Defining Context Menus

As a prominent example for the use of actions, we will illustrate their connection to a UI component using a context menu.

For this purpose, we will create a context menu and ensure that it is connected with the desired UI component (for example, Model Viewer).

Default Path Provider

As a plug-in developer you generally do not have to concern yourself directly with the path provider, since you can use a default implementation, the default path provider. By using the default path provider you can also ensure that the display information of an action category is processed consistently by the context menu.

However, if you want to implement your own versions of the context menu display, you must also implement your own path provider and add it to the provider manager.

Note that the default path provider only returns categories with display information - that is, of the type IDisplayableCategory.

Dynamic and Static Context Menus

The framework allows you to use different types of context menus.

Dynamic context menu
	For dynamic context menus, menu data is created at runtime using the action provider manager. These context menus are created using the class com.tssap.util.ui.menu.context.DynamicContextMenu.
Static context menu
	Static context menus are used for UI components that have fixed functions and do not permit the integration of additional functions. The menu data is predefined and cannot be extended. These context menus are created using the class com.tssap.util.ui.menu.context.StaticContextMenu.
Mixed context menu
	A mixed menu is used if the UI component already has default functions and also allows you to add additional functions. In the case of mixed context menus, the menu data is both static and dynamic. These context menus are created using the class com.tssap.util.ui.menu.context.MixedContextMenu.

Menu and Path Provider Classes

Package com.tssap.util.ui.menu.

IMenuFactory
	This interface defines methods for creating menus from a predefined context.
MenuFactory
	The factory class implements the interface IMenuFactory and provides method implementations for creating menus. These create methods return the relevant menu references from the given context. If, as a tool developer, you want to create dynamic context menus, you need to specify the path provider explicitly at runtime. To obtain a path provider you first need access to the path provider manager. For this purpose, the MenuFactory class provides the following get method:
	public IPathProviderManager getPathProviderManager() Returns a path provider manager reference to the menu. The path provider manager can make a query to all providers and assign selected path providers at runtime.

Package com.tssap.util.ui.menu.context

IContextMenu
	This interface defines methods for converting context data to a visual display. Method:
	void show(Control parent, IContext context) Displays a context menu on a control.
IContextMenuParticipant
	This interface defines convenience methods for linking context menus with UI components. As a tool developer, you will normally use predefined participants (such as the Model Viewer, SAP Tree Viewer, or SAP Table Viewer), which already implement this interface. Methods:
	IContextMenu getContextMenu() Returns a context menu.
	void setContextMenu(IContextMenu contextMenu) Assigns a context menu to the UI component.
ContextMenu
	This abstract class serves as a basis class for the implementation of specific context menus (dynamic, static, or mixed). ContextMenu provides two static methods that are used to link context menus with SWT components:
	public static void setContextMenuToStructuredViewer(                                               StructuredViewer viewer,                                               IContextMenu contextMenu) Assigns a context menu to a structure-oriented SWT/JFace viewer (tree viewer, table viewer, list). Only a viewer instance and the context menu are passed as parameters.
	public static void setContextMenuToControl(Control control, IContextMenu contextMenu ,                                            IContext context) Assigns a context menu to an SWT/JFace control, such as a button or a text field. As well as the control instance and a context menu, the relevant context must also be passed. The reason for this is that, unlike a structure-oriented viewer, the selection context is not automatically known to controls.
DynamicContextMenu
	Inherits from the basis class ContextMenu and instantiates a dynamic context menu as a specific version of context menu. Unlike a static context menu, you must assign a path provider at runtime when creating dynamic context menus.

Package com.tssap.util.action.path

IPathProvider
	The interface requires a method for ascertaining the path information. IPath getPath(ICategory category, IContext context) Returns a path for category and a context that is used to identify the UI elements.
IPathProviderManager
	Interface for defining a path provider manager. A path provider manager manages all path providers and can add providers or remove them.
	void addPathProvider(IPathProvider pathProvider) Adds a path provider.
	void removePathProvider(IPathProvider pathProvider) Removes a path provider.
	IPathProvider[] getPathProviders() Returns a list of all providers in the container.
PathProviderManager
	Class that implements the path provider manager.
DefaultPathProvider
	The default implementation of the path provider that provides the relevant path information from a given category.

Relationships Between Classes

Different viewer implementations, including the SAP Viewer classes SAPTreeViewer, SAPTable Viewer, or the GenericDataModelTreeViewer, implement the interface IContextMenuParticipant.