--- title: 2. Grouping Actions --- If some part of the functionality requires to implement several actions or actions are simply too many and overload the menu they can be joined into groups. In this case the group will be available as a top-level menu item, action will be represented as drop-down menu items. ### 2.1. Creating simple action groups Grouping can be done by extending adding `` attribute to `` [plugin.xml](https://github.com/JetBrains/intellij-sdk/blob/master/code_samples/register_actions/META-INF/plugin.xml) file. ```xml ``` ### 2.2. Binding action groups to UI component The following sample shows how to place a custom action group on top of the editor popup menu: ```xml ``` ### 2.3. Adding actions to the group To create an action we need to extend [AnAction.java](https://github.com/JetBrains/intellij-community/blob/master/platform/editor-ui-api/src/com/intellij/openapi/actionSystem/AnAction.java) class: ```java public class GroupedAction extends AnAction { @Override public void update(AnActionEvent event) { event.getPresentation().setEnabledAndVisible(true); } @Override public void actionPerformed(AnActionEvent event) { //Does nothing } } ``` And then the actions needs to be registered in the newly created group: ```xml ``` After performing the steps described above the action group nad it's content will be available in the editor popup menu: ![Simple Action Group](img/grouped_action.png) ### 2.4. Working with DefaultActionGroup In some cases we need to implement some specific behaviour of a group of actions dependently on the context. The steps below are meant to show how to make a group of actions available and visible if a certain condition is met and how to set up a group icon dynamically. In our case the condition is: an instance of the editor is available. ### 2.5. Extending DefaultActionGroup [DefaultActionGroup.java](https://github.com/JetBrains/intellij-community/blob/master/platform/platform-api/src/com/intellij/openapi/actionSystem/DefaultActionGroup.java) is a default implementations of [ActionGroup.java](https://github.com/JetBrains/intellij-community/blob/master/platform/editor-ui-api/src/com/intellij/openapi/actionSystem/ActionGroup.java) and used to add children actions and separators between them to a group. This class is used if a set of actions belonging to the group is fixed, which is the majority of all the cases. Firstly, [DefaultActionGroup.java](https://github.com/JetBrains/intellij-community/blob/master/platform/platform-api/src/com/intellij/openapi/actionSystem/DefaultActionGroup.java) should be derived: ```java public class CustomDefaultActionGroup extends DefaultActionGroup { @Override public void update(AnActionEvent event) { } } ``` ### 2.6. Registering action group As in case with the simple action group, the inheritor of [DefaultActionGroup.java](https://github.com/JetBrains/intellij-community/blob/master/platform/platform-api/src/com/intellij/openapi/actionSystem/DefaultActionGroup.java) should be declared in [plugin.xml](https://github.com/JetBrains/intellij-sdk/blob/master/code_samples/register_actions/META-INF/plugin.xml) file: ```xml ``` ### 2.7. Creating an action [AnAction.java](https://github.com/JetBrains/intellij-community/blob/master/platform/editor-ui-api/src/com/intellij/openapi/actionSystem/AnAction.java) needs to be extended: ```java public class CustomGroupedAction extends AnAction { @Override public void actionPerformed(AnActionEvent anActionEvent) { //Does nothing } } ``` ### 2.8. Adding actions to the group Action's class should be registered in [plugin.xml](https://github.com/JetBrains/intellij-sdk/blob/master/code_samples/register_actions/META-INF/plugin.xml) : ```xml ``` ### 2.9. Providing specific behaviour for the group In this case we override ```public void update(AnActionEvent event);``` method to make the group visible as a *Tools* menu item, however, it will be enabled only if there's an instance of the editor available. Also a custom icon is set up: ```java public class CustomDefaultActionGroup extends DefaultActionGroup { @Override public void update(AnActionEvent event) { Editor editor = event.getData(CommonDataKeys.EDITOR); event.getPresentation().setVisible(true); event.getPresentation().setEnabled(editor != null); event.getPresentation().setIcon(AllIcons.General.Error); } } ``` After compiling and running the code sample above, *Tools* menu item should contain an extra group of action with a user-defined icon: ![Default Action Group](img/default_action_group.png) ### 2.10. Action groups with variable actions set If a set of actions belonging to a custom actions group may vary dependently on the context, we need to work with [ActionGroup.java](https://github.com/JetBrains/intellij-community/blob/master/platform/editor-ui-api/src/com/intellij/openapi/actionSystem/ActionGroup.java). In this case set of actions to be grouped can be dynamically defined. ### 2.11. Creating variable action group To create a group of actions with a variable actions set we extend [ActionGroup.java](https://github.com/JetBrains/intellij-community/blob/master/platform/editor-ui-api/src/com/intellij/openapi/actionSystem/ActionGroup.java) first: ```java public class BaseActionGroup extends ActionGroup { } ``` ### 2.12. Registering variable action group To register the group `` attribute needs to be placed in the *``* section of [plugin.xml](https://github.com/JetBrains/intellij-sdk/blob/master/code_samples/register_actions/META-INF/plugin.xml): ```xml ``` **Note**: Since the set of actions is defined dynamically no action definitions should be placed in [plugin.xml](https://github.com/JetBrains/intellij-sdk/blob/master/code_samples/register_actions/META-INF/plugin.xml). If `` attribute contains any static action definition an exception will be thrown. For statically defined group of action use [DefaultActionGroup.java](https://github.com/JetBrains/intellij-community/blob/master/platform/platform-api/src/com/intellij/openapi/actionSystem/DefaultActionGroup.java) ### 2.13. Accessing children actions An array of children actions should be returned by the method ```public AnAction[] getChildren(AnActionEvent anActionEvent);``` of the a created group: ```java public class BaseActionGroup extends ActionGroup { @NotNull @Override public AnAction[] getChildren(AnActionEvent anActionEvent) { return new AnAction[0]; } } ``` ### 2.14. Adding children actions to the group To make the group contain actions a non-empty array of [AnAction.java](https://github.com/JetBrains/intellij-community/blob/master/platform/editor-ui-api/src/com/intellij/openapi/actionSystem/AnAction.java) elements should be returned: ```java public class BaseActionGroup extends ActionGroup { @NotNull @Override public AnAction[] getChildren(AnActionEvent anActionEvent) { return new AnAction[]{new MyAction()}; } class MyAction extends AnAction { public MyAction() { super("Dynamically Added Action"); } @Override public void actionPerformed(@NotNull AnActionEvent anActionEvent) { } } } ``` After providing an implementation of [AnAction.java](https://github.com/JetBrains/intellij-community/blob/master/platform/editor-ui-api/src/com/intellij/openapi/actionSystem/AnAction.java) and making it return a non-empty array of action Tools Menu should contain an extra group of action: ![Dynamic Action Group](img/dynamic_action_group.png)