Extending the functionality of Kanzi Engine

With a Kanzi Engine plugin you can extend the functionality of Kanzi Engine and set how Kanzi Studio shows the custom content you create:

Create your own nodes and property types. See Creating custom nodes and property types.
Create your own message types that users of Kanzi Studio can use as either triggers or actions. See Creating custom message types.
Set how Kanzi Studio shows the property types you create in your Kanzi Engine plugin. See Setting custom property types.
Set the icons for the node types you create. See Setting the icon for your node type.

Creating custom nodes and property types

In a Kanzi Engine plugin you can create custom nodes with custom property types. You can set how Kanzi Studio shows and lets users interact with these nodes.

To create a custom node with custom property types:

To pass to Kanzi Studio information about the custom node, declare the metadata where you describe the node:

In the hpp file of your Kanzi Engine plugin project, after the metaclass definition, declare the function which returns the metadata:
```
    ...
    KZ_METACLASS_END()

    static kanzi::PropertyTypeEditorInfoSharedPtr makeEditorInfo();
    ...
```

In the cpp file of your Kanzi Engine plugin project, create the metadata.
For example, to create a tooltip and to set automatically added and frequently used properties, add this code snippet:

PropertyTypeEditorInfoSharedPtr MyPlugin::makeEditorInfo()
{
    return PropertyTypeEditorInfoSharedPtr(
        KZ_PROPERTY_TYPE_EDITOR_INFO(
            []() -> PropertyTypeEditorInfo::AttributeDictionary {
        PropertyTypeEditorInfo::AttributeDictionary dict;
        // Set the name that you want to use for your node in Kanzi Studio.
        dict.displayName = "My Node";
        // Set the tooltip that you want to use in the Kanzi Studio Create menu.
        dict.tooltip = "This example custom node uses custom properties.";
        // Add the Horizontal Alignment and Vertical Alignment properties to the node.
        dict["AutomaticallyAddedProperties"] = "Node.HorizontalAlignment, Node.VerticalAlignment";
        // Add the State Manager property as a frequently used property which users can add by clicking  next to the property name.
        dict["FrequentlyAddedProperties"] = "Node.StateManager";
        // Let the user add the Focus Scope property using the Add Property context menu or the context tab of the Add Properties window.
        dict["ContextProperties"] = "FocusManager.FocusScope";

        return dict;
    }()));
}

Create the custom property types and their metadata.
For example:

In the hpp file of your Kanzi Engine plugin project, replace

    KZ_METACLASS_BEGIN(MyPlugin, Node3D, "CustomComponentType")
    KZ_METACLASS_END()

with

    // String property
    static kanzi::PropertyType<kanzi::string> StringProperty;
    // String reference to a node
    static kanzi::PropertyType<kanzi::string> NodeRefByStringProperty;
    // String reference to a prefab
    static kanzi::PropertyType<kanzi::string> PrefabRefByStringProperty;
    // Shared pointer reference to a prefab
    static kanzi::PropertyType<kanzi::ResourceSharedPtr> PrefabRefBySharedPtrProperty;
    // Shared pointer reference to a material
    static kanzi::PropertyType<kanzi::ResourceSharedPtr> MaterialRefBySharedPtrProperty;

    KZ_METACLASS_BEGIN(MyPlugin, Node3D, "MyNode")
        // Add the property types to the class metadata.
        KZ_METACLASS_PROPERTY_TYPE(StringProperty)
        KZ_METACLASS_PROPERTY_TYPE(NodeRefByStringProperty)
        KZ_METACLASS_PROPERTY_TYPE(PrefabRefByStringProperty)
        KZ_METACLASS_PROPERTY_TYPE(PrefabRefBySharedPtrProperty)
        KZ_METACLASS_PROPERTY_TYPE(MaterialRefBySharedPtrProperty)
    KZ_METACLASS_END()

In the cpp file of your Kanzi Engine plugin project, add the metadata for the custom property types. See Reference for showing Kanzi Engine plugin custom types in Kanzi Studio.
For example, to declare the metadata for the custom property types you created in the previous step:

String property with a one-line text editor:

// Creates a string property.
// This example does not set the editor. If you do not set the editor, Kanzi Studio uses
// the default editor for this property type.
PropertyType<string> MyPlugin::StringProperty(kzMakeFixedString("MyPlugin.String"), "", 0, false,
                                              KZ_DECLARE_EDITOR_METADATA
                                              (
                                                  metadata.displayName = "String";
                                              ));

String reference to a 3D node the user can select from a dropdown menu:

// Creates a string reference to a node.
PropertyType<string> MyPlugin::NodeRefByStringProperty(kzMakeFixedString("MyPlugin.NodeRefByString"), "", 0, false,
                                                       KZ_DECLARE_EDITOR_METADATA
                                                       (
                                                           metadata.displayName = "Node Reference by String";
                                                           // When you set valueProvider to ProjectObject:Node3D, 
                                                           // Kanzi Studio automatically uses the Node 3D selector editor.
                                                           metadata.valueProvider = "ProjectObject:Node3D";
                                                       ));

String reference to a prefab the user can select from a dropdown menu:

// Creates a string reference to a prefab resource.
PropertyType<string> MyPlugin::PrefabRefByStringProperty(kzMakeFixedString("MyPlugin.PrefabRefByString"), "", 0, false,
                                                         KZ_DECLARE_EDITOR_METADATA
                                                         (
                                                             metadata.displayName = "Prefab Reference by String";
                                                             // When you set valueProvider to ProjectObject:PrefabTemplate, 
                                                             // Kanzi Studio automatically uses the Prefab template selector editor.			
                                                             metadata.valueProvider = "ProjectObject:PrefabTemplate";
                                                         ));

Shared pointer reference to a prefab resource the user can select from a dropdown menu:

// Creates a shared pointer reference to a prefab resource.
PropertyType<ResourceSharedPtr> MyPlugin::PrefabRefBySharedPtrProperty(kzMakeFixedString("MyPlugin.PrefabRefBySharedPtr"), ResourceSharedPtr(), 0, false,
                                                                       KZ_DECLARE_EDITOR_METADATA
                                                                       (
                                                                           metadata.displayName = "Prefab Reference by Shared Pointer";
                                                                           // When you set valueProvider to ProjectObject:PrefabTemplate, 
                                                                           // Kanzi Studio automatically uses the Prefab template selector editor.		
                                                                           metadata.valueProvider = "ProjectObject:PrefabTemplate";
                                                                       ));

Shared pointer reference to a material resource the user can select from a dropdown menu:

// Creates a shared pointer reference to a material resource.
PropertyType<ResourceSharedPtr> MyPlugin::MaterialRefBySharedPtrProperty(kzMakeFixedString("MyPlugin.MaterialRefBySharedPtr"), ResourceSharedPtr(), 0, false,
                                                                 KZ_DECLARE_EDITOR_METADATA
                                                                 (
                                                                     metadata.displayName = "Material Reference by Shared Pointer";
                                                                     // When you set valueProvider to ProjectObject:Material, 
                                                                     // Kanzi Studio automatically uses the Material dropdown editor.
                                                                     metadata.valueProvider = "ProjectObject:Material";
                                                                 ));

Build and install your plugin. See Adding a Kanzi Engine plugin to a Kanzi Studio project.
In Kanzi Studio in the Library > Kanzi Engine Plugins select your plugin. In the Properties you can see the custom property types.
In the Project select a node to which you want to add your node, press Alt and right-click, and select My Node.
(Optional) Set the icons for the node types you create. See Setting the icon for your node type.
(Optional) By default Kanzi Studio adds custom properties as frequently used properties to the nodes of the type for which you created the property type. To set the node types for which Kanzi Studio suggests the property, and whether Kanzi Studio adds the property automatically or lets the user add it, set the metadata.host attribute. See host.

Creating custom message types

You can create and configure custom message types which you use to add functionality to your application. For example, you can create a custom trigger and action which set a property of a custom node. When you are using Kanzi Connect you can use custom message types to get information about a Kanzi Connect server or service that your application uses.

Creating custom triggers

In a Kanzi Engine plugin, you can create a custom message type which you show in Kanzi Studio as a trigger.

For example, to allow the Kanzi Studio user to add a trigger called On Fuel Level Changed which is set off when the fuel level of a custom node called Fuel Indicator changes:

In the hpp file of your Kanzi Engine plugin project create the class that represents the custom message type and define that message type:

    // Represents message arguments of FuelIndicator.OnFuelLevelChanged message type.
    class OnFuelLevelChangedMessageArguments : public MessageArguments
    {
    public:
        KZ_MESSAGE_ARGUMENTS_METACLASS_BEGIN(OnFuelLevelChangedMessageArguments, MessageArguments, "On Fuel Level Changed Message Arguments")
        KZ_METACLASS_END()
    };

    // Define the message type of the FuelIndicator.OnFuelLevelChanged message.
    static MessageType<OnFuelLevelChangedMessageArguments> OnFuelLevelChangedMessage;

In the hpp file of your Kanzi Engine plugin project create a function which dispatches the FuelIndicator.OnFuelLevelChanged message when the fuel level changes:

    // Sends a FuelIndicator.OnFuelLevelChanged message.
    void onFuelLevelChanged(int fuelLevel)
    {
        OnFuelLevelChangedMessageArguments messageArguments;
        dispatchMessage(OnFuelLevelChangedMessage, messageArguments);
    }

In the cpp file of your Kanzi Engine plugin project declare the metadata for the FuelIndicator.OnFuelLevelChanged message:

MessageType<FuelIndicator::OnFuelLevelChangedMessageArguments> FuelIndicator::OnFuelLevelChangedMessage(kzMakeFixedString("Message.FuelIndicator.OnFuelLevelChanged"),
                                                                       KZ_DECLARE_EDITOR_METADATA
                                                                       (
                                                                           // Set the name of the message the way you want to show it in Kanzi Studio.
                                                                           metadata.displayName = "On Fuel Level Changed";
                                                                           // Set the tooltip for the message.
                                                                           metadata.tooltip = "Fuel Indicator sets off this trigger when its level changes.";
                                                                           // Set the category under which this message is listed in the triggers list.
                                                                           metadata.category = "Custom Controls";
                                                                           // Do not show the message in the trigger actions dropdown menu.
                                                                           metadata["Sendable"] = "False";
                                                                       ));

Creating custom actions

In a Kanzi Engine plugin, you can create a custom message type which you show in Kanzi Studio as an action.

For example, to allow the Kanzi Studio user to add to a trigger an action called Update Level which shows the level of a custom node called Fuel Indicator in a Text Block 3D node:

In the hpp file of your Kanzi Engine plugin project create the class that represents the custom message type and define that message type:

    // Represents the message arguments of the FuelIndicator.UpdateLevel message.
    class FuelIndicatorUpdateLevelMessageArguments : public MessageArguments
    {
    public:

        KZ_MESSAGE_ARGUMENTS_METACLASS_BEGIN(FuelIndicatorUpdateLevelMessageArguments, MessageArguments, "Fuel Indicator Update Level Message Arguments")
            KZ_METACLASS_PROPERTY_TYPE(FuelIndicatorLevelProperty)
        KZ_METACLASS_END()

        // The property type which represents the value of the Fuel Indicator node.
        static PropertyType<int> FuelIndicatorLevelProperty;

        // Returns the value of the Fuel Indicator message argument.
        int getFuelIndicatorLevel()
        {
            return getArgument(FuelIndicatorLevelProperty);
        }

    };

    // The message type of the FuelIndicator.UpdateLevel message.
    static MessageType<FuelIndicatorUpdateLevelMessageArguments> FuelIndicatorUpdateLevelMessage;

In the hpp file of your Kanzi Engine plugin project define the message handler for the FuelIndicator.UpdateLevel message:

    // The message handler for the FuelIndicator.UpdateLevel message.
    // Shows the level of the Fuel Indicator in a Text Block 3D node.
    void fuelIndicatorUpdateLevelHandler(FuelIndicatorUpdateLevelMessageArguments& arguments)
    {
        // Get the level of the Fuel Indicator node.
        m_currentLevel += arguments.getFuelIndicatorLevel();

        // Show the level of the Fuel Indicator node in a Text Block 3D node.
        TextBlock3DSharedPtr textBlock = m_textBlockReference.get();

        if (textBlock)
        {
            textBlock->setText(to_string(m_currentLevel));
        }
    }

In the hpp file in the initialize() function register the message handler for the FuelIndicator.UpdateLevel message:

    void initialize()
    {
        ...

        // Register the message handler for the FuelIndicator.UpdateLevel message.
        addMessageHandler(FuelIndicatorUpdateLevelMessage, this, &FuelIndicator::fuelIndicatorUpdateLevelHandler);
    }

In the cpp file of your Kanzi Engine plugin project declare the metadata for the FuelIndicator.UpdateLevel message:

MessageType<FuelIndicator::FuelIndicatorUpdateLevelMessageArguments> FuelIndicator::FuelIndicatorUpdateLevelMessage(kzMakeFixedString("Message.FuelIndicator.UpdateLevel"),
                                                                                            KZ_DECLARE_EDITOR_METADATA
                                                                                            (
                                                                                                // Set the name of the message the way you want to show it in Kanzi Studio.
                                                                                                metadata.displayName = "Update Level";
                                                                                                // Show the message in the actions dropdown menu.
                                                                                                metadata["Listenable"] = "False";
                                                                                            ));

Setting custom property types

To pass to Kanzi Studio information about the custom property types you create in a Kanzi Engine plugin, you declare metadata that describe these property types. The metadata enable Kanzi Engine plugin users to interact with the plugin content in Kanzi Studio. See Reference for showing Kanzi Engine plugin custom types in Kanzi Studio.

For example, to create the metadata for the custom property type VideoFileNameProperty to allow Kanzi Studio user to select a video file:

PropertyType<string> VideoView2D::VideoFileNameProperty(kzMakeFixedString("VideoView2D.VideoFileName"), "video.mp4", 0, false,
			KZ_DECLARE_EDITOR_METADATA
			(
			// Set the name of the property type the way you want to show it in Kanzi Studio.
			metadata.displayName = "Video Filename";
			// Set the tooltip for the property type.
			metadata.tooltip = "Name of the video file to be played";
			// Set the category under which this property type is listed in the Properties.
			metadata.category = "Video";
			// Set the editor you want the user to use to edit the value of this property type.
			// BrowseFileTextEditor editor contains a text box with a Browse button next to it.
			metadata.editor = "BrowseFileTextEditor";
			// Set the default value of the property in Kanzi Studio.
			// The Kanzi Engine default value is set in the first line of this example.
			metadata["DefaultValue"] = "video.mp4";
		));

When the user adds a new VideoView2D node, Kanzi Studio adds to the properties of the node in the category Video the Video Filename property, which has a text editor with a Browse button, a tooltip, and the default value set to video.mp4.

Property type names cannot contain:

A period (.) in the beginning or at the end of a property name
Spaces
Tabs
Slashes (/)
Backslashes (\)
Hashes (#)
Opening or closing braces ({})
At signs (@)

Setting the icon for your node type

If you do not set the icon for your node type, Kanzi Studio uses the default icon (). To make it easier for Kanzi Studio users to visually keep track of the nodes in the Project, you can set your own icons for your nodes.

To set the icon for your node type:

In Visual Studio open the Visual Studio solution for your project in <KanziWorkspace>/Projects/<ProjectName>/Application/configs/platforms/win32.
In the Solution Explorer double-click the Resource File (<ProjectName>.rc) of your plugin project to open the Resource View, right-click the selected .rc folder, select Add Resource, and import the .ico file you want to use as the icon for your node.
In the Resource View in the folder named Icon select the icon you imported and in the Properties set the ID of the icon resource to the name of your node type in all caps inside double quotes.
For example, if your node type is VideoView2D, set ID to "VIDEOVIEW2D".
Copy the .dll files of the plugins to the same location where the previous versions of the plugins are located.
In Kanzi Studio in the Library > Kanzi Engine Plugins right-click the plugin you have updated and select Update Kanzi Engine Plugin.
When Kanzi Studio loads the new version of the plugin, it shows changes in the properties and classes defined in the plugin.

For an example where a custom node type uses its own icon, see Node2D plugin example.