Customize a document view controller in Xamarin

This article explains how to customize the document viewer classes PTDocumentViewController and PTTabbedDocumentViewController.

Because the document viewer classes are part of the open source Tools UI framework, it is possible to achieve virtually any required modification. That said, it is usually faster and more convenient to configure the viewers via APIs, which this guide describes.

The image on the left indicates areas that are controllable via the PTDocumentViewController's API. Information on customizing these is available directly below.

The image on the right indicates a number of default buttons that create and present new controls. Information on where to look to customize these presented controls can be found in the component controls table.

When presented in a UINavigationController, the PTDocumentViewController's left bar button item will display the name of the previous view controller's navigation item's title (or, if set, its backBarButtonItem). When presented as a UINavigationController's root controller, the space will be empty.

The PTDocumentViewController's left bar button item can be added or replaced as follows:

var title = "Apryse";
tabViewController.NavigationItem.LeftBarButtonItem = new UIBarButtonItem(title, UIBarButtonItemStyle.Plain, (sender, e) => {
    // handle bar button item action
});

These buttons, which are contained in the rightBarButtonItems array, are completely customizable. It is possible to

• Remove (hide) buttons
• Add buttons
• Move buttons
• Change icons

Default buttons can be removed ("hidden") using built-in properties. From left-to-right:

• searchButtonHidden
• shareButtonHidden
• viewerSettingsButtonHidden
• annotationToolbarButtonHidden

For example to hide the share and viewer settings buttons:

documentViewController.ShareButtonHidden = true;
documentViewController.ViewerSettingsButtonHidden = true;

Buttons can be added by accessing the appropriate BarButtonItem array and adding a button:

Adds a button to the top navigation bar:

// add a button to the top bar
var plusButtonTop = new UIBarButtonItem(UIBarButtonSystemItem.Add, (sender, e) =>
{
    Console.WriteLine("button pressed:" + sender);
});

var currentItems = documentViewController.NavigationItem.RightBarButtonItems;
var itemsArray = new List<UIBarButtonItem>(currentItems);
itemsArray.Add(plusButtonTop);

documentViewController.NavigationItem.RightBarButtonItems = itemsArray.ToArray();

// add a button to the right of the page slider
var refreshButtonBottom = new UIBarButtonItem(UIBarButtonSystemItem.Refresh,(sender, e) => 
{
    Console.WriteLine("button pressed:" + sender);
});

currentItems = documentViewController.ThumbnailSliderController.TrailingToolbarItems;
itemsArray = new List<UIBarButtonItem>(currentItems);
itemsArray.Add(refreshButtonBottom);

documentViewController.ThumbnailSliderController.TrailingToolbarItems = itemsArray.ToArray();

The default buttons are all accessible via properties, making it easy to rearrange or move them. The following code swaps the position of the search button and navigation lists button:

var rightItems = documentViewController.NavigationItem.RightBarButtonItems;
var rightItemsList = new List<UIBarButtonItem>(rightItems);
rightItemsList.Remove(documentViewController.SearchButtonItem);
rightItemsList.Add(documentViewController.NavigationListsButtonItem);

var bottomRightItems = documentViewController.ThumbnailSliderController.TrailingToolbarItems;
var bottomRightItemsList = new List<UIBarButtonItem>(bottomRightItems);
bottomRightItemsList.Remove(documentViewController.NavigationListsButtonItem);
bottomRightItemsList.Add(documentViewController.SearchButtonItem);

documentViewController.NavigationItem.RightBarButtonItems = rightItemsList.ToArray();
documentViewController.ThumbnailSliderController.TrailingToolbarItems = bottomRightItemsList.ToArray();

The icons of existing buttons may be changed by creating new UIBarButtonItems that have the same target and action as an existing item, and replacing the existing item with the new item:

// new share UIBarButtonItem
var newShareItem = new UIBarButtonItem(UIBarButtonSystemItem.Action, documentViewController.ShareButtonItem.Target, documentViewController.ShareButtonItem.Action);
var rightItems = documentViewController.NavigationItem.RightBarButtonItems;
var rightItemsList = new List<UIBarButtonItem>(rightItems);
var index = rightItemsList.IndexOf(documentViewController.ShareButtonItem);
rightItemsList.Remove(documentViewController.ShareButtonItem);
rightItemsList.Insert(index, newShareItem);

// new search UIBarButtonItem
var newSearchItem = new UIBarButtonItem(UIBarButtonSystemItem.Search, documentViewController.SearchButtonItem.Target, documentViewController.SearchButtonItem.Action);
index = rightItemsList.IndexOf(documentViewController.SearchButtonItem);
rightItemsList.Remove(documentViewController.SearchButtonItem);
rightItemsList.Insert(index, newSearchItem);

// update the icons
documentViewController.NavigationItem.RightBarButtonItems = rightItemsList.ToArray();

The PTPDFViewCtrl is a UIView that displays the PDF. It is customizable via is properties/methods and delegate methods.

For an overview see the PTPDFViewCtrl Guide , or the detailed API documentation.

Note that all PDF "interaction" (annotations, form filling, text selection, link following, etc.) is supplementary to the PDFViewCtrl, and is implemented in the open source tools.framework .

The page indicator can be enabled/disabled via the pageIndicatorEnabled property.

The thumbnail slider can be enabled/disabled via the bottomToolbarEnabled property.

The default buttons presented to the right and left of the slider are easily hidden through the convenience properties thumbnailBrowserButtonHidden and navigationListsButtonHidden on the PTDocumentViewController:

documentViewController.ThumbnailBrowserButtonHidden = true;

To customize the controls that are presented by the PTDocumentViewController's default buttons, please see the corresponding guide or API:

The tabbed document view controller displays a collection of document viewer controllers in tabs.

Tabs can be disabled using the TabsEnabled property, and the maximum number of allowed tabs can be set using MaximumTabCount.

The current document view controller can be accessed via SelectedViewController, and others via documentViewControllerAtIndex

To configure a document view controller before it is displayed, conform to and implement the PTTabbedDocumentViewControllerDelegate method willAddDocumentViewController. Note that it is permissible to assign the internal PTDocumentViewController's delegate to an external object.

tabbedDocumentViewController.WillAddDocumentViewController += (sender, e) =>
{
    // do something with e.DocumentViewController
};