@capgo/capacitor-pdf-viewer

underWebView / toBack

Open with mode: 'underWebView' or toBack: true to place the native PDF behind a transparent Capacitor WebView. nativeUi defaults to false in this mode so you can ship your own HTML chrome.

Custom HTML controls

Draw toolbars, page indicators, and buttons in HTML (Ionic, Tailwind, or plain markup). The native layer keeps PDFKit / Pdfium scroll, pinch zoom, and link hit testing.

Touch routing

Touches on button, a, form controls, [data-capgo-pdf-interactive], .custom-toolbar, and .custom-pdf-ui button stay in the WebView. Other touches go to the PDF.

updateLayout()

Reposition or resize the native PDF in CSS pixels relative to the WebView viewport. Call it after rotation or when your chrome changes size.

Tip

underWebView / toBack is iOS and Android only. On web, use fullscreen or inline. Full setup: underWebView.

Overview

Embed native PDF viewing on iOS, Android, and web with paths, URLs, base64, inline mode, password support, and an optional underWebView presentation for custom HTML UI.

Start with open() and the other core methods listed below.

Platform support

Platform	Support	Notes
iOS	Yes	PDFKit. underWebView / toBack is supported. hide() and show() are accepted only in underWebView or inline mode.
Android	Yes	Pdfium. underWebView / toBack is supported. hide() and show() work in any open mode.
Web	Partial	Browser PDF viewer with blob URLs. underWebView / toBack is not available. Use fullscreen or inline. nativeUi: false with mode: 'fullscreen' is rejected.

Core Capabilities

• open - Open a PDF from a file, path, URL, or base64 source, including mode: 'underWebView' or toBack: true.
• close - Close the active viewer and remove any overlay.
• goToPage / nextPage / previousPage - Jump or step through 1-based pages.
• setZoom - Set the zoom scale multiplier (1 is the default fit scale on native).
• hide / show - Hide or show the PDF layer without unloading the document.
• updateLayout - Reposition or resize the native PDF in underWebView / toBack mode.

Public API

Method	Description
open	Open a PDF from a file, path, URL, or base64 source.
close	Close the active viewer and remove any overlay.
goToPage	Jump to a 1-based page number.
nextPage	Move to the next page when one exists.
previousPage	Move to the previous page when one exists.
setZoom	Set the zoom scale multiplier. On web this resolves without changing the browser zoom.
getPageCount	Read the total page count. On web this always returns 1.
getCurrentPage	Read the current 1-based page. On web this reflects the last programmatic page only.
hide	Hide the PDF layer without unloading the document.
show	Show the PDF layer after hide().
updateLayout	Reposition or resize the native PDF when using underWebView / toBack.
getPluginVersion	Get the native or web implementation version marker.
addListener	Listen for load, pageChange, zoomChange, error, close, and linkTap events.

Source Of Truth

This reference is synced from src/definitions.ts in capacitor-pdf-viewer.

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