Annotations in JavaScript Linear Gauge control

20 Apr 2021 / 3 minutes to read

Annotations are used to mark the specific area of interest in the gauge area with texts, shapes or images. You can add any number of annotations to the gauge.

Annotation

By using the content property of annotation object, you can either specify the id of the element or specify the code to create a new element, that needs to be displayed in the gauge area.

<script id='fruits' type="text/x-template">
   <div id='apple'>
       <img src='src/lineargauge/images/apple.png'>
   </div>
</script>

import { LinearGauge, Annotations } from '@syncfusion/ej2-lineargauge';
LinearGauge.Inject(Annotations);
let gauge: LinearGauge = new LinearGauge({
    annotations: [{
        content: 'fruits',
        x: 100,
        y: 100
    }]
}, '#element');

Annotation Customization

You can customize the annotation using following properties.

zIndex - When annotation overlaps with another element, you can use this property to bring annotation to the front or back.
horizontalAlignment - To move annotation horizontally. Possible values are “Center”, “Far”, “Near”, “None”
verticalAlignment - To move annotation vertically. Possible values are “Center”, “Far”, “Near”, “None”
x and y - To move annotation to the specified location.

Changing the z-order

You can change the z-order of the annotation element by using the zIndex property.

Source

Preview

index.ts

index.html

import { LinearGauge, Annotations } from '@syncfusion/ej2-lineargauge';
LinearGauge.Inject(Annotations);
let gauge: LinearGauge = new LinearGauge({
 annotations: [{
   content: '<div id="first"><h1>Gauge</h1></div>',
   verticalAlignment: 'Center',
   horizontalAlignment: 'Center',
   zIndex: '1'
}]
}, '#element');

<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Animation</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Positioning the Annotation

You can place the annotation anywhere in gauge area by specifying pixel values to the x and y properties.

Source

Preview

index.ts

index.html

import { LinearGauge, Annotations } from '@syncfusion/ej2-lineargauge';
LinearGauge.Inject(Annotations);
let gauge: LinearGauge = new LinearGauge({
annotations: [{
    content: '<div id="first"><h1>Gauge</h1></div>',
    x: 100,
    y: 100,
    zIndex: '1'
}]
}, '#element');

<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Animation</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Alignment of Annotation

You can align the annotation using horizontalAlignment and verticalAlignment properties.

Source

Preview

index.ts

index.html

import { LinearGauge, Annotations } from '@syncfusion/ej2-lineargauge';
LinearGauge.Inject(Annotations);
let gauge: LinearGauge = new LinearGauge({
annotations: [{
   content: '<div id="first"><h1>Gauge</h1></div>',
   verticalAlignment: 'Center',
   horizontalAlignment: 'Center',
   zIndex: '1'
}]
}, '#element');

<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Animation</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Multiple Annotations

You can add multiple annotations to the gauge as demonstrated below.

Source

Preview

index.ts

index.html

import { LinearGauge, Annotations } from '@syncfusion/ej2-lineargauge';
LinearGauge.Inject(Annotations);
let gauge: LinearGauge = new LinearGauge({
  annotations: [
        {
            content: '<div id="first"><h1 style="color:red;">Speed</h1></div>',
            verticalAlignment: 'Near',
            horizontalAlignment: 'Center',
            x: 100,
            y: 150,
            zIndex: '1'
        },
        {
            content: '<div id="first"><h1 style="color:blue;">Meter</h1></div>',
            verticalAlignment: 'Center',
            horizontalAlignment: 'Center',
            x: -100,
            y: -100,
            zIndex: '1'
        }]
}, '#element');

<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Animation</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Contents

Annotation
Annotation Customization
Multiple Annotations

Contents

Annotation
Annotation Customization
Multiple Annotations