# Document Presenters

This article will help you get familiar with the concept of a document presenter in **RadPDFViewer**.

* [What Is a Document Presenter](https://www.telerik.com/products/wpf/documentation/controls/radpdfviewer/ui/document-presenters#what-is-a-document-presenter)

* [Using FixedDocumentPagesPresenter](https://www.telerik.com/products/wpf/documentation/controls/radpdfviewer/ui/document-presenters#using-fixeddocumentpagespresenter)

* [Using FixedDocumentSinglePageViewPresenter](https://www.telerik.com/products/wpf/documentation/controls/radpdfviewer/ui/document-presenters#using-fixeddocumentsinglepageviewpresenter)

## What Is a Document Presenter

The document presenter is responsible for displaying the pages of the document, navigating in it, managing the selection markers, conversion between view coordinates and document location coordinates, plus proper response to mouse and touch events.

**RadPdfViewer** provides two presenters out of the box:

* **FixedDocumentPagesPresenter**

* **FixedDocumentSinglePageViewPresenter**

Both of those presenters inherit the abstract **Telerik.Windows.Documents.UI.FixedDocumentPresenterBase** class, which implements the **Telerik.Windows.Documents.UI.IFixedDocumentPresenter** interface.

> You can access the document presenter in **RadPdfViewer** by accessing the **FixedDocumentPresenter** property.

> tip FixedDocumentPresenterBase exposes the **VisiblePagesCacheOffset property**, which you can use to control the amount of pages that are cached before and after the visible ones. The default value of VisiblePagesCacheOffset is 1.

## Using FixedDocumentPagesPresenter

This document presenter displays the pages in a vertical order and is used by default by **RadPdfViewer**. There is a fixed margin between the pages, and each pages is centered horizontally inside the **RadPdfViewer** viewport. The code from **Example 1** shows how to set it as the currently used presenter.

**Example 1: Using FixedDocumentPagesPresenter**

```C#
this.radPdfViewer.FixedDocumentPresenter = this.radPdfViewer.GetRegisteredPresenter(FixedDocumentPresenterNames.FixedDocumentPagesPresenter);
```

> caption FixedDocumentPagesPresenter

![Rad Pdf Viewer Ui Document Presenters 01](https://www.telerik.com/products/wpf/documentation/assets/ed4bb2db094b165905a6f1bcb5d0bbff/radpdfviewer_ui_document_presenters_01.png)

## Using FixedDocumentSinglePageViewPresenter

This document presenter displays a single page inside the viewport. The page is vertically and horizontally centered. **Example 2** shows how to set the **FixedDocumentSinglePageViewPresenter** as the currently used presenter.

**Example 2: Using FixedDocumentSinglePageViewPresenter**

```C#
this.radPdfViewer.FixedDocumentPresenter = this.radPdfViewer.GetRegisteredPresenter(FixedDocumentPresenterNames.FixedDocumentSinglePageViewPresenter);
```

> caption FixedDocumentSinglePageViewPresenter

![Rad Pdf Viewer Ui Document Presenters 02](https://www.telerik.com/products/wpf/documentation/assets/03355a6a1ddb3de56edecad204d07e0d/radpdfviewer_ui_document_presenters_02.png)

## See Also

* [Rotation](https://www.telerik.com/products/wpf/documentation/controls/radpdfviewer/ui/rotation)

* [Custom Document Presenter](https://www.telerik.com/products/wpf/documentation/controls/radpdfviewer/customization-and-extensibility/custom-document-presenter)