resolution Property

Summary

Resolution of the item, in dots per inch (DPI).

Syntax
TypeScript
JavaScript
Object.defineProperty(ImageViewerItem.prototype, 'resolution', 
	get: function(), 
	set: function(value) 
) 
resolution: LeadSizeD; 

Property Value

The resolution (in dots per inch) of the original image data if accounting for the logical size of the image when display is desired. The default value is 0,0.

Remarks

This value is important when UseDpi is used. A value of 0 means use the current screen resolution. This is the same value set in ScreenDpi.

For more information, refer to Image Viewer Items.

Example

This example adds three canvas elements to the viewer, all with different resolutions.

Resolution.ts
ImageViewer.ts
Resolution.js
ImageViewer.js
Resolution.html
import { ImageViewer_Example } from "../ImageViewer"; 
 
export class ImageViewerItem_ResolutionExample { 
   private viewerExample; 
   constructor() { 
      this.viewerExample = new ImageViewer_Example(this.run); 
   } 
 
   private run = (viewer: lt.Controls.ImageViewer) => { 
      // Set up margin and padding and layout 
      viewer.viewLayout = new lt.Controls.ImageViewerVerticalViewLayout(); 
      viewer.itemBorderThickness = 5; 
      viewer.itemPadding = lt.Controls.ControlPadding.createAll(20); 
      viewer.itemMargin = lt.Controls.ControlPadding.createAll(10); 
      viewer.items.clear(); 
 
      // Create a canvas for each item and draw the same image to it 
      const createCanvas = () => { 
         const canvas = document.createElement("canvas") as HTMLCanvasElement; 
         canvas.width = 200; 
         canvas.height = 200; 
         const ctx: CanvasRenderingContext2D = canvas.getContext("2d"); 
         // Red background 
         ctx.fillStyle = "red"; 
         ctx.fillRect(0, 0, 200, 200); 
         // White circle 
         ctx.fillStyle = "white"; 
         ctx.beginPath(); 
         ctx.arc(100, 100, 50, 0, Math.PI * 2); 
         ctx.closePath(); 
         ctx.fill(); 
         return canvas; 
      } 
 
      // Must use DPI to see the effects 
      viewer.useDpi = true; 
 
      // 96 (Default), 300, 600 
      const resolutions: lt.LeadSizeD[] = [lt.LeadSizeD.create(96, 96), lt.LeadSizeD.create(300, 300), lt.LeadSizeD.create(600, 600)]; 
 
      viewer.beginTransform(); 
      for (let i = 0; i < resolutions.length; i++) { 
         const item: lt.Controls.ImageViewerItem = new lt.Controls.ImageViewerItem(); 
         item.text = "Item " + i; 
         item.canvas = createCanvas(); 
         item.resolution = resolutions[i]; 
 
         viewer.items.add(item); 
      } 
      viewer.endTransform(); 
   } 
} 
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 ImageViewerItem_ImageSizeExample { 
   viewerExample; 
   constructor() { 
      this.viewerExample = new ImageViewer_Example(this.run); 
   } 
 
   run = (viewer) => { 
      // Set up margin and padding and layout 
      viewer.viewLayout = new lt.Controls.ImageViewerVerticalViewLayout(); 
      viewer.itemBorderThickness = 5; 
      viewer.itemPadding = lt.Controls.ControlPadding.createAll(20); 
      viewer.itemMargin = lt.Controls.ControlPadding.createAll(10); 
      viewer.items.clear(); 
 
      // Create a canvas for each item and draw the same image to it 
      const createCanvas = () => { 
         const canvas = document.createElement("canvas"); 
         canvas.width = 200; 
         canvas.height = 200; 
         const ctx = canvas.getContext("2d"); 
         // Red background 
         ctx.fillStyle = "red"; 
         ctx.fillRect(0, 0, 200, 200); 
         // White circle 
         ctx.fillStyle = "white"; 
         ctx.beginPath(); 
         ctx.arc(100, 100, 50, 0, Math.PI * 2); 
         ctx.closePath(); 
         ctx.fill(); 
         return canvas; 
      } 
 
      // Must use DPI to see the effects 
      viewer.useDpi = true; 
 
      // 96 (Default), 300, 600 
      const resolutions = [lt.LeadSizeD.create(96, 96), lt.LeadSizeD.create(300, 300), lt.LeadSizeD.create(600, 600)]; 
 
      viewer.beginTransform(); 
      for (let i = 0; i < resolutions.length; i++) { 
         const item = new lt.Controls.ImageViewerItem(); 
         item.text = "Item " + i; 
         item.canvas = createCanvas(); 
         item.resolution = resolutions[i]; 
 
         viewer.items.add(item); 
      } 
      viewer.endTransform(); 
   } 
} 
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 | Resolution</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.ImageViewerItem.Resolution(); 
 
   }; 
</script> 
</html> 

Requirements

Target Platforms

Help Version 20.0.2020.2.17
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Leadtools.Controls Assembly