Largest visible item or part of it in the viewer.
ImageViewer.prototype.getLargestVisibleItem = function(
part
)
getLargestVisibleItem(
part: ImageViewerItemPart
): ImageViewerItem;
part
The item part requested. To use the whole item, pass ImageViewerItemPart.View.
The largest visible item or null if the item does not have any visible items.
For more information refer to Image Viewer Layouts, Image Viewer Appearance, Image Viewer Items, Image Viewer Transformation, and Image Viewer Bounds and Transform.
import { ImageViewer_Example } from "../ImageViewer";
export class ImageViewer_TransformChangedExample {
private viewerExample;
constructor() {
this.viewerExample = new ImageViewer_Example(this.run);
}
private run = (viewer: lt.Controls.ImageViewer) => {
// Clear all the images already the viewer
viewer.items.clear();
// Use vertical view layout
viewer.viewLayout = new lt.Controls.ImageViewerVerticalViewLayout();
// Add padding and margins
viewer.itemSpacing = lt.LeadSizeD.create(10, 10);
viewer.itemPadding = lt.Controls.ControlPadding.create(0, 0, 0, 20);
// Add 4 items to the viewer
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);
}
const output = document.getElementById("output");
// Hook to the TransformChanged event for when we pan and zoom
viewer.transformChanged.add((sender, e) => {
// Get the first and largest visible items
const firstVisibleIndex: lt.Controls.ImageViewerItemPart = viewer.getFirstVisibleItemIndex(lt.Controls.ImageViewerItemPart.item);
const largestVisibleIndex: number = viewer.getLargestVisibleItemIndex(lt.Controls.ImageViewerItemPart.item);
let text: string = "";
text += "<p>First Visible (0-Based): " + (firstVisibleIndex !== -1 ? firstVisibleIndex : "[None]") + "</p>";
text += "<p>Most/Largest Visible (0-Based): " + (largestVisibleIndex !== -1 ? largestVisibleIndex : "[None]") + "</p>";
output.innerHTML = text;
});
}
}
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_TransformChangedExample {
viewerExample;
constructor() {
this.viewerExample = new ImageViewer_Example(this.run);
}
run = (viewer) => {
// Clear all the images already the viewer
viewer.items.clear();
// Use vertical view layout
viewer.viewLayout = new lt.Controls.ImageViewerVerticalViewLayout();
// Add padding and margins
viewer.itemSpacing = lt.LeadSizeD.create(10, 10);
viewer.itemPadding = lt.Controls.ControlPadding.create(0, 0, 0, 20);
// Add 4 items to the viewer
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);
}
const output = document.getElementById("output");
// Hook to the TransformChanged event for when we pan and zoom
viewer.transformChanged.add((sender, e) => {
// Get the first and largest visible items
const firstVisibleIndex = viewer.getFirstVisibleItemIndex(lt.Controls.ImageViewerItemPart.item);
const largestVisibleIndex = viewer.getLargestVisibleItemIndex(lt.Controls.ImageViewerItemPart.item);
let text = "";
text += "<p>First Visible (0-Based): " + (firstVisibleIndex !== -1 ? firstVisibleIndex : "[None]") + "</p>";
text += "<p>Most/Largest Visible (0-Based): " + (largestVisibleIndex !== -1 ? largestVisibleIndex : "[None]") + "</p>";
output.innerHTML = text;
});
}
}
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 | TransformChanged</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.TransformChanged();
};
</script>
</html>
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