Indicates if this item is visible.
Object.defineProperty(ImageViewerItem.prototype, 'isVisible',
get: function(),
set: function(value)
)
isVisible: boolean;
true if this item is visible; otherwise, false. The default value is true.
Invisible items (the value of IsVisible is false) will neither be rendered nor participate in layout calculations.
For more information, refer Image Viewer Items, Image Viewer Layouts and Image Viewer Rendering.
This example adds four items to the viewer, then makes one item invisible after a time. The viewer will re-calculate and no longer show that item.
import { ImageViewer_Example } from "../ImageViewer";
export class ImageViewerItem_IsVisibleExample {
private viewerExample;
constructor() {
this.viewerExample = new ImageViewer_Example(this.run);
}
private run = (viewer: lt.Controls.ImageViewer) => {
// Add a few more items
viewer.beginUpdate();
viewer.items.clear();
viewer.viewLayout = new lt.Controls.ImageViewerVerticalViewLayout();
viewer.itemBorderThickness = 5;
viewer.itemPadding = lt.Controls.ControlPadding.createAll(20);
viewer.itemSpacing = lt.LeadSizeD.create(10, 10);
for (let i = 0; i < 4; i++) {
const item: lt.Controls.ImageViewerItem = new lt.Controls.ImageViewerItem();
item.url = "https://demo.leadtools.com/images/jpeg/cannon.jpg";
item.text = "Item " + i;
viewer.items.add(item);
}
viewer.zoom(lt.Controls.ControlSizeMode.none, .5, viewer.defaultZoomOrigin);
viewer.endUpdate();
// Use a timeout to show the difference
setTimeout(() => {
// Make the second (index 1) item invisible
let item: lt.Controls.ImageViewerItem = viewer.items.item(1);
item.isVisible = false;
}, 1500);
}
}
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 ImageViewerItem_IsVisibleExample {
viewerExample;
constructor() {
this.viewerExample = new ImageViewer_Example(this.run);
}
run = (viewer) => {
// Add a few more items
viewer.beginUpdate();
viewer.items.clear();
viewer.viewLayout = new lt.Controls.ImageViewerVerticalViewLayout();
viewer.itemBorderThickness = 5;
viewer.itemPadding = lt.Controls.ControlPadding.createAll(20);
viewer.itemSpacing = lt.LeadSizeD.create(10, 10);
for (let i = 0; i < 4; i++) {
const item = new lt.Controls.ImageViewerItem();
item.url = "https://demo.leadtools.com/images/jpeg/cannon.jpg";
item.text = "Item " + i;
viewer.items.add(item);
}
viewer.zoom(lt.Controls.ControlSizeMode.none, .5, viewer.defaultZoomOrigin);
viewer.endUpdate();
// Use a timeout to show the difference
setTimeout(() => {
// Make the second (index 1) item invisible
let item = viewer.items.item(1);
item.isVisible = false;
}, 1500);
}
}
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 | IsVisible</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.IsVisible();
};
</script>
</html>
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