewer; 
         const targetItem: lt.Controls.ImageViewerItem = e.targetItem; 
         const targetImageViewer: lt.Controls.ImageViewer = e.targetImageViewer; 
 
         // Log all the information to the console 
         console.log({ 
            operation: getOpName(e.operation), 
            sourceItem: sourceItem && sourceImageViewer.items.indexOf(sourceItem), 
            sourceImageViewer: sourceImageViewer, 
            targetItem: targetItem && targetImageViewer && targetImageViewer.items.indexOf(targetItem), 
            targetImageViewer: targetImageViewer 
         }); 
      }); 
   } 
} 
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_ItemDragDropExample { 
   viewerExample; 
   constructor() { 
      this.viewerExample = new ImageViewer_Example(this.run); 
   } 
 
   run = (viewer) => { 
      // Set margins, padding, and borders 
      viewer.viewMargin = lt.Controls.ControlPadding.createAll(15); 
      viewer.itemPadding = lt.Controls.ControlPadding.createAll(20); 
      viewer.itemBorderThickness = 5; 
      viewer.itemMargin = lt.Controls.ControlPadding.createAll(10); 
 
      // Clear the items and add new ones 
      viewer.beginUpdate(); 
      viewer.items.clear(); 
      viewer.viewLayout = new lt.Controls.ImageViewerVerticalViewLayout(); 
      let item0 = new lt.Controls.ImageViewerItem(); 
      item0.text = "Item 0"; 
      item0.url = "https://demo.leadtools.com/images/jpeg/cannon.jpg"; 
      viewer.items.add(item0); 
      let item1 = new lt.Controls.ImageViewerItem(); 
      item1.text = "Item 1"; 
      item1.url = "https://demo.leadtools.com/images/png/pngimage.png"; 
      viewer.items.add(item1); 
      viewer.endUpdate(); 
 
      viewer.allowDrop = true; 
      viewer.activeItem = viewer.items.item(0); 
 
      viewer.interactiveModes.beginUpdate(); 
      const dragMode = new lt.Controls.ImageViewerDragInteractiveMode(); 
      viewer.interactiveModes.insert(0, dragMode); 
      viewer.interactiveModes.endUpdate(); 
 
      const getOpName = (value) => { 
         const enumOb = lt.Controls.ImageViewerItemDragDropOperation; 
         for (const prop in enumOb) { 
            if (enumOb.hasOwnProperty(prop)) { 
               if (enumOb[prop] === value) 
                  return prop; 
            } 
         } 
         return null; 
      } 
 
      let previousOp = null; 
 
      // Drag items to use 
      viewer.itemDragDrop.add((sender, e) => { 
         if (previousOp === e.operation) 
            return; 
         previousOp = e.operation; 
 
         const sourceItem = e.sourceItem; 
         const sourceImageViewer = e.sourceImageViewer; 
         const targetItem = e.targetItem; 
         const targetImageViewer = e.targetImageViewer; 
 
         // Log all the information to the console 
         console.log({ 
            operation: getOpName(e.operation), 
            sourceItem: sourceItem && sourceImageViewer.items.indexOf(sourceItem), 
            sourceImageViewer: sourceImageViewer, 
            targetItem: targetItem && targetImageViewer && targetImageViewer.items.indexOf(targetItem), 
            targetImageViewer: targetImageViewer 
         }); 
      }); 
   } 
} 
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 | ItemDragonDrop</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.ItemDragDrop(); 
   }; 
</script> 
</html> 
Requirements

Target Platforms

Help Version 23.0.2024.2.29
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© 1991-2024 LEAD Technologies, Inc. All Rights Reserved.

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