Draws a shape on the viewer.
function lt.Controls.ImageViewerRubberBandInteractiveMode
extends lt.Controls.ImageViewerInteractiveMode
class lt.Controls.ImageViewerRubberBandInteractiveMode()
extends ImageViewerInteractiveMode
The ImageViewerRubberBandInteractiveMode object derives from the ImageViewerInteractiveMode and subscribes to the following events of the InteractiveService:
The ImageViewerRubberBandInteractiveMode works as follows:
canvas
:Shape, BorderColor, BorderStyle, and BorderThickness, and the RubberBandStarted event is fired.
Note that if you set your own canvas
into the InteractiveModeCanvas property, then this object will not create a canvas
(nor use the above properties). Instead, your canvas
will be used as the surface for rubber banding.
When dragDelta is received, InteractiveEventArgs.IsHandled is set to true and the temporary canvas
is moved to the current position. The RubberBandDelta event is fired.
When dragCompleted is received, InteractiveEventArgs.IsHandled is set to true, the temporary canvas
is removed, and the RubberBandCompleted event is fired.
The ImageViewerRubberBandInteractiveMode interactive mode does not perform any action on the viewer (besides drawing, moving, and then removing the shape). It is up to the user to implement any custom operation required, (for example, to select a region of interest on the image). ImageViewerZoomToInteractiveMode derives from ImageViewerRubberBandInteractiveMode and calls the ImageViewer.zoomToRect upon the receiving of RubberBandCompleted event. Drawing a rubber-band on the viewer is usually followed by another user operation to perform the action. In most cases, the rubber band is to be restricted on the "work" area. The RestrictToWorkBounds can control this behavior.
For more information, refer to Image Viewer Interactive Modes.
This example will use ImageViewerRubberBandInteractiveMode to select a region of interest in the image. When the user finishes selecting the area, the example will draw a blue with yellow border rectangle on the image.
Tip: Zoom and pan the image before clicking 'Example' to show that the calculations for getting the rubber band value in image coordinates are correct.
import { ImageViewer_Example } from "../ImageViewer";
export class ImageViewer_RubberBandInteractiveModeExample {
private viewerExample;
constructor() {
this.viewerExample = new ImageViewer_Example(this.run);
}
private run = (viewer: lt.Controls.ImageViewer) => {
const rubberBandMode: lt.Controls.ImageViewerRubberBandInteractiveMode = new lt.Controls.ImageViewerRubberBandInteractiveMode();
rubberBandMode.rubberBandCompleted.add((sender, e) => {
if (e.isCanceled || !rubberBandMode.item)
return;
const points: lt.LeadPointD[] = e.points.map((point) => { return point.clone(); });
let min = lt.LeadPointD.empty;
let max = lt.LeadPointD.empty;
for (let i = 0; i < points.length; i++) {
points[i] = viewer.convertPoint(rubberBandMode.item, lt.Controls.ImageViewerCoordinateType.control, lt.Controls.ImageViewerCoordinateType.image, points[i]);
if (i === 0) {
min = points[i].clone();
max = points[i].clone();
}
else {
min.x = Math.min(min.x, points[i].x);
min.y = Math.min(min.y, points[i].y);
max.x = Math.max(max.x, points[i].x);
max.y = Math.max(max.y, points[i].y);
}
}
const center: lt.LeadPointD = lt.LeadPointD.create(min.x + (max.x - min.x) / 2, min.y + (max.y - min.y) / 2);
const item: lt.Controls.ImageViewerItem = rubberBandMode.item;
const itemCanvas = item.canvas as HTMLCanvasElement;
const ctx: CanvasRenderingContext2D = itemCanvas.getContext("2d");
ctx.save();
ctx.beginPath();
const rect: lt.LeadRectD = lt.LeadRectD.fromLTRB(points[0].x, points[0].y, points[1].x, points[1].y);
ctx.rect(rect.x, rect.y, rect.width, rect.height)
ctx.closePath();
ctx.fillStyle = "rgba(0, 0, 255, .2)";
ctx.fill();
ctx.strokeStyle = "yellow";
ctx.stroke();
ctx.restore();
viewer.invalidate(lt.LeadRectD.empty);
});
rubberBandMode.autoItemMode = lt.Controls.ImageViewerAutoItemMode.autoSet;
rubberBandMode.itemPart = lt.Controls.ImageViewerItemPart.image;
viewer.interactiveModes.beginUpdate();
viewer.interactiveModes.clear();
viewer.interactiveModes.add(rubberBandMode);
viewer.interactiveModes.endUpdate();
}
}
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_RubberBandInteractiveModeExample {
viewerExample;
constructor() {
this.viewerExample = new ImageViewer_Example(this.run);
}
run = (viewer) => {
const rubberBandMode = new lt.Controls.ImageViewerRubberBandInteractiveMode();
rubberBandMode.rubberBandCompleted.add((sender, e) => {
if (e.isCanceled || !rubberBandMode.item)
return;
const points = e.points.map((point) => { return point.clone(); });
let min = lt.LeadPointD.empty;
let max = lt.LeadPointD.empty;
for (let i = 0; i < points.length; i++) {
points[i] = viewer.convertPoint(rubberBandMode.item, lt.Controls.ImageViewerCoordinateType.control, lt.Controls.ImageViewerCoordinateType.image, points[i]);
if (i === 0) {
min = points[i].clone();
max = points[i].clone();
}
else {
min.x = Math.min(min.x, points[i].x);
min.y = Math.min(min.y, points[i].y);
max.x = Math.max(max.x, points[i].x);
max.y = Math.max(max.y, points[i].y);
}
}
const center = lt.LeadPointD.create(min.x + (max.x - min.x) / 2, min.y + (max.y - min.y) / 2);
const item = rubberBandMode.item;
const itemCanvas = item.canvas;
const ctx = itemCanvas.getContext("2d");
ctx.save();
ctx.beginPath();
const rect = lt.LeadRectD.fromLTRB(points[0].x, points[0].y, points[1].x, points[1].y);
ctx.rect(rect.x, rect.y, rect.width, rect.height)
ctx.closePath();
ctx.fillStyle = "rgba(0, 0, 255, .2)";
ctx.fill();
ctx.strokeStyle = "yellow";
ctx.stroke();
ctx.restore();
viewer.invalidate(lt.LeadRectD.empty);
});
rubberBandMode.autoItemMode = lt.Controls.ImageViewerAutoItemMode.autoSet;
rubberBandMode.itemPart = lt.Controls.ImageViewerItemPart.image;
viewer.interactiveModes.beginUpdate();
viewer.interactiveModes.clear();
viewer.interactiveModes.add(rubberBandMode);
viewer.interactiveModes.endUpdate();
}
}
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 | RubberBandInteractiveMode</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.InteractiveMode.RubberBandInteractiveMode();
};
</script>
</html>
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