> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/ios/viewer/viewer.md). # iOS PDF Viewer Library Configure your document viewer with ease using Config Viewer. Customize PTPDFViewCtrl, change view modes, themes, and more for an enhanced viewing experience. Learn about localization, keyboard shortc The viewer is a viewing and rasterization scroll view component that handles a number of viewing operations including rendering, caching, high level zoom rendering and layout modes. Viewing represents reading a document and displaying it as the author intended. Through the process of rasterization, it can take document data and convert it into pixels that come together to be rendered on a display. Apryse SDK offers the following benefits: * Interactive PDF Viewing or Rasterization * Full transparency support (Transparency Groups, Soft Masks, including all supported Blend Modes) * Core viewing operations (scrolling, panning, zooming, jumping to pages) * Standard & custom page viewing modes (e.g. single, facing, cover, scrolling, fit-page, fit-width, etc.) * Extensive support for PDF forms & digital signatures * Extensive annotation & real-time collaboration support * Regex text search across a page or an entire document * Manipulate pages (rotate, crop, move, copy/export, delete, merge documents) * View PDF separations * Easy navigation (with thumbnails, bookmarks, links, and history) * Selective viewing and hiding of contents in different layers (OCGs) * Security settings (custom encryption & DRM controls, dynamic watermarks) * PDF/A viewing mode * Support for R2L (Right to Left) languages (e.g. Arabic, Hebrew, etc) * Keyboard shortcuts More features: * PDF Image Export (JPEG, TIFF, PNG, and BMP) * Advanced image quality and compression settings controlling the rasterization process, allowing the user to choose between the output image quality and rendering speed * Reflow * Night, sepia and custom-color mode * ICC color management * Overprint control & preview * Display-list caching (speeding-up viewing of complex documents) * Direct & serverless rendering support for PDF, Word, PowerPoint, Excel, XPS, plain-text, mark-down, TIFF, and other image formats * PDF package support * Pressure-sensitive stylus support * Infinite Undo/Redo * Text to Speech Support * Font-substitution control ## Get started [Config viewer](/ios/ui-customization/viewer-configuration.md) To configure the document viewer for customizations. [Custom viewer](/ios/ui-customization/viewer-configuration.md) To configure the PTPDFViewCtrl for customizations. [View mode](/ios/viewer/view-mode.md) To change the view display mode such as layout, fit, reflow. [Scroll direction](/ios/viewer/scrolling-direction.md) To change the scroll direction by setting the page presentation mode. [Themes](/ios/viewer/night-mode.md) To change the color mode presentation to assistance in document readability/accessibility. [Stream PDF](/ios/viewer/view-online-pdfs.md) To show a document on-demand as it is partially downloaded providing a fast and responsive viewing experience. [Coordinates](/ios/viewer/coordinates.md) To convert between PDF page and screen coordinates. [Localization](/ios/viewer/localization.md) An introduction to localization and translation resources. [Keyboard shortcuts](/ios/viewer/keyboard-shortcuts.md) An list of keyboard shortcuts for document navigation and interaction (scroll, zoom, delete annotation, etc.). --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.apryse.com/ios/viewer/viewer.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. 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