ratkaiga/ngx-image-zoom

Angular component for zoomable images

ngx-image-zoom

Project status

This version is only tested with Angular13. Moving forward this library may or may not work on older versions of Angular anymore.

Still in early development, more features are planned and incoming. Should be in a working state right now but it's not tested in lots of different setups yet.

Breaking changes in version 0.5.0, see changelog for details.

Demonstration of available features available here.

About

NgxImageZoom is inspired by angular2-image-zoom and JQuery libraries such as jQuery Zoom and elevateZoom-plus but a pure Angular2+ implementation of similar concepts. This plugin works with both URLs to images and in-line images (Data URI).

Available options

All settings except thumbImage are optional. If no fullImage is provided the thumbImage will be used as the high resolution version as well.

Option	Default value	Description
thumbImage	none	(Required) The smaller version of the image that will be shown when there's no interaction by the user.
fullImage	none	The full resolution version of the image to be used when zooming. If not supplied thumbImage will be used.
magnification	1	The zoom factor to be used by default. 1 means we use the fullImage at its actual resolution.
zoomMode	'hover'	The mode of zooming to use, these are explained in a table below.
enableScrollZoom	false	Boolean that toggles if the mouse wheel should be captured when hovering over the image to adjust magnification.
scrollStepSize	0.1	When using scroll zoom this setting determines how big steps each scroll changes the zoom.
enableLens	false	If enabled only a small portion around the mouse cursor will actually magnify instead of the entire image area.
lensWidth	100	Width of the lens, if enabled.
lensHeight	100	Height of the lens, if enabled.
circularLens	false	Make the lens circular instead of square. This will only look good if width and height are equal.
minZoomRatio	baseRatio	Lower limit on how much zoom can be applied with scrollZoom enabled. See below for details.
maxZoomRatio	2	Upper limit on how much zoom can be applied with scrollZoom enabled. See below for details.
altText	''	alt attribute of the thumb and full image.
titleText	''	title attribute of the thumb and full image.

Zoom modes

Mode	Description
hover	Whenever the mouse cursor moves over the thumbnail it will show the zoomed image until it leaves the thumbnail.
click	Similar to hover but it only starts zooming if the user clicks the image. Moving the cursor away from the image disables it again.
toggle	A click in the image will zoom at the point of the cursor. Another click will restore the small image.
toggle-click	Combination of toggle and click. A click in the image will start zooming. Another click or moving the cursor away from the image will restore the small image.
hover-freeze	First click enables hover mode, second click freezes the zoomed image where it is, third click restores thumbnail.

Zoom ratio

The zoom ratio used in the minZoomRatio and maxZoomRatio settings refer to the relative size of the thumbnail and the full size image. The baseRatio default value is the calculated ratio that would make the zoomed image equal in size to the thumbnail. For example, if the full size image is 10x larger than the thumbnail, then minZoomRatio will default to 0.1, as in the full size image can at its smallest be shown at 0.1 times its original size. The default value for maxZoomRatio being 1 means the largest the fullSize image can appear is twice its original size.

Available output

The component outputs the follow events that can be triggered on.

Event name	Description
zoomScroll	Whenever the user changes the zoom level using the scroll wheel this event will fire with the current zoom ratio (see above).
zoomPosition	When the point on where the zoom is focused changes this event emits a Coord event (interface exported from the module) with X/Y in pixels relative thumbnails top left corner. Practically whenever the user moves the mouse cursor over the image.
imagesLoaded	When the thumbnail and fullImage are loaded and ready to be used this output emits "true". It will emit "false" if images are changed and on initial setup

Installation

To install this library, run:

$ npm install ngx-image-zoom --save

Using this library

From your Angular AppModule:

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppComponent } from './app.component';

// Import the library
import { NgxImageZoomModule } from 'ngx-image-zoom';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    NgxImageZoomModule // <-- Add this line
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Once the library is imported, you can use its component in your Angular application:

<!-- You can now use NgxImageZoom component in app.component.html -->
<h1>
  {{title}}
</h1>
<lib-ngx-image-zoom
    [thumbImage]=myThumbnail
    [fullImage]=myFullresImage
></lib-ngx-image-zoom>

License

MIT © Mathias Wittlock