Distance annotation in TypeScript PDF Viewer
9 Jan 202616 minutes to read
Distance is a measurement annotation used to measure the length between two points in the PDF.

Add Distance Annotation
Add distance annotation via UI
Use the annotation toolbar:
- Click the Edit Annotation button in the PDF Viewer toolbar.
- Open the Measurement Annotation dropdown.
- Choose Distance, then draw on the page.
NOTE
When in pan mode, selecting a measurement annotation switches the viewer to text select mode.

Enable distance mode
The PDF Viewer component allows drawing Distance annotations programmatically after enabling Distance mode in button clicks.
<button id="distanceMode">Distance</button>import { PdfViewer, Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer } from '@syncfusion/ej2-pdfviewer';
PdfViewer.Inject(Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer);
let pdfviewer: PdfViewer = new PdfViewer();
pdfviewer.documentPath = "https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf";
pdfviewer.resourceUrl = "https://cdn.syncfusion.com/ej2/31.1.23/dist/ej2-pdfviewer-lib";
pdfviewer.appendTo('#PdfViewer');
document.getElementById('distanceMode')?.addEventListener('click', () => {
pdfviewer.annotationModule.setAnnotationMode('Distance');
});import { PdfViewer, Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer } from '@syncfusion/ej2-pdfviewer';
PdfViewer.Inject(Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer);
let pdfviewer: PdfViewer = new PdfViewer();
pdfviewer.serviceUrl = 'https://document.syncfusion.com/web-services/pdf-viewer/api/pdfviewer/';
pdfviewer.documentPath = "https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf";
pdfviewer.appendTo('#PdfViewer');
document.getElementById('distanceMode')?.addEventListener('click', () => {
pdfviewer.annotationModule.setAnnotationMode('Distance');
});Exit distance mode
<button id="setNone">Normal Mode</button>document.getElementById('setNone')?.addEventListener('click', () => {
pdfviewer.annotationModule.setAnnotationMode('None');
});Add a distance annotation programmatically
Add measurement annotations programmatically using the addAnnotation() method.
<button id="addDistanceAnnotation">Add Distance annotation programmatically</button>import { PdfViewer, Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer, DistanceSettings } from '@syncfusion/ej2-pdfviewer';
PdfViewer.Inject(Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer);
let pdfviewer: PdfViewer = new PdfViewer();
pdfviewer.documentPath = "https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf";
pdfviewer.resourceUrl = "https://cdn.syncfusion.com/ej2/31.1.23/dist/ej2-pdfviewer-lib";
pdfviewer.appendTo('#PdfViewer');
document.getElementById('addDistanceAnnotation')?.addEventListener('click', () => {
pdfviewer.annotation.addAnnotation('Distance', {
offset: { x: 200, y: 230 },
pageNumber: 1,
vertexPoints: [{ x: 200, y: 230 }, { x: 350, y: 230 }]
} as DistanceSettings);
});import { PdfViewer, Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer, DistanceSettings } from '@syncfusion/ej2-pdfviewer';
PdfViewer.Inject(Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer);
let pdfviewer: PdfViewer = new PdfViewer();
pdfviewer.serviceUrl = 'https://document.syncfusion.com/web-services/pdf-viewer/api/pdfviewer/';
pdfviewer.documentPath = "https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf";
pdfviewer.appendTo('#PdfViewer');
document.getElementById('addDistanceAnnotation')?.addEventListener('click', () => {
pdfviewer.annotation.addAnnotation('Distance', {
offset: { x: 200, y: 230 },
pageNumber: 1,
vertexPoints: [{ x: 200, y: 230 }, { x: 350, y: 230 }]
} as DistanceSettings);
});Edit Distance Annotation
Edit distance annotation in UI
You can select, move, and resize Distance annotations directly in the viewer:
- Select a Distance measurement to show its handles.
- Move: drag the line to reposition it on the page.
- Resize: drag the end handles to adjust its length.
- Delete or access more options from the context menu.
Edit the properties of area annotations
The fill color, stroke color, thickness, and opacity can be edited using the Edit Color, Edit Stroke Color, Edit Thickness, and Edit Opacity tools in the annotation toolbar.
Edit fill color
The fill color of the annotation can be edited using the color palette provided in the Edit Color tool.

Edit stroke color
The stroke color of the annotation can be edited using the color palette provided in the Edit Stroke Color tool.

Edit thickness
Edit border thickness using the range slider provided in the Edit Thickness tool.

Edit opacity
The opacity of the annotation can be edited using the range slider provided in the Edit Opacity tool.

Edit an existing distance annotation programmatically
Use editAnnotation on items from annotationCollection.
<button id="editDistanceAnnotation">Edit Distance annotation programmatically</button>import { PdfViewer, Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer } from '@syncfusion/ej2-pdfviewer';
PdfViewer.Inject(Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer);
let pdfviewer: PdfViewer = new PdfViewer();
pdfviewer.documentPath = "https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf";
pdfviewer.resourceUrl = "https://cdn.syncfusion.com/ej2/31.1.23/dist/ej2-pdfviewer-lib";
pdfviewer.appendTo('#PdfViewer');
document.getElementById('editDistanceAnnotation')?.addEventListener('click', () => {
for (let i = 0; i < pdfviewer.annotationCollection.length; i++) {
if (pdfviewer.annotationCollection[i].subject === 'Distance calculation') {
pdfviewer.annotationCollection[i].strokeColor = '#0000FF';
pdfviewer.annotationCollection[i].thickness = 2;
pdfviewer.annotationCollection[i].opacity = 0.8;
pdfviewer.annotation.editAnnotation(pdfviewer.annotationCollection[i]);
}
}
});import { PdfViewer, Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer } from '@syncfusion/ej2-pdfviewer';
PdfViewer.Inject(Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer);
let pdfviewer: PdfViewer = new PdfViewer();
pdfviewer.serviceUrl = 'https://document.syncfusion.com/web-services/pdf-viewer/api/pdfviewer/';
pdfviewer.documentPath = "https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf";
pdfviewer.appendTo('#PdfViewer');
document.getElementById('editDistanceAnnotation')?.addEventListener('click', () => {
for (let i = 0; i < pdfviewer.annotationCollection.length; i++) {
if (pdfviewer.annotationCollection[i].subject === 'Distance calculation') {
pdfviewer.annotationCollection[i].strokeColor = '#0000FF';
pdfviewer.annotationCollection[i].thickness = 2;
pdfviewer.annotationCollection[i].opacity = 0.8;
pdfviewer.annotation.editAnnotation(pdfviewer.annotationCollection[i]);
}
}
});Default distance settings during initialization
Set default distanceSettings before creating the control.
import { PdfViewer, Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer } from '@syncfusion/ej2-pdfviewer';
PdfViewer.Inject(Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer);
let pdfviewer: PdfViewer = new PdfViewer();
pdfviewer.documentPath = "https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf";
pdfviewer.resourceUrl = "https://cdn.syncfusion.com/ej2/31.1.23/dist/ej2-pdfviewer-lib";
pdfviewer.distanceSettings = { fillColor: 'blue', opacity: 0.6, strokeColor: 'green' };
pdfviewer.appendTo('#PdfViewer');import { PdfViewer, Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer } from '@syncfusion/ej2-pdfviewer';
PdfViewer.Inject(Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer);
let pdfviewer: PdfViewer = new PdfViewer();
pdfviewer.serviceUrl = 'https://document.syncfusion.com/web-services/pdf-viewer/api/pdfviewer/';
pdfviewer.documentPath = "https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf";
pdfviewer.distanceSettings = { fillColor: 'blue', opacity: 0.6, strokeColor: 'green' };
pdfviewer.appendTo('#PdfViewer');Set properties while adding Individual Annotation
Set properties for individual annotation before creating the control using DistanceSettings.
After editing default color and opacity using the Edit Color and Edit Opacity tools, the values update to the selected settings.
Refer to the following code snippet to set the default Distance settings.
<button id="Distance">Add Distance</button>import { PdfViewer, Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, DistanceSettings} from '@syncfusion/ej2-pdfviewer';
PdfViewer.Inject(Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner);
const pdfviewer: PdfViewer = new PdfViewer();
pdfviewer.documentPath = 'https://cdn.syncfusion.com/content/pdf/form-designer.pdf';
pdfviewer.resourceUrl = 'https://cdn.syncfusion.com/ej2/31.1.23/dist/ej2-pdfviewer-lib';
pdfviewer.appendTo('#PdfViewer');
//Apply Distance Settings while adding individual Annotation
document.getElementById('Ink')?.addEventListener('click', function () {
pdfviewer.annotation.addAnnotation('Distance', {
offset: { x: 200, y: 230 },
pageNumber: 1,
vertexPoints: [{ x: 200, y: 230 }, { x: 350, y: 230 }],
fillColor: 'blue', opacity: 0.6, strokeColor: 'green'
} as DistanceSettings);
});import { PdfViewer, Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, DistanceSettings} from '@syncfusion/ej2-pdfviewer';
PdfViewer.Inject(Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner);
const pdfviewer: PdfViewer = new PdfViewer();
pdfviewer.documentPath = 'https://cdn.syncfusion.com/content/pdf/form-designer.pdf';
pdfviewer.resourceUrl = 'https://cdn.syncfusion.com/ej2/31.1.23/dist/ej2-pdfviewer-lib';
pdfviewer.appendTo('#PdfViewer');
//Apply Distance Settings while adding individual Annotation
document.getElementById('Ink')?.addEventListener('click', function () {
pdfviewer.annotation.addAnnotation('Distance', {
offset: { x: 200, y: 230 },
pageNumber: 1,
vertexPoints: [{ x: 200, y: 230 }, { x: 350, y: 230 }],
fillColor: 'blue', opacity: 0.6, strokeColor: 'green'
} as DistanceSettings);
});Scale ratio and units
You can modify scale ratio and units using the Scale Ratio option in the context menu.

Supported units:
- Inch, Millimeter, Centimeter, Point, Pica, Feet

Set defaults via measurementSettings:
import { PdfViewer, Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer } from '@syncfusion/ej2-pdfviewer';
PdfViewer.Inject(Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer);
let pdfviewer: PdfViewer = new PdfViewer();
pdfviewer.documentPath = "https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf";
pdfviewer.resourceUrl = "https://cdn.syncfusion.com/ej2/31.1.23/dist/ej2-pdfviewer-lib";
pdfviewer.measurementSettings = { scaleRatio: 2, conversionUnit: 'cm', displayUnit: 'cm' };
pdfviewer.appendTo('#PdfViewer');import { PdfViewer, Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer } from '@syncfusion/ej2-pdfviewer';
PdfViewer.Inject(Toolbar, Magnification, Navigation, Annotation, LinkAnnotation, ThumbnailView, BookmarkView, TextSelection, TextSearch, FormFields, FormDesigner, PageOrganizer);
let pdfviewer: PdfViewer = new PdfViewer();
pdfviewer.serviceUrl = 'https://document.syncfusion.com/web-services/pdf-viewer/api/pdfviewer/';
pdfviewer.documentPath = "https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf";
pdfviewer.measurementSettings = { scaleRatio: 2, conversionUnit: 'cm', displayUnit: 'cm' };
pdfviewer.appendTo('#PdfViewer');