Annotations

Annotations are what people add on top of a page: highlights, sticky notes, shapes, stamps and text boxes. The annotation plugin shows the ones a PDF already has, lets people draw and edit new ones, and gives your code the same abilities. Every annotation is saved into the PDF, so it looks the same in every other PDF app.

Show the annotations in a PDF#

Loading live preview…

import {
  ChangeDetectionStrategy,
  Component,
  computed,
  inject,
  ViewEncapsulation,
} from '@angular/core';
import { EpdfDocumentGate, provideEmbedPdf } from '@embedpdf/angular/runtime';
import type { OpenInput } from '@embedpdf/angular/runtime';
import { EpdfPageTemplate, EpdfStage, withStage } from '@embedpdf/angular/stage';
import { EpdfRenderLayer, withRender } from '@embedpdf/angular/render';
import { EpdfSelectionLayer, withSelection } from '@embedpdf/angular/selection';
import { withInteraction } from '@embedpdf/angular/interaction';
import { EpdfAnnotation, EpdfAnnotationLayer, withAnnotation } from '@embedpdf/angular/annotation';
import { cloudEngine } from '@cloudpdf/engine';

const report: OpenInput = { kind: 'grant', grant: 'shr__TWhIGdJtaKlcnVgJdg--bcm' };

@Component({
  selector: 'demo-status',
  changeDetection: ChangeDetectionStrategy.OnPush,
  template: `
    <div class="toolbar">
      <p class="hint">{{ text() }}</p>
    </div>
  `,
})
export class Status {
  private readonly annotation = inject(EpdfAnnotation);

  protected readonly text = computed(() => {
    const selected = this.annotation.selected();
    if (this.annotation.status() === 'loading') return 'Loading the annotations…';
    if (selected.length > 0) return `Selected: ${selected.map((a) => a.subtype).join(', ')}`;
    return 'Click an annotation to select it';
  });
}

@Component({
  selector: 'demo-root',
  imports: [
    EpdfDocumentGate,
    EpdfStage,
    EpdfPageTemplate,
    EpdfRenderLayer,
    EpdfSelectionLayer,
    EpdfAnnotationLayer,
    Status,
  ],
  providers: [
    provideEmbedPdf(
      { engine: () => cloudEngine(), initialDocuments: [{ source: report }] },
      withStage(),
      withRender(),
      withInteraction(),
      withSelection(),
      withAnnotation(),
    ),
  ],
  changeDetection: ChangeDetectionStrategy.OnPush,
  styleUrl: './layer.css',
  encapsulation: ViewEncapsulation.None,
  template: `
    <ng-container *epdfDocumentGate="let document; fallback: loading">
      <demo-status />
      <epdf-stage class="stage">
        <ng-template epdfPage>
          <epdf-render-layer />
          <epdf-selection-layer />
          <epdf-annotation-layer />
        </ng-template>
      </epdf-stage>
    </ng-container>

    <ng-template #loading><p class="loading">Loading…</p></ng-template>
  `,
})
export class App {}

Try it: click the red box around the downloads row and drag it, or a corner to resize it. Double-click the yellow text box to type in it. Drag across a sentence to select its text.

layer.ts

import { Component } from '@angular/core';
import { EpdfAnnotationLayer, withAnnotation } from '@embedpdf/angular/annotation';
import { withInteraction } from '@embedpdf/angular/interaction';
import { EpdfRenderLayer, withRender } from '@embedpdf/angular/render';
import { provideEmbedPdf } from '@embedpdf/angular/runtime';
import { EpdfPageTemplate, EpdfStage, withStage } from '@embedpdf/angular/stage';

import { engine } from './setup';

@Component({
  selector: 'app-document-view',
  imports: [EpdfStage, EpdfPageTemplate, EpdfRenderLayer, EpdfAnnotationLayer],
  providers: [
    provideEmbedPdf({ engine }, withStage(), withRender(), withInteraction(), withAnnotation()),
  ],
  template: `
    <epdf-stage>
      <ng-template epdfPage>
        <epdf-render-layer />
        <epdf-annotation-layer />
      </ng-template>
    </epdf-stage>
  `,
})
export class DocumentView {}

While the annotation layer is on the page, the render layer leaves the annotations out of the page picture by itself. The annotation layer draws them instead, so they can be selected, moved and changed.

withInteraction() is the shared input system. Every tool, from text selection to drawing, speaks through it; see Selecting & copying for how it works.

Let people draw#

A tool says what a click or a drag on the page creates. Activate one and people can draw:

Loading live preview…

import {
  ChangeDetectionStrategy,
  Component,
  computed,
  inject,
  ViewEncapsulation,
} from '@angular/core';
import { EpdfDocumentGate, provideEmbedPdf } from '@embedpdf/angular/runtime';
import type { OpenInput } from '@embedpdf/angular/runtime';
import { EpdfPageTemplate, EpdfStage, withStage } from '@embedpdf/angular/stage';
import { EpdfRenderLayer, withRender } from '@embedpdf/angular/render';
import { EpdfInteraction, withInteraction } from '@embedpdf/angular/interaction';
import { EpdfSelectionLayer, withSelection } from '@embedpdf/angular/selection';
import { EpdfAnnotation, EpdfAnnotationLayer, withAnnotation } from '@embedpdf/angular/annotation';
import { cloudEngine } from '@cloudpdf/engine';

const article: OpenInput = { kind: 'grant', grant: 'shr_v09cJHOmj3C8vrfUlZNTDyqX' };

const TOOLS = [
  { id: 'pointer', label: 'Select' },
  { id: 'square', label: 'Rectangle' },
  { id: 'ink', label: 'Pen' },
  { id: 'highlight', label: 'Highlight' },
  { id: 'note', label: 'Note' },
];

@Component({
  selector: 'demo-toolbar',
  changeDetection: ChangeDetectionStrategy.OnPush,
  template: `
    <div class="toolbar">
      <div class="segmented" role="group" aria-label="Tool">
        @for (tool of tools; track tool.id) {
          <button
            type="button"
            [attr.aria-pressed]="interaction.activeToolId() === tool.id"
            (click)="interaction.activateTool(tool.id)"
          >
            {{ tool.label }}
          </button>
        }
      </div>
      <output class="readout">
        {{ count() }} {{ count() === 1 ? 'annotation' : 'annotations' }}
      </output>
    </div>
  `,
})
export class Toolbar {
  protected readonly tools = TOOLS;
  protected readonly interaction = inject(EpdfInteraction);
  private readonly annotations = inject(EpdfAnnotation).watch();
  protected readonly count = computed(() => this.annotations().length);

  constructor() {
    // The rectangle tool is active on load: drag on the page to draw one.
    this.interaction.activateTool('square');
  }
}

@Component({
  selector: 'demo-root',
  imports: [
    EpdfDocumentGate,
    EpdfStage,
    EpdfPageTemplate,
    EpdfRenderLayer,
    EpdfSelectionLayer,
    EpdfAnnotationLayer,
    Toolbar,
  ],
  providers: [
    provideEmbedPdf(
      { engine: () => cloudEngine(), initialDocuments: [{ source: article }] },
      withStage(),
      withRender(),
      withInteraction(),
      // The selection plugin lets the highlight tool mark the text you select.
      withSelection(),
      withAnnotation(),
    ),
  ],
  changeDetection: ChangeDetectionStrategy.OnPush,
  styleUrl: './draw.css',
  encapsulation: ViewEncapsulation.None,
  template: `
    <ng-container *epdfDocumentGate="let document; fallback: loading">
      <demo-toolbar />
      <epdf-stage class="stage">
        <ng-template epdfPage>
          <epdf-render-layer />
          <epdf-selection-layer />
          <epdf-annotation-layer />
        </ng-template>
      </epdf-stage>
    </ng-container>

    <ng-template #loading><p class="loading">Loading…</p></ng-template>
  `,
})
export class App {}

Try it: drag on the page to draw a rectangle, then pick another tool. Highlight marks the text you select.

toolbar.ts

import { Component, inject } from '@angular/core';
import { EpdfInteraction } from '@embedpdf/angular/interaction';

@Component({
  selector: 'app-toolbar',
  template: `
    @for (id of tools; track id) {
      <button
        [attr.aria-pressed]="interaction.activeToolId() === id"
        (click)="interaction.activateTool(id)"
      >
        {{ id }}
      </button>
    }
  `,
})
export class Toolbar {
  protected readonly interaction = inject(EpdfInteraction);
  protected readonly tools = ['pointer', 'square', 'ink', 'highlight', 'note'];
}

pointer selects: click an annotation to select it, then move, resize or turn it.
square draws a rectangle: drag, or just click for a default-size one.
ink draws freehand.
highlight highlights the text you select.
note drops a sticky note where you click.

After you draw, the new annotation is selected and the tool stays active, so you can draw another. You can change both; see What happens after drawing.

How it fits together#

Everything on these pages is one of five things:

Thing	What it is	Where you use it
Annotation	A record in the PDF: its kind, position, colors and text.	`annotation.list()`
Tool	What a click or drag creates, with which defaults, cursor and preview.	`withAnnotation({ tools })`
Layer	What each page draws: the annotations, the selection box and handles, the preview.	`<epdf-annotation-layer>`
Overlay	Your own UI attached to an annotation, such as a menu or a hover card.	`<epdf-annotation-menu>`
API	Reading, creating, changing and deleting annotations, and listening for changes.	`inject(EpdfAnnotation)`

An annotation here is the same record the engine reads and writes: the same kinds, the same fields and the same names. What you learn in the engine’s annotation pages holds here too.

The built-in tools#

Tool	Makes	How
`square`, `circle`	A rectangle or an ellipse	Drag, or click for a default size
`line`	A line	Drag, or click for a default length
`polygon`, `polyline`	A closed or open shape of points	Click each point, double-click to end
`ink`, `ink-highlight`	Freehand drawing, or a see-through marker	Draw
`free-text`, `free-text-callout`	A text box, or one with a line pointing out	Click or drag, then type
`highlight`, `underline`, `strikeout`, `squiggly`	A mark over text	Select text
`insert-text`, `replace-text`	A suggested insertion or replacement	Select text
`note`	A sticky note	Click
`stamp`	An image or a PDF drawing	Click, then pick a file
`attachment`	A file pinned to a spot	Click, then pick a file
`link`	An area that opens a page or a website	Drag

Measurement tools (distance, perimeter, area) and redaction (redact) are annotation tools too. Their plugins add the rest of what they need.

You can change any tool, or add your own; see Tools & defaults.

Who wrote it#

Every annotation records who made it and who last changed it (author, createdAt, modifiedAt). You don’t set these on the annotation: they come from the user the document was opened for.

It comes from the identity in the user’s token; see Authentication.

Settings#

Set them when you register the plugin. snap, chrome, afterCreate and editable can change while the app runs, with annotation.updateSettings({ … }); annotation.resetSettings() goes back to what you registered, and inject(EpdfAnnotation).settings() gives you the current settings.

Setting	What it does	Page
`tools`	Change the built-in tools, or add your own	Tools & defaults
`afterCreate`	Select a new annotation? Keep the tool active?	What happens after drawing
`chrome`	The selection’s outline, handles and rotation handle, and their colors	Change the handles
`snap`	Snapping to other annotations and to angles	Snapping
`editable`	Which annotations people may change by hand: `true`, `false`, or kinds	What people may change

Every color in chrome can also come from CSS, for dark mode or a different look per viewer: see Colors & theming.

Next steps#

Annotations in codeRead, create, change and delete annotations from your own code.Events, saving & sharingListen for changes, save them into the PDF, or move them to your own server.Tools & defaultsDefault colors, your own tools, the cursor, and a preview before placing.Selecting & editingSelection, a menu, a style panel, and your own handles.Your own annotation lookDraw an annotation with your own component, and show cards on hover.Comments & repliesBuild a comments sidebar with threads, replies and review states.