insertFromCanvas Method

Summary

Inserts a new item from an HTML5 Canvas Element.

Syntax

JavaScript Syntax
ImageViewerItems.prototype.insertFromCanvas = function(index, canvas, resolution) 
TypeScript Syntax
insertFromCanvas(index: number, canvas: HTMLCanvasElement, resolution: LeadSizeD): ImageViewerItem; 

Parameters

index

0-based index of the item.

canvas

Source HTML5 Canvas Element.

resolution

The resolution to use for the image in dots/inch (DPI). A value of 0,0 or Empty means to use the default image resolution of 96 pixels.

Return Value

The newly created item, if successful.

Remarks

This method allows you to quickly insert an item from an HTML5 Canvas Element. It is the equivalent of the following code:

var item = new lt.Controls.ImageViewerItem(); 
item.canvas = canvas; 
item.resolution = resolution; // Optional 
imageViewer.items.insert(index, item); 

InsertFromElement can be used as a shortcut for InsertFromCanvas or InsertFromImage. Passing a valid HTML5 Canvas Element to InsertFromElement will create an ImageViewerItem with the Canvas property set, just as it does with InsertFromCanvas. Similarly, passing a valid HTML Image Element to InsertFromElement will create an ImageViewerItem with the Image property set, just as it does with InsertFromImage. The item can have a value in only one of Image, Element or Canvas. Setting one value will automatically delete the values of the others.

To add the ImageViewerItem to the end of the collection, see AddFromCanvas or AddFromElement. To create an item without adding it to any ImageViewer, refer to CreateFromCanvas or CreateFromElement.

If canvas is null, then an empty item is added.

Requirements

Target Platforms

Help Version 19.0.2017.10.18
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