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Add Perimeter Measurement Annotations in React PDF Viewer

27 Feb 20267 minutes to read

Perimeter is a measurement annotation used to calculate the length around a closed polyline on a PDF page—useful for technical markups and reviews.

Perimeter overview

Enable Perimeter Measurement

To enable Perimeter annotations, inject the following modules into the React PDF Viewer:

import * as React from 'react';
import * as ReactDOM from 'react-dom/client';
import { PdfViewerComponent, Inject, Toolbar, Annotation } from '@syncfusion/ej2-react-pdfviewer';

function App() {
  return (
    <PdfViewerComponent
      id="container"
      documentPath="https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf"
      resourceUrl="https://cdn.syncfusion.com/ej2/31.2.2/dist/ej2-pdfviewer-lib"
      style={{ height: '650px' }}
    >
      <Inject services={[Toolbar, Annotation]} />
    </PdfViewerComponent>
  );
}

ReactDOM.createRoot(document.getElementById('sample')).render(<App />);

Add Perimeter Annotation

Add Perimeter Annotation Using the Toolbar

  1. Open the Annotation Toolbar.
  2. Select Measurement → Perimeter.
  3. Click multiple points to define the polyline; double‑click to close and finalize the perimeter.

Measurement toolbar

NOTE

If Pan mode is active, choosing a measurement tool switches the viewer into the appropriate interaction mode for a smoother workflow.

Enable Perimeter Mode

Programmatically switch the viewer into Perimeter mode.

function enablePerimeterMode() {
  const viewer = document.getElementById('container').ej2_instances[0];
  viewer.annotation.setAnnotationMode('Perimeter');
}

Exit Perimeter Mode

function exitPerimeterMode() {
  const viewer = document.getElementById('container').ej2_instances[0];
  viewer.annotation.setAnnotationMode('None');
}

Add Perimeter Programmatically

Use the addAnnotation API to draw a perimeter by providing multiple vertexPoints.

function addPerimeter() {
  const viewer = document.getElementById('container').ej2_instances[0];
  viewer.annotation.addAnnotation('Perimeter', {
    offset: { x: 200, y: 350 },
    pageNumber: 1,
    vertexPoints: [
      { x: 200, y: 350 },
      { x: 285, y: 350 },
      { x: 286, y: 412 }
    ]
  });
}

Customize Perimeter Appearance

Configure default properties using the Perimeter Settings property (for example, default fill color, stroke color, opacity).

<PdfViewerComponent
  id="container"
  documentPath="https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf"
  resourceUrl="https://cdn.syncfusion.com/ej2/31.2.2/dist/ej2-pdfviewer-lib"
  distanceSettings={{ fillColor: 'blue', strokeColor: 'green', opacity: 0.6 }}
  style={{ height: '650px' }}
>
  <Inject services={[Toolbar, Annotation]} />
</PdfViewerComponent>

Manage Perimeter (Move, Reshape, Edit, Delete)

  • Move: Drag inside the shape to reposition it.
  • Reshape: Drag any vertex handle to adjust points and shape.

Edit Perimeter

Edit Perimeter (UI)

  • Edit the fill color using the Edit Color tool.
    Fill color
  • Edit the stroke color using the Edit Stroke Color tool.
    Stroke color
  • Edit the border thickness using the Edit Thickness tool.
    Thickness
  • Edit the opacity using the Edit Opacity tool.
    Opacity
  • Open Right Click → Properties for additional line‑based options.
    Line properties

Edit Perimeter Programmatically

Update properties and call editAnnotation().

function editPerimeterProgrammatically() {
  const viewer = document.getElementById('container').ej2_instances[0];
  for (const ann of viewer.annotationCollection) {
    if (ann.subject === 'Perimeter calculation') {
      ann.strokeColor = '#0000FF';
      ann.thickness = 2;
      ann.fillColor = '#FFFF00';
      viewer.annotation.editAnnotation(ann);
      break;
    }
  }
}

Delete Distance Annotation

Delete Distance Annotation via UI (toolbar/context menu) or programmatically. For supported workflows and APIs, see Delete Annotation.

Set Default Properties During Initialization

Apply defaults for Perimeter using the perimeterSettings property.

<PdfViewerComponent
  id="container"
  documentPath="https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf"
  resourceUrl="https://cdn.syncfusion.com/ej2/31.2.2/dist/ej2-pdfviewer-lib"
  perimeterSettings={{ fillColor: 'green', strokeColor: 'blue', opacity: 0.6 }}
  style={{ height: '650px' }}
>
  <Inject services={[Toolbar, Annotation]} />
</PdfViewerComponent>

Set Properties While Adding Individual Annotation

Pass per‑annotation values directly when calling addAnnotation.

function addStyledPerimeter() {
  const viewer = document.getElementById('container').ej2_instances[0];
  viewer.annotation.addAnnotation('Perimeter', {
    offset: { x: 240, y: 360 },
    pageNumber: 1,
    vertexPoints: [
      { x: 240, y: 360 },
      { x: 320, y: 360 },
      { x: 330, y: 410 }
    ],
    strokeColor: '#1D4ED8',
    fillColor: '#DBEAFE',
    thickness: 2,
    opacity: 0.85
  });
}

Scale Ratio and Units

  • Use Scale Ratio from the context menu to set the actual‑to‑page scale.
    Scale ratio
  • Supported units include Inch, Millimeter, Centimeter, Point, Pica, Feet.
    Scale dialog

Set Default Scale Ratio During Initialization

Configure scale defaults using measurementSettings.

<PdfViewerComponent
  id="container"
  documentPath="https://cdn.syncfusion.com/content/pdf/pdf-succinctly.pdf"
  resourceUrl="https://cdn.syncfusion.com/ej2/31.2.2/dist/ej2-pdfviewer-lib"
  measurementSettings={{ scaleRatio: 2, conversionUnit: 'cm', displayUnit: 'cm' }}
  style={{ height: '650px' }}
>
  <Inject services={[Toolbar, Annotation]} />
</PdfViewerComponent>

Handle Perimeter Events

Listen to annotation life-cycle events (add/modify/select/remove). For the full list and parameters, see Annotation Events.

Export and Import

Perimeter measurements can be exported or imported with other annotations. For workflows and supported formats, see Export and Import annotations.

See Also