getItemViewBounds Method

Summary

Current physical bounds (in control pixel coordinates) of any part of an item.

Syntax
TypeScript
JavaScript
ImageViewer.prototype.getItemViewBounds = function( 
   item, 
   part, 
   clipped 
) 
getItemViewBounds( 
   item: ImageViewerItem, 
   part: ImageViewerItemPart, 
   clipped: boolean 
): LeadRectD; 

Parameters

item

The item. Must be a valid item inside this viewer.

part

The item part requested.

clipped

true to return the bounding rectangle intersected with the current viewer control area; otherwise, false.

Return Value

The bounding rectangle in pixels or LeadRectD.Empty if the item is not visible, does not have an image, or is outside the clipping area.

Remarks

Use ConvertBoundsToView to convert a bounding rectangle from logical to physical coordinates.

For more information refer to Image Viewer Appearance, Image Viewer Transformation, and Image Viewer Bounds and Transform.

Example

This example will show how to use GetItemViewBounds to draw a rectangle around the visible area of the item.

GetItemViewBounds.ts
ImageViewer.ts
GetItemViewBounds.js
ImageViewer.js
GetItemViewBounds.html
import { ImageViewer_Example } from "../ImageViewer"; 
 
export class ImageViewer_GetItemViewBoundsExample { 
   private viewerExample; 
   constructor() { 
      this.viewerExample = new ImageViewer_Example(this.run); 
   } 
 
   private run = (viewer: lt.Controls.ImageViewer) => { 
      // Add item padding and border to show that we're getting the *image* bounds 
      viewer.itemPadding = lt.Controls.ControlPadding.createAll(15);; 
      viewer.itemBorderThickness = 5; 
      viewer.itemBorderColor = "#333"; 
 
      const output = document.getElementById("output"); 
 
      const item: lt.Controls.ImageViewerItem = viewer.items.item(0); 
      viewer.postRender.add((sender, e) => { 
         // Get the bounds of the image, clipped 
         const bounds: lt.LeadRectD = viewer.getItemViewBounds(item, lt.Controls.ImageViewerItemPart.image, true); 
         const ctx: CanvasRenderingContext2D = e.context; 
         ctx.lineWidth = 6; 
         // Move the bounds inward by half the line width to create an inner border 
         bounds.inflate(-3, -3); 
         ctx.strokeStyle = "red"; 
         ctx.globalAlpha = .5; 
         ctx.strokeRect(bounds.x, bounds.y, bounds.width, bounds.height); 
 
         output.innerHTML = "The red border around the image is always visible because it is clipped. Current bounds: " + bounds.toString(); 
      }); 
   } 
} 
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/v200/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_GetItemViewBoundsExample { 
   viewerExample; 
   constructor() { 
      this.viewerExample = new ImageViewer_Example(this.run); 
   } 
 
   run = (viewer) => { 
      // Add item padding and border to show that we're getting the *image* bounds 
      viewer.itemPadding = lt.Controls.ControlPadding.createAll(15);; 
      viewer.itemBorderThickness = 5; 
      viewer.itemBorderColor = "#333"; 
 
      const output = document.getElementById("output"); 
 
      const item = viewer.items.item(0); 
      viewer.postRender.add((sender, e) => { 
         // Get the bounds of the image, clipped 
         const bounds = viewer.getItemViewBounds(item, lt.Controls.ImageViewerItemPart.image, true); 
         const ctx = e.context; 
         ctx.lineWidth = 6; 
         // Move the bounds inward by half the line width to create an inner border 
         bounds.inflate(-3, -3); 
         ctx.strokeStyle = "red"; 
         ctx.globalAlpha = .5; 
         ctx.strokeRect(bounds.x, bounds.y, bounds.width, bounds.height); 
 
         output.innerHTML = "The red border around the image is always visible because it is clipped. Current bounds: " + bounds.toString(); 
      }); 
   } 
} 
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/v200/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 | GetItemViewBounds</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.GetItemViewBounds(); 
 
   }; 
</script> 
</html> 

Requirements

Target Platforms

Help Version 20.0.2020.2.17
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Leadtools.Controls Assembly