Current transformation matrix of the view.
Object.defineProperty(ImageViewer.prototype, 'viewTransform',
get: function()
)
viewTransform: LeadMatrix; // read-only
The current transformation matrix of the view.
The view consists of all current the items in the viewer plus any padding (set in ViewPadding). This is the area that the viewer use to determine whether horizontal and vertical scrollbars are needed and to calculate their size and position.
The view area is calculated during UpdateTransform. The current ViewLayout determines where each item is placed and calculates their sizes. The total of these sizes is calculated and multiplied by any scale factor (XScaleFactor and YScaleFactor) set by the Zoom method. The final size is the view area.
During the calculations, the viewer will calculate the transformation matrix used when rendering the view. This matrix contains the current padding, scroll offset and scale factors and stored in ViewTransform. For example, to render the view border, the viewer simply draws the value of GetViewBounds transformed with ViewTransform.
For more information, refer to Image Viewer Appearance, Image Viewer Transformation, and Image Viewer Bounds and Transform.
import { ImageViewer_Example } from "../ImageViewer";
export class ImageViewer_RenderRedirectExample {
private viewerExample;
constructor() {
this.viewerExample = new ImageViewer_Example(this.run);
}
private run = (viewer: lt.Controls.ImageViewer) => {
viewer.itemBorderThickness = 5;
// Create the canvas we will render to
const redirectCanvas = document.createElement("canvas");
redirectCanvas.style.border = "2px solid black";
const redirectWidth: number = 300;
const redirectHeight: number = 300;
redirectCanvas.width = redirectWidth;
redirectCanvas.height = redirectHeight;
// Add it to the page
const output = document.getElementById("output");
output.appendChild(redirectCanvas);
// Add a 20px margin around the redirect render area
const delta: number = 20;
const destRect: lt.LeadRectD = lt.LeadRectD.create(0, 0, redirectWidth, redirectHeight);
destRect.inflate(-delta, -delta);
const options: lt.Controls.ImageViewerRenderRedirectOptions = new lt.Controls.ImageViewerRenderRedirectOptions();
viewer.rotateAngle = 35;
// Use "null" to draw the whole imageViewer
//let item = null;
const item: lt.Controls.ImageViewerItem = viewer.activeItem;
if (item) {
// Don't worry about rendering the below
options.renderBackgrounds = false;
options.renderBorders = false;
options.renderItemStates = false;
options.renderShadows = false;
options.renderText = false;
}
// On imageViewer render...
viewer.redirectRender.add(() => {
let sourceRect: lt.LeadRectD;
let sourceRectClipped: lt.LeadRectD;
if (!item) {
// Draw the whole imageViewer
sourceRect = viewer.getViewBounds(true, false);
sourceRectClipped = viewer.getViewBounds(true, true);
}
else {
// Only draw the rect for the active item
sourceRect = viewer.getItemViewBounds(item, lt.Controls.ImageViewerItemPart.image, false);
sourceRectClipped = viewer.getItemViewBounds(item, lt.Controls.ImageViewerItemPart.image, true);
}
const ctx: CanvasRenderingContext2D = redirectCanvas.getContext("2d");
ctx.clearRect(0, 0, redirectWidth, redirectHeight);
// Draw a rect around the maximum render area
ctx.strokeStyle = "green";
ctx.strokeRect(destRect.x, destRect.y, destRect.width, destRect.height);
// Create the transformation for this rect
options.createTransform(viewer, destRect, sourceRect, lt.Controls.ControlSizeMode.fit, lt.Controls.ControlAlignment.center, lt.Controls.ControlAlignment.center);
// Draw a rect around the actual render area
const clipRect: lt.LeadRectD = options.transform.transformRect(sourceRect);
ctx.strokeStyle = "orange";
ctx.strokeRect(clipRect.x, clipRect.y, clipRect.width, clipRect.height);
// Do the redirect render
viewer.renderRedirect(ctx, options, lt.LeadRectD.empty);
// Show how to draw the item's border
const manuallyComputeRedirectedBorder = () => {
const points: lt.LeadPointD[] = [lt.LeadPointD.create(sourceRectClipped.left, sourceRectClipped.top), lt.LeadPointD.create(sourceRectClipped.right, sourceRectClipped.bottom)];
options.transform.transformPoints(points);
let xmin = points[0].x;
let ymin = points[0].y;
let xmax = xmin;
let ymax = ymin;
for (let i = 1; i < points.length; i++) {
if (points[i].x < xmin) xmin = points[i].x;
if (points[i].x > xmax) xmax = points[i].x;
if (points[i].y < ymin) ymin = points[i].y;
if (points[i].y > ymax) ymax = points[i].y;
}
const bounds: lt.LeadRectD = lt.LeadRectD.fromLTRB(xmin, ymin, xmax, ymax);
ctx.strokeStyle = "blue";
ctx.strokeRect(bounds.x, bounds.y, bounds.width, bounds.height);
};
manuallyComputeRedirectedBorder();
});
viewer.invalidate(lt.LeadRectD.empty);
}
}
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_RenderRedirectExample {
viewerExample;
constructor() {
this.viewerExample = new ImageViewer_Example(this.run);
}
run = (viewer) => {
viewer.itemBorderThickness = 5;
// Create the canvas we will render to
const redirectCanvas = document.createElement("canvas");
redirectCanvas.style.border = "2px solid black";
const redirectWidth = 300;
const redirectHeight = 300;
redirectCanvas.width = redirectWidth;
redirectCanvas.height = redirectHeight;
// Add it to the page
const output = document.getElementById("output");
output.appendChild(redirectCanvas);
// Add a 20px margin around the redirect render area
const delta = 20;
const destRect = lt.LeadRectD.create(0, 0, redirectWidth, redirectHeight);
destRect.inflate(-delta, -delta);
const options = new lt.Controls.ImageViewerRenderRedirectOptions();
viewer.rotateAngle = 35;
// Use "null" to draw the whole imageViewer
//let item = null;
const item = viewer.activeItem;
if (item) {
// Don't worry about rendering the below
options.renderBackgrounds = false;
options.renderBorders = false;
options.renderItemStates = false;
options.renderShadows = false;
options.renderText = false;
}
// On imageViewer render...
viewer.redirectRender.add(() => {
let sourceRect;
let sourceRectClipped;
if (!item) {
// Draw the whole imageViewer
sourceRect = viewer.getViewBounds(true, false);
sourceRectClipped = viewer.getViewBounds(true, true);
}
else {
// Only draw the rect for the active item
sourceRect = viewer.getItemViewBounds(item, lt.Controls.ImageViewerItemPart.image, false);
sourceRectClipped = viewer.getItemViewBounds(item, lt.Controls.ImageViewerItemPart.image, true);
}
const ctx = redirectCanvas.getContext("2d");
ctx.clearRect(0, 0, redirectWidth, redirectHeight);
// Draw a rect around the maximum render area
ctx.strokeStyle = "green";
ctx.strokeRect(destRect.x, destRect.y, destRect.width, destRect.height);
// Create the transformation for this rect
options.createTransform(viewer, destRect, sourceRect, lt.Controls.ControlSizeMode.fit, lt.Controls.ControlAlignment.center, lt.Controls.ControlAlignment.center);
// Draw a rect around the actual render area
const clipRect = options.transform.transformRect(sourceRect);
ctx.strokeStyle = "orange";
ctx.strokeRect(clipRect.x, clipRect.y, clipRect.width, clipRect.height);
// Do the redirect render
viewer.renderRedirect(ctx, options, lt.LeadRectD.empty);
// Show how to draw the item's border
const manuallyComputeRedirectedBorder = () => {
const points = [lt.LeadPointD.create(sourceRectClipped.left, sourceRectClipped.top), lt.LeadPointD.create(sourceRectClipped.right, sourceRectClipped.bottom)];
options.transform.transformPoints(points);
let xmin = points[0].x;
let ymin = points[0].y;
let xmax = xmin;
let ymax = ymin;
for (let i = 1; i < points.length; i++) {
if (points[i].x < xmin) xmin = points[i].x;
if (points[i].x > xmax) xmax = points[i].x;
if (points[i].y < ymin) ymin = points[i].y;
if (points[i].y > ymax) ymax = points[i].y;
}
const bounds = lt.LeadRectD.fromLTRB(xmin, ymin, xmax, ymax);
ctx.strokeStyle = "blue";
ctx.strokeRect(bounds.x, bounds.y, bounds.width, bounds.height);
};
manuallyComputeRedirectedBorder();
});
viewer.invalidate(lt.LeadRectD.empty);
}
}
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 | RenderRedirect</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.RenderRedirect();
};
</script>
</html>
Help Collections
Raster .NET | C API | C++ Class Library | HTML5 JavaScript
Document .NET | C API | C++ Class Library | HTML5 JavaScript
Medical .NET | C API | C++ Class Library | HTML5 JavaScript
Medical Web Viewer .NET
Multimedia
Direct Show .NET | C API | Filters
Media Foundation .NET | C API | Transforms
Supported Platforms
.NET, Java, Android, and iOS/macOS Assemblies
Imaging, Medical, and Document
C API/C++ Class Libraries
Imaging, Medical, and Document
HTML5 JavaScript Libraries
Imaging, Medical, and Document