Double-clicking on the object boundary invokes the server application associated with the object. If the object is unitary (that is, if only the whole object can be selected in the container document) the user can double-click anywhere on the object to invoke the server application. The double-click starts the server application and invokes the primary verb for that object.
Note Instead of double-clicking, the client application may implement a method of selecting an object and pressing ENTER to activate an object. However, Selection + ENTER should not be implemented in a single- or multiple-edit line because, by default, this should replace the selection with a carriage return and line feed. You can also activate the object by selecting it and using the <Class> Object command.
Note Sometimes the primary verb is not Edit. Instead, it is an activate-type verb such as Run (for a script), Play (for a voice note), and so on. The distinction between primary and secondary verbs in described later in the section, "The <Descriptive-Class-Name> Object Command."
If the server is an SDI server, OLE starts a new instance of the server, even if one is already running. This tight connection between the new instance and the current object helps promote the impression that the object is an integral part of the document in which it is displayed.
There are three exceptions to the rule that OLE should start a new instance of the server application to edit an object. No new instance is necessary in the following cases:
1.The object is already open in an existing instance of the server. In this case, OLE instructs the existing instance to surface.
2.The server application is an MDI application and is the same as the client application (that is, the editor for the object is the client itself). The appropriate behavior depends on whether the link is external or internal.
External links: For example, suppose that a Microsoft Word document contains a link to another Word document. In this case, double-clicking on the linked object should not start a new instance of Word. Instead, if a document window for the source document is already open within the current instance (case 1 above), that document window should be surfaced. Otherwise, a new document window should be opened for it within the current instance of Word.
Internal links: If the link refers to another part of the same document, double-clicking on the linked object should scroll to show the source of the link.
3.If the server is an MDI application that does not use memory efficiently when multiple instances are running, it should make an intelligent decision about what to do. For example, the application can check available memory to see whether running one more instance is likely to cause problems. If so, the application can issue a warning and/or offer the user a choice between starting a new instance or loading the file into an existing instance.