When Navisworks loads it examines the 'Plugins' subfolder under the installation directory of the product being loaded. For each directory contained therein, Navisworks uses the folder name to identify the assembly to load within that folder. For example Abc.Def\Abc.Def.dll.

Note
The format of the subdirectory name must be exactly the same as the name of the main assembly, minus the '.dll' file extension. For example, a plug-in built to an assembly named ABC.XYZ.dll must be installed in '{Navisworks Installation Location}\Plugins\ABC.XYZ\'. If this location is incorrect then the plug-in will not be loaded.

Navisworks will not fully load a plug-in until it is required but will identify the plug-ins within the assembly using .NET reflection.

Note
There is a 'dependencies' folder in the '<drive>:\Program Files\Autodesk\Navisworks <Product> 2015' folder which is intended to be used for plug-ins dependent assemblies.

The 'Plugin' abstract base class is found under the 'Autodesk.Navisworks.Api.Plugins' namespace in the 'Autodesk.Navisworks.Api' assembly and all Plug-ins should be derived from one of the existing subclasses.

.NET Attributes are used to describe the nature of plug-ins; for example, when the plug-in should be loaded.

The current list of classes in the API, derived from the 'Plugin' abstract base class, is listed below.

Note
Developers implement classes derived from the required Plugin class and add the required attributes to the class definition. Examples are given both in the provided samples and in this guide.

The common attribute used for ALL 'Plugin' derived classes is named 'PluginAttribute'. Its constructor and properties are detailed in the Reference Guide.

Note
This Attribute must be present on ALL Plug-ins.

This attribute is important as it dictates to Navisworks the detail that makes this plug-in unique. For example if we examine the attribute below:

CopyPluginAttribute usage

[Plugin("AppInfo.AppInfoDockPane",                   //Plugin name
                 "ADSK",                              //4 character Developer ID or GUID
                 ToolTip = "Application Information", //The tooltip for the item in the ribbon
                 DisplayName = "AppInfo")]            //Display name for the Plugin in the Ribbon

The attribute has two mandatory fields which are set in the constructor.

The first parameter <name> gives a unique name for the plug-in, in the samples we have used the full qualified name (<namespace>.<class name>) as this parameter. The second parameter can be either the developer's unique 4 character RDS or a GUID. These two are used together to uniquely identify the plug-in as <unique name>.<RDS/GUID> . For example 'BasicPlugIn.ABasicPlugin.ADSK', this combination can be used using the Automation parts of the API to invoke the plug-in.

Note
The combination of name and RDS/GUID MUST be unique between different plug-ins. If two plug-ins have the same combination, only one of them may be loaded by Navisworks at runtime making results unpredictable.

AddInPlugin is the most commonly used plug-in and it is recommended by the API developers that this should be the first type of plug-in to try implementing.

See 'Writing Plug-ins for Navisworks' for a step by step example to creating AddInPlugin derived classes.

The attributes used on this tag are:

• AddInPluginAttribute

An example of using this attribute would be:

CopyAddInPluginAttribute usage

[AddInPluginAttribute(AddInLocation.AddIn)]

Developers often wish to integrate custom information into the Navisworks GUI.

DockPanePlugin enables developers to create customised dockable panes into the Navisworks GUI. The attributes used on this tag are:

• DockPanePluginAttribute

An simple example of using this attribute would be:

CopyDockPanePluginAttribute usage

[DockPanePlugin(755, 575,     //the preferred sizes
   FixedSize = false,           //(Optional) Can the DockPane can grow and shrink
   AutoScroll = true,           //(Optional) Controls the showing and hiding of the scrollbars
   MinimumWidth = 585,          //(Optional) The minimum Width of the Dock Pane
   MinimumHeight = 280          //(Optional) The minimum Height of the Dock Pane
   )]

Many advanced GUI addins need to subscribe to events in the Navisworks API. The existing plugins are designed specifically so that they are loaded as late as possible. An EventWatcherPlugin is the one type of plugin that is always loaded and activated as soon as possible and which will remain active for the duration of the session.

The EventWatcherPlugin offers no extra methods or functionality beyond those already present on the Plugin base type.

A typical implementation will subscribe to some API events in EventWatcherPlugin..::..OnLoaded and unsubscribe in EventWatcherPlugin..::..OnUnloading.

CustomPlugin can be used as a base class for a plugin to Navisworks when none of the other specialized plugin behaviour is required.

For example, if a user wishes to write a set of plugins which can be called by a third party program, and wants the benefits of the plugins architecture within Navisworks, they may choose to use this class as a base class.

Combining this class and InterfaceAttribute is an effective way of providing an easily identifiable customised plugin.

Reference