Exclusive Activity Host nodes

Exclusive Activity Host nodes can have only one of its child Activity nodes active at a time. When one child Activity node of an Exclusive Activity Host node is active, all other Activity nodes of that Activity Host node are inactive. For example, you can use a an Exclusive Activity Host node to toggle between views in your application.

Using Exclusive Activity Host nodes

To use an Exclusive Activity Host node:

1. In the Activity Browser click and create the root Exclusive Activity Host node.

   Kanzi Studio creates an Exclusive Activity Host node in the RootPage node.

   

2. In the Activity Browser below the root Exclusive Activity Host node click to create an Activity node and create or assign a prefab to that Activity node.

   For example, create Activity nodes named Media, Navigation, and Phone. For each Activity node use the same name for the Activity prefab.

   Kanzi Studio creates Activity nodes, assigns them to the Exclusive Activity Host node, and for each Activity node creates a prefab in the Prefabs.

   

3. Create a property type that you use in the Activity Host as a Controller Property property:

   1. In the Activity Browser right-click the Exclusive Activity Host node, select Create Controller Property, and then select the data type for the property type.

      An Activity Host node uses the Controller Property property to set and control which Activity node in that Activity Host node is active. To change the state of an Activity node, you can also use any Trigger with the Activate Activity Message or a Data Trigger with the Apply Activation Action.

      For example, select Create Controller Property > Enum to create a property type with the enumeration data type.

      

   2. Name the property type, and click OK.

      For example, name the property type MyActivities.

      

      Kanzi Studio:

      • Creates the property type.

        When you create a property type with the enumeration data type, Kanzi Studio creates a property type with enumeration keys with the names from the Activity nodes from that Activity Host node.

        

      • In the Activity Host node adds the created property type and sets the Controller Property property to the created property type.

        To set which Activity node is active in this Activity Host node, in the Activity Host node you can set the value of the created property type.

        

4. In the Prefabs add content to each Activity node prefab.

   For example, in each Activity node create a Text Block 2D node with the name of that Activity.

   

5. In the Activity Browser in the Activity that you want to activate, click .

   The Activity Browser simulates the activation of Activity nodes in your application. To activate Activity nodes in your Kanzi application, use triggers and actions.

   

Activating Activities

When you activate an Activity, Kanzi:

1. Creates an Activity node using its prefab

2. Attaches the Activity node to the node tree

3. Makes the Activity visible so that the user can interact with its content

You can activate an Activity using:

• An Activate Activity Message. See Activating Activities with an Activate Activity Message.

• A Set Property Action. See Activating Activities with a Set Property Action.

• An Navigate To Next Activity and Navigate To Previous Activity actions. See Activating the next or previous Activity..

• An Apply Activation Action. See Activating Activities with an Apply Activation Action.

Finding out whether an Activity is active

To find out whether an Activity is active:

• Check the value of the Activity Status property for that Activity.

• Check the value of the Controller Property property in the Activity Host for that Activity.

Activating Activities with an Activate Activity Message

Use the Activate Activity Message when:

• The condition for activating an Activity is too complex to be expressed with the value of a property

• You do not know in advance the number of Activities in an Activity Host

To activate an Activity with the Activate Activity Message:

1. Create an Activity Host with several Activities the activation state of which you can control with a Controller Property.

   

2. Create a node with a trigger that you want to use to activate an Activity.

   For example, create a Button node and use the Button: Click trigger.

   

3. In the Node Tree select the node that you created in the previous step, in the Node Components > Triggers press Alt and right-click the trigger that you want to use to activate an Activity, select Dispatch Message Action > Activate Activity Message, and in the action set:

   • Target Item to the Activity Host that contains the Activity that you want to activate.

   • Activation Path to the path from the Activity Host to the Activity that you want to activate.

     If you nest Activity nodes in other types of nodes, include in the path only the ancestor Activity nodes.

     Tip

     To get the full activation path to an Activity node, in the Activity Browser right-click an Activity node and select Copy Activation Path. This command copies the entire path from the top-level Activity Host node to that Activity node.

     
   

Activating Activities with a Set Property Action

Use the Set Property Action to activate Activity nodes when the logic of your application relies on the value of the Controller Property property to activate an Activity node.

To activate an Activity node with the Set Property Action:

1. Create an Activity Host with several Activities the activation state of which you can control with a Controller Property.

   

2. Create a node with a trigger that you want to use to activate an Activity node.

   For example, create a Button node and use the Button: Click trigger.

   

3. In the Node Tree select the node that you created in the previous step, in the Node Components > Triggers press Alt and right-click the trigger that you want to use to activate an Activity node, select the Set Property Action, and in the action set:

   • Target Item to the Activity Host node that contains the Activity node that you want to activate.

   • Target Property to the property type that you set in the Activity Host in the Controller Property property.

   • Fixed Value to the value of the Controller Property property that you use in the Activity that you want to activate.

   

Activating the next or previous Activity

To activate the next or previous Activity:

1. Create an Activity Host with several Activities the activation state of which you can control with a Controller Property.

   

2. Create a node with a trigger that you want to use to activate an Activity.

   For example, create a Button node and use the Button: Click trigger.

   

3. In the Node Tree select the node that you created in the previous step, in the Node Components > Triggers press Alt and right-click the trigger that you want to use to activate an Activity, select either Navigate To Next Activity or Navigate To Previous Activity action, and in the action set:

   • Target Item to the Activity Host that contains the Activities that you want to activate.

   • (Optional) If you want the Activity Host to activate the first or last Activity when you set off the trigger after you reach the last or first Activity in that Activity Host, set the Loop Activity property to enabled.

   

Activating Activities with an Apply Activation Action

An Apply Activation Action keeps an Activity activated for as long as the condition is met in a Data Trigger that contains this action. When the trigger condition is no longer met, Kanzi rolls back the state of the Activity to the state before the action was applied. Use the Apply Activation Action only with a Data Trigger.

Use the Apply Activation Action when you want to synchronize the activation of an Activity with your application logic.

For example, use an Apply Activation Action to show a cluster indicator when a property has a specific value, and then hide the same indicator when the value of that property no longer has that value.

When using a Data Trigger, keep in mind that actions of a Data Trigger have higher priority than the actions of any other trigger.

You can learn how use a Data Trigger with a Apply Activation Action to control the activation state of Activities by completing Tutorial: Control activation state of Activities.

To activate an Activity with an Apply Activation Action:

1. In the Activity Browser create an Exclusive Activity Host with Activities.

   For example, create an Exclusive Activity Host node with two Activities, each with own content:

   • Automatic and in the side panel enable the InitiallyActive

     This way you set the Automatic Activity to be active by default.

   • High

   

2. Create a node with which you want to control the activation state of one of the Activities that you created in the previous step.

   For example, from the Asset Packages drag the Checkbox to the Preview.

   

3. Create a Data Trigger with an Apply Activation Action:

   1. In the Node Tree select the Exclusive Activity Host node, in the Node Components press Alt and right-click Triggers, and select Data Trigger.

      

   2. In the Data Trigger in the Expression click , in the Node Tree select the Checkbox, and from the Properties drag the Toggle State property to the Expression field and edit the expression to

      {@Checkbox/ButtonConcept.ToggleState}==1
      

      This condition expression must evaluate to either True or False. As a source you can use either a property or a data object from a data source.

      Click Save.

      This way you set the Data Trigger to execute the Apply Activation Action when the Checkbox is checked.

      

   3. In the Data Trigger press Alt and right-click Actions, and select Apply Activation Action.

      

   4. In the Apply Activation Action set:

      • Activity Host Path to .

      • Activity Activation Path to High

      The path to the Activity that that you set in the Activity Activation Path property is relative to the Activity Host node that you set in the Activity Host Path property.

      The Activity Browser indicates that an Activity Host has a Data Trigger with the icon.

      

   Tip

   The Activity Activation Path contains only Activities and Activity Hosts.

   To get the full activation path to an Activity node, in the Activity Browser right-click an Activity node and select Copy Activation Path. This command copies the entire path from the top-level Activity Host node to that Activity node.

   

In the Preview toggle the checkbox:

• When the checkbox is checked, the value of the Toggle State property in the Checkbox is 1 and the Data Trigger activates the Activity that you set in the Apply Activation Action.

  An Apply Activation Action keeps an Activity activated for as long as the condition is met in a Data Trigger that contains this action.

• When the checkbox is not checked, the value of the Toggle State property in the Checkbox is 0 and the Data Trigger deactivates the Activity that you set in the Apply Activation Action.

  When the trigger condition is no longer met, Kanzi rolls back the state of the Activity to the state before the action was applied.

Tip

During the application development, use these Data Trigger tools in the Activity Browser side panel:

Tool	Description
	Shows where a Data Trigger is and where the source and target Activity nodes of that Data Trigger are.
	Simulates the state when you apply a Data Trigger. This enables you to see the state of your application when the conditions for a Data Trigger are met without having to change the property values in your application.
	Shows a Data Trigger in the Node Components window.

Activating Activities with a Toggle Button Group

You can use the Toggle Button nodes in a Toggle Button Group to activate Activities in an Activity Host. For example, you can create an application navigation bar to allow the user to switch between application screens.

To activate Activities with a Toggle Button Group:

1. Create an Activity Host with several Activities whose activation state you control with a Controller Property.

   For example, create an Exclusive Activity Host with Activities that show different application screens and use a Controller Property to control which Activity is active. See Using Exclusive Activity Host nodes.

   

2. Create a Toggle Button Group with a Toggle Button node for each Activity that you created in the previous step. See Creating a toggle button group.

   In the Toggle Button Group order the Toggle Button nodes in the same order as the enumeration options that you use to control the Activities.

   

3. Select the Toggle Button Group, in the Properties click + Add Binding, and in the Binding Editor set:

   • Binding Mode to Two way

   • Property to Current Button Index

     You use the Current Button Index property to access the index of the Toggle Button that is toggled on in the Toggle Button Group.

   • Source to the controller property in the Activity Host that controls which Activity is active in that Activity Host.

   Click Save.

   With this binding you create a two-way connection between the toggle button that is toggled on in the toggle button group and the Activity that is active in the Activity Host.

   

Now when you activate an Activity, Kanzi toggles on the corresponding Toggle Button, and when you toggle on a Toggle Button, Kanzi activates the corresponding Activity.

Using the Activity nodes in the API

For details, see the Activity2D, Activity3D, ExclusiveActivityHost2D, and ExclusiveActivityHost3D classes in the Kanzi Engine API reference.