Customize a document view controller in Xamarin

This article explains how to customize the document viewer classes PTDocumentController 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.

On iPad and other regular horizontal size class devices, a number of default UI controls are accessible from the navigation bar, whereas on iPhones and compact size classes some of those controls appear in the toolbar at the bottom of the view.

The toolbar switcher can be hidden:

documentController.ToolGroupIndicatorView.Hidden = true;

Toolbars can be removed by removing them from the toolGroupManager's groups array. The following code removes the "Draw" and "Pens" toolbars:

var mutableGroups = documentController.ToolGroupManager.Groups;
var groupsToRemove = new List<PTToolGroup> { documentController.ToolGroupManager.DrawItemGroup, documentController.ToolGroupManager.PensItemGroup};
documentController.ToolGroupManager.Groups = mutableGroups.Except(groupsToRemove).ToArray();

The buttons which are contained in the leftBarButtonItems and rightBarButtonItems arrays, are completely customizable. It is possible to

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

You can modify the navigation bar items. Here is an example of adding a new button (for the current size class):

var myItem = new UIBarButtonItem(UIImage.GetSystemImage("square.and.pencil"), UIBarButtonItemStyle.Plain, (sender, e) =>
{
    Console.WriteLine("button pressed:" + sender);
});

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

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

Tools can also be added:

var freeHand = documentController.ToolGroupManager.CreateItemForToolClass(new ObjCRuntime.Class(typeof(PTFreeHandCreate)));

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

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

Note that in the example above, de-selecting the tool button item needs to be implemented by the app, by listening to the Tool Did Change notification.

To remove any of the default buttons see the instructions here: Hide default buttons

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

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

The currently-visible annotation toolbar is selected with the toolbar switcher.

The toolbar can be programmatically hidden by setting the mode to view group, which is a special group and the only group where the toolbar is hidden:

documentController.ToolGroupManager.SelectedGroup = documentController.ToolGroupManager.ViewItemGroup;

The toolbar can be shown again by changing the group to any group other than view:

documentController.ToolGroupManager.SelectedGroup = documentController.ToolGroupManager.DrawItemGroup;

The example below shows how to remove the text highlight and text underline button from a toolbar.

var annotateGroup = documentController.ToolGroupManager.AnnotateItemGroup;

// tool buttons that exist currently
var defaultAnnotateGroupTools = annotateGroup.BarButtonItems;

// new set of tools to replace current ones
var newAnnotateGroupTools = new List<UIBarButtonItem>();

// add all currently existing tools except for the ones we don't want            
foreach (UIBarButtonItem defaultToolItem in defaultAnnotateGroupTools)
{
    if (defaultToolItem.IsKindOfClass(new ObjCRuntime.Class(typeof(PTToolBarButtonItem)))) {
        var toolBarButton = (PTToolBarButtonItem)defaultToolItem;
        if ( toolBarButton.ToolClass.Equals(new ObjCRuntime.Class(typeof(PTTextHighlightCreate))) ||
                toolBarButton.ToolClass.Equals(new ObjCRuntime.Class(typeof(PTTextUnderlineCreate))) )
        {
            // do not add this tool
            continue;
        }
        else
        {
            newAnnotateGroupTools.Add(toolBarButton);
        }
    }
    else
    {
        newAnnotateGroupTools.Add(defaultToolItem);
    }
}
// assign tools to new array
documentController.ToolGroupManager.AnnotateItemGroup.BarButtonItems = newAnnotateGroupTools.ToArray();

// create a mutable array of the current items in the annotation toolbar group
var availableTools = new List<UIBarButtonItem>(documentController.ToolGroupManager.AnnotateItemGroup.BarButtonItems);

// create a new toolbar item for freehand annotations
var freeHandItem = documentController.ToolGroupManager.CreateItemForToolClass(new ObjCRuntime.Class(typeof(PTFreeHandCreate)));

// add the freehand annotation item to the front of the list
availableTools.Insert(0, freeHandItem);

// assign the array back to the annotation toolbar group.
documentController.ToolGroupManager.AnnotateItemGroup.BarButtonItems = availableTools.ToArray();

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

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 .

These are the buttons that appear at the bottom of the screen on iPhones and in Compact horizontal size classes. Buttons can be added, removed, or rearranged with convenient APIs.

To remove any of the default buttons see the instructions here: Hide default buttons

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

Default buttons can be removed ("hidden") using built-in properties.

• searchButtonHidden
• moreItemsButtonHidden
• navigationListsButtonHidden
• thumbnailBrowserButtonHidden
• readerModeButtonHidden

For example to hide the search and more items buttons:

documentController.SearchButtonHidden = true;
documentController.MoreItemsButtonHidden = true;

The tabbed document view controller displays a collection of document 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 controller can be accessed via SelectedViewController, and others via documentViewControllerAtIndex

To configure a document 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
};