Allowing only one instance of an application

By default, a user can work with multiple instances of a ZIETrans rich client application at one time by opening multiple instances of the application's transformation view. To restrict a user from starting multiple instances of an application, you can set a flag in the plug-in manifest file, plugin.xml, for the plug-in project. This flag tells Eclipse to allow only one instance of the application's view. To set this flag:
  1. Open the plug-in manifest file for the project by clicking Open the plug-in manifest on the Overview page of the Project Settings editor.
  2. Click the Extensions tab.
  3. In the All Extensions tree, expand the org.eclipse.ui.views node and select the node corresponding to your project. By default, only one view is listed.
  4. In the Extension Element Details section, change the allowMultiple setting from true to false.
  5. Save the file.
Note: Any change to a plug-in manifest file while the application is running requires a restart of the runtime workbench.

At runtime, if a user attempts to open a second instance of the application, the view corresponding to the first application instance receives the focus.